Here’s a question worth asking.
If blocking a specific ion channel reduces seizures in human brain tissue, gets published in Science Translational Medicine, gets replicated across animal models for close to two decades… why has it taken until 2026 for someone to build a dedicated drug around it?
PannTheraPi, a small biotech out of Nîmes, France, is trying to answer that.
The company announced today that it filed a Phase 2a application through the European CTIS system for PTI5803, an oral small molecule targeting the pannexin-1 channel. Same day, it locked down a European patent covering Panx1 inhibition in epilepsy and brought on Sophie Binay as General Manager and CSO.
Three milestones in one press release. For a company most people haven’t heard of, that’s a statement.
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The target indication is focal cortical dysplasia (FCD), a malformation in the brain’s cortical layers and the leading cause of drug-resistant epilepsy in children. “Drug-resistant” meaning standard anti-epileptic medications don’t work. The primary treatment for these kids is surgical resection of the affected brain tissue.
That succeeds about 60% of the time. Some children aren’t even candidates because the dysplasia sits too close to critical brain regions.
Options are thin. mTOR inhibitors like everolimus are being explored. Radiprodil, an NMDA receptor modulator, is in trials for FCD and TSC patients. Last month, Unixell Biotech got FDA IND clearance for an iPSC-derived cell therapy aimed at drug-resistant focal epilepsy. Completely different approach.
But pannexin-1 has been sitting in the literature since 2008. Researchers showed that Panx1 channels, when they open, flood the extracellular space with ATP and glutamate, driving neuronal hyperexcitability. Block the channel and seizure activity calms down.
The problem?
The only tools anyone ever used to test this were repurposed drugs. Probenecid, originally for gout. Mefloquine, for malaria. Nobody designed a molecule from scratch to go after the target.
PTI5803 would be first-in-class. The Phase 2a will evaluate safety, tolerability, and early efficacy in both adult and pediatric FCD patients.
It took a company from the south of France, not a major pharma neuro franchise, to finally close this channel. The science was there for 18 years. Somebody had to build the drug.
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