Immunex Corp. said Genentech Inc. agreed to begin making Enbrel in 2004, helping bolster the supply of Immunex's top-selling treatment for rheumatoid arthritis.
Manufacturing constraints have limited Enbrel supplies and checked growth of the drug, which had sales of $762 million last year. Immunex has a waiting list of about 13,000 patients who want the drug. It last month notified others already on the drug to expect delays until June.
