(Adds trial details, share move)
Sept 12 (Reuters) - Sage Therapeutics Inc said on Tuesday its drug to treat a life-threatening seizure disorder failed to meet the main goal of a late-stage trial, sending its shares down about 24 percent.
The trial was testing Sage's drug, brexanolone, plus standard of care in patients with super-refractory status epilepticus (SRSE) whose seizures persisted despite earlier treatments. The drug was compared to a placebo plus standard treatment.
SRSE is the most severe form of status epilepticus, under which seizures last for a long time and often recur.
A patient with status epilepticus is initially treated with a class of psychoactive drugs called benzodiazepines. If one does not respond to them, the patient is given anti-seizure drugs.
If the seizure still persists, the patient is placed into a medically induced coma and is given anesthesia along with another line of anti-seizure drugs, under which efforts are made to wean the impact of those three treatments to determine if the seizure has been resolved or not.
In the brexanolone arm, 43.9 percent of patients weaned off third-line agents, versus 42.4 percent in the placebo arm, the company said.
SRSE accounts for about 25,000 to 41,000 cases each year in the United States and there are currently no treatments approved by the U.S. Food and Drug Administration for the disorder, Sage said.
The company's shares, which closed at $88.52 on Monday, were down at $67.00 in premarket trading on Tuesday. (Reporting by Divya Grover in Bengaluru; Editing by Maju Samuel)