Edgar Filing: ALEXION PHARMACEUTICALS INC

Form S-3

As filed with the Securities and Exchange Commission on November 26, 2003

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ALEXION PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Its Charter)

Delaware

13-364831

(State or Other Jurisdiction of

Incorporation or Organization)

(I.R.S. Employer

Identification Number)

352 Knotter Drive Cheshire,

Connecticut 06410

(203) 272-2596

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Thomas I.H. Dubin, Esq.

352 Knotter Drive Cheshire,

Connecticut 06410

(203) 272-2596

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies of all communications, including all communications sent to the agent for service, should be sent to:

Merrill M. Kraines, Esq.

Lawrence A. Spector, Esq.

Fulbright & Jaworski L.L.P.

666 Fifth Avenue

New York, New York 10103

(212) 318-3000

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plan, please check the following box: ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box. ¨

CALCULATION OF REGISTRATION FEE


Title Of Each Class of Securities To Be Registered	Amount To Be Registered(1)	Proposed Maximum Offering Price Per Unit	Proposed Maximum Aggregate Offering Price(2)	Amount Of Registration Fee(1)

Common Stock, $.0001 par value per share Preferred Stock, $.0001 par value per share (3) Debt Securities (3)
Warrants (3)	$150,000,000	100%	$150,000,000	$8,537

(1)

In accordance with Rule 429 under the Securities Act of 1933, the prospectus included herein is a combined prospectus, which also relates to the securities covered in the registrant’s Form S-3 Registration Statement, File No. 333-47594, which was declared effective on October 16, 2000. The amount of securities remaining eligible to be sold under such prior Registration Statement ($44,475,000) shall be carried forward to this Registration Statement. The filing fee related to the amount of securities being carried forward was paid with the prior Registration Statement.

(2)	Estimated solely for purposes of calculating the registration fee pursuant to Rule 457(o) under the Securities Act.

(3)

In addition to any Preferred Stock, Debt Securities or Warrants that may be issued directly under this Registration Statement, there are being registered hereunder an indeterminate number of shares of Common Stock as may be issued upon conversion or exchange of the Preferred Stock or Debt Securities or conversion of the Warrants, as the case may be. No separate consideration will be received for any shares of Common Stock so issued upon conversion or exchange.

This registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

(Subject to Completion)

Issued November 26, 2003

PROSPECTUS

LOGO

Common Stock

Preferred Stock

Debt Securities

Warrants

Alexion Pharmaceuticals, Inc. is offering securities

of up to an aggregate of $150,000,000

From time to time, we may sell any of the securities listed above.

We will provide the specific terms of these securities in one or more supplements to this prospectus. You should read this prospectus, the information incorporated by reference in this prospectus and any prospectus supplement carefully before you invest.

Our common stock is listed on the Nasdaq National Market under the symbol “ALXN.” On November 25, 2003, the last sale price of our common stock was $18.40 per share.

Investing in these securities involves a high degree of risk. See “ Risk Factors” beginning on page 8.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this Prospectus is , 2003.

TABLE OF CONTENTS

About This Prospectus		1
Summary		3
Risk Factors		8
Forward-Looking Information		20
Financial Ratios		21
Use of Proceeds		21
Description of Capital Stock		22
Description of Debt Securities		28
Description of Warrants		35
Legal Ownership of Securities		39
Plan of Distribution		43
Legal Matters		44
Experts		44
Notice Regarding Arthur Andersen LLP		45
Where You Can Find More Information		45

You should rely only on the information contained or incorporated by reference into this prospectus or any applicable prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer of the securities to be sold under this prospectus in any jurisdiction where the offer or sale is not permitted. You should not assume that the information contained in this prospectus or any applicable prospectus supplement is accurate as of any date other than the date on the front cover of this prospectus or the prospectus supplement, or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security.

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, using a “shelf” registration process. Under this shelf registration process, we may sell common stock, preferred stock, debt securities and warrants, in one or more offerings up to a total dollar amount of $150 million. This prospectus provides you with a general description of the securities we may offer. Each time we sell any securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of those securities. We may also add, update or change in a prospectus supplement any of the information contained in this prospectus or in documents we have incorporated by reference into this prospectus. This prospectus, together with the

applicable prospectus supplements and the documents incorporated by reference into this prospectus, includes all material information relating to this offering. You should carefully read both this prospectus and the applicable prospectus supplement together with the additional information described under “Where You Can Find More Information” before buying securities in this offering.

SUMMARY

We are engaged in the discovery and development of therapeutic products aimed at treating patients with a wide array of severe disease states, including cardiovascular, autoimmune and hematologic disorders, inflammation and cancer. Since our incorporation in January 1992, we have devoted substantially all of our resources to drug discovery, research, and product and clinical development. Additionally, through our wholly owned subsidiary, Alexion Antibody Technologies, Inc., or AAT, we are engaged in the discovery and development of a portfolio of additional antibody therapeutics targeting severe unmet medical needs.

Our two lead product candidates are therapeutic antibodies that address specific diseases that arise when the human immune system produces inflammation in the human body. Antibodies are proteins that bind specifically to selected targets, or antigens, in the body. After the antibody binds to its target, it may activate the body’s immune system against the target, block activities of the target or stimulate activities of the target. We are currently examining our two lead antibody product candidates in a variety of clinical development programs.

One of our antibody product candidates, pexelizumab, is an antibody fragment under development in acute cardiovascular disorders. We completed a Phase III clinical trial of pexelizumab, known as the PRIMO-CABG trial, in approximately 3,000 patients undergoing coronary artery bypass graft surgery, or CABG, with cardiopulmonary bypass, or CPB. The PRIMO-CABG trial was conducted in collaboration with Procter & Gamble Pharmaceuticals, or P&G. In November 2003 at the Late-Breaking Clinical Trials Session of the 2003 Scientific Sessions Meeting of the American Heart Association, we disclosed results of the Phase III clinical trial that indicated that although there was reduction in the primary endpoint, it was not achieved with statistical significance. The primary endpoint in this trial was a composite of the incidence of death or myocardial infarction, measured at 30 days post-procedure, in the subpopulation of patients undergoing CABG without concomitant valve surgery. However, key pre-specified secondary endpoints consisting of the same composite in the overall study population, which included all patients undergoing CABG with or without concomitant valve surgery, were achieved. While our objective to achieve statistical significance in the primary endpoint was not met, and although this trial alone may not provide a basis for us to seek approval for further development of pexelizumab, because of our view regarding the potential clinical benefit observed with pexelizumab in this trial, we have initiated discussions with the FDA. We expect these discussions to continue. We also expect to commence planning for a subsequent CABG clinical trial to expand upon and confirm observations from the PRIMO-CABG trial. In September 2000 the FDA granted “Fast Track” status for the development of pexelizumab in CPB. Fast Track designation provides for expedited development and application review for approval of a drug through the FDA.

We are not currently able to predict the determination of the FDA and other regulatory agencies regarding the results of this Phase III trial. Such determinations may include, but not be limited to, the view that the results may be sufficient for filing and approval of a Biologics License Application, or BLA, supportive of the filing and approval of a BLA together with additional studies, or not supportive of the filing or approval of a BLA. Further, we are not currently able to predict the reaction of P&G, our collaborative partner, to the results of this Phase III trial, including how those results may affect P&G’s views of pexelizumab for CABG or

other indications. P&G retains the development rights and the rights to terminate the collaboration or sublicense its collaboration rights at any time.

In addition to our Phase III trial of pexelizumab in PRIMO-CABG, P&G and we have together concluded two Phase II studies with pexelizumab in acute myocardial infarction, or AMI: one study in patients receiving angioplasty, a procedure for opening up narrowed or blocked arteries that supply blood to the heart, and the other in patients receiving thrombolytic therapy, a procedure for dissolving clots that block heart vessels. Results from both studies were reported at the November 2002 annual meeting of the American Heart Association. In both studies, the primary endpoint of a reduction of myocardial infarction, or death of heart muscle, was not reached; however in the angioplasty study, called COMMA, pexelizumab treatment was associated with a statistically significant, dose dependent reduction in death.

Our other lead antibody product candidate, eculizumab, is in clinical development for the treatment of a variety of chronic inflammatory diseases. In particular, eculizumab is under evaluation in a Phase I extension study in paroxysmal nocturnal hemoglobinuria, or PNH, patients. PNH is a rare chronic blood disease characterized by severe anemia and risk of blood clotting or thrombosis. Preliminary results from the open-label three month PNH pilot study performed in the United Kingdom were presented at the American Society of Hematology, or ASH, meeting in December 2002. In this PNH study, eculizumab was well-tolerated and associated with a 69% reduction in the need for blood transfusions, up to 81% reduction in biochemical parameters of hemolysis or destruction of red cells, and 96% reduction in clinical paroxysms. An open-label extension trial that will help us evaluate long term-safety is ongoing in which all eleven PNH patients are participating. Preliminary results from this extension trial will be presented at the ASH meeting in December 2003.

Eculizumab is also under evaluation for the treatment of rheumatoid arthritis and membranous nephritis, a kidney disease. We completed enrollment in January 2003 for the ongoing Phase IIb study with eculizumab in approximately 350 rheumatoid arthritis patients. We expect to release the full results later in 2003 or during the first half of 2004. In November 2002, preliminary results were reported at the American Society of Nephrology annual meeting from two clinical trials evaluating eculizumab in patients with membranous nephritis. Results from the first, randomized, placebo controlled double blind, membranous nephritis study showed that eculizumab was well tolerated, but did not reach its primary clinical efficacy endpoint of reduction in proteinuria, an abnormal loss of substantial amounts of protein in a patient’s urine, after four months of therapy. In the second membranous nephritis study, both placebo and eculizumab treated patients from the four month study were treated in an open-label extension trial for an additional 12 months with eculizumab therapy. In this second study, eculizumab was well tolerated and was associated with an increased remission rate at 12 months and with significant improvements in proteinuria and other important components of nephrotic syndrome.

In January 2002, we completed a Phase I pilot safety trial in dermatomyositis, an inflammatory skin and muscle disorder, which indicated that eculizumab appeared to be safe and well tolerated in this patient population. We reviewed the clinical data with the FDA and after considering whether to initiate a Phase II clinical study for eculizumab in this disease, have elected not to pursue this program further at this time to more efficiently focus resources on other on-going eculizumab development programs.

Through AAT, our wholly owned subsidiary with extensive combinatorial human antibody library technologies and expertise, we have developed important additional capabilities to discover and develop additional antibody product candidates for the treatment of inflammatory diseases and cancer.

To date, we have not received any revenues from the sale of our products. We have incurred operating losses since our inception. As of July 31, 2003, we had an accumulated deficit of approximately $265 million. We expect to incur substantial and increasing operating losses for the next several years due to expenses associated with product research and development, pre-clinical studies and clinical testing, regulatory activities, manufacturing development, scale-up and commercial manufacturing, pre-commercialization activities and developing a sales and marketing force. We will need to obtain additional financing to cover these costs. We have executed a large-scale product supply agreement with Lonza Biologics, plc for the long-term commercial manufacture of eculizumab and P&G has executed a product supply agreement with a third party for the commercial manufacture of pexelizumab.

We plan to develop and commercialize on our own those product candidates for which the clinical trials and commercialization requirements can be funded and accomplished by our own resources. For those products which require greater resources, our strategy is to form corporate partnerships with major pharmaceutical companies for product development and commercialization, where we will still play a major role.

Our principal executive offices are located at 352 Knotter Drive, Cheshire, Connecticut 06410 and our telephone number is (203) 272-2596.

The Securities We May Offer

We may offer shares of our common stock and preferred stock, various series of debt securities and warrants to purchase any of such securities, with a total value of up to $150 million from time to time under this prospectus at prices and on terms to be determined by market conditions at the time of offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

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designation or classification;

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aggregate principal amount or aggregate offering price;

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maturity;

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original issue discount, if any;

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rates and times of payment of interest, dividends or other payments, if any;

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redemption, conversion, exchange, settlement or sinking fund terms, if any;

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conversion, exchange or settlement prices or rates, if any, and, if applicable, any provisions for changes to or adjustments in the conversion, exchange or settlement prices or rates and in the securities or other property receivable upon conversion, exchange or settlement;

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ranking;

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restrictive covenants, if any

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voting or other rights, if any; and

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important federal income tax considerations.

