CAMBRIDGE, Mass. (AP) — Biogen Idec Inc. said Tuesday an arbitration panel affirmed its right to participate in strategic decisions in a partnership with Genentech, which includes the cancer drug Rituxan and other drug candidates. The panel ruled that a committee of three Biogen employees and three Genentech employees must unanimously approve all plans to develop drug candidates for each possible indication, Biogen said. The companies have collaborated since 1995, but when Biogen Inc. and IDEC Pharmaceuticals combined in 2003, Genentech said the terms of the partnership were no longer valid. Biogen Idec co-markets Rituxan in the U.S. with Genentech, which is being bought by Roche Holding AG. The drug is approved to treat B-cell non-Hodgkin lymphoma and rheumatoid arthritis. Biogen said the ruling means South San Francisco-based Genentech can’t proceed with developing 2H7v16 for neuromyelitis optica or relapsing-remitting multiple sclerosis, or 2H7v114 for cancer. However, Genentech can continue trials of 2H7 drugs for rheumatoid arthritis and lupus.