Merck's Injectable Keytruda Sparks Legal Dispute with Halozyme

Merck's plans to introduce a subcutaneous formulation of its blockbuster cancer drug Keytruda have ignited a legal battle with Halozyme Therapeutics, a company specializing in drug delivery technology. The dispute centers around patent infringement claims and could have significant implications for both companies and the broader pharmaceutical industry.

Patent Controversy Emerges

Merck, the manufacturer of Keytruda—the world's highest-selling drug with nearly $30 billion in sales last year—is currently awaiting FDA review for its new injectable formulation. However, Halozyme contends that this new version infringes on its patents for a specific enzyme used to convert intravenous drugs into injectable forms.

The conflict came to light when Merck challenged seven of Halozyme's patents for its hyaluronidase enzyme, Mdase, at the U.S. Patent and Trademark Office. Merck argues that these patents are overly broad and should not have been granted. In response, Halozyme asserts that Merck's new Keytruda formulation, which incorporates a hyaluronidase enzyme, violates these patents and necessitates a licensing agreement.

Strategic Implications for Merck

Merck's pursuit of an injectable Keytruda formulation is part of a broader strategy to extend the drug's market dominance beyond its current patent expiration date in 2028. The company began collaborating with South Korean firm Alteogen in 2020 to develop the subcutaneous version using hyaluronidase enzymes.

In November 2024, Merck announced positive results from a Phase III trial, demonstrating that the subcutaneous injection of Keytruda performed equally well compared to the traditional infusion method. The company estimates that up to 40% of patients currently receiving Keytruda could switch to the injectable version within two years of its approval, highlighting the potential market impact of this new formulation.

Industry Ramifications and Future Outlook

The dispute between Merck and Halozyme underscores the complex interplay of innovation, patent protection, and market competition in the pharmaceutical industry. Halozyme's technology, which enables the conversion of lengthy intravenous treatments into quick subcutaneous injections, has already been licensed to other major pharmaceutical companies, including Bristol Myers Squibb for its cancer drug Opdivo and Roche for its multiple sclerosis treatment Ocrevus.

As the legal battle unfolds, the outcome could have far-reaching consequences for drug delivery technologies and patent strategies in the pharmaceutical sector. The industry will be closely watching the resolution of this dispute, which may set important precedents for future collaborations and patent challenges in the field of drug formulation and delivery.