The prospectus supplement also may add, update or change information contained in this prospectus or in documents we have incorporated by reference into this prospectus.

This prospectus may not be used to offer or sell any securities unless accompanied by a prospectus supplement.

We may sell the securities directly to or through underwriters, dealers or agents. We, and our underwriters or agents, reserve the right to accept or reject all or part of any proposed purchase of securities. If we do offer securities through underwriters or agents, we will include in the applicable prospectus supplement:

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the names of those underwriters or agents;

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applicable fees, discounts and commissions to be paid to them;

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details regarding over-allotment options, if any; and

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the net proceeds to us.

Common Stock. We may issue shares of our common stock from time to time. Holders of our common stock are entitled to one vote per share for the election of directors and on all other matters that require stockholder approval. Subject to any preferential rights of any outstanding preferred stock, in the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in the assets remaining after payment of liabilities and the liquidation preferences of any outstanding preferred stock. Our common stock does not carry any preemptive rights enabling a holder to subscribe for, or receive shares of, any class of our common stock or any other securities convertible into shares of any class of our common stock, or any redemption rights.

Preferred Stock. We may issue shares of our preferred stock from time to time, in one or more series. Under our certificate of incorporation, our board of directors has the authority, without further action by stockholders, to designate up to 5,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges, qualifications and restrictions granted to or imposed upon the preferred stock, including dividend rights, conversion rights, voting rights, rights and terms of redemption, liquidation preference and sinking fund terms, any or all of which may be greater than the rights of the common stock. To date, our board of directors has designated 120,000 of the 5,000,000 authorized shares of preferred stock as Junior Participating Cumulative Preferred Stock, which series is described in greater detail in this prospectus under “Description of Capital Stock — Preferred Stock — Stockholder Rights Plan.”

We will fix the rights, preferences, privileges, qualifications and restrictions of the preferred stock of each series that we sell under this prospectus and applicable prospectus supplements in the certificate of designation relating to that series. We will incorporate by reference into the registration statement of which this prospectus is a part the form of any certificate of designation that describes the terms of the series of preferred stock we are offering before the issuance of the related series of preferred stock. We urge you to read the prospectus supplements related to the series of preferred stock being offered, as well as the complete certificate of designation that contains the terms of the applicable series of preferred stock.

Debt Securities. We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. The senior debt securities will rank equally with any other unsubordinated debt that we may have and may be secured or unsecured. The subordinated debt securities will be subordinate and junior in right of payment, to the extent and in the manner described in the instrument governing the debt, to all or some portion of our indebtedness. Any convertible debt securities that we issue will be convertible into or exchangeable for our common stock or other securities of ours. Conversion may be mandatory or at your option and would be at prescribed conversion rates.

The debt securities will be issued under one or more documents called indentures, which are contracts between us and a trustee for the holders of the debt securities. In this prospectus, we have summarized certain general features of the debt securities. We urge you, however, to read the prospectus supplements related to the series of debt securities being offered, as well as the complete indentures that contain the terms of the debt securities. Indentures have been filed as exhibits to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of debt securities being offered will be incorporated by reference into the registration statement of which this prospectus is a part from reports we file with the SEC.

Warrants. We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series, from time to time. We may issue warrants independently or together with common stock, preferred stock and/or debt securities, and the warrants may be attached to or separate from those securities.

The warrants will be evidenced by warrant certificates issued under one or more warrant agreements, which are contracts between us and an agent for the holders of the warrants. In this prospectus, we have summarized certain general features of the warrants. We urge you, however, to read the prospectus supplements related to the series of warrants being offered, as well as the complete warrant agreements and warrant certificates that contain the terms of the warrants. Complete warrant agreements and warrant certificates containing the terms of the warrants being offered will be incorporated by reference into the registration statement of which this prospectus is a part from reports we file with the SEC.

RISK FACTORS

An investment in our securities is risky. Prior to making a decision about investing in our securities, you should carefully consider the specific risks discussed under “Risk Factors” in both the prospectus and the applicable prospectus supplement, together with all of the other information contained in this prospectus and the prospectus supplement or incorporated by reference in this prospectus. The risks and uncertainties described below are not the only ones facing us. Additional risks and uncertainties not presently known to us, or that we currently see as immaterial, may also harm our business. If any of the risks or uncertainties described below or any such additional risks and uncertainties actually occur, our business, results of operations and financial condition could be materially and adversely affected. In that case, the trading price of the securities being offered by this prospectus and the applicable prospectus supplements could decline, and you might lose all or part of your investment.

You should carefully consider the following risk factors before you decide to invest in our Company and our business because these risk factors may have a significant impact on our business, operating results, financial condition, and cash flows. If any of these risks actually occurs, our business, financial condition, operating results and/or cash flows could be harmed.

If we continue to incur operating losses, we may be unable to continue our operations.

We have incurred losses since we started our company in January 1992. As of July 31, 2003, we had an accumulated deficit of approximately $265 million. If we continue to incur operating losses and fail to become a profitable company, we may be unable to continue our operations. Since we began our business, we have focused on research and development of product candidates. We have no products that are available for sale and do not know when we will have products available for sale, if ever. We expect to continue to operate at a net loss for at least the next several years as we continue our research and development efforts, continue to conduct clinical trials and develop manufacturing, sales, marketing and distribution capabilities. Our future profitability depends on our receiving regulatory approval of our product candidates and our ability to successfully manufacture and market approved drugs. The extent and the timing of our future losses and our profitability, if we are ever profitable, are highly uncertain.

If we do not obtain regulatory approval for our drug products, we will not be able to sell our drug products.

We cannot sell or market our drugs without regulatory approval. If we do not obtain and maintain regulatory approval for our products, the value of our company and our results of operations will be harmed. In the United States, we must obtain and maintain approval from the U.S. Food and Drug Administration, or FDA, for each drug that we intend to sell. Obtaining FDA approval is typically a lengthy and expensive process, and approval is highly uncertain. Foreign governments also regulate drugs distributed outside the United States, whose approval can also be lengthy, expensive and highly uncertain. None of our product candidates has received regulatory approval to be marketed and sold in the United States or any other country. We may not receive regulatory approval for any of our product candidates for at least the next several years, if ever.

If our drug trials are delayed or achieve unfavorable results, we will have to delay or may be unable to obtain regulatory approval for our products.

We must conduct extensive testing of our product candidates before we can obtain regulatory approval for our products. We need to conduct both preclinical animal testing and clinical human trials. These tests and trials may not achieve favorable results. We would need to reevaluate any drug that did not test favorably and either alter the study, the drug or the dose and perform additional or repeat tests, or abandon the drug development project. In those circumstances, we would not be able to obtain regulatory approval on a timely basis, if ever. Even if approval is granted, the approval may require limitations on the indicated uses for which the drug may be marketed.

Clinical trials completed to date have not achieved their primary endpoints.

In December 1999 we completed a Phase IIb trial of pexelizumab, one of our two lead antibody product candidates, for the treatment of complications in patients after cardiopulmonary bypass surgery, including the reduction of the frequency and severity of myocardial infarctions, or heart attacks, and frequency of death. The primary therapeutic pre-set goal of the trial, referred to as the primary endpoint, was not achieved. However, in the pre-specified population that included approximately 90% of the patient population, (i.e. the 800 patients who had coronary artery bypass graft surgery without valve surgery), those that received pexelizumab at the highest dose level experienced a statistically significant reduction in larger post-surgical heart attacks. Based on these results, in January 2002, we commenced enrollment of a Phase III clinical trial of pexelizumab in patients undergoing coronary artery bypass graft surgery, or CABG, with cardiopulmonary bypass operations. This study completed the target patient enrollment of approximately 3,000 patients in February 2003. In August 2003, we disclosed preliminary results that indicated that the primary endpoint was not achieved with statistical significance. The primary endpoint in this Phase III trial was a composite of the incidence of death or myocardial infarction, measured at 30 days post-procedure, in patients undergoing CABG without concomitant valve surgery.

We are not currently able to predict the determination of the United States Food and Drug Administration and other regulatory agencies regarding the results of this Phase III trial of pexelizumab in CABG patients. Such determinations may include, but not be limited to, the view that the results may be sufficient for filing and approval of a Biologics License Application, or BLA, supportive of the filing and approval of a BLA together with additional studies, or not supportive of the filing or approval of a BLA.

We have also announced, in 2001, the completion of a Phase IIa trial of eculizumab, our other lead antibody product candidate, for the treatment of rheumatoid arthritis, or RA. The primary endpoint, or therapeutic pre-set goal, for this trial was met by the group of patients who received the mid-level dosing regimen of eculizumab. Patients who received higher or lower doses of eculizumab in the clinical trial did not achieve the primary endpoint. The primary endpoint in this Phase IIa trial was ACR 20 at 3.25 months.

In January 2002, we initiated a Phase IIb multi-center study in RA patients. The trial is designed to assess safety and efficacy of eculizumab and to confirm the most efficacious dose regimen of the drug in RA patients. The trial consists of approximately 350 patients who are

being treated concomitantly with disease-modifying anti-rheumatic drugs. We completed enrollment in January 2003 for this ongoing Phase IIb study. We expect to release the full results later in 2003 or during the first half of 2004. We are also conducting an on-going 12 month open-label extension study in RA which will continue to help us assess long-term safety.

Completion of these and other trials does not guarantee that we will initiate additional trials for our product candidates, that if the trials are initiated what the scope and phase of the trial will be or that they will be completed, or that if the trials are completed, the results will provide a sufficient basis to proceed with further trials or to apply for or receive regulatory approvals or to commercialize products. Results of trials could be inconclusive, requiring additional or repeat trials. If the results achieved in our clinical trials are insufficient to proceed to further trials or to regulatory approval of our product candidates our company could be materially adversely affected. Failure of a trial to achieve its prespecified primary endpoint generally increases the likelihood that additional studies will be required if the sponsoring company determines to continue development of the product candidate, and reduces the likelihood of timely development of and regulatory approval to market the product candidate.

There are many additional reasons why drug testing could be delayed or terminated.

For human trials, patients must be recruited and each product candidate must be tested at various doses and formulations for each clinical indication. Also, to ensure safety and effectiveness, the effect of drugs often must be studied over a long period of time, especially for the chronic diseases that we are studying. Unfavorable results or insufficient patient enrollment in our clinical trials could delay or cause us to abandon a product development program.

Additional factors that can cause delay or termination of our clinical trials include:

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slow patient enrollment;

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long treatment time required to demonstrate effectiveness;

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lack of sufficient supplies of the product candidate;

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adverse medical events or side effects in treated patients;

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lack of effectiveness of the product candidate being tested; and

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lack of sufficient funds.

We may expand our business through new acquisitions that could disrupt our business and harm our financial condition.

Our business strategy includes expanding our products and capabilities, and we may seek acquisitions to do so. Acquisitions involve numerous risks, including:

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substantial cash expenditures;

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potentially dilutive issuance of equity securities;

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incurrence of debt and contingent liabilities, some of which may be difficult or impossible to identify at the time of acquisition;

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difficulties in assimilating the operations of the acquired companies;

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diverting our management’s attention away from other business concerns;

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risks of entering markets in which we have limited or no direct experience; and

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the potential loss of our key employees or key employees of the acquired companies.

We cannot assure you that any acquisition will result in short-term or long-term benefits to us. We may incorrectly judge the value or worth of an acquired company or business. In addition, our future success would depend in part on our ability to manage the rapid growth associated with some of these acquisitions. We cannot assure you that we will be able to make the combination of our business with that of acquired businesses or companies work or be successful. Furthermore, the development or expansion of our business or any acquired business or companies may require a substantial capital investment by us. We may not have these necessary funds or they might not be available to us on acceptable terms or at all. We may also seek to raise funds by selling shares of our stock, which could dilute current shareholder’s ownership interest in our company.

On September 22, 2000, we purchased all of the capital stock and other outstanding securities of Prolifaron, Inc., a privately held biopharmaceutical company that is developing therapeutic antibodies addressing multiple diseases, including cancer, for approximately 400,000 shares of our outstanding capital stock. The business of Prolifaron, now our wholly-owned subsidiary, Alexion Antibody Technologies, Inc., or AAT, is subject to many of the same risks that our business is subject to. We cannot assure you that AAT will successfully develop any products or that we will realize any benefits from the acquisition of Prolifaron.

