Merck Sharp & Dohme LLC

Merck Sharp & Dohme LLC is the international trade name for Merck & Co., Inc., a prominent American multinational pharmaceutical company. Known as MSD outside the United States and Canada, the company is headquartered in Rahway, New Jersey, and was founded in 1891 as a U.S. subsidiary before becoming independent in 1917. Merck & Co., Inc. is a publicly traded company on the New York Stock Exchange under the ticker symbol MRK. As of December 31, 2025, it employed approximately 75,000 people and reported an annual revenue of $65.01 billion for fiscal year 2025.

Merck is a research-intensive biopharmaceutical company that discovers, develops, manufactures, and markets a broad range of innovative products for human and animal health. Its major product lines include prescription medicines, vaccines, and biologic therapies. Key therapeutic areas encompass oncology, with flagship drugs like Keytruda, as well as vaccines such as Gardasil, and treatments for infectious diseases, cardiometabolic disorders, and immunology. The company also maintains a significant Animal Health division.

In terms of patent litigation, Merck Sharp & Dohme LLC primarily appears as a plaintiff in Patent Trial and Appeal Board (PTAB) proceedings, with one tracked case. This indicates an operating company actively seeking to challenge the validity of competitor patents. Concurrently, Merck Sharp & Dohme Corp. is a defendant in a co-pending district court litigation (Halozyme Inc. v. Merck Sharp & Dohme Corp., D.N.J., Case No. 2:25-cv-03179), where it is accused of infringing patents related to its subcutaneous (SC) formulation of Keytruda. The district court litigation has been temporarily suspended pending the outcome of the PTAB reviews.

A notable case reflecting Merck's litigation posture is Merck Sharp & Dohme LLC v. Halozyme Inc. at the PTAB, initiated in November 2024. In this proceeding, Merck is challenging multiple patents owned by Halozyme, Inc. directed to modified PH20 hyaluronidase polypeptides, which are relevant to Merck's Keytruda Qlex™ subcutaneous formulation. Recent PTAB decisions have favored Merck in some of these challenges, finding certain Halozyme patents invalid, which could significantly influence the related district court infringement suit.