156 patients with knee osteoarthritis were included in this study and randomized to receive a single injection of either Invossa (TissueGene-C) gene therapy, containing non-transformed and transduced chondrocytes, or saline. The study was conducted in order to determine if the gene therapy was effective in improving cartilage integrity via assessing clinical outcomes at 1 year. The findings of this study displayed significantly improved International Knee Document Committee scores, VAS pain, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and the Knee Injury and Osteoarthritis Outcome Scores with the intervention therapy.