As earlier posts on this blog have noted (here and here), the Supreme Court’s 2017 ruling in Sandoz v. Amgen effectively put an end to arguments that biosimilar applicants can be forced to participate in the “patent dance” with biologics innovators. Even still, there are lots of interesting issues relating to the patent litigation provisions of the 2010 biosimilars law. Here’s one percolating in the courts right now: can a biosimilar company start to dance and then change its mind? Or does it have to finish what it started?
This arises in a dispute between Genentech and Celltrion over a biosimilar copy of Rituxan (rituximab). There’s a second issue in this dispute, which I will describe in another blog post. First some background, and then I’ll unpack the litigation.