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Shares of biotechnology firm Sage Therapeutics Inc. (SAGE - Get Report) 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.