Cipla Secures U.S. Rights to Keytruda Biosimilar Ahead of 2028 Patent Cliff

Merck (NYSE:MRK) received a fresh reminder Thursday that competition for Keytruda, its biggest franchise, is drawing closer. Cipla's U.S. subsidiary secured exclusive American commercialization rights to Qilu Pharmaceutical's proposed pembrolizumab biosimilar, QL2107, ahead of Keytruda's expected 2028 core patent expiration.

The threat is not immediate. Qilu must still complete development, win regulatory approval and prove it can manufacture a comparable product at scale. Cipla takes over only if QL2107 reaches the U.S. market. The timing remains uncertain, but lower-priced competition is lining up as Merck's window to protect the franchise narrows.

Merck posted $8.4 billion in quarterly Keytruda and Keytruda Qlex sales, including $463 million from the newer subcutaneous version. Qlex already contributes about 5.5% of franchise revenue, making it a key part of Merck's patent-cliff defense.

Shares were priced at $151.07, which sits 25.87% above the $120.02 GF Value, according to GuruFocus. To defend against the coming biosimilar competition, Merck aims to shift patients to Qlex, widen Keytruda's reach and build its next growth engine.