Biosimilar Threat Looms for Merck's Keytruda Franchise

Merck's Keytruda franchise has been touted as one of its biggest strengths, with $8.4 billion in quarterly sales. However, a recent development may threaten this lucrative business. Cipla's U.S. subsidiary secured exclusive commercialization rights to Qilu Pharmaceutical's proposed biosimilar, QL2107, ahead of Keytruda's expected 2028 patent expiration.

While the timing is uncertain, investors are growing increasingly anxious about the potential for lower-priced competition. Merck's share price sits at $151.07, a 25.87% premium to its GF Value of $120.02. This premium raises the stakes for the company, which must now work to protect its biggest franchise.

Merck is counting on its newer subcutaneous version, Qlex, to contribute significantly to Keytruda's revenue. However, with Cipla's biosimilar in the pipeline, Merck faces a narrowing window to protect its business. To mitigate this risk, the company must move patients to Qlex, expand Keytruda's reach, and develop new growth engines before biosimilars arrive.