GSK has entered into an agreement to acquire 35Pharma Inc., a Canada-based private clinical-stage biopharmaceutical company focused on developing novel protein-based therapeutics. The acquisition includes HS235, a potentially best-in-class activin signalling inhibitor currently in clinical development for cardiopulmonary diseases.
HS235 has completed Phase I trials in healthy volunteers, and clinical studies are set to begin shortly in patients with pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with heart failure with preserved ejection fraction (PH-HFpEF). The candidate is designed to address key limitations in existing pulmonary hypertension (PH) therapies while offering additional metabolic benefits.
Pulmonary hypertension is a progressive and life-shortening condition characterised by elevated blood pressure in the lungs. Early symptoms include breathlessness, fatigue and chest pain, and as the disease advances, it can lead to heart failure. The condition affects an estimated 82 million people globally across multiple forms. Despite available treatments, options remain limited and the five-year survival rate stands at approximately 50%. The global PH treatment market is projected to reach $18 billion by 2032, with activin signalling inhibitors expected to account for roughly half of that value.
HS235 targets the activin receptor signalling pathway, a clinically validated target in pulmonary hypertension. The molecule has been engineered with enhanced selectivity, limiting its binding to BMP9 and BMP10 — ligands associated with adverse events such as bleeding and telangiectasia. By potentially reducing bleeding risk, HS235 may overcome a significant constraint of current therapies, particularly since many PH patients require concurrent anticoagulant or antiplatelet treatment.
Beyond vascular effects, HS235’s mechanism of action may also deliver broader metabolic benefits. Early clinical data suggest the therapy could support fat-selective weight loss, preserve lean muscle mass and improve insulin sensitivity. These effects are accompanied by favourable changes in inflammation markers and adipokines, or fat-derived hormones. Given the high prevalence of obesity and insulin resistance among PH patients, these metabolic attributes may enhance both clinical and commercial value.
Tony Wood, Chief Scientific Officer, GSK, said: “Pulmonary hypertension affects millions of people worldwide, yet patients are underserved. We’re delighted to add HS235 to our pipeline, a potential best-in-class medicine with a differentiated profile to reduce risk of bleeding and provide potential metabolic benefits clinically relevant to PH patients. HS235’s potential protective effects on vascular function, alongside potential benefits on fat-derived markers of metabolism and inflammation, also offer new development opportunities within our RI&I portfolio to achieve broader coverage across the metabolic, inflammatory, vascular and fibrotic drivers of multiple chronic diseases that affect the lung, liver and kidney.”
Ilia Tikhomirov, CEO, 35Pharma, said: “In recent years, we witnessed a revolution in our understanding of pulmonary hypertension and how this life-threatening disease could be reversed. We are pleased to be joining forces with GSK, a leader in respiratory and inflammatory drivers of disease, who shares our vision of HS235’s potential to transform the treatment of this debilitating condition.”
The addition of HS235 strengthens GSK’s emerging pipeline of therapies aimed at protecting metabolic and vascular function. The asset aligns with the company’s Respiratory, Immunology and Inflammation (RI&I) portfolio strategy, expanding its development opportunities across metabolic, inflammatory, vascular and fibrotic pathways implicated in chronic diseases affecting the lung, liver and kidney.
