Merck banks on expanding pipeline and new launches to offset Keytruda patent loss

Keytruda remains Merck’s top-selling product, delivering $16.40 billion in the first half of 2026, yet its patent protection ends in 2028, after which biosimilars are expected to erode sales sharply. To counter this, Merck has expanded its late-stage pipeline almost threefold since 2021 and aims to roll out 20 new medicines by 2030, many of which already show blockbuster potential. Newer offerings like the pulmonary arterial hypertension drug Winrevair, the 21-valent vaccine Capvaxive and the cancer therapy Welireg posted first-half 2026 revenues of $1.1 billion, $325 million and $470 million respectively.

Additional approvals include the RSV antibody Enflonsia, the HIV regimen Idvynso and the oral PCSK9 inhibitor Lipfendra. Late-stage candidates such as sac-TMT, a weekly HIV combo and a monthly PrEP candidate are moving toward commercial validation, supporting Merck’s estimate of over $70 billion in non-risk-adjusted opportunity by the mid-2030s. The company’s recent acquisitions of Verona Pharma, Cidara Therapeutics and Terns Pharmaceuticals further diversify its portfolio ahead of Keytruda’s loss of exclusivity.