Join the EXPERIENCE Clinical Trials
(Also Known As BPN14770-CNS-204 or NCT05163808, BPN14770-CNS-301 or NCT05358886, BPN14770-CNS-302 or NCT05367960, and the Tetra Studies)

Shionogi is conducting multicenter, late-stage (Phase 2b/3) clinical studies to further evaluate the safety and efficacy of an investigational study drug called zatolmilast (a PDE4D inhibitor) on cognition and other aspects of Fragile X syndrome (FXS). The zatolmilast clinical program, which has also been referred to as BPN14770-CNS-204, BPN14770-CNS-301, BPN14770-CNS-302 and the Tetra studies, will now be known as EXPERIENCE (Evaluation of Fragile X Experience in Cognition Expression). Tetra Therapeutics, the company that discovered zatolmilast, was acquired by Shionogi in 2019.

Zatolmilast is an investigational drug. Safety and efficacy have not been established. There is no guarantee that zatolmilast will be approved by any health authority.

What is Fragile X Syndrome?

FXS is the leading cause of inherited intellectual disabilities like autism spectrum disorder. FXS is known to have a greater effect on males than females because the mutation of the FMR1 gene is carried on the X chromosome. The most important clinical abnormality associated with FXS is global developmental delay and intellectual disability. The IQ of males with full mutation varies, with a mean value of 40–51. Other common symptoms of FXS include aggressiveness, attention problems and anxiety. FXS can cause challenges across many aspects of daily life, such as impacting individuals’ ability to care for themselves and communicate with others.

Who is Eligible?

Males with a genetic diagnosis of FXS between the ages of 9–45 may be eligible to participate in either the adolescent (ages 9–17) or adult (ages 18–45) study, as well as an up to two-year, open-label (all participants are aware they are receiving active drug) extension study in which all participants will receive zatolmilast.
Travel to and from sites for a study participant and his caregiver may be covered by Shionogi and may include transportation and lodging arrangements, as well as reimbursement for expenses, such as meals (limitations may apply).

Select Study Eligibility Requirements

This is a subset of the full eligibility criteria. A comprehensive list of eligibility criteria will be discussed during a participant’s screening visit.

Male with FXS and confirmed FMR1 gene mutation (≥ 200 CGG repetitions).

Participants must have a consistent caregiver who will attend all visits.

Currently receiving treatment with no more than three psychotropic medications (e.g., antidepressants, anti-anxiety medications, stimulants, antipsychotics, and mood stabilizers).*

Participants may continue with psychotropic medications*, behavioral/non-pharmacological treatments* and anti-epileptic medications throughout the 13-week study.

EXPERIENCE-204: Adolescent Study in Fragile X Syndrome
(Also Known As BPN14770-CNS-204 or NCT05163808)

Males aged 9 to 17 with a genetic diagnosis of FXS.

Weigh at least 55 pounds and have a body mass index (BMI) less than or equal to 97 percent of their age group.

EXPERIENCE-301: Adult Study in Fragile X Syndrome
(Also Known As BPN14770-CNS-301 or NCT05358886)

Males aged 18 to 45 with a genetic diagnosis of FXS.

Have a body mass index (BMI) between 18–36 kg/m2.

EXPERIENCE-302: Open-Label Extension Study in Fragile X Syndrome
(Also Known As BPN14770-CNS-302 or NCT05367960)

Up to two-year open-label extension for participants who complete the full 13 weeks of EXPERIENCE-204 or EXPERIENCE-301.

* Participants must be at a stable dose and dosing regimen for at least four weeks prior to screening. Dosing must remain stable throughout the 13-week study.

Participants with a history of seizure, who are currently receiving treatment, must be seizure-free for three months prior to screening, or for two years if not on treatment.

EXPERIENCE-204 and EXPERIENCE-301 are double-blind, which means that neither the participants nor the researchers know which treatment the participants are receiving. In both studies, participants will be randomly selected to receive either zatolmilast (the investigational study drug) or placebo (a pill that does not include active drug) for 13 weeks. Approximately two of three participants will receive zatolmilast and one of three participants will receive placebo.

  • Shionogi & Co., Ltd. and its subsidiary companies, including Shionogi Inc. in the U.S. (Shionogi), are committed to developing safe and effective medicines and treatments for patients worldwide through clinical trials of unlicensed medicinal products (investigational drugs). 

    Early Access Policy
  • Additional study details can be found on ClinicalTrials.gov.

    ClinicalTrials.gov