A major French hospital group has chosen a cheap copycat version of a top-selling drug for treating its patients with rheumatoid arthritis, Crohn's disease and psoriasis in a victory for a new type of medicine known as biosimilars. In a document seen by Reuters, the central purchasing agency for the Assistance Publique - HA pitaux de Paris said on Friday it had decided to buy the biosimilar version of infliximab from Hospira, after the company offered a discount of some 45 percent to branded Remicade.