Favorable results support advancement into further clinical development

Corsair Pharma, Inc., a private biopharmaceutical company, today announced the successful completion of its first-in-human Phase 1 clinical trial evaluating the TRX-248 Transdermal System, a once-daily transdermal patch designed for the treatment of pulmonary arterial hypertension (PAH).

The positive results demonstrated that the TRX-248 Transdermal System achieved desired, therapeutically relevant, steady and continuous blood levels of treprostinil. The findings support transdermal delivery as a potentially superior alternative to existing treprostinil administration methods and provide a foundation for advancing the program into further clinical development.

Prostacyclins remain a standard of care drug class for the treatment of PAH. Corsair’s proprietary transdermal patch is designed to provide steady and continuous systemic exposure to treprostinil by administering an inactive prodrug, TRX-248, which is absorbed through the skin, enters systemic circulation, and is rapidly converted to active treprostinil by the liver. The once-daily patch is designed to offer a convenient, noninvasive alternative that may also have potential applications in other forms of pulmonary hypertension.

Phase 1 Trial Overview

The Phase 1 clinical trial evaluated the safety and pharmacokinetics (PK) of treprostinil following single-dose administration of the TRX-248 Transdermal System. The study enrolled nine female volunteers, each of whom received a single patch application designed for 24-hour wear per treatment period.

Key findings include:

• Steady and continuous treprostinil plasma levels over 24 hours with low peak-to-trough fluctuation,
• Pharmacokinetic profiles comparable with published data for subcutaneous delivery,
• Data supporting dose proportionality across patch sizes, which would enable ease of dose titration, and
• Acceptable safety and skin tolerability.

“We are excited by these first-in-human results demonstrating steady, therapeutically meaningful treprostinil levels using our proprietary prodrug and transdermal technology,” said Dr. Bobby Singh, President and COO, Corsair Pharma. “These data support the potential of our transdermal platform as a clinically meaningful alternative to existing treprostinil delivery modalities.”

“These Phase 1 results are exciting and reinforce our prior preclinical findings,” said George Mahaffey, CEO, Corsair Pharma. “The prostacyclin drug class generates over $3.3 billion in annual U.S. sales, with treprostinil accounting for about $2 billion. Each current delivery system for treprostinil has significant challenges for patients. These positive results provide further evidence that the Corsair Transdermal System may improve the lives of PAH patients.”

About PAH and Treprostinil

Pulmonary arterial hypertension (PAH) is a serious, progressive, and ultimately fatal disease that causes shortness of breath and markedly reduces quality of life. In the U.S., approximately 45,000 patients are currently taking treatments labeled for PAH. Current therapies clearly improve function and outcomes, but there remains a tremendous unmet medical need. Importantly, many patients are unwilling or unable to utilize prostanoids, one of the most effective therapies, and Corsair believes that the TRX-248 Transdermal System could provide an important new option for them.

Treprostinil is commonly used in the treatment of PAH and exerts its pharmacological effects through vasodilation, reduced platelet aggregation, and inhibition of smooth muscle proliferation. Treprostinil is currently marketed by United Therapeutics and Liquidia in different forms to alleviate symptoms, maintain or improve functional class, delay disease progression, and enhance quality of life in patients with PAH. The U.S. prostacyclin market for PAH is estimated at approximately $3.3 billion annually.

About Corsair Pharma, Inc.

Corsair Pharma is developing transformative solutions to improve the therapeutic profile of medications and provide superior treatment options for patients. The company is focused on developing novel prodrugs of treprostinil to treat patients with pulmonary arterial hypertension using a once-daily transdermal patch. The company intends to pursue a 505(b)(2) regulatory pathway, which is a streamlined process to develop new versions of approved drugs. For more information, visit www.corsairpharma.com.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260601124952/en/

“We are excited by these first-in-human results demonstrating steady, therapeutically meaningful treprostinil levels using our proprietary prodrug and transdermal technology,” said Dr. Bobby Singh, President and COO, Corsair Pharma.