Harmony Bio Faces Significant Setback: Fragile X Syndrome Therapy Misses Primary Endpoint in Pivotal Trial

Harmony Biosciences, a biopharmaceutical company known for its narcolepsy treatment Wakix (pitolisant), has announced a significant clinical trial setback. Its investigational drug, pitolisant, failed to meet its primary efficacy endpoint in a Phase 2 study for Fragile X Syndrome (FXS), a leading inherited cause of intellectual disability and autism.

The study, known as INTUNE, was designed to evaluate the safety and efficacy of pitolisant in patients living with Fragile X Syndrome.

The primary endpoint for the trial was a change from baseline in the Aberrant Behavior Checklist - Community (ABC-C) Irritability subscale score at week 12. Despite demonstrating a numerical improvement, the results did not achieve statistical significance compared to placebo.

While the primary endpoint proved elusive, Harmony Biosciences highlighted several encouraging signals from the trial's secondary endpoints.

These included positive trends in the Clinical Global Impression - Severity (CGI-S) scale, suggesting a perceived improvement in overall condition by clinicians. Furthermore, specific subscales within the ABC-C, such as lethargy/social withdrawal and hyperactivity/noncompliance, also showed favorable numerical differences, indicating potential benefits in these areas for patients.

The company emphasized that pitolisant was generally well-tolerated throughout the study, with its safety profile consistent with previous clinical experience.

This is a crucial aspect for any therapeutic development, especially for conditions requiring long-term treatment.

Following this outcome, Harmony Biosciences plans to conduct a comprehensive analysis of the full data set. The company also intends to engage with the U.S. Food and Drug Administration (FDA) to discuss the trial results and determine the appropriate next steps for the pitolisant program in Fragile X Syndrome.

This strategic discussion will be vital in charting a path forward, considering the unmet medical need in the FXS community.

This development marks a significant challenge for Harmony Bio's pipeline expansion strategy, as the company sought to leverage pitolisant's mechanism of action beyond its approved indication for narcolepsy.

Investors and the patient community will be closely watching for further updates as Harmony navigates this unexpected turn in its clinical development journey.