Article From: "Don Seiffert"   Read full article

Cambridge biotech Sage Therapeutics says it plans to apply for U.S. approval of its experimental drug to treat postpartum depression next year after the drug achieved the main goals in two late-stage trials involving more than 200 women.

The company’s stock soared 44 percent in premarket trading as of 6:50 a.m. Thursday morning, to more than $90 a share. If the stock spike holds when market opens today, it could add about $1 billion to the company’s market capitalization.

Sage (Nasdaq: SAGE), which…