• Retension Pharmaceuticals announces close of $15 Million Series B financing round
• Newly issued U.S. patent extends core intellectual property protection through at least 2044
• Phase 2b study evaluating RTN-001 in patients with uncontrolled hypertension in collaboration with the Cleveland Clinic Coordinating Center for Clinical Research and Dr. Luke Laffin to commence in Q4 2025

FALLS CHURCH, Va.–(BUSINESS WIRE)–Retension Pharmaceuticals Inc., a clinical-stage biopharmaceutical company focused on developing therapies for the treatment of hypertension and other serious cardiovascular diseases, today announced the successful closing of its $15 million Series B financing to advance the clinical development of RTN-001 for patients with uncontrolled and resistant hypertension.

“Patients with uncontrolled and resistant hypertension remain at high risk for major adverse cardiovascular events, and current treatment options often fall short in both efficacy and tolerability,” said Dr. Luke Laffin from Cleveland Clinic.Share

Retension Pharmaceuticals also announced the issuance of US Patent Number 12,258,350 covering preferred crystalline polymorph forms of RTN-001 that will provide extended patent protection through at least 2044.

Hypertension, which is defined by the American College of Cardiology and the American Heart Association as resting blood pressure above 130/80 mmHg, is generally acknowledged to be one of the most common preventable risk factors for premature death worldwide. Though often asymptomatic, hypertension significantly increases the risk of heart disease, stroke, and kidney disease, amongst other diseases. It is estimated that as much as 20% of the global population suffers from hypertension, including nearly one-half of the adult population in the U.S.

RTN-001, a unique PDE5 inhibitor, leverages a well-established mechanism of enhancing nitric oxide signaling, which plays a key role in blood pressure regulation. RTN-001 is specifically designed to preferentially target central cardiovascular arteries that determine blood pressure, addressing key limitations of earlier, first generation PDE5 therapies.

RTN-001 has been studied in 243 human subjects to date, including two Phase 2 studies in patients with hypertension taking up to four other antihypertensive medications. In these studies, RTN-001 was shown to be well tolerated and demonstrated clinically significant reductions in blood pressure.

Retension Pharmaceuticals intends to use the net proceeds to support the initiation of a multicenter, double-blind, placebo-controlled, randomized Phase 2b clinical study in patients with uncontrolled and resistant hypertension in the fourth quarter of 2025. The Phase 2b clinical trial will evaluate the efficacy and safety across a range of doses of a once-daily, modified-release formulation of RTN-001 designed to deliver sustained blood pressure reduction over 24 hours, a key objective for improving adherence and outcomes in this high-risk population. The planned Phase 2b trial will enroll approximately 280 patients across multiple US sites and will evaluate the effect of the once-daily formulation on systolic and diastolic peripheral blood pressure as well as central and ambulatory blood pressure over a 12-week treatment period.

“We are thrilled by the strong support from both new and existing investors who share our commitment to addressing one of the most persistent challenges in cardiovascular medicine,” said Eric Keller, Retension Pharmaceuticals’ Chief Executive Officer. “This financing enables us to move into mid-stage clinical development with a formulation specifically designed to maintain 24-hour blood pressure control allowing for once-daily dosing, which could offer a meaningful advantage for patients with uncontrolled and resistant hypertension. There is a substantial need for new hypertension therapies. RTN-001 has the potential to combine durable efficacy with ease of use from a class of drugs with a large, existing safety and tolerability track record. We are advancing an investigational therapy that aims to address all three factors, and which can be used in combination with existing hypertension drugs.”

Hypertension affects approximately 120 million adults in the United States and is a leading contributor to stroke, heart attack, kidney disease, and premature death. Despite the availability and use of multiple antihypertensive drugs, many patients fail to achieve blood pressure goals—underscoring the need for therapies with novel mechanisms, strong efficacy, and improved tolerability.

“Patients with uncontrolled and resistant hypertension remain at high risk for major adverse cardiovascular events, and current treatment options often fall short in both efficacy and tolerability,” said Dr. Luke Laffin, Co-Director of the Center for Blood Pressure Disordersat Cleveland Clinic. “RTN-001 has the potential to address this unmet need and could represent a meaningful advancement in how we manage treatment-resistant hypertension.”

About Retension Pharmaceuticals

Retension Pharmaceuticals is a clinical-stage biopharmaceutical company developing therapies for the treatment of hypertension and other serious cardiovascular conditions. The company’s lead clinical candidate, RTN-001, focuses on the treatment of patients with uncontrolled and resistant hypertension that have difficulty regulating blood pressure despite being on two to four other antihypertensive medications.

About RTN-001

RTN-001 is a unique oral small molecule inhibitor of PDE5 that, unlike earlier PDE5 inhibitors for erectile dysfunction, preferentially distributes to cardiovascular tissues. The compound is a potent and highly selective modulator of the cGMP pathway, enhancing nitric oxide (NO) signaling — an essential mechanism that helps regulate blood pressure — and has been studied in multiple clinical trials including in over 265 subjects. RTN-001 has a demonstrated efficacy and safety profile in patients and healthy volunteers demonstrating clinically meaningful reductions in blood pressure in patients with uncontrolled and resistant hypertension. RTN-001 is being developed under an exclusive world-wide license from Sanofi S.A.

For more information, please see www.retensionpharmaceuticals.com

Contacts

Press and Investor Contact
Sabine Bisson, PhD
Chief Operating Officer, Retension Pharmaceuticals Inc.
press@retensionpharmaceuticals.com

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