BioAge Labs (BIOA) said late Friday it is terminating its phase 2 study of the investigational drug candidate azelaprag as both monotherapy and in combination with tirzepatide following observations of liver transaminitis in some subjects, without clinically significant symptoms.

The company also noted that no transaminase elevations were detected in the tirzepatide-only treatment group.

BioAge had planned to enroll approximately 220 individuals aged 55 years and older for the trial.

BioAge Chief Executive Kristen Fortney said that the difficult decision was made to discontinue the Phase 2 study of azelaprag as the emerging safety profile of the current doses tested was not consistent with the company's goal of a best-in-class oral obesity therapy.

"While this outcome is a significant disappointment, we remain encouraged by azelaprag's promising preclinical and Ph1b efficacy profile," Fortney said.

Trading of shares of BioAge was halted and set to resume later Friday.