Core Insights - Tectonic Therapeutic, Inc. announced complete results from Part A of the Phase 1b clinical trial of TX45 for patients with Group 2 Pulmonary Hypertension in Heart Failure with preserved Ejection Fraction (PH-HFpEF) [1][2] - The trial demonstrated that TX45 is well tolerated and showed significant hemodynamic improvements, including a 19.0% reduction in pulmonary capillary wedge pressure (PCWP) and over 30% reduction in pulmonary vascular resistance (PVR) in a specific patient subgroup [2][11] - The results were presented at the European Society of Cardiology Heart Failure 2025 Congress, highlighting the potential of TX45 as a best-in-class therapy for a condition with high morbidity and no approved treatments [3][4] Clinical Trial Results - The Phase 1b trial included a cohort of 19 patients, confirming the tolerability and hemodynamic effects of TX45 previously reported in interim data [2][6] - TX45 treatment resulted in sustained hemodynamic effects for up to 29 days, with improvements in left ventricular function and pulmonary hemodynamics across various left ventricular ejection fractions (LVEF) [4][5] - Specific improvements included a 19.7% reduction in PCWP for patients with LVEF≥50% and an 18.4% reduction for those with LVEF 41-49% [5] Safety Profile - TX45 was well tolerated with no serious or severe adverse events reported during the trial [7][11] - There were no clinically significant changes in vital signs or safety laboratory values, indicating a favorable safety profile for TX45 [11] Mechanism of Action - TX45 is a long-acting Fc-relaxin fusion protein that activates the RXFP1 receptor, providing both pulmonary and systemic vasodilatory effects [13] - The differentiated mechanism of TX45 improves both left ventricular function and pulmonary hemodynamics, particularly beneficial for patients with combined pre- and post-capillary pulmonary hypertension (CpcPH) [11][12] Future Outlook - The topline data from Part B of the Phase 1b study, which will evaluate TX45 in patients with Heart Failure with reduced Ejection Fraction (HFrEF), is expected in the second half of 2025 [3][9] - The ongoing APEX Phase 2 clinical trial is anticipated to provide further insights into the efficacy of TX45 in PH-HFpEF, with topline results expected in 2026 [2][9]
Tectonic Therapeutic Presents Complete Results for Positive Phase 1b Clinical Trial of TX45 in Patients with Group 2 Pulmonary Hypertension in HFpEF in Late-Breaking Presentation at ESC Heart Failure 2025