Regeneus Ltd., of Sydney, said it completed enrollment of all 20 patients in the STEP (Safety, Tolerability and Efficacy of Progenza) phase I trial. Progenza is an allogeneic off-the-shelf stem cell product for the treatment of knee osteoarthritis. The randomized, double-blind, placebo-controlled single ascending-dose study is evaluating the safety, tolerability and preliminary efficacy of intra-articular Progenza in adults with symptomatic knee osteoarthritis.