Encysive delays human studies on TBC3711

Encysive Pharmaceuticals of the USA says that the US Food and Drug Administration has placed TBC3711, its next-generation selective endothelin receptor antagonist entering early clinical studies, on clinical hold after the firm reported an unusual finding following dosing with intravenous TBC3711 in a single rat that had displayed abnormalities at baseline.

The delay follows a standard 30-day review process associated with the Investigational New Drug application for the intravenous form of the agent. The FDA believes, that it requires further review before proceeding with patient dosing and the firm agrees with the agency's opinion. All clinical testing with TBC3711, including oral and intravenous formulations, will be suspended and Encysive says it will work with the FDA to resolve the issue as quickly as possible.