[Feature Stock] ABL Bio, plummeting due to failure to prove OS superiority in clinical trials of its US subsidiary

ABL Bio experienced a sharp decline during trading due to the announcement of clinical results from the main pipeline of its U.S. subsidiary, Compass Therapeutics.

According to the Korea Exchange, ABL Bio fell 32.3k won (18.70%) from the previous trading day, closing at 140.4k won. During the session, it briefly dropped to 131.9k won, with the decline widening.

The weakening stock price is interpreted as being influenced by Compass Therapeutics’ clinical data on tovesimig combined with the chemotherapy drug paclitaxel. The results showed that the overall survival (OS) for the combination therapy was 8.9 months, lower than the 9.4 months for monotherapy, failing to demonstrate significant improvement in the core endpoint.

On the other hand, in terms of progression-free survival (PFS), the combination therapy was 4.7 months, compared to 2.6 months for monotherapy, showing a statistically significant improvement. However, the market tends to place more emphasis on the OS results, which are considered the key criterion for new drug approval.

The company explained that, due to the impact of crossover treatment in the control group, the survival data was somewhat diluted. Compass Therapeutics plans to negotiate with the U.S. Food and Drug Administration (FDA) regarding the new drug application (BLA) based on these data.

However, the securities industry generally believes that the approval expectation has been lowered. DS Investment Securities analyst Kim Min-jung pointed out, “In the past, the FDA required not only objective response rate (ORR) data but also final median OS data,” and added, “Since the core endpoint did not demonstrate superiority, approval will not be easy.” She further commented, “Building a case for approval based solely on partial subgroup data is limited.”

Previously, ABL Bio’s stock also plummeted after announcing that Sanofi had adjusted the development priority of the Parkinson’s disease treatment drug ABL301. The recent clinical results seem to add additional pressure to an already shrinking investor sentiment.