GSK's $950M 35Pharma Buy-Boosts Shares 0.71% Despite Ranking 478th in Daily Trading Volume

Market Snapshot

On February 25, 2026, shares of GlaxoSmithKline (GSK) rose 0.71%, with a trading volume of $0.28 billion, ranking 478th in market activity for the day. The modest gain followed the announcement of GSK’s $950 million acquisition of Canadian biotech firm 35Pharma, which owns the experimental drug HS235. While the stock’s performance was relatively muted compared to broader market trends, the transaction signaled renewed strategic momentum under new CEO Luke Miels, who has prioritized aggressive R&D expansion since taking the helm in early 2026.

Key Drivers

GSK’s acquisition of 35Pharma represents a pivotal step in its strategy to bolster its pipeline in respiratory, immunology, and inflammation (RI&I) therapies. The $950 million cash deal targets HS235, a protein-based therapeutic currently in Phase 1 trials for pulmonary arterial hypertension (PAH) and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF). HS235’s mechanism—targeting the activin receptor signaling pathway with enhanced selectivity to reduce bleeding risks—positions it as a potential competitor to Merck’s Winrevair, which generated $1.4 billion in sales in 2024. GSKGSK+0.71% highlighted HS235’s potential to address unmet needs in PH treatment, where current options require concurrent anticoagulant therapy and are limited by adverse events.

The deal aligns with CEO Luke Miels’ emphasis on “smart business development” to accelerate R&D and pipeline diversification. This acquisition follows GSK’s $2.2 billion purchase of Rapt Therapeutics in January, which provided an anti-IgE antibody to compete in the food allergy market. Miels has framed such acquisitions as critical to enhancing shareholder value, particularly after a period of investor skepticism during his predecessor Emma Walmsley’s tenure. The rapid succession of deals underscores GSK’s commitment to expanding in high-growth therapeutic areas, particularly those linked to metabolic and inflammatory diseases.

The market potential for PH therapies is a significant catalyst for the acquisition. GSK cited forecasts projecting the global PH treatment market to reach $18 billion by 2032, with activin signaling inhibitors like HS235 expected to capture half of this revenue. HS235’s dual therapeutic and metabolic benefits—such as fat-selective weight loss and improved insulin sensitivity—add further commercial appeal, given the high prevalence of obesity and insulin resistance among PH patients. Early-phase clinical data from 35Pharma demonstrated dose-dependent visceral fat reduction and sustained target engagement, reinforcing investor confidence in the drug’s development trajectory.

GSK’s strategic focus on metabolic and vascular diseases extends beyond PH. The company recently secured a $1 billion licensing agreement for oligonucleotides from China’s Frontier Biotechnologies, targeting kidney diseases. These moves reflect a broader effort to leverage scientific advancements in metabolic pathways to address chronic conditions across multiple organs. By integrating 35Pharma’s expertise in protein-based therapeutics, GSK aims to expand its footprint in cardiopulmonary and metabolic disorders, areas with substantial unmet medical needs and robust market potential.

The stock’s 0.71% gain on the day can be attributed to the market’s positive reception of GSK’s aggressive acquisition strategy and the perceived value of its expanding pipeline. Analysts have noted that the company’s recent deals, combined with successful Phase 3 trials for an experimental hepatitis treatment and approvals for multiple myeloma and asthma therapies, signal a turning point in its R&D productivity. With Miels prioritizing agility and scientific innovation, GSK’s ability to execute on these strategic initiatives will likely remain a key driver of its stock performance in the near term.