Biogen Dodges IPR Bullet on Key Tysabri® Patents

On Monday, the PTAB issued its ruling denying institution of three IPRs challenging Biogen's patents claiming formulations and methods of treatment using natalizumab. Specifically, the PTAB denied institution of IPR2016-00912, IPR2016-00915, and IPR2016-00916, all brought by India's Swiss Pharma International, targeting Biogen's U.S. Patent Nos. 8,815,236, 8,349,321, and 8,900,577, which issued between 2013-2014. In reaching these decisions, the PTAB concluded that Swiss Pharma had not established a reasonable likelihood that the 32 challenged claims are rendered obvious by the prior art.

Natalizumab is a humanized monoclonal antibody used in the treatment of multiple sclerosis (MS) and Crohn's disease. Currently marketed as Tysabri^®, it brings in roughly $2 billion annually in sales for the Massachusetts-based Biogen, Inc. The three patents at issue cover formulations of a range of high-dose, stable natalizumab concentrations (20-150 mg/mL), as well as methods of treating MS patients with these formulations. Swiss Pharma challenged claims covering either the 20 mg/mL dosage or the full 20-150 mg/mL dosage range, but chose not to challenge the individual claims reciting only the 150 mg/mL dosage.

In its petitions, Swiss Pharma argued that the three patents are rendered obvious under 35 U.S.C. § 103(a) in light of a series of prior art references which primarily describe unrelated antibodies or small molecules. Only one reference discloses natalizumab, but lacks both the claimed excipients and the claimed dosage range. The rest of the references describing unrelated antibodies teach the claimed excipients, but do not teach a high dosage. Rather, the highest antibody concentration disclosed is 10 mg/mL, only half of the lowest claimed natalizumab dosage. While Swiss Pharma asserted that, once natalizumab was published, increasing the dosage to 20 mg/mL was "nothing more than routine optimization," the PTAB disagreed. The PTAB found that Swiss Pharma "has failed to provide sufficient and credible evidence that the combination renders obvious a natalizumab formulation containing about 20 mg/mL to about 150 mg/mL of natalizumab."

Although these decisions are unappealable, other challenges could be raised against these patents in potential future litigation. Additionally, Biogen and others hold over 90 patents that also recite natalizumab in their claims. These patents cover a range of formulations and methods of treatment for a variety of diseases, including MS. However, to date, the three patents at issue here are the only ones which have been challenged at the Patent Office. Unless they are challenged further, they will remain valid through 2024.

Authors: Craig Kraning, Jenny Shmuel, and Tasha Francis