If we fail to obtain the capital necessary to fund our operations, we will be unable to continue or complete our product development.

We believe we have sufficient capital to fund our operations and product development for at least twenty-four months. We may need to raise additional capital before or after that time to complete the development and commercialization of our product candidates. We are currently conducting or completing several clinical trials, including the Phase III trial of pexelizumab in CABG patients. Funding needs may shift between programs and potentially accelerate and increase if we initiate new pivotal trials for our product candidates, including any pivotal clinical trial of pexelizumab for acute myocardial infarction, or heart attack, patients undergoing angioplasty, a procedure for opening up narrowed or blocked arteries that supply blood to the heart. We rely heavily on Procter & Gamble to fund development of pexelizumab. If Procter & Gamble were to terminate the pexelizumab collaboration, we could have to raise additional capital or find new collaboration partners in order to continue the development of pexelizumab.

Additional financing could take the form of public or private debt or equity offerings, equity line facilities, bank loans, collaborative research and development arrangements with corporate partners and/or the sale or licensing of some of our property. The amount of capital we may need depends on many factors, including:

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the existence, terms and status of collaborative arrangements and strategic partnerships, such as our collaboration with Procter & Gamble;

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the progress, timing and scope of our research and development programs;

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the progress, timing and scope of our preclinical studies and clinical trials;

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the time and cost necessary to obtain regulatory approvals;

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the time and cost necessary to further develop manufacturing processes, arrange for contract manufacturing or build manufacturing facilities and obtain the necessary regulatory approvals for those facilities;

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the time and cost necessary to develop sales, marketing and distribution capabilities;

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the cost necessary to sell, market and distribute our products, if any are approved;

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changes in applicable governmental regulatory policies; and

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any new collaborative, licensing and other commercial relationships that we may establish.

We may not get funding when we need it or funding may only be available on unfavorable terms. If we cannot raise adequate funds to satisfy our capital requirements, we may have to delay, scale-back or eliminate our research and development activities or future operations. We might have to license our technology to others. This could result in sharing revenues that we might otherwise retain for ourselves. Any of these actions would harm our business.

If our collaboration with Procter & Gamble is terminated or Procter & Gamble reduces its commitment to our collaboration, our ability to develop and commercialize pexelizumab in the time expected, or at all, would be harmed and our business would suffer accordingly.

We rely heavily on Procter & Gamble to perform development, obtain commercial manufacturing, and provide sales and marketing for pexelizumab. While we cannot assure you that pexelizumab will ever be successfully developed and commercialized, if Procter & Gamble does not perform its obligations in a timely manner, or at all, our ability to commercialize pexelizumab will be significantly adversely affected. We rely on Procter & Gamble, or P&G, to provide funding and additional resources for the development and commercialization of pexelizumab. These include funds and resources for:

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clinical development and clinical and commercial manufacturing;

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obtaining regulatory approvals; and

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sales, marketing and distribution efforts worldwide.

P&G has rights to terminate the collaboration or sublicense its collaboration rights at any time. Termination of our agreement with Procter & Gamble would cause significant delays in the development of pexelizumab and result in significant additional development costs to us. If we were to continue development of pexelizumab following termination by P&G, we would need to fund the development and commercialization of pexelizumab on our own or identify a new development partner. We would need to develop or acquire replacement expertise in many areas necessary for the development and potential commercialization of pexelizumab, or enter into agreements with other companies with respect to those matters. We do not have the resources to replace some of the functions provided or funded by P&G. Accordingly, we might have to stop the development of pexelizumab or shift resources from other product development programs until alternative resources are obtained. Sublicense of its rights by P&G also could cause significant delays in the development of pexelizumab and result in substantial additional development costs to us. In addition, sublicense would introduce a new collaboration partner which could create new and additional risks to the development of pexelizumab that can not be identified at this time.

We cannot guarantee that Procter & Gamble will devote the resources necessary to successfully develop and commercialize pexelizumab in a timely manner, if at all. Furthermore, Procter & Gamble may devote the necessary resources, but we may still not successfully develop

and commercialize pexelizumab. We might also have to repeat testing already completed with Procter & Gamble.

We are not currently able to predict the determination of P&G to regarding the results of the Phase III PRIMO-CABG trial of pexelizumab, including how those results may affect P&G’s future plans for pexelizumab.

If we are unable to engage and retain third-party collaborators, our research and development efforts may be delayed.

We depend upon third-party collaborators to assist us in the development of our product candidates. If any of our existing collaborators breaches or terminates its agreement with us or does not perform its development work under an agreement in a timely manner or at all, we would experience significant delays in the development or commercialization of our product candidates. We would also experience significant delays if we could not engage additional collaborators when required. In either event, we would be required to devote additional funds or other resources to these activities or to terminate them. This would divert funds or other resources from other parts of our business.

We cannot assure you that:

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current collaboration arrangements will be continued in their current form;

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we will be able to negotiate acceptable collaborative agreements to develop or commercialize our product candidates;

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any arrangements with third parties will be successful; or

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current or potential collaborators will not pursue treatments for other diseases or seek other ways of developing treatments for our disease targets.

If the trading price of our common stock continues to fluctuate in a wide range, our stockholders will suffer considerable uncertainty with respect to an investment in our stock.

The trading price of our common stock has been volatile and may continue to be volatile in the future. Factors such as announcements of fluctuations in our or our competitors’ operating results or clinical or scientific results, fluctuations in the trading prices or business prospects of our competitors and collaborators, including, but not limited to Procter & Gamble, changes in our prospects, and market conditions for biotechnology stocks in general could have a significant impact on the future trading prices of our common stock and our outstanding notes. In particular, the trading price of the common stock of many biotechnology companies, including ours, has experienced extreme price and volume fluctuations, which have at times been unrelated to the operating performance of the companies whose stocks were affected. This is due to several factors, including general market conditions, the announcement of the results of our clinical trials or product development and the results of our attempts to obtain FDA approval for our products. In particular, since August 1, 2001, the sales price of our common stock has ranged from a low of $9.05 per share to a high of $26.69 per share and since August 1, 1999, the sales price of our common stock has ranged from a low of $9.05 per share to a high of $119.88 per share. While we cannot predict our future performance, if our stock continues to fluctuate in a wide range, an investment in our stock or our outstanding notes may result in considerable uncertainty for an investor.

If we cannot protect the confidentiality and proprietary nature of our trade secrets, our business and competitive position will be harmed.

Our business requires using sensitive technology, techniques and proprietary compounds that we protect as trade secrets. However, since we are a small company, we also rely heavily on collaboration with suppliers, outside scientists and other drug companies. Collaboration presents a strong risk of exposing our trade secrets. If our trade secrets were exposed, it would help our competitors and adversely affect our business prospects.

In order to protect our drugs and technology more effectively, we need to obtain patents covering the drugs and technologies we develop. We may obtain patents through ownership or license. Our drugs are expensive and time-consuming to test and develop. Without patent protection, competitors may copy our methods, or the chemical structure or other aspects of our drugs. Even if we obtain patents, the patents may not be broad enough to protect our drugs from copycat products.

If we are found to be infringing on patents owned by others, we may be forced to obtain a license to continue the manufacture, sale or development of our drugs and/or pay damages. If we cannot obtain a license, we may be prevented from the sale or development of our drugs.

Parts of our technology, techniques and proprietary compounds and potential drug candidates may conflict with patents owned by or granted to others. If we cannot resolve these conflicts, we may be liable for damages, be required to obtain costly licenses or be stopped from manufacturing, using or selling our products or conducting other activities. For example, we are aware of broad patents owned by others relating to the manufacture, use and sale of recombinant humanized antibodies, recombinant humanized single chain antibodies, recombinant human antibodies, and recombinant human single chain antibodies. Many of our product candidates are genetically engineered antibodies, including recombinant humanized antibodies, recombinant humanized single chain antibodies, recombinant human antibodies, and recombinant human single chain antibodies.

We have received notices from the owners of some of these patents claiming that their patents may be relevant to the development, manufacture or sale of some of our drug candidates. In response to some of these notices, we have obtained licenses, or expect to obtain licenses. However, with regard to other patents, we have either determined in our judgment that:

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our products do not infringe the patents;

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we do not believe the patents are valid; or

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we have identified and are testing various modifications that we believe should not infringe the patents and which should permit commercialization of our product candidates.

Any patent holders could sue us for damages and seek to prevent us from manufacturing, selling or developing our drugs. Legal disputes can be costly and time consuming to defend. If any of these actions are successful, we could be required to pay costly damages or to obtain a license to sell or develop our drugs. A required license may be costly or may not be available on acceptable terms, if at all.

If the testing or use of our products harms people, we could be subject to costly and damaging product liability claims.

The testing, manufacturing, marketing and sale of drugs for use in humans exposes us to product liability risks. Side effects and other problems from using our products could give rise to product liability claims against us. We might have to recall our products, if any, from the marketplace. Some of these risks are unknown at this time.

In addition, we may be sued by people who participate in our trials. A number of patients who participate in such trials are already very ill when they enter the trial. Any informed consents or waivers obtained from people who sign up for our trials may not protect us from liability or litigation. Our product liability insurance may not cover all potential liabilities or may not completely cover any covered liabilities. Moreover, we may not be able to maintain our insurance on acceptable terms. In addition, negative publicity relating to a product liability claim may make it more difficult, or impossible, for us to recruit patients for our clinical trials or to market and sell our products. As a result of these factors, a product liability claim, even if successfully defended, could have a material adverse effect on our business, financial condition or results of operations.

Use of C5 Inhibitors, such as pexelizumab and eculizumab, is associated with an increased risk for infection with Neisseria bacteria. One patient in our eculizumab membranous nephritis trials became infected with Neisseria bacteria. Serious cases of Neisseria infection can result in brain damage, loss of limbs or parts of limbs, kidney failure, or death.

If we cannot manufacture our drug candidates in sufficient amounts at acceptable costs and on a timely basis, we may be unable to have the necessary materials for product testing, and later for potential sale in the market. Either event would harm our business.

For our drug trials, we need to produce sufficient amounts of product for testing. Our small manufacturing plant cannot manufacture enough of our product candidates for later stage clinical development. In addition, we do not have the capacity to produce more than one product candidate at a time. We depend on a few outside suppliers for manufacturing. If we experience interruptions in the manufacture of our products for testing, our drug development and commercialization efforts will be delayed. If any of our outside manufacturers stops manufacturing our products or reduces the amount manufactured, or is otherwise unable to manufacture our required amounts at our required quality, we will need to find other alternatives. If we are unable to find an acceptable outside manufacturer on reasonable terms, we will have to divert our own resources to manufacturing, which may not be sufficient to produce the necessary quantity or quality of product. As a result, our ability to conduct testing and drug trials and our plans for commercialization would be materially adversely affected. Submission of products and new development programs for regulatory approval, as well as our plans for commercialization, would be delayed. Our competitive position and our prospects for achieving profitability would be materially and adversely affected.

Manufacture of drug products is highly regulated by the FDA and other domestic and foreign authorities, including the need to develop and utilize manufacturing processes that consistently produce our drug products to their required quality specifications. We cannot assure

you that we or our third-party collaborators will successfully comply with all of those regulations, which would have a materially adverse effect on our business.

Manufacture of our drug products is highly technical and only a few third-parties have the ability and capacity to manufacture our drug products for our development and commercialization needs. We can not assure you that these potential third-party collaborators will agree to manufacture our products on our behalf on commercially reasonable terms, if at all. If we do achieve agreement from one or more third parties to manufacture our drug products, we can not assure you that they will be able or willing to honor the terms of the agreements, including any obligations to manufacture the drug products in accordance with regulatory requirements and to our specific quality specifications and volume requirements. Due to the highly technical requirements of manufacturing our drug products, our third-party collaborators and we may be unable to manufacture our drug products despite their and our efforts. Inability to contract with third-party manufacturers on commercially reasonable terms, or failure or delay by our third-party manufacturers, if any, in manufacturing our drug products in the volumes and quality required, would have a material adverse effect on our business.

