Bristol Myers sues Amgen over proposed Opdivo biosimilar

Opdivo earned Bristol Myers more than $5.9 billion in revenue in the United States last year, according to a company report.

Bristol Myers said in a report filed with the U.S. Securities and Exchange Commission in February that it expects to maintain patent exclusivity over Opdivo until 2028.

Opdivo has been approved in the U.S. to treat advanced or metastatic cancers, including melanoma, non-small cell lung cancer and kidney cancer.

Biosimilars are based on existing versions of biologic drugs and are comparable to generic versions of traditional pharmaceuticals. Unlike traditional drugs, complex biologics are made from living cells and cannot be copied exactly.

Bristol Myers and Ono settled a patent dispute with Merck in 2017 over its rival blockbuster cancer drug Keytruda. Under the settlement, Merck agreed to pay $625 million and a share of Keytruda royalties through 2023.

The case is Bristol-Myers Squibb Co. v. Amgen Inc., U.S. District Court for the District of Delaware, No. 1:26-cv-01134.

For BMS and Ono: Steven Maslowski of Akin Gump Strauss Hauer & Feld

For Amgen: attorney information not yet available

Bristol Myers Squibb BMY.N and Ono Pharmaceutical 4528.T have sued Amgen AMGN.O in Delaware federal court, seeking to block Amgen's proposed U.S. biosimilar of their blockbuster cancer immunotherapy drug Opdivo.

• The lawsuit, filed last week and made public on Monday, alleges that Amgen's biosimilar would infringe several patents.