Merck’s pharmaceutical unit, which develops a wide range of drugs, booked $14.84 billion in revenue during the fourth quarter. That’s up 6% from the same period a year earlier.

Sales of Keytruda topped $8.37 billion for the quarter, rising 7% from the same period a year ago. Analysts were expecting revenue of $8.35 billion, according to StreetAccount estimates. 

The increase in Keytruda revenue was driven by higher uptake of the drug for earlier-stage cancers and strong demand for the treatment for metastatic cancers, which spread to other parts of the body, the company said. 

Sales of the more convenient subcutaneous version of Keytruda, which won approval last year, came in at $35 million during the fourth quarter. 

That version of Keytruda is key to Merck’s efforts to offset likely declines in revenue after the original formulation of the drug, which is administered intravenously, goes off patent. 

Meanwhile, Merck’s newer drug Winrevair, which is used to treat a rare, deadly lung condition, recorded $467 million in sales for the quarter, up 133% from the same period a year earlier. 

Analysts had expected the medication to bring in $459 million, according to StreetAccount estimates. 

The growth of Winrevair, which first entered the market in mid-2024, largely reflects higher uptake in the U.S. and its early launch in some international markets.

Merck continued to see trouble with China sales of Gardasil, a vaccine that prevents cancer from HPV, the most common sexually transmitted infection in the U.S.

Last February, Merck announced it would halt shipments of Gardasil into China beginning that month. In July, CFO Caroline Litchfield said the company would not resume shipments to China through at least the end of 2025, noting that inventories remain high and demand is still soft.

Gardasil generated sales of $1.03 billion for the quarter, down 34% from the same period a year ago because of lower demand in China. Still, that was in line with what analysts were expecting, according to StreetAccount.

Gardasil’s revenue could face more pressure in 2026. As part of the Centers for Disease Control and Prevention’s changes to the pediatric vaccine schedule, the agency said that children should get one dose of the HPV vaccine instead of the two to three doses recommended on the label.

Merck’s animal health division, which develops vaccines and medicines for dogs, cats and cattle, posted nearly $1.51 billion in sales, up 8% from the same period a year prior. The company said that reflects higher demand across all species.