Tonix Pharmaceuticals Holding Corp. stocks tumbled after the company said it was terminating a late-stage study of its drug Tonmya for the treatment of military-related post-traumatic stress disorder.
The New York-based company's stock plunged 66.84% to $1.31 per share as of 11:19 a.m. ET on July 27.
The company was studying the medicine in a phase 3 study dubbed Honor, which enrolled 550 patients. An independent review of a portion of the trial results showed the drug was not better than placebo in improving PTSD symptoms after 12 weeks of treatment — the primary goal of the study.
Tonmya, also called TNX-102, is an under-the-tongue formulation of cyclobenzaprine, commonly used as a muscle relaxer.
The company is not completely scrapping the program, however, hoping to use data from the four-week cutoff to design a new study.
After four weeks of treatment, patients saw an improvement in their symptoms, including in measures related to sleep.
"We plan to meet with the [U.S. Food and Drug Administration] as soon as possible to discuss the Honor results and our proposal to conduct the primary analysis at the week-4 time point in the next pivotal study," Tonix Pharmaceuticals President and CEO Seth Lederman said in a statement.
"These results underscore the challenges in designing and conducting well-controlled clinical studies in PTSD, especially military-related PTSD," Lederman added.
About 11 million adults in the U.S. have PTSD.