Celltrion, Inc. (“Celltrion”) filed three new petitions with the Patent Trial and Appeal Board (“PTAB”) on March 15, 2017 for inter partes review (“IPR”) of Biogen’s U.S. Patent Nos. 8,329,172 (“the ’172 patent”), 8,557,244 (“the ’244 patent”), and 9,296,821 (“the ’821 patent”) related to rituximab.

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 proceedings are IPR2017-01093 (the ’172 patent), IPR2017-1094 (the’244 patent), and IPR2017-1095 (the ’821 patent). The real parties-in-interest identified for Petitioner are Celltrion, Inc., Celltrion Healthcare Co. Ltd., and Teva Pharmaceuticals International GmbH.

The sole claim of the ’172 patent is directed to a method of treating low-grade B-cell non-Hodgkin’s lymphoma (“NHL”) by administering a well-known chemotherapy regimen of cyclophosphamide, vincristine, and prednisone (“CVP”), followed by rituximab maintenance therapy administered in four weekly doses of 375 mg/m2 every six months for two years.  The ’244 patent has two claims.  Claim 1 of the ’244 patent is directed to a method of treating a patient with diffuse large cell lymphoma (a subset of Non-Hodgkin’s Lymphoma) by administering a combination of an unlabeled chimeric anti-CD20 antibody and chemotherapy (the chemotherapy consisting of cyclophosphamide, hydroxydaunorubicin/doxorubicin, vincristine, and prednisone/prednisolonew).  The treatment claimed in the ’244 patent is specific to a patient who is greater than 60 years old, has bulky disease, and has a tumor greater than 10 cm in diameter. Claim 2 of the ’244 patent further limits the chimeric anti-CD20 antibody to rituximab.  The ’821 patent has six claim which are generally directed to methods for treating low-grade or follicular NHL by administering rituximab during a chemotherapy regimen of CVP.

The PTAB recently issued institution decisions on two other patents related to rituximab.  On February 24, 2017, the PTAB instituted review of certain claims of U.S. Patent No. 7,820,161 (“the ’161 patent”) based on a petition filed by Celltrion in IPR2016-01614 as we reported here, and on March 2, 2017, the PTAB denied Celltrion’s request for inter partes review of U.S. Patent No. 7,976,838 in IPR2016-01667 as we reported here.

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.