Biogen Idec, Inc. v. GlaxoSmithKline, LLC

In the mid-1990s, Biogen scientists discovered that patients with Chronic Lymphocytic Leukemia could be treated using anti-CD20 antibodies like Biogen’s Rituxan. Biogen obtained the 612 patent covering a method for treating patients with CLL involving administering a therapeutically effective amount of the anti-CD20 antibody, entitled “Treatment of Hematologic Malignancies Associated with Circulating Tumor Cells Using Chimeric Anti-CD20 Antibody.” The patent was not limited to any particular type of antiCD20 antibody. In 2002, GSK and Genmab developed a breakthrough anti-CD20 antibody, Arzerra, which is distinctly different from Rituxan in several respects. Unlike Rituxan, which is a chimeric antibody, Arzerra is a fully human antibody, with less risk that the body will reject it and it can bind longer, giving the antibody more time to kill the target B cell. In 2010, Biogen sued GSK for infringement. The district court applied a construction of “anti-CD20 antibody” that narrowed the term based on prosecution history disclaimer. Under that construction, Biogen stipulated that it could not prove infringement and appealed the claim construction. The Federal Circuit affirmed; the district court did not err in finding a clear and unmistakable disclaimer. View "Biogen Idec, Inc. v. GlaxoSmithKline, LLC" on Justia Law