(Reuters) - Alkermes Plc’s experimental depression drug significantly reduced symptoms in patients suffering from major depressive disorder who were not helped by standard treatments in a pivotal late-stage trial, the company said on Thursday, and its shares surged 47 percent.
The results marked a reversal of fortune for the drug, which had failed to achieve efficacy goals in two earlier Phase III trials announced in January, casting serious doubt on the program.
In the 407-patient trial, the drug, ALKS 5461, significantly reduced symptoms of depression compared with a placebo, according to initial results released by the company.
Based on the results of this third Phase III trial, Alkermes said it plans to speak with U.S. health regulators about the next steps toward seeking approval.
At the time of the failure of the drug in the two earlier Phase III trials, the company said it believed that success in the third Phase III study, called Forward-5, could still lead to a path to approval.
ALKS 5461, a once-daily pill combining samidorphan and buprenorphine, is designed to rebalance brain function that becomes dysregulated in the state of depression.
“We designed ALKS 5461 to have a novel mechanism of action for the treatment of major depressive disorder, a serious disease where new therapeutic options are highly sought after as millions of patients in the U.S. do not respond to standard courses of antidepressant therapy,” Alkermes’ chief medical officer, Elliot Ehrich, said in a statement.
While the drug demonstrated clear superiority over placebo on two different depression scales at the higher of two tested doses, the lower dose did not achieve significance compared with placebo, the company said.
The most commonly reported side effects for ALKS 5461 in the study were nausea, dizziness and fatigue, consistent with what had been seen in earlier trials, the company said.
Alkermes shares jumped to $64 in after-hours trading from a Nasdaq close at $43.51.
Reporting by Bill Berkrot in New York and Shailesh Kuber in Bangaluru; Editing by Leslie Adler