Corsair Pharma Reports Successful Phase 1 Results for TRX-248 Transdermal System in Pulmonary Arterial Hypertension
Corsair Pharma, Inc., a private biopharmaceutical company focused on innovative drug delivery technologies, has announced positive results from its first-in-human Phase 1 clinical trial evaluating the TRX-248 Transdermal System, a once-daily patch designed for the treatment of pulmonary arterial hypertension (PAH). The study findings demonstrate that the investigational system can achieve steady, therapeutically relevant plasma levels of treprostinil over a 24-hour period, supporting further clinical development of the platform.
The results mark an important milestone for Corsair’s proprietary transdermal technology, which aims to offer a more convenient and potentially better-tolerated alternative to existing treprostinil delivery methods used in PAH management.
Pulmonary arterial hypertension is a progressive and life-threatening condition characterized by elevated blood pressure in the pulmonary arteries, which leads to increased strain on the right side of the heart. Prostacyclin analogs such as treprostinil are a cornerstone of therapy for many patients, helping to dilate blood vessels, reduce pulmonary pressure, and improve exercise capacity. However, current delivery methods—including continuous subcutaneous infusion, intravenous infusion, inhaled formulations, and oral therapies—can be associated with significant patient burden, tolerability issues, or complex administration requirements.
Corsair’s TRX-248 Transdermal System is designed to address these limitations by providing continuous systemic exposure to treprostinil through a simple, once-daily patch applied to the skin.
A Prodrug-Based Transdermal Delivery Approach
Unlike conventional transdermal systems that directly deliver active pharmaceutical compounds through the skin, TRX-248 employs a prodrug strategy. The patch administers an inactive precursor molecule, TRX-248, which is absorbed through the skin and enters systemic circulation. Once in the body, the compound is rapidly converted in the liver into active treprostinil.
This design is intended to overcome key barriers associated with transdermal delivery of prostacyclins, including skin permeability and chemical stability, while maintaining consistent therapeutic exposure over time.
By enabling controlled absorption and systemic conversion, the system is engineered to deliver steady plasma concentrations of treprostinil, minimizing the peaks and troughs often associated with other administration routes.
Corsair believes that this approach could not only improve the treatment experience for patients with PAH but may also expand into other forms of pulmonary hypertension in the future.
Phase 1 Study Design and Objectives
The Phase 1 clinical trial was designed to evaluate both the safety and pharmacokinetic profile of treprostinil following single-dose administration of the TRX-248 Transdermal System.
The study enrolled nine healthy female volunteers. Each participant received a single application of the investigational patch, designed to remain in place for a 24-hour dosing period. Researchers collected serial blood samples over the dosing interval to assess systemic drug exposure and characterize the pharmacokinetic behavior of the prodrug-to-active conversion process.
The primary goal of the study was to determine whether the transdermal system could achieve sustained and predictable levels of treprostinil in circulation while maintaining acceptable safety and skin tolerability.
Consistent and Sustained Drug Exposure
One of the most significant findings from the study was the demonstration of steady and continuous treprostinil plasma concentrations over the full 24-hour dosing period.
Unlike some existing prostacyclin delivery systems that may produce fluctuating drug levels, the TRX-248 Transdermal System showed low peak-to-trough variability. This consistent exposure profile is considered important in chronic conditions like PAH, where stable pharmacologic activity is needed to maintain vascular effects and reduce disease progression.
Researchers also observed pharmacokinetic profiles that were comparable to published data for subcutaneous treprostinil delivery. This suggests that the transdermal system may be capable of achieving clinically relevant systemic exposure without the need for invasive infusion-based methods.
In addition, the study demonstrated dose proportionality across different patch sizes. This finding is particularly important from a clinical development perspective, as it suggests that future dose adjustments could be made in a predictable and scalable manner by modifying patch surface area or formulation strength.
Such flexibility could simplify titration strategies in clinical practice and allow for more individualized patient dosing.
