BALTIMORE--(BUSINESS WIRE)--April 25, 2006--Osiris Therapeutics, Inc. announced today that it has completed enrollment in the first human clinical trial of a stem cell therapy to repair tissue in the knee. A total of 55 patients were treated in the Phase I/II double blinded, placebo-controlled trial designed to evaluate the safety and effectiveness of Chondrogen(TM), a preparation of adult stem cells formulated for direct injection into the knee.