05:04 PM EDT, 07/26/2024 (MT Newswires) -- vTv Therapeutics ( VTVT ) said late Friday the US Food and Drug Administration has placed a "clinical hold" on its cadisegliatin clinical program, including an ongoing CATT1 phase 3 trial in type 1 diabetes.

The clinical hold was based on the discovery of a chromatographic signal in a recent human absorption, distribution, metabolism, and excretion study of cadisegliatin that could not be resolved by standard mass spectroscopy, the late-stage drugmaker said.

The FDA requires a single in vitro study to characterize this signal before the program can resume, vTv said, adding that no patient had been dosed in CATT1 at the time of the hold, and past studies did not reveal any clinically concerning safety issues.

"We are working diligently with the Agency to resolve the clinical hold and resume enrollment as quickly as possible," said CEO Paul Sekhri. Cadisegliatin has been well-tolerated in over 500 subjects to date with up to six months of treatment.

vTv shares tumbled about 43% in extended trading.