Bristol Myers Squibb, Ono Pharmaceutical Sue Amgen Over Opdivo Biosimilar

Bristol Myers Squibb and Ono Pharmaceutical have filed a lawsuit against Amgen in Delaware federal court to block its proposed biosimilar of Opdivo, a cancer drug. The suit alleges that Amgen's biosimilar candidate would infringe seven U.S. patents covering the blockbuster immunotherapy.

The two companies are asking the court to block all sales of the Amgen biosimilar while those patents remain in force. Opdivo has been approved in the U.S. to treat advanced or metastatic cancers, including melanoma, non-small cell lung cancer, and kidney cancer.

Bristol Myers and Ono contend that Amgen's biosimilar would infringe on seven U.S. patents covering Opdivo, which generated over $5.9 billion in U.S. sales last year alone.