| SECURITIES AND EXCHANGE COMMISSION | |
| Washington, D.C. 20549 | |
| SCHEDULE 13G | |
| Under the Securities Exchange Act of 1934 | |
| (Amendment No. )* | |
|
Marinus Pharmaceuticals, Inc. | |
| (Name of Issuer) | |
|
Common Stock, $0.001 par value | |
| (Title of Class of Securities) | |
|
56854Q101 | |
| (CUSIP Number) | |
|
July 6, 2017 | |
| (Date of Event Which Requires Filing of This Statement) | |
| Check the appropriate box to designate the rule pursuant to which this Schedule is filed: | |
| ¨ | Rule 13d-1(b) |
| ý | Rule 13d-1(c) |
| ¨ | Rule 13d-1(d) |
| (Page 1 of 13 Pages) | |
______________________________
*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).
| CUSIP No. 56854Q101 | 13G | Page 2 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Granite Point Capital Master Fund, L.P. | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 1,063,790 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 1,063,790 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,063,790 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.74% | |||
| 12 |
TYPE OF REPORTING PERSON PN | |||
| CUSIP No. 56854Q101 | 13G | Page 3 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Granite Point Capital Panacea Global Healthcare Fund | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION Delaware | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 653,266 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 653,266 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 653,266 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.91% | |||
| 12 |
TYPE OF REPORTING PERSON PN | |||
| CUSIP No. 56854Q101 | 13G | Page 4 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Granite Point Capital Scorpion Focused Ideas Fund | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION Delaware | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 467,792 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 467,792 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 467,792 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.09% | |||
| 12 |
TYPE OF REPORTING PERSON PN | |||
| CUSIP No. 56854Q101 | 13G | Page 5 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Granite Point Capital L.L.C. | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION Delaware | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 2,184,848 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 2,184,848 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,184,848 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 9.75% | |||
| 12 |
TYPE OF REPORTING PERSON CO | |||
| CUSIP No. 56854Q101 | 13G | Page 6 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Granite Point Capital Management, L.P. | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION Delaware | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 2,184,848 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 2,184,848 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,184,848 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 9.75% | |||
| 12 |
TYPE OF REPORTING PERSON PN, IA | |||
| CUSIP No. 56854Q101 | 13G | Page 7 of 13 Pages |
| 1 |
NAME OF REPORTING PERSON Warren B. Lammert, III | |||
| 2 | CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP |
(a) ¨ (b) ¨ | ||
| 3 | SEC USE ONLY | |||
| 4 |
CITIZENSHIP OR PLACE OF ORGANIZATION United States | |||
| NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: |
5 |
SOLE VOTING POWER 0 | ||
| 6 |
SHARED VOTING POWER 2,184,848 | |||
| 7 |
SOLE DISPOSITIVE POWER 0 | |||
| 8 |
SHARED DISPOSITIVE POWER 2,184,848 | |||
| 9 |
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,184,848 | |||
| 10 | CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES | ¨ | ||
| 11 |
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 9.75% | |||
| 12 |
TYPE OF REPORTING PERSON IN | |||
| CUSIP No. 56854Q101 | 13G | Page 8 of 13 Pages |
| Item 1(a). | NAME OF ISSUER |
| The name of the issuer is Marinus Pharmaceuticals, Inc. (the "Company"). |
| Item 1(b). | ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES |
| The Company's principal executive offices are located at 170 N. Radnor Chester Road, Suite 250, Radnor, PA 19087. |
| Item 2(a). | NAME OF PERSON FILING | |
| This statement is filed by: | ||
| (i) | Granite Point Capital Master Fund, L.P., a Cayman Islands exempted limited partnership ("Master Fund") with respect to the shares of Common Stock directly held by it; | |
| (ii) | Granite Point Capital Panacea Global Healthcare Fund, a limited partnership organized under the laws of the State of Delaware ("Panacea Fund") with respect to the shares of Common Stock directly held by it; | |
| (iii) | Granite Point Capital Scorpion Focused Ideas Fund, a limited partnership organized under the laws of the State of Delaware ("Scorpion Fund", and together with Master Fund and Panacea Fund, the "Granite Funds") with respect to the shares of Common Stock directly held by it; | |
| (iv) | Granite Point Capital L.L.C., a limited liability corporation organized under the laws of the State of Delaware ("GPC"), as general partner of each of the Granite Funds; | |
