60 patients with Kellgren-Lawrence grade II-II knee osteoarthritis were randomized to one of five treatments: bone marrow--derived allogeneic mesenchymal stromal cell injection at either a 25, 50, 75, or 150 million cell dose, or placebo injection. At each dose level, randomization was conducted at a 2:1 ratio of intervention to placebo; therefore a total of 10 patients were administered at each dose level, and 20 patients overall were administered placebo. Analyses were separated by lower and higher dose levels, with the patients of the placebo groups at the first two dose levels treated as one group (placebo group 1), and the patients of the placebo groups at the last two dose levels treated as one group (placebo group 2). The 25M and 50M dose groups were analyzed relative to placebo group 1, and 75M and 150M dose groups were analyzed relative to placebo group 2. Overall, incidence of adverse events were similar between treatment and placebo groups, with the most common AEs documented related to arthralgia and injection site pain. Only results of the comparisons between the 25M, 50M, and placebo 1 group were reported. Despite the greatest changes from baseline after 12 months documented in the 25M group for pain scores and results on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), between-group comparisons yield non-significant differences, with the exception of WOMAC stiffness scores.