On April 15, 2026, GSK plc (GSK) completed its acquisition of 35Pharma Inc., a Montréal-based, private, clinical-stage biopharmaceutical company specializing in the development of novel protein-based therapeutics, for US$950 million in cash. The transaction, first announced on February 25, 2026, gives GSK full ownership of 35Pharma and its pipeline, headlined by HS235, a potential best-in-class investigational medicine for the treatment of pulmonary hypertension (PH).
HS235 targets the activin receptor signalling pathway, a clinically validated therapeutic target in PH, and is engineered for enhanced selectivity that may lower the risk of bleeding, pericardial effusion, and dose-limiting increases in haemoglobin associated with current pulmonary arterial hypertension (PAH) treatments. The molecule has completed Phase I healthy volunteer trials, with proof-of-concept studies expected to begin imminently in PAH and in PH due to heart failure with preserved ejection fraction (PH-HFpEF). GSK has cited forecasts that the global market for PH therapies will grow to US$18 billion by 2032, with activin signalling inhibitors expected to account for roughly half of that total.
The acquisition adds HS235 to GSK's Respiratory, Immunology & Inflammation (RI&I) pipeline, complementing a portfolio targeting the inflammatory and fibrotic drivers of chronic disease, and follows the company's broader push under CEO Luke Miels to expand its pipeline. Completion of the all-cash transaction was subject to customary conditions, including clearance under the Hart-Scott-Rodino Act in the United States and the Competition Act in Canada, together with a filing under the Investment Canada Act.
Stikeman Elliott LLP acted as legal counsel to 35Pharma, with a team comprising Jeremy Sculnick, Samantha Allen, and Milena Kukolj (Corporate); Frank Mathieu and Candace Cerone (Tax); Michael Kilby and Irma Shaboian (Regulatory); Sara Zborovski and Ian Trimble (Health Regulatory); Stephanie Weschler and Antoine Métayer (Employment); Jordan Fremont (Benefits); Jonathan Auerbach and Denise Felsztyna (Intellectual Property); Jean-Guillaume Shooner (International Trade); Danielle Miller Olofsson (Privacy); Connie Scott (Paralegal); and Frédéric Paré and Éloïse Noiseux (Litigation). Cooley LLP acted as US legal counsel to GSK.