Despite posting strong results in the final quarter of 2025, MSD (Merck & Co) has cut its 2026 guidance more than analysts had expected as the drugmaker prepares for the loss of exclusivity of several of its medicines.
MSD reported Q4 global sales of $16.4bn, a 5% increase from the same period in 2024. Full-year sales in 2025 grew 1% to reach $65bn.
While year-end results outperformed consensus analyst expectations, investor buoyancy was overshadowed by the 2026 sales forecast. The big pharma company anticipates global sales of between $65.5bn and $67bn. The higher end of this range falls short of the average analyst estimate of $67.6bn, as per LSEG data.
As has been the case for recent years, cancer blockbuster Keytruda (pembrolizumab) was the top-performing drug in the big pharma company’s portfolio. The immunotherapy reached $31.7bn in global sales, driving much of the company’s higher-than-expected 2025 performance, especially its strong Q4. Keytruda is one of MSD’s products facing loss of exclusivity later this decade, while type 2 diabetes drugs Januvia (sitagliptin) and neuromuscular blockage Bridion (sugammadex) lose patent protection in 2026.
Eyes have therefore been firmly on the company’s pipeline and M&A activity in search of revenue replacement.
Reacting to the results, Citi analysts wrote: “We note 2026 guidance came in below expectations as investor interest remains on the anticipated Keytruda loss of exclusivity and the strategy to offset the impact with new launches and pipeline catalysts.”
MSD conducted two large deals in 2025 as it seeks to replenish its portfolio. This included a $10bn buyout of Verona Pharma and a $9.2bn acquisition of antiviral developer Cidara Therapeutics in August and November last year, respectively. In January 2026, there were suggestions that MSD was looking to buy Revolution Medicines for up to $32bn, though talks reportedly ended after price disagreements.
Speaking on an earnings call, CEO Rob Davis said: “Our belief in our ability to have sustainable growth once we get past the loss of exclusivity is as high as it’s ever been. We have early-stage pipeline assets that we will be reading out in the next two years. Plus, we’ve conducted additional business development.”
Keytruda’s strong performance was joined by MSD’s new drug Winrevair, which is used to treat pulmonary arterial hypertension (PAH). The injection recorded $467m in sales for Q4, up 133% from the same period a year earlier. While it was recently approved in 2024, Winrevair is touted as a major growth driver for the company as it transitions reliance away from Keytruda.