We have no experience or capacity for manufacturing drug products in volumes that would be necessary to support commercial sales. If we are unable to establish and maintain commercial scale manufacturing within our planned time and cost parameters, sales of our products and our financial performance would be adversely affected.

Currently, we are relying on Procter & Gamble to retain appropriate commercial manufacturing for pexelizumab through one or more third-party manufacturers. P&G has contracted with one third-party manufacturer for the large-scale commercial manufacture of pexelizumab. The failure of Procter & Gamble to obtain appropriate commercial manufacturing for pexelizumab on a timely basis, or at all, may prevent or impede the commercialization of pexelizumab. We have executed a large-scale product supply agreement with Lonza Biologics, plc for the long-term manufacture of eculizumab. The failure of Lonza Biologics, plc to manufacture appropriate supplies of eculizumab on a timely basis, or at all, may prevent or impede the commercialization of eculizumab.

Due to the nature of the current market for third-party commercial manufacturing arrangements, many arrangements require substantial penalty payments by the customer for failure to use the manufacturing capacity contracted for. We could owe substantial penalty payments to Lonza Biologics, plc if we were not to use the manufacturing capacity contracted for with them. Also, we could be required to share on an equal basis with P&G substantial penalty payments owed by P&G for its failure to utilize the manufacturing capacity contracted for by it with a third-party manufacturer for supply of pexelizumab; or we could be solely liable for such potential penalty payments if P&G were to terminate our collaboration and if we were to assume such third-party manufacturing agreement. The payment of a substantial penalty would harm our financial condition.

If we are unable to establish sales, marketing and distribution capabilities, or to enter into agreements with third parties to do so, we will be unable to successfully market and sell future drug products.

We have no sales or distribution personnel or capabilities, and have only recently established core pre-commercial marketing capabilities. If we are unable to continue developing or contracting those capabilities, either by developing our own capabilities or entering into agreements with others, we will not be able to successfully sell our products. In that event, we will not be able to generate significant revenues. We cannot guarantee that we will be able to hire the qualified sales and marketing personnel we need. We may not be able to enter into any marketing or distribution agreements with third-party providers on acceptable terms, if at all. Currently, we are relying on Procter & Gamble for sales, marketing and distribution of pexelizumab. Procter & Gamble, or any future third-party collaborators, may not succeed at selling, marketing or distributing any of our future drug products.

If we are unable to obtain reimbursement from government health administration authorities, private health insurers and other organizations for our future products, our products may be too costly for regular use and our ability to generate revenues would be harmed.

Our products, if commercialized, like similar products in the marketplace, may be significantly more expensive than traditional drug treatments. Our future revenues and profitability will be adversely affected if we cannot depend on governmental and private third-party payors to defray the cost of our products to the consumer. If these entities refuse to provide reimbursement with respect to our products or determine to provide an insufficient level of reimbursement, our products may be too costly for general use. Our profitability may be adversely impacted if we choose to offer our products at a reduced price. Any limitation on the use of our products or any decrease on the price of our products without a corresponding decrease in expenses will have a material adverse effect on our ability to achieve profitability.

If our competitors get to the marketplace before we do with better or cheaper drugs, our drugs may not be profitable to sell or to continue to develop.

Each of Abbott Laboratories, Adprotech Ltd., Avant Immunotherapeutics, Inc., Baxter International, Inc., Millennium Pharmaceuticals, Inc., Neurogen Corporation, Tanox, Inc., and Xoma, Inc. have publicly announced their intentions to develop drugs which target the inflammatory effects of complement in the immune system. We are also aware that GlaxoSmithKline plc, Merck & Co., Inc. and Pfizer, Inc. are also attempting to develop complement inhibitor therapies. Each of Cambridge Antibody Technology Group plc, MorphoSys AG and Dyax Corporation has publicly announced intentions to develop therapeutic human antibodies from libraries of human antibody genes. Additionally, each of Abgenix Inc. and Medarex, Inc. has publicly announced intentions to develop therapeutic human antibodies from mice that have been bred to include some human antibody genes. These and other pharmaceutical companies, many of which have significantly greater resources than we, may develop, manufacture and market better or cheaper drugs than our product candidates. They may establish themselves in the marketplace before we are able to even finish our clinical trials. Other pharmaceutical companies also compete with us to attract academic research institutions as drug development partners, including for licensing these institutions’ proprietary technology. If our competitors successfully enter into such arrangements with academic institutions, we will be precluded from pursuing those specific unique opportunities and may not be able to find equivalent opportunities elsewhere.

If we fail to recruit and retain personnel, our research and product development programs may be delayed.

We are highly dependent upon the efforts of our senior management and scientific personnel, particularly, Leonard Bell, M.D., our Chief Executive Officer and a member of our Board of Directors, David W. Keiser, our President, Chief Operating Officer and a member of our Board of Directors, and Stephen P. Squinto, Ph.D., our Executive Vice President and Head of Research. There is intense competition in the biotechnology industry for qualified scientific and technical personnel. Since our business is very science-oriented and specialized, we need to continue to attract and retain such people. We may not be able to continue to attract and retain the qualified personnel necessary for developing our business. We have a key man insurance policy for Dr. Bell and employment agreements with Dr. Bell, Mr. Keiser and Dr. Squinto. To our knowledge, none of our key personnel is planning to retire or is nearing retirement age. Further, to our knowledge, there is no tension between any of our key personnel and the Board of Directors. If we lose the services of our management and scientific personnel or fail to recruit other scientific and technical personnel, our research and product development programs would be materially and adversely affected.

In particular, we highly value the services of Dr. Leonard Bell, our Chief Executive Officer. The loss of his services could materially and adversely affect our ability to achieve our development objectives.

The large number of shares that may be sold in the market following our September 2003 sale of common stock may depress the market price of our stock.

Sale or issuance of a substantial number of shares of our common stock could cause the market price of our common stock to decline. All of the 3,600,000 shares sold in our September 2003 offering of common stock are freely tradable without restriction or further registration under the Securities Act of 1933. In addition, as of November 20, 2003, there were 2,807,399 shares of common stock issuable upon exercise of options granted by us, which also have been registered for resale on registration statements filed with the Securities and Exchange Commission. We also may issue up to 1,127,555 shares of common stock upon conversion of 5 3/4% convertible subordinated notes due in March 2007, which have been registered for resale pursuant to a registration statement filed with the Securities and Exchange Commission.

The conviction of our former independent public accountants, Arthur Andersen LLP, on federal obstruction of justice charges may adversely affect Arthur Andersen LLP’s ability to satisfy any claims arising from the provision of auditing services to us and may impede our access to the capital markets.

On March 14, 2002, our previous independent public accounting firm, Arthur Andersen LLP, was indicted on federal obstruction of justice charges arising from the federal government’s investigation of Enron Corp. On June 15, 2002, a jury returned with a guilty verdict against Arthur Andersen LLP following a trial. As a public company, we are required to file with the U.S. Securities and Exchange Commission, or SEC, periodic financial statements audited or reviewed by an independent public accountant. On May 31, 2002, we dismissed Arthur Andersen LLP as our independent public accountants, and engaged a new independent public accounting firm to audit our financial statements for fiscal 2002. It may be impossible for you to obtain

recoveries from Arthur Andersen LLP with respect to its audits of our financial statements as a result of its conviction in the Enron matter. In addition, Arthur Andersen LLP has not performed any procedures in connection with our Annual Report on Form 10-K for the fiscal years ended July 31, 2002 and July 31, 2003 and has not consented to the incorporation by reference of its reports in our Annual Report on Form 10-K for the fiscal years ended July 31, 2002, and July 31, 2003 and therefore, you will not be able to recover against Arthur Andersen LLP for any untrue statements of material fact contained in the financial statements audited by Arthur Andersen LLP or any omissions to state a material fact required to be stated therein.

Should we seek access to the public capital markets, the SEC rules will require us to include or incorporate by reference in any prospectus three years of audited financial statements. The SEC’s rules normally would require us to present audited financial statements for one or more fiscal years audited by Arthur Andersen LLP and obtain their consent and representations until our audited financial statements for the fiscal year ending July 31, 2004 become available in the first quarter ended October 31, 2004. We expect that we would not be able to obtain the necessary consent and representations from Arthur Andersen LLP who have ceased operations. Although the SEC presently accepts financial statements previously audited by Arthur Andersen LLP but without Arthur Andersen’s current consent and representations, those financial statements would not provide us and any underwriters with the same level of protection under current securities laws as would otherwise be the case. In either of these situations, our access to the capital markets would be impaired unless PricewaterhouseCoopers LLP, our current independent public accounting firm, or another independent public accounting firm, is able to audit the financial statements originally audited by Arthur Andersen LLP. Any delay or inability to access the public capital markets caused by these circumstances could have a material adverse effect on our business, profitability and growth prospects.

FORWARD-LOOKING INFORMATION

This prospectus contains or incorporates by reference, and the applicable prospectus supplement may contain, “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. These forward-looking statements can generally be identified as such because the context of the statement will include words such as “may,” “will,” “intends,” “plans,” “believes,” “anticipates,” “expects,” “estimates,” “predicts,” “potential,” “continue,” or “opportunity,” the negative of these words or words of similar import. Similarly, statements that describe our reserves and our future plans, strategies, intentions, expectations, objectives, goals or prospects are also forward-looking statements. Discussions containing these forward-looking statements may be found, among other places, in “Business” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” incorporated by reference from our most recent Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q for the quarters ended subsequent to our filing of such Annual Report on Form 10-K with the SEC, as well as any amendments thereto reflected in subsequent filings with the SEC. These forward-looking statements are or will be, as applicable, based largely on our expectations and projections about future events and future trends affecting our business, and so are or will be, as applicable, subject to risks and uncertainties that could cause actual results to differ materially from those anticipated in the forward-looking statements.

Our actual results of operations and execution of our business strategy could differ materially from those expressed in, or implied by, the forward-looking statements. In addition, past financial and/or operating performance is not necessarily a reliable indicator of future performance and you should not use our historical performance to anticipate results or future period trends. We can give no assurances that any of the events anticipated by the forward-looking statements will occur or, if any of them do, what impact they will have on our results of operations and financial condition. In evaluating our forward-looking statements, you should specifically consider the risks and uncertainties discussed under “Risk Factors” in this prospectus and any applicable prospectus supplement. Except as required by law, we undertake no obligation to publicly revise our forward-looking statements to reflect events or circumstances that arise after the date of this prospectus or the date of documents incorporated by reference in this prospectus that include forward-looking statements.

FINANCIAL RATIOS

Our earnings were insufficient to cover fixed charges in each of the years in the five-year period ended July 31, 2003. The extent to which earnings were insufficient to cover fixed charges is as follows:

	Years Ended July 31,
Ratio of earnings to fixed charges	1999			2000			2001			2002			2003
Deficiency of earnings available to cover fixed charges⁽¹⁾	$	(6,395	)	$	(20,227	)	$	(47,925	)	$	(57,242	)	$	(85,231	)

⁽¹⁾

For purposes of computing the deficiency of earnings to fixed charges, our “earnings” consist of losses before income taxes plus fixed charges. Fixed charges represent interest expense on all debt, including amortized premiums, discounts and capitalized expenses related to indebtedness, and the estimated interest factor attributable to rental expenses.

We currently have no preferred stock outstanding and accordingly have no obligation to pay preference dividends. If we issue preferred stock, the appropriate ratio of combined fixed charges and preference dividends will be included in a prospectus supplement. In addition, if we use the proceeds from the sale of debt or preference securities to repay any of our outstanding debt or retire other securities and the change in the ratio of earnings to fixed charges or combined fixed charges and preference dividends to earnings would be ten percent or greater, we will include a pro forma ratio showing the application of the proceeds in our prospectus supplement.

USE OF PROCEEDS

Except as described in any prospectus supplement, we currently intend to use the net proceeds from the sale of our securities under this prospectus for general corporate purposes. We may also use a portion of the net proceeds to acquire or invest in businesses, products and technologies that are complementary to our own, although we currently are not planning or negotiating any such transactions.

