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Shares of biotechnology firm Sage Therapeutics Inc. (SAGE) more than doubled in value on Monday after the company announced promising study results related to its postpartum depression treatment.

Sage soared 55%, or $52.99, to as high as $150.50 in early trading on the Nasdaq Stock Exchange, up from Friday's close of $97.51. As of 10:30 am ET, the company's shares were up 46%, or $45.28, at $142.80.

SAGE announced Monday that a Phase 3 study of its postpartum depression treatment SAGE-217 met its primary and secondary endpoints in patients with postpartum depression.

Specifically, the company said a 30-milligram dose of the treatment over a two-week period improved symptoms of depression on the so-called Hamilton Rating Scale of Depression by 17.8 points vs. 13.6 points for a placebo.

Additionally, 45% of patients achieved remission at two weeks as measured by the same scale, according to the company. Some 23% of those who received the placebo were in remission at two weeks.

"These are strong and consistent data demonstrating a rapid, stable and clinically meaningful improvement in postpartum depression symptoms in the SAGE-217 treatment group compared to the placebo," CEO Jeff Jonas said in the statement.

SAGE-217 isn't the only depressive order drug Sage is working on. The company's lead postpartum depression treatment, Zulresso, has completed Phase 3 clinical development for postpartum depression and is currently under review with the U.S. Food and Drug Administration.