Announcement • Jun 11
Tectonic Therapeutic, Inc. Completes Enrollment in TX45 APEX Phase 2 Clinical Trial in PH-HFpEF Patients Tectonic Therapeutic, Inc. announced the completion of enrollment for the APEX trial, a 24-week Phase 2 clinical trial evaluating the safety and efficacy of TX45 in patients with pulmonary hypertension associated with heart failure with preserved ejection fraction (“PH-HFpEF”). The trial was designed to include an enriched population of a more severe disease subtype of combined pre- and post-capillary pulmonary hypertension (“CpcPH”) patients with a pulmonary vascular resistance (“PVR”)>3 Wood Units (“WU”) at baseline. The APEX Phase 2 clinical trial enrolled a total of 191 patients across 14 countries of which 137 patients were enrolled with CpcPH and PVR>3 WU at baseline, consistent with the goal for this patient population to represent approximately 70% of the overall patients enrolled in APEX. In the APEX clinical trial, the mean baseline PVR in the overall patient population and the subset of patients with CpcPH and PVR>3 WU was 4.2 WU¹ and 5.2 WU¹, respectively. Tectonic expects topline results from the APEX clinical trial in early First Quarter 2027. The APEX Phase 2 clinical trial is a global, randomized, double-blind, placebo-controlled, proof-of-concept trial designed to evaluate the safety and efficacy of two dose regimens of TX45 administered subcutaneously (“SC”) in patients with PH-HFpEF, enriched for patients with CpcPH. Patients were randomized to receive 300 mg SC (2 ml injection) once monthly of TX45, 300 mg SC every other week of TX45, or a placebo. Change from baseline in PVR in the PVR>3 WU population is the primary endpoint of the trial. The World Health Organization has defined 5 groups of pulmonary hypertension (“PH”). Tectonic is focused on the Group 2 subtype, a condition that develops due to left-sided heart disease, specifically PH-HFpEF. In patients with PH-HFpEF, chronic heart failure leads to increased blood pressure in the pulmonary arteries, exerting severe strain on the right side of the heart, which adapts poorly to the increased pressure. This increased pulmonary pressure gradually causes worsening exercise capacity, shortness of breath and right-sided heart failure, which can lead to death. PH-HFpEF is further segmented based on pulmonary hemodynamics into Isolated, post-capillary PH (“IpcPH”) and CpcPH. CpcPH is more severe, accounts for about one third to one half of the 1.4 million PH-HFpEF patients in the U.S. and is characterized by additional, abnormal changes to the pulmonary vasculature, leading to an increase in PVR. Although several Group 1 PH (Pulmonary Arterial Hypertension, “PAH”) medications have been explored in Group 2 PH, to date, no medications have been approved for its treatment. TX45 is an Fc-relaxin fusion protein with optimized pharmacokinetics and biophysical properties that activates the RXFP1 receptor, the G-protein coupled receptor target of the hormone relaxin. Relaxin is an endogenous protein, expressed at low levels in both men and women that is a pulmonary and systemic vasodilator with lusitropic, anti-fibrotic and anti-inflammatory activity. In normal human physiology, relaxin is upregulated during pregnancy where it exerts vasodilative effects, reduces systemic and pulmonary vascular resistance and increases cardiac output to accommodate the increased demand for oxygen and nutrients from the developing fetus. Relaxin also exerts anti-fibrotic effects on pelvic ligaments to facilitate delivery of the baby. Announcement • Apr 27
Tectonic Therapeutic, Inc., Annual General Meeting, Jun 08, 2026 Tectonic Therapeutic, Inc., Annual General Meeting, Jun 08, 2026. 