Additionally, we may use a portion of the proceeds from the sale of our securities to redeem all or a portion of our outstanding Subordinated Convertible Notes which mature in March 2007 (the “Notes”). The Notes bear interest at an annual rate of 5 ¾%. We may elect to redeem the Notes on at least 30 days’ notice as a whole, or, from time to time, in part at the following prices, expressed as a percentage of the principal amount, together with accrued interest to, but excluding, the date fixed for redemption:

Period	Redemption Price
Beginning March 20, 2003 and ending on March 14, 2004	103.286	%
Beginning March 15, 2004 and ending on March 14, 2005	102.464	%
Beginning March 15, 2005 and ending on March 14, 2006	101.643	%
Beginning March 15, 2006 and ending on March 14, 2007	100.822	%
and 100% on March 15, 2007

In addition, we may offer to repurchase some or all of the Notes at other prices, payable in cash or other securities.

DESCRIPTION OF CAPITAL STOCK

As of the date of this prospectus, our certificate of incorporation authorizes us to issue 145,000,000 shares of common stock, par value $0.0001 per share, and 5,000,000 shares of preferred stock, par value $0.0001 per share. As of November 20, 2003, 21,860,407 shares of our common stock were outstanding and no shares of preferred stock were outstanding. To date, our board of directors has designated 120,000 of the 5,000,000 authorized shares of preferred stock as Junior Participating Cumulative Preferred Stock, which series is described in greater detail below under “— Preferred Stock — Stockholder Rights Plan.”

The following summary describes the material terms of our capital stock and stockholder rights plan. The description of capital stock and stockholder rights plan is qualified by reference to our amended and restated certificate of incorporation, as amended, our bylaws, as amended, the certificate of designation for our Junior Participating Cumulative Preferred Stock, and our stockholder rights plan, which are incorporated by reference as exhibits into the registration statement of which this prospectus is a part.

Common Stock

Voting. Common stockholders are entitled to one vote per share for the election of directors and on all other matters that require stockholder approval. There is no cumulative voting.

Dividends and Other Distributions. Holders of our common stock are entitled to share in an equal amount per share any dividends declared by our board of directors on the common stock and paid out of legally available assets.

Distribution on Dissolution. Subject to any preferential rights of any outstanding preferred stock, in the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in the assets remaining after payment of liabilities and the liquidation preferences of any outstanding preferred stock.

Other Rights. Our common stock does not carry any preemptive rights enabling a holder to subscribe for, or receive shares of, any class of our common stock or any other securities convertible into shares of any class of our common stock, or any redemption rights.

Preferred Stock

Under our certificate of incorporation, our board of directors has the authority, without further action by stockholders, to designate up to 5,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges, qualifications and restrictions granted to or imposed upon the preferred stock, including dividend rights, conversion rights, voting rights, rights and terms of redemption, and liquidation preference, any or all of which may be greater than the rights of the common stock. To date, our board of directors has designated 120,000 of the 5,000,000 authorized shares of preferred stock as Junior Participating Cumulative Preferred Stock, which series is described in greater detail below under “Stockholder Rights Plan.”

The issuance of preferred stock could adversely affect the voting power of holders of common stock and reduce the likelihood that common stockholders will receive dividend payments and payments upon liquidation. The issuance could have the effect of decreasing the market price of our common stock. The issuance of preferred stock also could have the effect of delaying, deterring or preventing a change in control of us.

Our board of directors will fix the rights, preferences, privileges, qualifications and restrictions of the preferred stock of each series that we sell under this prospectus and applicable prospectus supplements in the certificate of designation relating to that series. We will incorporate by reference into the registration statement of which this prospectus is a part the form of any certificate of designation that describes the terms of the series of preferred stock we are offering before the issuance of the related series of preferred stock. This description will include:

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the title and stated value;

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the number of shares we are offering;

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the liquidation preference per share;

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the purchase price per share;

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the dividend rate per share, dividend period and payment dates and method of calculation for dividends;

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whether dividends will be cumulative or non-cumulative and, if cumulative, the date from which dividends will accumulate;

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our right, if any, to defer payment of dividends and the maximum length of any such deferral period;

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the procedures for any auction and remarketing, if any;

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the provisions for a sinking fund, if any;

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the provisions for redemption or repurchase, if applicable, and any restrictions on our ability to exercise those redemption and repurchase rights;

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any listing of the preferred stock on any securities exchange or market;

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whether the preferred stock will be convertible into our common stock or other securities of ours, including warrants, and, if applicable, the conversion period, the conversion price, or how it will be calculated, and under what circumstances it may be adjusted;

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whether the preferred stock will be exchangeable into debt securities, and, if applicable, the exchange period, the exchange price, or how it will be calculated, and under what circumstances it may be adjusted;

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voting rights, if any, of the preferred stock;

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preemption rights, if any;

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restrictions on transfer, sale or other assignment, if any;

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a discussion of any material or special United States federal income tax considerations applicable to the preferred stock;

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the relative ranking and preferences of the preferred stock as to dividend rights and rights if we liquidate, dissolve or wind up our affairs;

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any limitations on issuances of any class or series of preferred stock ranking senior to or on a parity with the series of preferred stock being issued as to dividend rights and rights if we liquidate, dissolve or wind up our affairs; and

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any other specific terms, rights, preferences, privileges, qualifications or restrictions of the preferred stock.

When we issue shares of preferred stock under this prospectus, the shares will be fully paid and nonassessable and will not have, or be subject to, any preemptive or similar rights.

Delaware law provides that the holders of preferred stock will have the right to vote separately as a class on any proposal involving fundamental changes in the rights of holders of that preferred stock. This right is in addition to any voting rights that may be provided for in the applicable certificate of designation.

Stockholder Rights Plan.

On February 14, 1997 our Board of Directors declared a dividend of one preferred stock purchase right (a “Right”) for each outstanding share of our common stock. The Rights were issued to the stockholders of record on March 6, 1997 and will expire on March 6, 2007, subject to earlier redemption. Under certain circumstances, each Right entitles the registered holder to purchase from us one one-hundredth of a share of our Junior Participating Cumulative Preferred Stock or, in certain circumstances, either our common stock or common stock of an acquiring company, at one-half the market price of our common stock or the acquiring company’s common stock, as the case may be. The Rights are designed to make it more likely that all of our stockholders receive fair and equal treatment in the event of any proposed takeover of us and to guard against the use of partial tender offers or other coercive tactics to gain control of us. The description and terms of the Rights are set forth in a Rights Agreement between us and Continental Stock Transfer & Trust Company, as Rights Agent.

Exercise Price When exercisable, except as set forth below, each Right entitles the registered holder to purchase from us one one-hundredth of a share of Junior Participating Cumulative Preferred Stock, at a price of $725.00 per one one-hundredth of a share, subject to adjustment in certain circumstances.

Transfer and Detachment Until the “Distribution Date”, which is the earlier to occur of (i) ten business days following the time (the “Stock Acquisition Date”) of a public announcement or notice to us that a person or group of affiliated or associated persons has acquired, or obtained the right to acquire, beneficial ownership (as defined in the Rights Agreement) of 20% or more of our outstanding shares of common stock (such 20% beneficial owner, an “Acquiring Person”), or (ii) ten business days, or such later date as may be determined by our Board of Directors, after the date of the commencement or announcement by a person of an intention to make a tender

offer or exchange offer for an amount of common stock which, together with the shares of such stock already owned by such person, constitutes 20% or more of the outstanding shares of our common stock, the Rights will be evidenced, with respect to any of our common stock certificates outstanding as of March 6, 1997, by such common stock certificate with a copy of the Summary of Rights attached thereto. The Rights Agreement provides that, until the Distribution Date, the Rights will be transferred with and only with our common stock.

Until the Distribution Date (or earlier redemption or expiration of the Rights), new common stock certificates issued after March 6, 1997, upon the transfer or issuance of new shares of common stock, will contain a notation incorporating the Rights Agreement by reference. Until the Distribution Date (or earlier redemption or expiration of the Rights), the surrender for the transfer of any of our common stock certificates outstanding as of March 6, 1997, even without a copy of the Summary of Rights attached thereto, will also constitute the transfer of the Rights associated with the shares of common stock represented by such certificate.

As soon as practicable following the Distribution Date, separate certificates evidencing the Rights (“Right Certificates”) will be mailed to holders of record of the common stock as of the close of business on the Distribution Date, and such separate Right Certificates alone will evidence the Rights.

Exercisability The Rights are not exercisable until the Distribution Date. The Rights will expire on March 6, 2007 unless earlier redeemed by us.

Right to Acquire Stock at Half Price In the event that after the Stock Acquisition Date, we are acquired in a merger or other business combination transaction or 50% or more of our assets, cash flow or earning power are sold or otherwise transferred, the Rights Agreement provides that proper provision shall be made so that each holder of a Right, upon the exercise thereof at the then current exercise price of the Right, shall be entitled to receive that number of shares of common stock of the acquiring company having a market value (as defined in the Rights Agreement) of two times the exercise price of the Right. In the event that we are the surviving corporation of a merger and our common stock is changed or exchanged, proper provision shall be made so that each holder of a Right will thereafter have the right to receive upon exercise that number of shares of common stock of the other party to the transaction having a market value of two times the exercise price of the Right.

In the event that a person or group becomes an Acquiring Person (otherwise than pursuant to a tender offer or exchange offer for all outstanding shares of our common stock at a price and on terms which are determined to be fair and in the best interests of us and our stockholders by a majority of the members of our Board of Directors who are not Acquiring Persons or representatives or nominees of or affiliated or associated with an Acquiring Person), proper provision shall be made so that each holder of a Right, other than the Acquiring Person, whose Rights will thereafter be void, will thereafter have the right to receive upon exercise that number of shares of our common stock having a market value (as defined in the Rights Agreement) of two times the exercise price of the Right. A person or group will not be deemed to be an Acquiring Person if our Board of Directors determines that such person or group became an Acquiring Person inadvertently and such person or group promptly divests itself of a sufficient number of shares of common stock so that such person or group is no longer an Acquiring Person.

Adjustments The Purchase Price payable and the number of shares of Junior Preferred Stock or other securities or property issuable upon the exercise of the Rights are subject to adjustment from time to time to prevent dilution (i) in the event of a stock dividend on or a subdivision, combination or reclassification of the shares of Junior Preferred Stock, (ii) upon the fixing of a record date for the issuance to holders of Junior Preferred Stock of certain rights, options or warrants to subscribe for shares of Junior Preferred Stock or convertible securities at less than the current market price of shares of Junior Preferred Stock or (iii) upon the fixing of a record date for the making of a distribution to holders of shares of Junior Preferred Stock of evidences of indebtedness or assets (excluding regular periodic cash dividends not exceeding 125% of the last regular periodic cash dividend or dividends payable in shares of Junior Preferred Stock) or of subscription rights or warrants (other than those referred to above). The number of Rights and the number of shares of Junior Preferred Stock issuable upon exercise of each Right are also subject to adjustment in the case of a stock split, combination or stock dividend on the shares of our common stock prior to the Distribution Date.

With certain exceptions, no adjustment in the Purchase Price will be required until cumulative adjustments require an adjustment of at least 1% in the Purchase Price. No fractional shares of common stock will be issued and, in lieu thereof, an adjustment in cash will be made based on the market value of shares of common stock on the last trading date prior to the date of exercise.

Redemption or Exchange At any time prior to ten business days after the Stock Acquisition Date we, by resolution of our Board of Directors, may redeem the Rights in whole, but not in part, at a price of $.01 per Right (the “Redemption Price”). If such resolution is adopted following the Stock Acquisition Date, it will be effective only with the concurrence of a majority of the members (the “Continuing Directors”) of our Board of Directors who are not Acquiring Persons or representatives or nominees of or affiliated or associated with an Acquiring Person and who either were members of our Board of Directors prior to the Stock Acquisition Date or subsequently became a member and whose election thereto was approved by a majority of the directors who were not Acquiring Persons or representatives or nominees of or affiliated or associated with an Acquiring Person. Our Board of Directors may extend the time within which the Rights may be redeemed at any time prior to the Stock Acquisition Date. Immediately upon the action of our Board of Directors electing to redeem the Rights, the right to exercise the Rights will terminate and the only right of the holders of Rights will be to receive the Redemption Price.

