By Blake Brittain Oct 23 (Reuters) - Swiss pharmaceutical company Roche has settled a patent lawsuit against U.S. biotech firm Biogen over its biosimilar version of Roche's blockbuster rheumatoid arthritis drug Actemra, according to a filing on Monday in Massachusetts federal court. Roche and its subsidiaries Genentech and Chugai Pharmaceutical jointly told the court without providing further details that they, Biogen and its manufacturer Bio-Thera had agreed to settle the case. A spokesperson for Genentech declined to comment. Representatives for Biogen and Bio-Thera did not immediately respond to requests for comment. Biosimilars are versions of biologic drugs that are comparable to generics of traditional small-molecule drugs. Unlike traditional drugs, complex biologic drugs are made from living cells and cannot be copied exactly.