Kolon TissueGene’s experimental knee osteoarthritis therapy, TG-C, failed to meet its primary endpoints in a US phase 3 trial, the company announced on Monday. The trial, called TGC-15302, evaluated the efficacy of TG-C in reducing pain and improving function in patients with knee osteoarthritis.
The results showed that patients who received a single injection of TG-C experienced a 38.7 point drop in pain on a 100 point visual analog scale (VAS) at 12 months, compared to a 39.2 point drop for the placebo group. The difference was not statistically significant, with a p-value of 0.83.
On the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), a composite score for pain, stiffness, and physical function, TG-C led by about one point, but this result also missed significance with a p-value of 0.57. Both endpoints were co-primary, meaning the study had to meet both to be considered a success.
The trial enrolled 531 patients across 27 US sites and randomized them 2 to 1 to receive either TG-C or a saline injection. They reported that TG-C was broadly safe over the two-year window, with similar rates of serious adverse events and treatment discontinuations between the two groups.
Related: AI Helps Cut Atrial Fibrillation Ablations Without Losing Rhythm
Total knee replacement, a marker of disease progression, was reported in 0.6 percent of TG-C patients and 5.3 percent of those on placebo. This was the only signal in the data that favored TG-C, but it was not a primary goal of the trial.
Kolon TissueGene plans to review the results of this trial alongside a second phase 3 trial, TGC-12301, before discussing the program’s next steps with the US FDA. The second trial is expected to report results in October.
TG-C was previously marketed in Korea as Invossa, where it was approved in 2017 as the world’s first cell and gene therapy for osteoarthritis. However, the company later disclosed that one of the product’s two cell components was a kidney-derived cell line rather than the cartilage cells described in its approval.
The US FDA placed the US trials on clinical hold, and Korean regulators revoked the approval in 2019. The company’s shares were suspended from the Kosdaq market in 2019 and resumed trading in October 2022. Ahead of the trial results, the company’s shares had already fallen 20.3 percent on Thursday, and they closed a further 1.45 percent lower on Monday.
Related: Organ failure after admission predicts worse liver outcomes
As Kolon TissueGene assesses the results of the failed trial, it may need to consider the implications for its cell and gene therapy program. The failure to meet primary endpoints could impact the company’s ability to secure US FDA approval for TG-C. They will likely need to carefully evaluate the data from both trials to determine the best course of action for the program.
The US FDA will play a significant role in determining the next steps for TG-C. The agency may require additional data or modifications to the trial design before considering approval. Kolon TissueGene’s decision to review the results of both trials before discussing the program with the US FDA suggests that it is taking a cautious approach to the situation.
The company’s shares fell due to the trial results.