At any time after a person becomes an Acquiring Person and prior to the acquisition by such person of 50% or more of our outstanding common stock, our Board of Directors, with the concurrence of a majority of the Continuing Directors, may exchange the Rights (other than Rights beneficially owned by such person which have become void), in whole or in part, for our common stock at an exchange ratio of one share of common stock per Right (subject to adjustment).

Preferred Stock The shares of Junior Preferred Stock purchasable upon exercise of the Rights will be nonredeemable and junior to any other series of preferred stock we may issue (unless otherwise provided in the terms of such preferred stock or in our certificate of incorporation). Each share of Junior Preferred Stock will be entitled to receive, in the aggregate, a dividend in an amount equal to 100 times the dividend per share of common stock, or, if

greater, $10.00 per year. In the event of liquidation, the holders of shares of Junior Preferred Stock will be entitled to receive a minimum liquidation payment equal to the greater of $100.00 per share or an amount equal to 100 times the amount to be paid in liquidation per share of common stock. Each share of Junior Preferred Stock will have 100 votes, voting together with the shares of common stock. In addition, if dividends on the Junior Preferred Stock are in arrears for four consecutive quarterly payment periods, the holders of the shares of Junior Preferred Stock will have the right, voting as a class, to elect two members to our Board of Directors. In the event of any merger, consolidation or other transaction in which shares of common stock are exchanged, each share of Junior Preferred Stock will be entitled to receive 100 times the amount and type of consideration received per share of common stock. The rights of the shares of Junior Preferred Stock as to dividends and liquidation, and in the event of mergers and consolidations, are protected by antidilution provisions.

Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder, including, without limitation, the right to vote or to receive dividends.

Amendment The Rights and the Rights Agreement can be amended by our Board of Directors in any respect (including, without limitation, any extension of the period in which the Rights may be redeemed) at any time prior to the Stock Acquisition Date. From and after such time, without the approval of our stockholders or the holders of the Rights, the Board of Directors may only supplement or amend the Rights Agreement in order (i) to cure any ambiguity, (ii) to correct or supplement any provision contained in the Rights Agreement which may be defective or inconsistent with any other provision in the Rights Agreement, (iii) to shorten or lengthen any time period under the Rights Agreement or (iv) to make any changes or supplements which we and the Rights Agent may deem necessary or desirable which shall not adversely affect the interests of the holders of Right Certificates (other than an Acquiring Person or an affiliate or associate thereof). We may, at any time prior to the Stock Acquisition Date, amend the Rights Agreement to lower the threshold of common stock beneficial ownership at which a person will become an Acquiring Person to not less than the greater of (i) a percentage larger than the largest percentage of Common Stock then known by the us to be beneficially owned by a person and (ii) 10%.

Anti-Takeover Provisions

Delaware Law. We are governed by the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years after the date of the transaction in which the person became an interested stockholder, unless before the date that the person became an “interested stockholder,” the board of directors approved either the “business combination” or the transaction which makes the person an “interested stockholder,” or after the date that the person became an “interested stockholder,” the business combination is approved by our board of directors and the vote of at least 66 2/3% of our outstanding voting stock that is not owned by the “interested stockholder.” Generally, a “business combination” includes a merger, asset sale or other transaction resulting in a financial benefit to the stockholder. An “interested stockholder” is a person who either owns 15% or more of our outstanding voting stock or, together with affiliates and associates, owns or, within three prior years, did own, 15% or more of our outstanding voting stock. The statute could have the effect of delaying, deferring or preventing a change in our control.

Bylaw and Certificate of Incorporation Provisions. Our bylaws provide that special meetings of our stockholders may be called only by the Chairman of the Board, the President, the Secretary, or a majority of the Board of Directors, or upon the written request of stockholders who together own of record 50% of the outstanding stock of all classes entitled to vote at such meeting. Our bylaws also specify that the authorized number of directors may be changed only by resolution of the board of directors. Our certificate does not include a provision for cumulative voting for directors. Under cumulative voting, a minority stockholder holding a sufficient percentage of a class of shares may be able to ensure the election of one or more directors. These and other provisions contained in our certificate of incorporation and bylaws could delay or discourage transactions involving an actual or potential change in control of us or our management, including transactions in which stockholders might otherwise receive a premium for their shares over then current prices. These provisions could also limit the ability of stockholders to remove current management or approve transactions that stockholders may deem to be in their best interests and could adversely affect the price of our common stock.

Transfer Agent And Registrar

The transfer agent and registrar for our common stock is Continental Stock Transfer & Trust Co.

Listing on the Nasdaq National Market

Our common stock is listed on the Nasdaq National Market under the symbol “ALXN.”

DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the debt securities that we may offer under this prospectus. While the terms we have summarized below will generally apply to any future debt securities we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities we offer under a prospectus supplement may differ from the terms we describe below.

We will issue the senior notes under the senior indenture which we entered into with U.S. Bank National Association. We will issue the subordinated notes under the subordinated indenture which we entered into with U.S. Bank National Association. We have filed forms of these documents as exhibits to the registration statement of which this prospectus is a part. Supplemental indentures and forms of debt securities containing the terms of debt securities being offered will be incorporated by reference into the registration statement of which this prospectus is a part from reports we file with the SEC. We use the term “indentures” to refer to both the senior indenture and the subordinated indenture.

The indentures will be qualified under the Trust Indenture Act of 1939. We use the term “trustee” to U.S. Bank National Association.

The following summaries of material provisions of the senior notes, the subordinated notes and the indentures are subject to, and qualified in their entirety by reference to, all the provisions of the indenture applicable to a particular series of debt securities. We urge you to

read the applicable prospectus supplements related to the debt securities that we sell under this prospectus, as well as the complete indentures that contain the terms of the debt securities. Except as we may otherwise indicate, the terms of the senior indenture and the subordinated indenture are identical.

General

We will describe in the applicable prospectus supplement the terms relating to a series of debt securities, including:

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the title;

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the principal amount being offered, and, if a series, the total amount authorized and the total amount outstanding;

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any limit on the amount that may be issued;

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whether or not we will issue the series of debt securities in global form and, if so, the terms and who the depositary will be;

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the maturity date;

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the principal amount due at maturity, and whether the debt securities will be issued with any original issue discount;

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whether and under what circumstances, if any, we will pay additional amounts on any debt securities held by a person who is not a United States person for tax purposes, and whether we can redeem the debt securities if we have to pay such additional amounts;

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the annual interest rate, which may be fixed or variable, or the method for determining the rate, the date interest will begin to accrue, the dates interest will be payable and the regular record dates for interest payment dates or the method for determining such dates;

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whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

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the terms of the subordination of any series of subordinated debt;

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the place where payments will be payable;

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restrictions on transfer, sale or other assignment, if any;

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our right, if any, to defer payment of interest and the maximum length of any such deferral period;

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the date, if any, after which, the conditions upon which, and the price at which we may, at our option, redeem the series of debt securities pursuant to any optional or provisional redemption provisions, and any other applicable terms of those redemption provisions;

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provisions for a sinking fund, purchase or other analogous fund, if any;

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the date, if any, on which, and the price at which we are obligated, pursuant to any mandatory sinking fund or analogous fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities;

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whether the indenture will restrict our ability and/or the ability of our subsidiaries to:

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incur additional indebtedness;

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issue additional securities;

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create liens;

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pay dividends and make distributions in respect of our capital stock and the capital stock of our subsidiaries;

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redeem capital stock;

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place restrictions on our subsidiaries’ ability to pay dividends, make distributions or transfer assets;

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make investments or other restricted payments;

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sell or otherwise dispose of assets;

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enter into sale-leaseback transactions;

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engage in transactions with stockholders and affiliates;

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issue or sell stock of our subsidiaries; or

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effect a consolidation or merger;

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whether the indenture will require us to maintain any interest coverage, fixed charge, cash flow-based, asset-based or other financial ratios;

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a discussion of any material or special United States federal income tax considerations applicable to the debt securities;

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information describing any book-entry features;

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the procedures for any auction and remarketing, if any;

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the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof;

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if other than dollars, the currency in which the series of debt securities will be denominated; and

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any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities, including any events of default that are in addition to those described in this prospectus or any covenants provided with respect to the debt securities that are in addition to those described above, and any terms which may be required by us or advisable under applicable laws or regulations or advisable in connection with the marketing of the debt securities.

Conversion or Exchange Rights

We will set forth in the prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for common stock or other securities of ours or a third party, including the conversion or exchange rate, as applicable, or how it will be calculated, and the applicable conversion or exchange period. We will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of our securities or the securities of a third party that the holders of the series of debt securities receive upon conversion or exchange would, under the circumstances described in those provisions, be subject to adjustment, or pursuant to which those holders would, under those circumstances, receive other property upon conversion or exchange, for example in the event of our merger or consolidation with another entity.

Consolidation, Merger or Sale

The indentures in the forms initially filed as exhibits to the registration statement of which this prospectus is a part do not contain any covenant which restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of all or substantially all of our assets. However, any successor of ours or acquiror of such assets must assume all of our obligations under the indentures and the debt securities.

If the debt securities are convertible for our other securities, the person with whom we consolidate or merge or to whom we sell all of our property must make provisions for the conversion of the debt securities into securities which the holders of the debt securities would have received if they had converted the debt securities before the consolidation, merger or sale.

Events of Default Under the Indenture

The following are events of default under the indentures with respect to any series of debt securities that we may issue:

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if we fail to pay interest when due and payable and our failure continues for 90 days and the time for payment has not been extended;

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if we fail to pay the principal, or premium, if any, when due and payable and the time for payment has not been extended;

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if we fail to observe or perform any other covenant contained in the debt securities or the indentures, other than a covenant specifically relating to another series of debt securities, and our failure continues for 90 days after we receive notice from the trustee or holders of at least 25% in principal amount of the outstanding debt securities of the applicable series; and

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if specified events of bankruptcy, insolvency or reorganization occur.

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default with respect to the series and its consequences, except defaults in payment of principal, premium, if any, or interest, unless we have cured the default in accordance with the indenture.

Subject to the terms of the indentures, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity.

The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee with respect to the debt securities of that series, provided that:

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the direction so given by the holder is not in conflict with any law or the applicable indenture; and

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subject to its duties under the Trust Indenture Act of 1939, the trustee may decline to follow any direction of such holders that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

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the holder has given written notice to the trustee of a continuing event of default with respect to that series;

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the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series have made written request, and such holders have offered reasonable indemnity to the trustee to institute the proceeding as trustee; and

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the trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series other conflicting directions within 90 days after the notice, request and offer.

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indentures.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters, including:

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to fix any ambiguity, defect or inconsistency in the indenture or in the debt securities of any series;

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to comply with the provisions described above under “— Consolidation, Merger or Sale”;

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to provide for uncertificated debt securities in addition to or in place of certificated debt securities;

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to add to our covenants such new covenants, restrictions, conditions or provisions for the protection of the holders, to make the occurrence, or the occurrence and the continuance, of a default in any such additional covenants, restrictions, conditions or provisions an event of default, or to surrender any of our rights or powers under the indenture;

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to add to, delete from, or revise the conditions, limitations and restrictions on the authorized amount, terms or purposes of issue, authentication and delivery of debt securities of any series;

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to change anything that does not adversely affect the rights of any holder of debt securities of any series in any material respect;

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to evidence and provide for the acceptance of appointment under an indenture by a successor trustee; or

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to comply with any requirements of the SEC in connection with the qualification of any indenture under the Trust Indenture Act of 1939.

In addition, under the indentures, we and the trustee may not change an indenture and the rights of holders of a series of debt securities may be changed by us and the trustee other than as set forth in the bullet points above with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, we and the trustee may only make the following changes with the consent of each holder of any outstanding debt securities affected:

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extending the fixed maturity of the series of debt securities;

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reducing the principal amount, reducing the rate of or extending the time of payment of interest, or reducing any premium payable upon the redemption of any debt securities; or

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reducing the percentage of debt securities, the holders of which are required to consent to any change to an indenture.

Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for obligations to:

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replace stolen, lost or mutilated debt securities of the series;

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maintain paying agencies;

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hold monies for payment in trust;

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recover excess money held by the trustee;

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compensate and indemnify the trustee; and

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appoint any successor trustee.

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we otherwise specify in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indentures provide that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company or another depositary named by us and identified in a prospectus supplement with respect to that series. See “Legal Ownership of Securities” for a further description of the terms relating to any book-entry securities.

