Tectonic Therapeutic, Inc. (NASDAQ: TECX) has announced the complete results from part A of the phase 1b clinical trial of TX45 in patients with group 2 pulmonary hypertension in heart failure with preserved ejection fraction (PH-HFPEF). The trial included the full cohort of 19 patients and confirmed the tolerability and hemodynamic effects of TX45. Here are the specific highlights from the complete phase 1b part A results:
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Hemodynamic Effects: TX45 achieved a 19.0% reduction in pulmonary capillary wedge pressure (PCWP) in the overall study population, an endpoint known to correlate with exercise capacity, morbidity, and mortality in patients with heart failure. In the subpopulation with combined pre* and post-capillary pulmonary hypertension (CPCPH), TX45 demonstrated over a 30% reduction in pulmonary vascular resistance (PVR), which is correlated to exercise capacity and mortality in this patient population.
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Sustained Hemodynamic Effects: New echocardiographic analysis showed sustained improvements in echocardiogram endpoints for 29 days following the administration of TX45, indicating a sustained effect after a single dose administration.
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Left Ventricular Ejection Fractions (LVEF): TX45 improved cardiac and pulmonary hemodynamics in PH-HFPEF patients across a range of LVEF, including LVEF>50% and LVEF 41-49%. Both subpopulations showed similar improvements in PCWP and cardiac output following administration of TX45.
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Safety Results: TX45 was well tolerated with no serious or severe adverse events, discontinuations, infusion reactions, or drug-related adverse events. There were no clinically significant changes in vital signs, physical exam, or safety laboratory values.
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Mechanism of Action: As a relaxin therapeutic, TX45 improved both left ventricular function and pulmonary hemodynamics, which matches the more severe pathophysiology of patients with CPCPH.
TX45 is a long-acting 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. The positive results from the phase 1b study position TX45 as a potential best-in-class therapy for group 2 pulmonary hypertension, a condition with high morbidity, mortality, and no approved treatments.
The company looks forward to the topline data from part B of the phase 1b study in patients with heart failure with reduced ejection fraction (HFREF), expected in the second half of 2025.
Tectonic Therapeutic, headquartered in Watertown, Massachusetts, is focused on the discovery and development of therapeutic proteins and antibodies that modulate the activity of G-protein-coupled receptors (GPCRs) to address areas of significant unmet medical need.
The complete results were presented in a late-breaking, oral session at the European Society of Cardiology (ESC) Heart Failure 2025 congress in Belgrade, Serbia. Today the company's shares have moved 12.41% to a price of $23.595. If you want to know more, read the company's complete 8-K report here.
