Shares of Irvine-based drug maker Cortex Pharmaceuticals Inc. plunged 61% on Thursday after a regulatory setback.
Cortex said in a release that the Food and Drug Administration’s psychiatric division rejected its request to run a second-phase clinical trial on its CX717 drug because of toxicity issues.
Cortex had been testing CX717 for treatment of attention deficit hyperactivity disorder.
The company also said it requested that regulators inactivate its Attention Deficit Hyperactivity Disorder application for the drug.
The company said it was planning to continue to develop the drug for other disorders, such as Alzheimer’s disease and respiratory depression.
While the FDA’s decision “represents a significant setback for the company,” Cortex has a pipeline that is producing other future clinical drug candidates, the company said.
Cortex has had several issues with CX717 in recent months. Last year, clinical trials for the drug were suspended.
The company counts a recent market value of about $26 million.
