Harmony Biosciences Holdings (HRMY) said Wednesday that the US Food and Drug Administration issued a Refusal to File letter related to its supplemental new drug application for pitolisant in adults with idiopathic hypersomnia, a rare disorder characterized by excessive daytime sleepiness.

The company said it continues to expect 2025 revenue of $820 million to $860 million.

Analysts polled by FactSet expect $848.5 million.

Harmony said it plans to start a phase 3 trial in Q4 for pitolisant HD, a higher-dose version, targeting a 2028 regulatory decision.

The study design follows FDA input and builds on findings from the phase 3 INTUNE trial, the company said, adding that while the trial did not achieve "statistical significance" in its primary endpoint, patients in an open-label phase showed improvements in sleepiness scores.

Shares of the company were down more than 7% in recent Wednesday premarket activity.