Bristol Myers Squibb and Ono Pharmaceutical filed a patent infringement lawsuit against Amgen in Delaware federal court. The suit aims to prevent Amgen from marketing a biosimilar version of the cancer immunotherapy drug Opdivo.
Opdivo represents a significant revenue source for Bristol Myers. Amgen is currently developing its biosimilar candidate, ABP 206, which is undergoing Phase 3 clinical trials.
The two companies have previously engaged in legal disputes over patents related to the drug. This action seeks to preserve market exclusivity for the nivolumab treatment.