Harmony Biosciences' genetic disorder drug fails to meet main goal in late-stage trial

By Sriparna Roy

Sept 24 (Reuters) - Harmony Biosciences HRMY.O said on Wednesday its experimental drug for a rare genetic disorder failed to meet the main goal in a late-stage trial, sending its shares down more than 8%.

The company has been studying the drug named ZYN002 in patients with Fragile X syndrome, which is the leading cause of inherited intellectual disabilities and autism spectrum disorder.

In the trial, 215 patients who were aged 3 to under 30 years either received the drug or placebo for 18 weeks.

The drug failed to show improvement in social avoidance as measured on a scale, primarily due to a higher-than-expected placebo response rate, the company said.

Investor expectations had been low, and the outcome was not entirely unexpected, as elevated placebo response has been a key reason for prior study failures in this area, said Needham & Co analyst Ami Fadia.

ZYN002 is being developed as a pharmaceutically manufactured cannabidiol administered as a transdermal gel.

Harmony said it will review the full data set to better understand the findings.

Fragile X syndrome is a rare genetic condition that can cause learning and behavior problems, driven by a mutation in the FMR1 gene of the X chromosome that stops production of the FMRP protein.

The protein plays a vital role in developing connections between the nerve cells critical for relaying impulses, which results in a spectrum of intellectual disabilities and behavioral symptoms, such as social avoidance and irritability.

There are currently no approved treatments for the disorder in the U.S.

Harmony Biosciences also said it is on track to start late-stage trials of drug pitolisant, meant for narcolepsy and idiopathic hypersomnia, in the fourth quarter. The drug, branded as Wakix, is approved to treat excessive daytime sleepiness.