| (v) | Granite Point Capital Management, L.P., a limited partnership organized under the laws of the State of Delaware ("GPCM"), as investment manager to each of the Granite Funds; and | |
| (vi) | Warren B. Lammert, III ("Mr. Lammert"), as managing member of GPC and as managing member of GPC 1, LLC, the general partner of GPCM. | |
| The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party. | ||
| The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of the securities reported herein. | ||
| Item 2(b). | ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE |
| The address of the business office of each of the Reporting Persons is 109 State Street, 5th Floor, Boston, MA 02109. |
| CUSIP No. 56854Q101 | 13G | Page 9 of 13 Pages |
| Item 2(c). | CITIZENSHIP |
| Master Fund is a Cayman Islands exempted limited partnership. Panacea Fund and Scorpion Fund are limited partnerships organized under the laws of the State of Delaware. GPC is a limited liability corporation organized under the laws of the State of Delaware. GPCM is a limited partnership organized under the laws of the State of Delaware. Mr. Lammert is a citizen of the United States. |
| Item 2(d). | TITLE OF CLASS OF SECURITIES |
| Common Stock, $0.001 par value (the "Common Stock"). |
| Item 2(e). | CUSIP NUMBER |
| 56854Q101 |
| Item 3. | IF THIS STATEMENT IS FILED PURSUANT TO Rules 13d-1(b), OR 13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A: |
| (a) | ¨ | Broker or dealer registered under Section 15 of the Act; | |
| (b) | ¨ | Bank as defined in Section 3(a)(6) of the Act; | |
| (c) | ¨ | Insurance company as defined in Section 3(a)(19) of the Act; | |
| (d) | ¨ | Investment company registered under Section 8 of the Investment Company Act of 1940; | |
| (e) | ¨ | An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); | |
| (f) | ¨ | An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); | |
| (g) | ¨ | A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); | |
| (h) | ¨ | A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act; | |
| (i) | ¨ | A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act; | |
| (j) | ¨ | A non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J); | |
| (k) | ¨ | Group, in accordance with Rule 13d-1(b)(1)(ii)(K). |
| If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please | |||
| specify the type of institution: | Not applicable. | ||
| CUSIP No. 56854Q101 | 13G | Page 10 of 13 Pages |
| Item 4. | OWNERSHIP | |
| The information required by Items 4(a) - (c) is set forth in Rows 5-11 of the cover page for each Reporting Person and is incorporated herein by reference. | ||
| The percentages set forth in this Schedule 13G are calculated based on a total of 22,419,504 shares of Common Stock outstanding as of April 28, 2017, as reported in the Company's Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017 filed with the Securities and Exchange Commission on May 1, 2017. | ||
| Item 5. | OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS |
| Not applicable. |
| Item 6. | OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON |
| Not applicable. |
| Item 7. | IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON |
| Not applicable. |
| Item 8. | IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP |
| Not applicable. |
| Item 9. | NOTICE OF DISSOLUTION OF GROUP |
| Not applicable. |
| Item 10. | CERTIFICATION | |
| Each of the Reporting Persons hereby makes the following certification: | ||
| By signing below each Reporting Person certifies that, to the best of his or its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. | ||
| CUSIP No. 56854Q101 | 13G | Page 11 of 13 Pages |
SIGNATURES
After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.
DATE: July 18, 2017
| GRANITE POINT CAPITAL MASTER FUND, L.P. | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL PANACEA GLOBAL HEALTHCARE FUND | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL SCORPION FOCUSED IDEAS FUND | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL L.L.C. | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL MANAGEMENT, L.P. | |
| By: GPC 1, LLC, its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| WARREN B. LAMMERT, III | |
| /s/ Warren B. Lammert, III | |
| Warren B. Lammert, III, individually |
| CUSIP No. 56854Q101 | 13G | Page 12 of 13 Pages |
EXHIBIT 1
JOINT FILING AGREEMENT
PURSUANT TO RULE 13d-1(k)
The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.
DATE: July 18, 2017
| GRANITE POINT CAPITAL MASTER FUND, L.P. | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL PANACEA GLOBAL HEALTHCARE FUND | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL SCORPION FOCUSED IDEAS FUND | |
| By: Granite Point Capital L.L.C., its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| GRANITE POINT CAPITAL L.L.C. | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer |
| CUSIP No. 56854Q101 | 13G | Page 13 of 13 Pages |
| GRANITE POINT CAPITAL MANAGEMENT, L.P. | |
| By: GPC 1, LLC, its general partner | |
| /s/ David Bushley | |
| Name: David Bushley | |
| Title: Chief Operating Officer | |
| WARREN B. LAMMERT, III | |
| /s/ Warren B. Lammert, III | |
| Warren B. Lammert, III, individually |