Retension Pharmaceuticals is a clinical-stage biopharmaceutical company developing therapies for the treatment of hypertension and other serious cardiovascular diseases, with a lead candidate RTN-001. RTN-001 is an oral, selective PDE5 inhibitor designed to preferentially distribute to central cardiovascular arteries and enhance nitric oxide/cGMP signaling to lower blood pressure. The company reports RTN-001 has been studied in 243 human subjects to date, and elsewhere in the release cites study exposure in over 265 subjects; clinical data have shown the drug to be well tolerated and to produce clinically meaningful blood pressure reductions. RTN-001 is being developed under an exclusive worldwide license from Sanofi S.A., and the company is developing a once-daily, modified-release formulation intended to provide sustained 24-hour blood pressure control. Retension plans to initiate a multicenter, randomized, double-blind, placebo-controlled Phase 2b study in Q4 2025 enrolling approximately 280 patients to evaluate peripheral, central, and ambulatory blood pressure over a 12-week treatment period. The company also announced issuance of U.S. Patent No. 12,258,350 covering preferred crystalline polymorphs of RTN-001, extending core intellectual property protection through at least 2044. Retension Pharmaceuticals is a clinical-stage biotech focused on developing RTN-001, a second-generation PDE5 inhibitor designed to preferentially distribute to cardiovascular tissues. RTN-001 was engineered to target higher vasculature tissues and overcome limitations of earlier PDE5 inhibitors in hypertension. The compound has been studied in over 265 human subjects, including two Phase 2 studies in patients with uncontrolled hypertension, and was reported to be well tolerated with clinically significant blood-pressure lowering effects and reductions in central blood pressure. Retension is preparing an expanded Phase 2 program focusing on resistant and uncontrolled hypertension and plans to initiate a well-powered, controlled Phase 2 efficacy study in patients uncontrolled on two or more antihypertensives. RTN-001 is being developed under an exclusive worldwide license from Sanofi S.A. The company recently completed an oversubscribed Series A financing to fund the next-stage clinical program and support ongoing development efforts.

Total raised

$25M

Funding rounds

2

Latest round

Series B

Latest activity

Aug 2025