Pfizer, Inc. (“Pfizer”) filed a new petition with the Patent Trial and Appeal Board (“PTAB”) on March 24, 2017, for inter partes review (“IPR”) of U.S. Patent No. 7,820,161 (“the ’161 patent”) related to Biogen’s and Genentech’s Rituxan® (rituximab).  The challenged claims of the ’161 patent are directed to a method for treating rheumatoid arthritis by administering more than one intravenous dose of a therapeutically effective amount of rituximab and administering methotrexate.

Rituximab is an anti-CD20 monoclonal antibody approved for the treatment of non-Hodgkin’s lymphoma, chronic lyphocytic leukemia, rheumatoid arthritis, granulomatosis with polyangitis, and microscopic polyangitis.

The proceeding is IPR2017-01115. The only real party-in-interest identified for Petitioner is Pfizer, Inc.  Pfizer reported in January that its proposed biosimilar rituximab (PF 05280586) is in Phase 3 development.  Earlier this month, the PTAB instituted an IPR for certain claims of the ’161 patent on a petition filed by Celltrion (as we reported here), and Pfizer has requested that its petition be joined with that proceeding.

Celltrion currently has petitions pending for review of three other patents related to rituximab as reported here, and the PTAB denied Celltrion’s petition related to U.S. Patent No. 7,976,838 as reported here.  Boehringer Ingelheim and Celltrion had previously filed petitions at the PTAB for patents related to this same product that were voluntarily dismissed in 2015. A complete list of IPRs related to rituximab and other proposed biosimilars can be found in RFEM’s IPR Dashboard.

We will continue to provide updates as these cases progress.