Harmony Biosciences Holdings Inc shares sank 38% to $18.66 in late-morning trading on Friday after the pharmaceutical company reported topline results from the INTUNE study of pitolisant, which missed the primary endpoint on the Epworth Sleepiness Scale (ESS).
Pitolisant is marketed as WAKIX in the US for the treatment of excessive daytime sleepiness (EDS) or cataplexy in adult patients with narcolepsy but is not approved for IH and is currently being evaluated as an investigational agent in adult patients with IH, the company said.
"Following a thorough review of the full data set, we will work closely with the FDA to discuss next steps and a path forward for pitolisant in IH," Harmony Biosciences chief medical officer Kumar Budur said in a statement.
The INTUNE study was a Phase 3 placebo-controlled, double-blind, randomized withdrawal study.
The company noted that a positive trend favoring pitolisant was observed during the four-week double-blind randomized withdrawal period, however no statistically significant difference was observed between pitolisant and placebo groups on the ESS, the primary endpoint.
Budur added, however, that positive trends in other important outcomes like sleep inertia add to the totality of evidence that pitolisant has a clinical benefit for patients with IH.
Shares of Harmony Biosciences have fallen 62% year to date.
Contact Sean at sean@proactiveinvestors.com