Merck'S $30 Billion Keytruda Sales Spark High-Stakes Patent Battle!

A high-stakes patent dispute involving Merck’s anti-PD-1 immunotherapy, Keytruda (pembrolizumab), with nearly $30 billion in sales recorded last year, illustrates the escalating intellectual property conflicts surrounding next-generation biologic drug formulations. The litigation, initiated by San Diego-based Halozyme Therapeutics, centers on Merck’s impending introduction of an injectable, subcutaneous formulation of Keytruda, a strategic move poised to extend the drug’s market exclusivity beyond its current patent expiration timeline.

Merck anticipates launching the injectable version of Keytruda by October 1, 2025, pending approval from the U.S. Food and Drug Administration (FDA) by September 23, 2025. Halozyme’s lawsuit alleges that this new formulation infringes upon its proprietary hyaluronidase technology. Halozyme seeks injunctive relief, a legal measure that, if granted, could prevent Merck from commercializing the injectable Keytruda. Merck has publicly characterized the legal challenge as "meritless."

The dispute carries significant commercial implications for Merck. Keytruda’s primary intellectual property protections are scheduled to expire beginning in 2028, rendering the drug vulnerable to competition from biosimilar alternatives. The introduction of an improved delivery method, such as a subcutaneous injection, could prolong the drug’s period of market exclusivity and potentially enhance patient convenience and adherence. This strategic shift is supported by a reported $1 billion investment from Merck into a new manufacturing facility specifically designed to accommodate the production demands of the injectable formulation.

Beyond the immediate financial interests of the involved corporations, this legal confrontation highlights broader industry dynamics. It underscores the intensifying competition in the development of injectable biologics, particularly within the oncology sector. The case also reflects growing tensions between multinational pharmaceutical corporations, such as Merck, and specialized biotechnology platform companies like Halozyme, which develop enabling technologies. This specific litigation emphasizes the critical role of intellectual property strategy as blockbuster biologic drugs approach their patent expiry dates, necessitating novel approaches to maintain market position and revenue streams.

The trajectory of this legal battle over Keytruda’s next pharmaceutical iteration is anticipated to influence future strategies concerning oncology drug access and the continued evolution of biologic innovation.