Repligen Corporation of Waltham, Massachusetts, announced that Repligen and the University of Michigan (UM) have filed a joint complaint against Bristol-Myers Squibb Corporation (BMS) for infringement of a US patent that covers methods of treating autoimmune diseases, including rheumatoid arthritis (RA), using CTLA4-Ig (a soluble form of the T-cell regulatory protein, CTLA4). BMS recently received US Food and Drug Administration (FDA) approval to market CTLA4-Ig under the brand name Orencia® (abatacept) for the treatment of RA.

Repligen has exclusive rights to US patent No. 6,685,941 (issued on February 3, 2004), which is owned by The Regents of UM and The United States of America as represented by the Secretary of the Navy. The patent will remain in force until 2021.

In addition to RA, the patent covers a method of treating multiple sclerosis (MS), systemic lupus erythematosus, and scleroderma with CTLA4-Ig, as well as the use of CTLA4-Ig in combination with other immunosuppressive agents. Repligen has also been granted a patent in Europe until 2013 for the use of CTLA4-Ig for the treatment of autoimmune disease including RA as well as organ transplants.

The issued US patent is independent of CTLA4-Ig patents that were the subject of an earlier lawsuit that Repligen and the UM filed against BMS. According to the company, Repligen and the UM believed that the UM had a rightful claim to ownership of certain patents of BMS that relate to compositions and uses of CTLA4. The suit asserted that a scientist from the UM made original contributions as part of a collaboration with BMS scientists and was therefore a rightful inventor on patents issued to BMS. In September 2003, the District Court found that Repligen and the UM had not proven that the UM scientist was a sole or joint inventor of any of the patents in the suit. Repligen appealed the ruling of the District Court with the United States Court of Appeals for the Federal Circuit. In a subsequent ruling, the Court upheld the District Court ruling in favor of BMS. The ruling of the court is final.

Repligen is currently evaluating their formulation of CTLA4-Ig, RG2077, in a phase I clinical trial in patients with MS, and is also supplying RG2077 to investigators of the NIH-sponsored Immune Tolerance Network for a clinical study in patients with lupus nephritis.

―A. Techman