[비즈한국] Variables have emerged in the U.S. regulatory approval process for ABL001 (tovesmirig), a biliary tract cancer treatment developed by ABL Bio. The U.S. Food and Drug Administration (FDA) has recommended an additional clinical trial to prove a survival benefit prior to the submission of a Biologics License Application (BLA). Compass Therapeutics, the global development partner, maintains that the existing clinical results are sufficient for a license application and plans to enter into further consultations with the FDA.
Meeting with a reporter ahead of SNU-BIODAY 2026 held at the Hoam Faculty House of Seoul National University in Gwanak-gu, Seoul, on the 29th, ABL Bio CEO Lee Sang-hoon commented on the future FDA approval strategy for ABL001, stating, "The partner company plans to reorganize the data, submit the application materials around November, and hold discussions with the FDA, so we will have to see the results."
FDA Demands Proof of Survival Benefit… Compass to Re-negotiate Based on Existing Data
On the 22nd, Compass announced that following discussions with the FDA, the agency recommended conducting an additional clinical trial to demonstrate a survival benefit before submitting a BLA for ABL001.
In this regard, Compass maintains the position that a new clinical trial is unnecessary before BLA submission, considering the existing Phase 2/3 clinical results and the unmet medical needs of biliary tract cancer patients. The company has decided to proceed with further consultations with the FDA while continuing to prepare for the BLA submission.
ABL001 is a bispecific antibody developed by ABL Bio that simultaneously targets VEGF-A and DLL4. In November 2018, ABL Bio out-licensed the global rights (excluding South Korea) for ABL001 to the U.S.-based Trigger Therapeutics in a deal worth a total of $595 million, with an upfront payment of $5 million. Rights were subsequently transferred to Compass Therapeutics following its merger with Trigger Therapeutics.
Clinical trials were conducted in the U.S. comparing a combination therapy of ABL001 and paclitaxel against paclitaxel monotherapy in patients with previously treated, advanced biliary tract cancer.
In the final analysis, the Objective Response Rate (ORR) for the ABL001 combination group was 18.0%, higher than the 5.3% observed in the paclitaxel-only group. The median Progression-Free Survival (PFS) also showed a statistically significant difference, at 4.7 months and 2.6 months, respectively. Conversely, Overall Survival (OS) did not reach statistical significance, as the results were impacted by a high crossover rate of patients in the control group to ABL001 treatment.
Industry observers believe the FDA's recommendation for an additional trial to prove survival benefits is linked to these OS results.
CEO Lee expects Compass to re-engage with the FDA based on the clinical data currently in hand. "Compass says the current data is sufficient to demonstrate the potential and validity of the drug as a second-line treatment," he said. "There have been cases in the U.S. where the FDA initially asked for more data, but approval was eventually granted after follow-up meetings. I believe we will likely reach a conclusion at the next FDA meeting."
However, he remained tight-lipped about whether the FDA's recommendation for an additional trial would lead to actual delays in the development schedule. Regarding the possibility of delays, CEO Lee explained, "I don't know for sure yet. Since our partner company meets with the FDA directly, we only hear about it indirectly or confirm information through shared official announcements." He added, "We have to wait and see. It would be premature to say whether it will or will not happen; ultimately, in the U.S. market, the FDA's opinion is what matters."
ABL001 has already been granted Fast Track and Orphan Drug designations by the FDA. Until early this year, Compass had been pushing to submit the BLA to the FDA within the year.
"Shocking" Regarding Investigations into Alleged Use of Undisclosed Information
ABL Bio is also currently under investigation by financial authorities over allegations of using undisclosed information during the technology transfer process. A joint task force for the eradication of stock manipulation, composed of the Financial Services Commission, the Financial Supervisory Service, and the Korea Exchange, is currently investigating about 10 ABL Bio employees, including CEO Lee Sang-hoon. Previously, the task force had raided the ABL Bio headquarters. While rumors circulated that CEO Lee's family was also under investigation, it has been confirmed that they are not currently included in the investigation.
CEO Lee expressed perplexity regarding the recent investigation. When asked if the current situation could be seen as shocking given the high market expectations for ABL Bio, Lee said, "It is shocking. I am doing my best and hoping that everything goes well," keeping his comments brief.
When asked if there are plans to improve internal information management and control systems regarding the allegations of using undisclosed information, CEO Lee stated, "I believe our external controls were very well-managed," without mentioning any specific improvement measures.
ABL Bio has drawn attention in the domestic biotech industry by achieving a series of large-scale technology transfer milestones with global pharmaceutical companies. The future development schedule of ABL001 is expected to take shape based on the results of follow-up discussions with the FDA, while the company's uncertainties will likely be clarified by the outcome of the financial authorities' investigation.