French clinical-stage biopharmaceutical company PannTheraPi has received approval from the French National Agency for the Safety of Medicines and Health Products (ANSM) to initiate a Phase 2a clinical trial of PTI5803 in patients with drug-resistant epilepsy associated with Focal Cortical Dysplasia (FCD).

PTI5803 is an oral small-molecule therapy targeting the pannexin 1 (Panx1) channel and is being developed as a potential first-in-class treatment for FCD, a rare and severe form of epilepsy. The company previously reported positive Phase 1 results in healthy volunteers, including safety, pharmacokinetic and pharmacodynamic findings.

The multicentre Phase 2a study will initially enrol adults and adolescents with drug-resistant seizures associated with FCD. Participants will receive PTI5803 across three dose levels, with the primary objective of evaluating safety and tolerability. Changes in seizure frequency will be assessed as a secondary measure of preliminary efficacy.

Patients completing the main study will have the option to enter a long-term open-label extension phase, allowing continued evaluation of PTI5803’s safety and potential treatment effects.

The trial will be led by Dr Marion Quirins, neurologist-epileptologist at Hôpital Fondation Adolphe de Rothschild in Paris, with participation from epilepsy centres at Marseille-Timone University Hospital, Hospices Civils de Lyon and Fondation La Teppe.

“ANSM approval marks an important milestone in the development of PTI5803 and brings us closer to evaluating its potential in patients with FCD, who have very limited treatment options, particularly when surgery is not possible or has failed,” said Dr. Gilles Huberfeld, neurologist-epileptologist at Rothschild Foundation Hospital, and Dr. Nathalie Rouach, neurobiologist at Collège de France and co-founders of PannTheraPi.

The Phase 2a trial will provide clinical data on the safety, tolerability and preliminary efficacy of PTI5803 in FCD, supporting decisions on its further development in drug-resistant epilepsy.