Safety and Skin Tolerability
The TRX-248 Transdermal System was generally well tolerated in the Phase 1 study population. No major safety concerns were reported, and the overall tolerability profile was consistent with expectations for a topical transdermal delivery system.
Skin tolerability is a critical factor for any patch-based therapy, particularly for chronic conditions requiring long-term daily use. In this study, the patch was reported to have acceptable local tolerability, suggesting that it may be suitable for continued evaluation in longer-term trials.
While the study was small and conducted in healthy volunteers, the absence of significant safety signals provides an encouraging foundation for further clinical development in patient populations with pulmonary arterial hypertension.
A Potential Alternative to Current Treprostinil Delivery Methods
Treprostinil is a widely used prostacyclin analog and represents one of the most important treatment options in the PAH therapeutic landscape. However, its administration is associated with several challenges depending on the delivery method used.
Continuous subcutaneous infusion can be associated with infusion site pain and irritation, while intravenous delivery requires central venous access and carries risks such as infection and catheter-related complications. Inhaled formulations require multiple daily dosing, and oral prostacyclins may be associated with variable absorption and systemic side effects.
Corsair Pharma believes that its transdermal approach could help address many of these limitations by offering a noninvasive, once-daily alternative that maintains steady systemic exposure without requiring pumps, inhalation devices, or repeated oral dosing.
According to the company, this convenience-driven approach could significantly reduce treatment burden for patients living with PAH, a condition that often requires lifelong therapy and complex medication regimens.
Company Perspective on Clinical Findings
Dr. Bobby Singh, President and Chief Operating Officer of Corsair Pharma, described the Phase 1 results as an important validation of the company’s transdermal prodrug technology. He emphasized that the study successfully demonstrated the ability to achieve steady and therapeutically meaningful levels of treprostinil using the TRX-248 system.
He noted that these results support the potential of Corsair’s platform as a clinically meaningful alternative to existing treprostinil delivery methods and reinforce confidence in continued development of the program.
Chief Executive Officer George Mahaffey highlighted the broader commercial and clinical context of the prostacyclin market. He noted that prostacyclin therapies collectively represent more than $3.3 billion in annual U.S. sales, with treprostinil accounting for approximately $2 billion of that total.
Despite their importance, he emphasized that current delivery systems each have notable limitations that can affect patient adherence and quality of life. He suggested that Corsair’s transdermal system may have the potential to improve treatment experience and outcomes for patients with PAH by simplifying administration and reducing treatment burden.
The Broader Significance of Transdermal Innovation in PAH
The positive Phase 1 results for TRX-248 reflect a broader trend in pulmonary hypertension research focused on improving drug delivery mechanisms in addition to developing new pharmacologic agents.
While significant progress has been made in expanding the number of available therapies for PAH, long-term disease management continues to be challenged by complex dosing regimens, administration-related complications, and patient adherence issues.
Innovations in drug delivery, such as transdermal systems, represent a promising strategy for addressing these challenges by improving convenience, reducing invasiveness, and maintaining consistent drug exposure.
If further clinical studies confirm the findings observed in this early trial, TRX-248 could represent a meaningful advancement in how prostacyclin therapies are administered.
Next Steps in Development
Following the successful completion of the Phase 1 study, Corsair Pharma plans to advance the TRX-248 Transdermal System into further clinical development. Future studies are expected to evaluate repeated dosing, long-term safety, and efficacy in patients with pulmonary arterial hypertension.
These later-stage trials will be critical in determining whether the pharmacokinetic and tolerability advantages observed in healthy volunteers translate into meaningful clinical benefits for patients living with PAH.
As development progresses, the company will also continue to explore the broader applicability of its transdermal prodrug platform across additional indications involving prostacyclin signaling pathways.
With encouraging early data in hand, Corsair Pharma now moves forward with increased confidence in the potential of TRX-248 to redefine prostacyclin delivery in pulmonary arterial hypertension therapy.
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.
