On March 31, 2017, Celltrion, Inc. (“Celltrion”) filed three new petition for inter partes review (“IPR”) of two additional patents related to Genentech and Biogen’s Rituxan® (rituximab).  Two of the petitions challenge claims of U.S. Patent No. 7,682,612 (“the ’612 patent”) and the other seeks review of all nine claims of U.S. Patent No.8,206,711 (“the ’711 patent”).  The proceedings are IPR2017-01227 and IPR2017-01230 (both involving the ’612 patent) and IPR2017-01229 (involving the ‘711 patent). The real parties-in-interest identified for Petitioner are Celltrion, Inc., Celltrion Healthcare Co. Ltd., and Teva Pharmaceuticals International GmbH.

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 challenged claims of the ’612 patent are directed to methods of treating chronic lymphocytic leukemia (“CLL”) by administering an anti-CD20 antibody to the patient in an amount effective to treat the chronic lymphocytic leukemia, wherein the method does not include treatment with a radiolabeled anti-CD20 antibody (referred to as “single agent” claims).  The challenged claims of the ’711 patent are directed to methods of treating CLL by administering an effective amount of rituximab to the patient at a dosage of 500 mg/m, either alone or in combination with another chemotherapeutic agent.

Earlier this year, the PTAB instituted trial proceedings in IPR2016-01614 based on Celltrion’s petition for review of U.S. Patent No. 7,820,161, which is also related to rituximab (as we reported here).  Last week, Pfizer, Inc. (“Pfizer”) also filed a petition seeking IPR review of the ’161 patent and requested that its case be joined with IPR2016-01614 as discussed in this post.

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.  As discussed in our earlier posts, 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.