At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indentures and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the

debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will make no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

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issue, register the transfer of, or exchange any debt securities of any series being redeemed in part during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

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register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest payment.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that, unless we otherwise indicate in the applicable prospectus supplement, we may make interest payments by check which we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in a prospectus supplement, we will designate an office or agency of the trustee in the City of New York as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other

paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities which remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York, except to the extent that the Trust Indenture Act of 1939 is applicable.

Subordination of Subordinated Debt Securities

The subordinated debt securities will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in a prospectus supplement. The indentures in the forms initially filed as exhibits to the registration statement of which this prospectus is a part do not limit the amount of indebtedness which we may incur, including senior indebtedness or subordinated indebtedness, and do not limit us from issuing any other debt, including secured debt or unsecured debt.

DESCRIPTION OF WARRANTS

The following description, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which consist of warrants to purchase common stock, preferred stock and/or debt securities in one or more series. Warrants may be offered independently or together with common stock, preferred stock and/or debt securities offered by any prospectus supplement, and may be attached to or separate from those securities. While the terms we have summarized below will generally apply to any future warrants we may offer under this prospectus, we will describe the particular terms of any warrants that we may offer in more detail in the applicable prospectus supplement. The terms of any warrants we offer under a prospectus supplement may differ from the terms we describe below.

We will issue the warrants under a warrant agreement which we will enter into with a warrant agent to be selected by us. Complete warrant agreements and warrant certificates containing the terms of the warrants being offered will be incorporated by reference into the registration statement of which this prospectus is a part from the reports we file with the SEC. We use the term “warrant agreement” to refer to any of these warrant agreements. We use the term “warrant agent” to refer to the warrant agent under any of these warrant agreements. The warrant agent will act solely as an agent of ours in connection with the warrants and will not act as an agent for the holders or beneficial owners of the warrants.

The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement applicable to a particular series of warrants. We urge you to read the

applicable prospectus supplements related to the warrants that we sell under this prospectus, as well as the complete warrant agreements that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms relating to a series of warrants. If warrants for the purchase of debt securities are offered, the prospectus supplement will describe the following terms, to the extent applicable:

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the offering price and the aggregate number of warrants offered;

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the currencies in which the warrants are being offered;

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the designation, aggregate principal amount, currencies, denominations and terms of the series of debt securities that can be purchased if a holder exercises a warrant;

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the designation and terms of any series of debt securities with which the warrants are being offered and the number of warrants offered with each such debt security;

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the date on and after which the holder of the warrants can transfer them separately from the related series of debt securities;

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the principal amount of the series of debt securities that can be purchased if a holder exercises a warrant and the price at which and currencies in which such principal amount may be purchased upon exercise;

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the terms of any rights to redeem or call the warrants;

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the date on which the right to exercise the warrants begins and the date on which such right expires;

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federal income tax consequences of holding or exercising the warrants; and

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any other specific terms, preferences, rights or limitations of, or restrictions on, the warrants.

Warrants for the purchase of debt securities will be in registered form only.

If warrants for the purchase of common stock or preferred stock are offered, the prospectus supplement will describe the following terms, to the extent applicable:

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the offering price and the aggregate number of warrants offered;

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the total number of shares that can be purchased if a holder of the warrants exercises them and, in the case of warrants for preferred stock, the designation, total number and terms of the series of preferred stock that can be purchased upon exercise;

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the designation and terms of any series of preferred stock with which the warrants are being offered and the number of warrants being offered with each share of common stock or preferred stock;

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the date on and after which the holder of the warrants can transfer them separately from the related common stock or series of preferred stock;

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the number of shares of common stock or preferred stock that can be purchased if a holder exercises the warrant and the price at which such common stock or preferred stock may be purchased upon exercise, including, if applicable, any provisions for changes to or adjustments in the exercise price and in the securities or other property receivable upon exercise;

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the terms of any rights to redeem or call, or accelerate the expiration of, the warrants;

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the date on which the right to exercise the warrants begins and the date on which that right expires;

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federal income tax consequences of holding or exercising the warrants; and

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any other specific terms, preferences, rights or limitations of, or restrictions on, the warrants.

Warrants for the purchase of common stock or preferred stock will be in registered form only.

A holder of warrant certificates may exchange them for new certificates of different denominations, present them for registration of transfer and exercise them at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Until any warrants to purchase debt securities are exercised, the holder of the warrants will not have any of the rights of holders of the debt securities that can be purchased upon exercise, including any rights to receive payments of principal, premium or interest on the underlying debt securities or to enforce covenants in the applicable indenture. Until any warrants to purchase common stock or preferred stock are exercised, holders of the warrants will not have any rights of holders of the underlying common stock or preferred stock, including any rights to receive dividends or to exercise any voting rights, except to the extent set forth under “— Warrant Adjustments” below.

Exercise of Warrants

Each holder of a warrant is entitled to purchase the principal amount of debt securities or number of shares of common stock or preferred stock, as the case may be, at the exercise price described in the applicable prospectus supplement. After the close of business on the day when the right to exercise terminates (or a later date if we extend the time for exercise), unexercised warrants will become void.

A holder of warrants may exercise them by following the general procedure outlined below:

•

delivering to the warrant agent the payment required by the applicable prospectus supplement to purchase the underlying security;

•

properly completing and signing the reverse side of the warrant certificate representing the warrants; and

•

delivering the warrant certificate representing the warrants to the warrant agent within five business days of the warrant agent receiving payment of the exercise price.

If you comply with the procedures described above, your warrants will be considered to have been exercised when the warrant agent receives payment of the exercise price, subject to the transfer books for the securities issuable upon exercise of the warrant not being closed on such date. After you have completed those procedures and subject to the foregoing, we will, as soon as practicable, issue and deliver to you the debt securities, common stock or preferred stock that you purchased upon exercise. If you exercise fewer than all of the warrants represented by a warrant certificate, a new warrant certificate will be issued to you for the unexercised amount of warrants. Holders of warrants will be required to pay any tax or governmental charge that may

be imposed in connection with transferring the underlying securities in connection with the exercise of the warrants.

Amendments and Supplements to the Warrant Agreements

We may amend or supplement a warrant agreement without the consent of the holders of the applicable warrants to cure ambiguities in the warrant agreement, to cure or correct a defective provision in the warrant agreement, or to provide for other matters under the warrant agreement that we and the warrant agent deem necessary or desirable, so long as, in each case, such amendments or supplements do not materially adversely affect the interests of the holders of the warrants.

Warrant Adjustments

Unless the applicable prospectus supplement states otherwise, the exercise price of, and the number of securities covered by, a common stock warrant or preferred stock warrant will be adjusted proportionately if we subdivide or combine our common stock or preferred stock, as applicable. In addition, unless the prospectus supplement states otherwise, if we, without payment there for:

•

issue capital stock or other securities convertible into or exchangeable for common stock or preferred stock, or any rights to subscribe for, purchase or otherwise acquire any of the foregoing, as a dividend or distribution to holders of our common stock or preferred stock;

•

pay any cash to holders of our common stock or preferred stock other than a cash dividend paid out of our current or retained earnings or other than in accordance with the terms of the preferred stock;

•

issue any evidence of our indebtedness or rights to subscribe for or purchase our indebtedness to holders of our common stock or preferred stock; or

•

issue common stock or preferred stock or additional stock or other securities or property to holders of our common stock or preferred stock by way of spinoff, split-up, reclassification, combination of shares or similar corporate rearrangement,

then the holders of common stock warrants and preferred stock warrants, as applicable, will be entitled to receive upon exercise of the warrants, in addition to the securities otherwise receivable upon exercise of the warrants and without paying any additional consideration, the amount of stock and other securities and property such holders would have been entitled to receive had they held the common stock or preferred stock, as applicable, issuable under the warrants on the dates on which holders of those securities received or became entitled to receive such additional stock and other securities and property.

Except as stated above, the exercise price and number of securities covered by a common stock warrant and preferred stock warrant, and the amounts of other securities or property to be received, if any, upon exercise of those warrants, will not be adjusted or provided for if we issue those securities or any securities convertible into or exchangeable for those securities, or securities carrying the right to purchase those securities or securities convertible into or exchangeable for those securities.

Holders of common stock warrants and preferred stock warrants may have additional rights under the following circumstances:

•

certain reclassifications, capital reorganizations or changes of the common stock or preferred stock, as applicable;

•

certain share exchanges, mergers, or similar transactions involving us and which result in changes of the common stock or preferred stock, as applicable; or

•

certain sales or dispositions to another entity of all or substantially all of our property and assets.

If one of the above transactions occurs and holders of our common stock or preferred stock are entitled to receive stock, securities or other property with respect to or in exchange for their securities, the holders of the common stock warrants and preferred stock warrants then outstanding, as applicable, will be entitled to receive upon exercise of their warrants the kind and amount of shares of stock and other securities or property that they would have received upon the applicable transaction if they had exercised their warrants immediately before the transaction.

LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee or depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Global securities will be registered in the name of the depositary. Consequently, for global securities, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee or third party employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with its participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the holders contact the indirect holders is up to the holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

•

how it handles securities payments and notices;

•

whether it imposes fees or charges;

•

how it would handle a request for the holders’ consent, if ever required;

•

whether and how you can instruct it to send you securities registered in your own name so you can be a holder, if that is permitted in the future;

•

how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

•

if the securities are global securities, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security which represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all global securities issued under this prospectus.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued as a global security, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations for Global Securities

As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only as a global security, an investor should be aware of the following:

•

An investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations we describe below;

•

An investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as we describe above;

•

An investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

•

An investor may not be able to pledge his or her interest in the global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

•

The depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in the global security. We and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in the global security. We and the trustee also do not supervise the depositary in any way;

•

The depositary may, and we understand that DTC will, require that those who purchase and sell interests in the global security within its book-entry system use immediately available funds, and your broker or bank may require you to do so as well; and

•

Financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in the global security, may also have their own policies affecting payments, notices and other matters relating to the securities. There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will be Terminated

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

A global security will terminate when the following special situations occur:

•

if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

•

if we notify any applicable trustee that we wish to terminate that global security; or

•

if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

The prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the prospectus supplement. When a global security terminates, the depositary, and not we or any applicable

trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

PLAN OF DISTRIBUTION

We may sell the securities covered by this prospectus in any of three ways (or in any combination):

•

to or through underwriters or dealers;

•

directly to a limited number of purchasers or to a single purchaser; or

•

through agents.

We will describe in a prospectus supplement the terms of the offering of the securities covered by this prospectus, including:

•

the name or names of any underwriters, dealers or agents and the amounts of securities underwritten or purchased by each of them;

•

any over-allotment options under which underwriters may purchase additional securities from us;

•

any underwriting discounts or commissions or agency fees and other items constituting underwriters’ or agents’ compensation;

•

the initial public offering price of the securities and the proceeds to us and any discounts, commissions or concessions allowed or reallowed or paid to dealers; and

•

any securities exchanges or markets on which the securities may be listed.

Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

Underwriters may offer and sell the offered securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. If underwriters are used in the sale of any securities, the securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions described above. The securities may be either offered to the public through underwriting syndicates represented by managing underwriters, or directly by underwriters. Generally, the underwriters’ obligations to purchase the securities will be subject to certain conditions precedent. The underwriters will be obligated to purchase all of the securities if they purchase any of the securities. We may use underwriters with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, the nature of any such relationship.

We may sell the securities through agents from time to time. The prospectus supplement will name any agent involved in the offer or sale of the securities and any commissions we pay to them. Generally, any agent will be acting on a best efforts basis for the period of its appointment.

We may authorize underwriters, dealers or agents to solicit offers by certain purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in

the future. The contracts will be subject only to those conditions set forth in the prospectus supplement, and the prospectus supplement will set forth any commissions we pay for solicitation of these contracts.

Agents and underwriters may be entitled to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which the agents or underwriters may be required to make in respect thereof. Agents and underwriters may be customers of, engage in transactions with, or perform services for us in the ordinary course of business.

All securities we offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

LEGAL MATTERS

The validity of the securities being offered hereby will be passed upon by Fulbright & Jaworski L.L.P., New York, New York.

