(Adds updated pricing detail)
By Saumya Joseph
March 19 (Reuters) - The U.S. Food and Drug Administration on Tuesday approved here Sage Therapeutics Inc's drug for postpartum depression, marking the first approval of a treatment specifically developed for the condition that affects a new mother's ability to care for herself or her baby.
The company said the list price for the treatment, to be sold under the brand name Zulresso, would be $7,450 per vial resulting in a projected average cost of $34,000 per patient before discounts. Sage shares rose more than 4 percent to $163 in extended trading.
The drug, which is administered as a single 60-hour intravenous infusion, is chemically identical to the hormone allopregnanolone.
"You're talking about someone coming into the hospital or treatment center on a Friday and go home Sunday night," Sage's Chief Executive Officer Jeff Jonas told Reuters ahead of the approval.
Postpartum depression affects one in nine women and is a common complication of childbirth, with onset typical during pregnancy or within four weeks of delivery.
In severe cases, the mother may have suicidal tendencies, may not want to nurse her child and might even harm the baby.
Existing treatments include conventional antidepressants that require weeks to take full effect, psychotherapy and even shock therapy, none of which have been specifically approved for postpartum depression.
Zulresso's label will include a so-called black box warning flagging risks of excessive sedation and sudden loss of consciousness, and will only be made available through a restricted distribution program at certified facilities where the patient can be monitored for these side effects, the FDA said.
Patients will be advised to avoid activities such as driving until feelings of sleepiness have gone away.
Zulresso is designed to reduce depression symptoms by targeting receptors of the neurotransmitter known as GABA, helping restore the normal balance in the brain that is disrupted around the time of childbirth.
During clinical trials, the drug was shown to reduce depression symptoms within hours, with patients maintaining the benefit for up to a month and a half, Jonas said, adding the "one and done" treatment will require no maintenance doses.
Guggenheim analyst Yatin Suneja expects Zulresso peak sales of about $300 million to $400 million.
But the inconvenience of a lengthy hospital stay for the required 60-hour infusion may limit sales.
"I do not see Zulresso having significant uptake given the requirements for IV infusion and duration of the infusion," Dr. Sanjay Mathew, a member of the Anxiety and Depression Association of America, told Reuters.
Sage has another drug for postpartum depression under development, SAGE-217, that will be in far more convenient pill form. In clinical trials, it has appeared to be effective in rapidly reducing symptoms without the loss of consciousness side effect.
Although inconvenient, Zulresso is likely worthwhile for mothers suffering from the disorder who face dangerous obstacles in caring for their newborn, said Dr. Marla Wald, professor of psychiatry and behavioral sciences at Duke University. (Reporting by Saumya Sibi Joseph in Bengaluru and Gabriella Borter in New York; Editing by Bill Berkrot and Sriraj Kalluvila)