BERKELEY, Calif., May 14, 2009 (GLOBE NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA), a leader in the discovery and development of antibody therapeutics, announced today that its bacterial cell expression (BCE) technology licensee UCB S.A. has received FDA approval to market CIMZIA(r) (certolizumab pegol), an anti-tumor necrosis factor product, for the treatment of moderate to severe rheumatoid arthritis (RA) in adults. XOMA will receive royalty payments on sales of CIMZIA for this indication and will continue to receive royalties on sales of CIMZIA for the treatment of moderate to severe Crohn's disease, for which it was approved in April 2008.