At a Glance
- Company: GSK acquiring 35Pharma
- Location: GSK (London); 35Pharma (US-based)
- Deal value: $950M upfront + milestones
- Focus area: Activin signalling inhibitor for PAH
- Next steps: Phase 2 data 2026; accelerate to phase 3
What happened?
GSK announced on 25 February 2026 an agreement to acquire 35Pharma for $950 million upfront plus undisclosed milestones, gaining full rights to 35PAH-001, a highly selective activin receptor inhibitor for pulmonary arterial hypertension (PAH). The deal mirrors Merck’s $11.5B acquisition of Actelton for Winrevair (sotatercept), positioning GSK in the emerging activin class.
Why does it matter?
PAH is a progressive, fatal disease affecting ~100,000 globally with poor prognosis; activin inhibitors trap growth factors to reverse vascular remodelling, offering superior efficacy to prostacyclins/endothelin antagonists. 35PAH-001’s preclinical potency and oral potential could challenge Winrevair’s dominance in a $6B+ market growing 10% annually.
Who’s behind it?
GSK seeks respiratory pipeline refresh post-Nucala; 35Pharma developed small-molecule activin inhibitors via proprietary platform. CEOs emphasised strategic fit for late-stage PAH unmet needs.
How was it achieved?
35PAH-001 selectively blocks activin A/B to normalise pulmonary pressures; phase 1 showed favourable safety and biomarker modulation. Deal includes phase 2-ready data package with animal models demonstrating right heart failure reversal.
What’s next?
GSK integrates asset for phase 2 initiation mid-2026 targeting WHO functional class II/III PAH patients; combination with existing therapies planned. Milestones tied to approval/sales; potential label expansion to CTEPH.