Recruiting: Tetra Therapeutics Initiates Phase 2B/3 Clinical Studies in Fragile X Syndrome

Grand Rapids, MI – Tetra Therapeutics, a Shionogi Group Company, focused on the development of compounds for the treatment of brain disorders associated with cognitive and memory deficits, today announced the initiation of three Phase 2b/3 clinical studies of the investigational drug BPN14770 (zatolmilast) as a potential treatment for Fragile X syndrome (FXS), the most common genetic form of autism. A selective small molecule inhibitor of phosphodiesterase-4D (PDE4D), BPN14770 has shown positive results in a previous Phase 2 study in FXS in adult males (Berry-Kravis EM, et al. Inhibition of phosphodiesterase-4D in adults with Fragile X syndrome: a randomized, placebo-controlled, phase 2 clinical trial. Nat Med. 2021;27(5):862-870.). BPN14770 has also received Orphan Drug Designation from the US Food and Drug Agency (FDA) for the potential treatment of FXS.

The Phase 2b/3 studies comprise two separate 150 subject, randomized, double-blind, placebo-controlled studies: one in an adolescent male population (ages 12-17), one in an adult male population (18-45), and a third open label extension study open to patients in both populations at the conclusion of the primary study. Endpoints for the studies include cognitive and behavioral assessments of the efficacy of BPN14770 by a variety of standard tests and determinations of the experimental drug’s safety and tolerability. The study will also gather pharmacokinetic data on BPN14770. The studies are being conducted at multiple sites across the United States lead by principal investigator Elizabeth M. Berry-Kravis, MD, PhD at Rush University Medical Center, Chicago, Illinois. The studies are expected to be conducted over the next two years. Additional information is available through clinicaltrials.gov (Identifiers: NCT05163808, NCT05358886, NCT05367960).

“We are excited to initiate these pivotal trials with BPN 14770 in patients with Fragile X syndrome, and are hopeful that the results of these studies will enable us to seek approval from FDA,” said Chad Coberly, JD, Chief Executive Officer of Tetra Therapeutics.”

“We are anxious to get started with these studies that offer hope for people living with Fragile X syndrome and their caregivers” said Dr. Elizabeth Berry-Kravis, pediatric neurologist, Rush University Medical Center, and principal investigator. “Given our previous positive results with BPN14770 in the phase 2 study, we are hopeful these studies at a larger scale will show similar results. I find it exciting that we have a drug that potentially corrects a core deficit in FXS, a decrease in cAMP, that has been documented in patients as well as in the fly and mouse models of the disorder.”