[Reporter’s Notebook] There Is No “Partial Success” in Clinical Trials

TG-C Fails to Meet Primary Endpoint in U.S. Phase 3 Trial
Acknowledging Missed Targets Is Crucial to Regain Market Trust

"I do not consider this a clinical failure. It is a partial success."

On July 21, Jeon Seung-ho, Co-CEO of Kolon TissueGene, assessed the topline results of the U.S. Phase 3 clinical trial for the osteoarthritis cell gene therapy TG-C (formerly Invossa) in this way. He also added that the current difficulties are simply growing pains. However, market sentiment remains cold. The share price, which had hovered around 140,000 won, hit the lower limit for three consecutive days and fell to the 20,000 won range in just two months. For investors, the price of lost expectations and financial losses is too great to simply be labeled as growing pains.

The company described the results as a "partial success," citing that improvements in pain and joint function among TG-C recipients were as good as, or better than, in previous trials. While they assert that TG-C's efficacy remains valid, the company explained that the higher-than-expected placebo response diluted the difference with the drug group.

Nonetheless, it is important to distinguish between the potential for TG-C’s further development and the success or failure of the clinical trial. Clinical trials do not simply assess whether patients improve compared to before receiving treatment. They are designed to evaluate whether the test drug demonstrates superior efficacy over a placebo. In this trial, the improvement seen in the placebo group was also significant, making it impossible to demonstrate a statistically significant difference between the TG-C and placebo groups. Failing to meet the primary endpoint means the trial did not achieve its pre-established goals.

Drug development is a process fraught with setbacks. It is unfair to condemn a company over a single failed clinical trial. However, insisting that "half the goal was achieved" is not a prudent way to assign meaning to these results. While analyzing why the placebo response was elevated is indeed necessary, this process should serve to determine the cause of failure and inform subsequent strategies—it cannot be justification for redefining the results already obtained. In that sense, it is disappointing that the recent briefing focused excessively on the unusual response in the placebo group.

The corporate value of listed biotech firms is formed in anticipation of future sales and approval possibilities that do not yet exist. This is why the management’s remarks become more than mere opinions—they serve as grounds for investment decisions. If a company provides the most optimistic interpretations when explaining potential for success and calls an unmet target a partial success, what can investors trust?

TG-C is a therapy that has already lost public trust once following controversies over its listed ingredients and the cancellation of its domestic product approval. The fact that the company resumed development with additional U.S. trials increases its responsibility in explaining the outcomes. To regain trust after past controversies, the company needs to present not only the favorable data but also the unfavorable results and uncertainties as they are. Language that refuses to acknowledge failure erodes trust in drug development firms.

This content was produced with the assistance of AI translation services.