Bristol Myers Sues Amgen Over Proposed Opdivo Biosimilar

Bristol Myers Squibb and Ono Pharmaceutical have filed a lawsuit against Amgen in Delaware federal court, seeking to block Amgen's proposed U.S. biosimilar of their cancer immunotherapy drug Opdivo.

The lawsuit alleges that Amgen's biosimilar would infringe seven U.S. patents covering the drug, which earned Bristol Myers more than $5.9 billion in revenue in the United States last year.

Biosimilars are based on existing versions of biologic drugs and are comparable to generic versions of traditional pharmaceuticals.

The case is related to a patent dispute that Bristol Myers settled with Merck in 2017 over its rival blockbuster cancer drug Keytruda, where Merck agreed to pay $625 million and a share of Keytruda royalties through 2023.