AliveGen's ALG-801 Demonstrates Superior Efficacy Over Standard PAH Therapies in Preclinical Studies

Key Insights

• AliveGen's investigational therapy ALG-801 outperformed current standard-of-care agents including Sildenafil and Sotatercept in preclinical studies using a gold standard pulmonary arterial hypertension animal model.
• The therapy demonstrated superior prevention of pulmonary hypertension during disease development and significantly reversed established PAH symptoms including elevated pulmonary arterial pressure and right ventricular hypertrophy.
• ALG-801 has completed Phase 1 trials and received FDA Orphan Drug Designation, positioning it as a promising candidate for Phase 2 clinical development in a disease where median transplant-free survival remains only six years.

AliveGen USA Inc., a clinical-stage biopharmaceutical company, has announced compelling preclinical data demonstrating that its investigational therapy ALG-801 delivered superior efficacy compared to current standard-of-care agents in treating pulmonary arterial hypertension (PAH). The findings were presented at the European Respiratory Society Congress held September 27–October 1, 2025, in Amsterdam.

Superior Performance in Disease Prevention and Treatment

Researchers conducted head-to-head studies in sugen-hypoxia (SuHx) rats, a gold standard model for pulmonary hypertension, comparing ALG-801 with Sildenafil and ActRIIA-Fc (Sotatercept), both approved therapies for PAH. The results revealed ALG-801's dual efficacy in both preventing disease progression and treating established PAH.

During disease development, ALG-801 prevented pulmonary hypertension, right ventricular hypertrophy and pulmonary vascular remodeling more effectively than Sildenafil. In established PAH cases, ALG-801 was significantly more effective than ActRIIA-Fc, successfully reversing elevated pulmonary arterial pressure, right ventricular hypertrophy, and pulmonary vascular remodeling. Additionally, ALG-801 treatment normalized circulating BNP levels and extended survival in the animal model.

Addressing Critical Unmet Medical Need

PAH represents a progressive and life-threatening disease characterized by increased pulmonary vascular resistance, leading to elevated pulmonary arterial pressure, right heart failure, and premature death. Despite multiple approved therapies currently available, median transplant-free survival remains only about six years, underscoring the urgent need for new treatments.

"These results demonstrate ALG-801's ability to outperform approved PAH therapies in rigorous preclinical testing," said Dr. HQ Han, CEO of AliveGen. "The data suggest that ALG-801 has potential to transform treatment outcomes for patients with PAH, where survival remains unacceptably poor despite recent advances."

Novel Mechanism and Clinical Development Status

ALG-801 is a next-generation ActRIIA/IIB hybrid ligand trap designed to selectively block Smad2/3 pathway-activating ligands implicated in the pathogenesis of PAH and other diseases. The therapy has completed Phase 1a and 1b trials in healthy volunteers and is ready to advance into Phase 2 clinical studies.

The U.S. Food and Drug Administration has granted Orphan Drug Designation to ALG-801 for the treatment of PAH, providing regulatory advantages for this rare disease indication. The findings position ALG-801 as a promising candidate for clinical development in PAH and related conditions.

AliveGen is a privately held, clinical-stage biotechnology company based in Thousand Oaks, California, dedicated to developing first-in-class and best-in-class biotherapeutics for diseases with high unmet medical needs, including cardiometabolic disorders, obesity, neuromuscular diseases, age-related osteosarcopenia, and various wasting disorders.