FDA feedback supports planned bioequivalence-based 505(b)(2) development pathway for once-daily treprostinil prodrug patch

Corsair Pharma, Inc., a private, clinical-stage biopharmaceutical company developing prodrug-based transdermal medicines to improve the delivery and therapeutic profile of established therapies, today announced a positive outcome from its pre-investigational new drug (pre-IND) meeting with the U.S. Food and Drug Administration (FDA) for the TRX-248 Transdermal System, a treprostinil prodrug patch in development for pulmonary arterial hypertension (PAH) that is intended to be administered once daily.

Following its review of Corsair’s pre-IND submission, including summary results from the company’s initial Phase 1 pharmacokinetic (PK) study, FDA provided feedback supporting Corsair’s planned development pathway and guidance on proposed registration strategy. Corsair intends to pursue approval through the 505(b)(2) regulatory pathway, relying in part on FDA’s previous findings of safety and effectiveness for Remodulin® as the listed drug. The company plans to establish a scientific bridge to those findings by demonstrating bioequivalence between the TRX-248 Transdermal System and subcutaneous Remodulin based on systemic treprostinil exposure.

“We are pleased with the outcome of our FDA meeting, which supports our planned bioequivalence-based 505(b)(2) development program,” said Bobby Singh, M.Pharm., Ph.D., President and Chief Operating Officer of Corsair. “Preparations are underway for a pilot bioequivalence study, which we expect to initiate in early 2027. Results from this U.S.-based study are expected to inform the final design of a pivotal bioequivalence study, which we anticipate initiating in late 2027 with data readout expected by the middle of 2028.”

TRX-248 Transdermal System is the only clinical-stage transdermal prostacyclin. The patch delivers an inert prodrug, TRX-248, that crosses the skin and is converted to treprostinil after absorption. The TRX-248 prodrug is a proprietary molecule covered by an issued composition of matter patent and other IP protections. Designed for once-daily application, the system is intended to provide steady, continuous treprostinil exposure over 24 hours without a pump, needle, or inhaler. Multiple patch sizes are intended to enable simple dose titration. In a completed Phase 1 study in healthy volunteers, the TRX-248 Transdermal System provided steady, continuous treprostinil levels during a 24-hour application and demonstrated a favorable safety and tolerability profile.

“While treprostinil is an established therapy for PAH, the burden of current administration methods can present challenges for patients and limit treatment flexibility. We believe TRX-248 has the potential to meaningfully address these challenges and offer patients a more convenient approach to treprostinil therapy,” said George Mahaffey, Chief Executive Officer of Corsair. “With encouraging Phase 1 results, we look forward to submitting our IND and continuing our engagement with FDA as we advance the program toward clinical development.”

About Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare, progressive, and fatal disease in which narrowed or blocked arteries in the lungs raise blood pressure and strain the heart. The disease affects approximately 45,000 people in the United States and can cause shortness of breath, fatigue, chest pain, edema, and heart failure.

About Prostacyclin Therapy and Treprostinil

One of the most effective therapies for PAH is treprostinil, a prostacyclin analog that dilates blood vessels and inhibits smooth muscle proliferation and platelet aggregation. United Therapeutics^® and Liquidia^® market treprostinil in subcutaneous, intravenous, oral, and inhaled formulations that improve symptoms and function. However, infused therapies require pumps and carry central-line or infusion-site risks, inhaled therapies require multiple daily treatments and can cause cough, and oral therapy can cause dose-limiting side effects. Corsair estimates that these administration and tolerability burdens limit prostacyclin use to 30% to 35% of eligible patients. The U.S. prostacyclin market is approximately $4.3 billion annually. Corsair is evaluating its once-daily TRX-248 patch to confirm it can provide steady and continuous treprostinil exposure with less administration burden.

About Corsair Pharma, Inc.

Corsair Pharma is developing transformative solutions to improve the therapeutic profile of medications and provide superior treatment options for patients. Its lead program, the TRX-248 Transdermal System, is a once-daily treprostinil prodrug patch being evaluated for the treatment of pulmonary arterial hypertension. TRX-248 is a proprietary molecule covered by issued patents including composition of matter and other protections. Corsair is advancing TRX-248 Transdermal System through a bioequivalence-based 505(b)(2) development pathway that leverages treprostinil’s established clinical profile. The company’s prodrug and transdermal technologies have potential applications for other pulmonary and systemic diseases. Corsair is backed by New Rhein Healthcare Investors, LLC, which led the recent financing rounds. The TRX-248 Transdermal System has not received marketing approval from the U.S. Food and Drug Administration, and the Company is awaiting FDA’s acceptance of its Investigational New Drug (IND) request to begin investigational clinical research. For more information, visit www.corsairpharma.com.

Remodulin® is a registered trademark of United Therapeutics Corporation.

View source version on businesswire.com: https://www.businesswire.com/news/home/20261109305262/en/

“With encouraging Phase 1 results, we look forward to submitting our IND and continuing our engagement with FDA as we advance the program toward clinical development,” said George Mahaffey, Chief Executive Officer of Corsair.