The FDA has placed a clinical hold on Praxis Precision Medicine’s new epilepsy drug.

While the reasons have not been shared yet, according to a regulatory filing, the company’s Investigational New Drug Application for the study of PRAX-222, a therapeutic for the treatment of patients with SCN2A gain-of-function mutations, was placed on clinical hold via an emailed letter from the FDA on April 28th.

The agency’s ‘not yet’ will be explained in a letter to Praxis within 30 days.

PRAX-222 is meant to treat patients with early-onset seizures. The drug is an antisense oligonucleotide, a form of therapy meant to target messenger RNA and alter expression. In 2020, more than 50 antisense therapy drug candidates were in clinical trials.