A phase 3 trial of Kolon TissueGene’s cell-based gene therapy has missed its co-primary endpoints. With a second late-stage study scheduled to report data in October, the biotech is holding off on determining the next steps for the osteoarthritis candidate.
The failed phase 3 trial tested TG-C, a drug candidate containing human allogeneic chondrocytes and an irradiated human embryonic kidney-derived cell line stably expressing TGF-β1. Authorities in South Korea authorized the medicine in 2017, only to retract the approval two years later over a mix-up regarding the type of cells used in the therapy.
Seeking to validate the candidate, Kolon enrolled 531 people with osteoarthritis of the knee at 27 sites in the U.S. The study, which was delayed by an FDA hold and began enrolling patients four years after Kolon registered the trial, compared intra-articular injections of the cell-based gene therapy and placebo.
One year after the injections, recipients of TG-C performed statistically no better on assessments of knee function and pain than their peers on placebo, causing the study to miss its co-primary endpoints. The study also missed all its key secondary endpoints.
Attention now turns to the expected October delivery of data from Kolon’s other phase 3 trial. The trials are similar, with the ongoing study having the same arms and co-primary endpoints as the failed trial, as well as nearly identical inclusion/exclusion criteria. Kolon will decide on the future of the program after seeing data from the second phase 3 trial.
The failure of Kolon’s first study adds to the list of setbacks encountered by companies trying to treat osteoarthritis of the knee. Ampio Pharmaceuticals ran into multiple obstacles before deciding to shut down in 2024. Centrexion Therapeutics’ CNTX-4975 failed to beat placebo in a phase 3 trial. More positive stories include Flexion Therapeutics, which won FDA approval in 2017 and was acquired in 2021.