EXPERTS

The consolidated financial statements as of July 31, 2003 and 2002 and for each of the two years then ended incorporated in this prospectus by reference to the Annual Report on Form 10-K for the year ended July 31, 2003 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, independent accountants, given on the authority of said firm as experts in auditing and accounting.

The audited financial statements as of July 31, 2001 and for the year then ended incorporated by reference in this prospectus have been audited by Arthur Andersen LLP, independent public accountants, as indicated in their report with respect thereto. In 2002, Arthur Andersen LLP ceased operations. A copy of the report previously issued by Arthur Andersen LLP on our financial statements as of July 31, 2001 and for the year then ended is included in our Annual Report on Form 10-K for the fiscal year ended July 31, 2003 as filed with the SEC on October 27, 2003, which is incorporated herein by reference. Such report has not been reissued by Arthur Andersen LLP.

NOTICE REGARDING ARTHUR ANDERSEN LLP

Section 11(a) of the Securities Act provides that if any part of a registration statement at the time it becomes effective contains an untrue statement of a material fact or an omission to state a material fact required to be stated therein or necessary to make the statements therein not misleading, any person acquiring a security pursuant to such registration statement (unless it is proved that at the time of such acquisition such person knew of such untruth or omission) may sue, among others, every accountant who has consented to be named as having prepared or certified any part of the registration statement or as having prepared or certified any report or valuation which is used in connection with the registration statement with respect to the statement in such registration statement, report or valuation which purports to have been prepared or certified by the accountant. On May 29, 2002, we announced that we dismissed Arthur Andersen LLP as our independent accountants. As Arthur Andersen LLP has ceased operations, we have been unable to obtain Arthur Andersen’s written consent to the incorporation by reference into this prospectus supplement of its audit reports with respect to our financial statements for the fiscal years ended July 31, 2001. Under these circumstances, Rule 437a under the Securities Act permits us to file this prospectus without a written consent from Arthur Andersen. Accordingly, Arthur Andersen will not be liable to you under Section 11(a) of the Securities Act because it has not consented to being named as an expert in the prospectus.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. Our SEC filings, and those of other companies which make electronic filings with the SEC, are available to the public over the Internet at the SEC’s web site at http://www.sec.gov. You may also read and copy any document we file at the SEC’s public reference room at 450 Fifth Street, N.W., Washington, D.C. 20549. You may obtain information on the operation of the SEC’s public reference room in Washington, D.C. by calling the SEC at 1-800-SEC-0330.

We “incorporate by reference” the information we file with the SEC (File No. 0-27756), which means that we can disclose important information to you by referring you to another document we filed with the SEC. The information incorporated by reference is an important part of this prospectus and information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, after the date of the prospectus but before the end of any offering made under this prospectus:

•

Our annual report on Form 10-K for the fiscal year ended July 31, 2003, filed on October 27, 2003;

•

Our registration statement on Form 8-A, filed on February 21, 1997, as amended by Amendment No. 1 to Form 8-A filed on October 6, 2000 and Amendment No. 2 to Form 8-A filed on February 12, 2002; and

•

Our registration statement on Form 8-A, filed on February 12, 1996.

You should read the information relating to us in this prospectus together with the information in the documents incorporated by reference.

Any statement contained in a document incorporated by reference herein, unless otherwise indicated therein, speaks as of the date of that document. Statements contained in this prospectus may modify or replace statements contained in the documents incorporated by reference.

We will furnish without charge to you, upon written or oral request, a copy of any or all of the documents described above, except for exhibits to such documents, unless such exhibits are specifically incorporated by reference into such documents. Requests should be addressed to: Alexion Pharmaceuticals, Inc., 352 Knotter Drive, Cheshire, Connecticut 06410, (203) 272-2596, Attention: Thomas I.H. Dubin, Vice President and General Counsel.

PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14.

Other Expenses of Issuance and Distribution

The following table sets forth the estimated costs and expenses, other than the underwriting discounts and commissions, payable by the registrant in connection with the offering of the securities being registered. All the amounts shown are estimates, except for the registration fee.

SEC registration fee	$	8,537
Accounting fees and expenses	$	20,000
Legal fees and expenses	$	25,000
Trustee fees and expenses	$	12,000
Printing and miscellaneous expenses	$	10,000

Total	$	75,537

Item 15.

Indemnification of Officers and Directors

Section 145 of the Delaware General Corporation Law (the “DGCL”) empowers a Delaware corporation to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative(other than an action by or in the right of such corporation) by reason of the fact that such person is or was a director, officer, employee or agent of such corporation, or is or was serving at the request of such corporation as a director, officer, employee or agent of another corporation or enterprise. A corporation may, in advance of the final disposition of any civil, criminal, administrative or investigative action, suit or proceeding, pay the expenses (including attorneys’ fees) incurred by any officer, director, employee or agent in defending such action, provided that the director or officer undertakes to repay such amount if it shall ultimately be determined that he is not entitled to be indemnified by the corporation. A corporation may indemnify such person against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful.

A Delaware corporation may indemnify officers and directors in an action by or in the right of the corporation to procure a judgment in its favor under the same conditions, except that no indemnification is permitted without judicial approval if the officer or director is adjudged to be liable to the corporation.

Where an officer or director is successful on the merits or otherwise in the defense of any action referred to above, the corporation must indemnify him against the expenses (including attorneys fees) which he actually and reasonably incurred in connection therewith. The indemnification provided by Section 145 of the DGCL is not deemed to be exclusive of any other rights to which an officer or director may be entitled under any corporation’s by-law, agreement, vote or otherwise.

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In accordance with Section 145 of the DGCL, Section EIGHTH of our Certificate of Incorporation, as amended provides that we shall indemnify each person who is or was a director, officer, employee or agent of us (including the heirs, executors, administrators or estate of such person) or is or was serving at our request as a director, officer, incorporator, employee, partner, trustee or agent of another corporation, partnership, joint venture, trust or other enterprise, to the fullest extent permitted. The indemnification provided by our amended Certificate of Incorporation shall not be deemed exclusive of any other rights to which any of those seeking indemnification or advancement of expenses may be entitled under any by-law, agreement, vote of shareholders or disinterested directors or otherwise, both as to action in his official capacity and as to action in another capacity while holding such office, and shall continue as to a person who has ceased to be a director, officer, employee or agent and shall inure to the benefit of the heirs, executors and administrators of such a person. Expenses (including attorneys’ fees) incurred in defending a civil, criminal, administrative or investigative action, suit or proceeding shall be paid by us in advance of the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of the indemnified person to repay such amount if it shall ultimately be determined that he is not entitled to be indemnified by us. Section NINTH of our amended Certificate of Incorporation provides that our directors shall not be personally liable to the us or our stockholders for monetary damages for breach of fiduciary duty as a director, except for liability (i) for any breach of the director’s duty of loyalty to us or our stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) under Section 174 of the DGCL, or (iv) for any transaction from which the director derived an improper personal benefit.

Insofar as the indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers or controlling persons pursuant to the foregoing provisions, we have been informed that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

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Item 16.

Exhibits and Financial Statement Schedules

Exhibit Number		Description of Document

4.1		Specimen Preferred Stock Certificate and Form of Certificate of Designation of Preferred Stock.⁽¹⁾

4.2		Senior Debt Indenture dated as of November 25, 2003 between Alexion Pharmaceuticals, Inc. and U.S. Bank National Association, as trustee.

4.3		Subordinated Debt Indenture dated as of November 25, 2003 between Alexion Pharmaceuticals, Inc. and U.S. Bank National Association, as trustee.

4.4		Form of Senior Note.⁽¹⁾

4.5		Form of Subordinated Note.⁽¹⁾

4.6		Form of Common Stock Warrant Agreement and Warrant Certificate⁽¹⁾.

4.7		Form of Preferred Stock Warrant Agreement and Warrant Certificate^.(1)

4.8		Form of Debt Securities Warrant Agreement and Warrant Certificate.⁽¹⁾

5.1		Opinion of Fulbright & Jaworski L.L.P.

12.1		Statement Regarding Computation of Ratio of Earnings to Fixed Charges and Ratio of Combined Fixed Charges and Preference Dividends to Earnings.

23.1		Consent of PricewaterhouseCoopers LLP, Independent Accountants.

23.2		Consent of Fulbright & Jaworski L.L.P. (included in Exhibit 5.1).

24.1		Power of Attorney (included on signature page).

25.1		Statement of Eligibility of Trustee under the Senior Debt Indenture.

25.2		Statement of Eligibility of Trustee under the Subordinated Debt Indenture.

⁽¹⁾	To be filed as an exhibit to a Current Report of the registrant on Form 8-K and incorporated herein by reference.

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Item 17.

Undertakings

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however, that paragraph (a)(1)(i) and (a)(1)(ii) of this section do not apply if the Registration Statement is on Form S-3, Form S-8 or Form F-3, and the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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(h) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

(i) The undersigned registrant hereby undertakes that:

(1) For purpose of determining any liability under the Securities Act of 1933, the information omitted from the form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this registration statement as of the time it was declared effective.

(2) For the purpose of determining any liability under the Securities Act of 1933, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(j) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act (the “Act”) in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Act.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant named below certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Cheshire, State of Connecticut, on this 25^th day of November, 2003.

ALEXION PHARMACEUTICALS, INC.

By:		/s/ Leonard Bell

		Leonard Bell
		Chief Executive Officer, Secretary and Treasurer


By:		/s/ David W. Keiser

		David W. Keiser
		President and Chief Operating Officer

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints LEONARD BELL and DAVID W. KEISER, and each of them, as his true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him and in his name, place, and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments, exhibits thereto and other documents in connection therewith) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith (including any registration statement relating to this Registration Statement and filed pursuant to Rule 462(b) of the Securities Act of 1933, as amended), with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or either of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

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IN WITNESS WHEREOF, each of the undersigned has executed this Power of Attorney as of the date indicated opposite his name.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

Signature	Title	Date

/s/ LEONARD BELL Leonard Bell	Chief Executive Officer (Principal Executive Officer)	November 25, 2000

/s/ DAVID W. KEISER David W. Keiser	President, Chief Officer and Director (Principal Financial Officer)	November 25, 2000

/s/ BARRY P. LUKE Barry P. Luke	Vice President, Finance and Administration Principal Accounting Officer	November 25, 2000

Max Link	Chairman of the Board of Directors	November , 2000

/s/ JERRY T. JACKSON Jerry T. Jackson	Director	November 25, 2000

/S/ JOSEPH A. MADRI Joseph A. Madri	Director	November 25, 2000

/s/ R. DOUGLAS NORBY R. Douglas Norby	Director	November 25, 2000

/S/ ALVIN S. PARVIN Alvin S. Parvin	Director	November 25, 2000

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INDEX TO EXHIBITS


4.1		Specimen Preferred Stock Certificate and Form of Certificate of Designation of Preferred Stock.(1)

4.2		Senior Debt Indenture dated as of November 25, 2003 between Alexion Pharmaceuticals, Inc. and U.S. Bank National Association, as trustee.

4.3		Subordinated Debt Indenture dated as of November 25, 2003 between Alexion Pharmaceuticals, Inc. and U.S. Bank National Association, as trustee.

4.4		Form of Senior Note.(1)

4.5		Form of Subordinated Note.(1)

4.6		Form of Common Stock Warrant Agreement and Warrant Certificate(1).

4.7		Form of Preferred Stock Warrant Agreement and Warrant Certificate.(1)

4.8		Form of Debt Securities Warrant Agreement and Warrant Certificate.(1)

5.1		Opinion of Fulbright & Jaworski L.L.P.

12.1		Statement Regarding Computation of Ratio of Earnings to Fixed Charges and Ratio of Combined Fixed Charges and Preference Dividends to Earnings.

23.1		Consent of PricewaterhouseCoopers LLP, Independent Accountants.

23.2		Consent of Fulbright & Jaworski L.L.P. (included in Exhibit 5.1).

24.1		Power of Attorney (included on signature page).

25.1		Statement of Eligibility of Trustee under the Senior Debt Indenture.

25.2		Statement of Eligibility of Trustee under the Subordinated Debt Indenture.

⁽¹⁾	To be filed as an exhibit to a Current Report of the registrant on Form 8-K and incorporated herein by reference.

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