FDA Puts Hold on Praxis Epilepsy Therapy

FDA has sent an email to Praxis Precision Medicines placing a clinical hold on PRAX-222, an antisense oligonucleotide for treating patients with SCN2A gain-of-function epilepsy. The company had been planning to begin a seamless study of PRAX-222 this quarter for treating SCN2A developmental and epileptic encephalopathy. Praxis says the clinical hold letter detailing the reasons for the hold is expected to be received within 30 days.

The therapy is described by the company as a synthetic, short segment of genetic sequence that can be designed to selectively modulate a target gene expression to help restore its normal function. PRAX-222 has been designed to selectively decrease SCN2A gene expression, and is believed to directly target the underlying cause of gain-of-function SCN2A epilepsy and other related symptoms, it says. The product is being developed in collaboration with Ionis Pharmaceuticals Inc. and RogCon Inc.