What happened

Shares of Sage Therapeutics (SAGE 3.70%), a biopharmaceutical company that specializes in brain disorder therapies, saw its shares rise 15.6% this week, according to data from S&P Global Market Intelligence. The stock closed last Friday at $32.24 but rose to $37.27 this Friday. Overall, the stock is down more than 13% this year. Its 52-week low is $27.36, and it has a 52-week high of $79.45.

A parent holds a baby.

Image source: Getty Images.

So what

The company announced on Wednesday that zuranolone, a drug it is developing with Biogen, had met its primary endpoints in a phase 3 study to treat women with postpartum depression. According to the release, the women who were treated with 50 milligrams of the therapy showed significant and meaningful improvement in depression symptoms. The drug was also found to be well tolerated and showed the same safety profile that it had in clinical development, with only mild symptoms in some women who took the daily dose of zuranolone for two weeks.

That study increases the chances for approval for zuranolone, which has a large target market. According to the Centers for Disease Control and Prevention, one in eight women have symptoms of postpartum depression shortly after giving birth. The study also represents a bounce-back after the drug's less-than-satisfactory phase 3 trial to treat major depressive disorder.

Sage's only marketed therapy is Zulresso (brexanolone), another drug used to treat postpartum depression.

Zuranolone has other potential applications as well. It is in phase 2 studies to treat treatment-resistant depression, generalized anxiety disorder, and bipolar depression. The company has other therapies in phase 2 studies, including its SAGE-718 program to treat mild cognitive impairment in Parkinson's patients, and mild cognitive impairment and mild dementia due to Alzheimer's disease. Another phase 3 trial is for SAGE-324 to treat essential tremor.

Now what

Investors have sound reasons to be optimistic. The biotech company, in its first quarter report on May 3, said it has $1.6 billion in cash, down only slightly from $1.7 billion at this time last year. Its revenue, solely from Zulresso, was $1.6 million in Q1, the same as it was in Q1 2021. Sage lost $122.1 million, up from $95.8 million, year over year, but it still has a long runway to develop zuranolone and begin to make profits. The key will be how much money the company has to spend on marketing for zuranolone's launch.