The FDA’s clearance of Relaxera’s IND application validates the company’s preclinical data package and the clinical development strategy for relaxin-2 in Heart Failure with Preserved Ejection Fraction and in Atrial Fibrillation. The submission is supported by a comprehensive body of pharmacological, toxicological, and translational evidence demonstrating the safety profile and mechanistic rationale of synthetic human relaxin-2 and reflects constructive engagement with the FDA throughout the regulatory process.
“Receiving IND clearance from the FDA is a defining moment for Relaxera and for the broader chronic heart failure field. This milestone reflects years of rigorous science and validates our approach to developing a truly differentiated, mechanism-driven therapy – treating causes not symptoms – for patients who currently have no targeted treatment options.” — CEO of Relaxera, Thomas Bernd Dschietzig
HFpEF: A High-Prevalence Disease with No Approved Disease-Modifying Therapy
HFpEF accounts for approximately 50% of all heart failure cases globally and is characterized by impaired cardiac relaxation (diastolic dysfunction), myocardial and vascular stiffness, and systemic inflammation. Despite affecting an estimated 3.5 million patients in the US and Europe combined — a number growing with the aging population and rising rates of obesity and hypertension — no pharmacological agent has demonstrated robust, disease-modifying benefit improving patient survival across the broad HFpEF population in pivotal trials. Current guideline-directed therapies primarily address symptom management, leaving the underlying pathophysiology and mortality largely untreated.
Relaxin-2: A Differentiated, Pleiotropic Mechanism Uniquely Suited to HFpEF
Relaxin-2 is a pleiotropic human peptide hormone with a uniquely broad mechanism of action that simultaneously addresses multiple core pathophysiological drivers of HFpEF — a profile no currently approved agent achieves.
Relaxin-2’s key competitive advantages rest on three complementary mechanisms: RXFP1 activation delivers vasodilation, improved renal perfusion, as well as myocardial relaxation and anti-fibrosis — directly targeting ventricular stiffness, HFpEF’s central structural defect; glucocorticoid receptor (GR) activation suppresses the systemic low-grade inflammation driving myocardial remodeling and contributes to vascular and organ protection, with particular relevance in obese and metabolically compromised patients; and the Wnt1 pathway activation supports anti-arrhythmic and rejuvenating effects on cardiomyocytes — a regenerative dimension absent from conventional therapies. Complementing this mechanistic breadth, relaxin-2’s endogenous human-sequence origin and well-characterized cardiovascular profile in pregnancy provide a de-risked safety rationale, while Relaxera’s biomarker- and imaging-driven patient stratification strategy maximizes the probability of demonstrating clinical benefit in Phase II.
“HFpEF demands a therapeutic strategy that addresses diastolic dysfunction, fibrosis, inflammation, arrhythmia, and renal involvement simultaneously. Relaxin-2 achieves this through three complementary receptor pathways — RXFP1, the glucocorticoid receptor, and Wnt1 — each contributing distinct and additive therapeutic effects. No currently approved agent comes close to this breadth of action.” — CMO of Relaxera, Marion Michaelis
Phase II Clinical Trial in Europe: Initiation in H1 2026
Relaxera plan to initiate their first Phase II clinical trial in HFpEF in the first half of 2026. The study is designed as a randomized, double-blind, placebo-controlled, multi-centre trial evaluating the dosing and efficacy of synthetic human relaxin-2 in patients with HFpEF, defined as left ventricular ejection fraction ≥ 45% with echocardiographic evidence of diastolic dysfunction and elevated filling pressures. The trial will be conducted exclusively at clinical sites across Europe, with a target enrolment of 320-350 patients.
“We have designed this Phase II trial to produce the highest-quality evidence package to guide the overall development efforts and for regulatory purposes. Our endpoints are also fully aligned with EMA guidance on HFpEF clinical development, and our biomarker strategy will allow us to identify the patients most likely to benefit.” — Trial Principal Investigator, Stefan Anker
Strategic Partnering Process: Accelerating Global Development
In parallel with clinical development, Relaxera has formally initiated a strategic partnering process to identify a development and commercialization partner for relaxin-2 in HFpEF and potentially broader cardiovascular indications. Relaxera are actively engaging with leading pharmaceutical and specialty cardiovascular companies to explore co-development agreements, licensing transactions, and broader strategic partnerships.
The FDA IND clearance and imminent Phase II initiation significantly strengthen Relaxera’s position as the program transitions to active clinical development with full regulatory endorsement. Relaxera is supported by a recognized healthcare advisory firm in conducting the process.
“Relaxin-2 addresses a major unmet need in cardiovascular medicine, with a mechanism that targets several key drivers of HFpEF. We are actively supporting a high-quality European Phase II program and welcome discussions with partners interested in advancing innovative therapies in this field.” —Hans-Dirk Duengen, CEO of Scirent (CRO for the European SOURCE-HF-01 Phase II trial)
Parties interested in partnering opportunities are invited to contact the Relaxera team directly.