The drug is administered under medical supervision as a continuous infusion over a total of 60 hours (2.5 days), according to the FDA.
Postpartumdepressioncan be life-threatening, can interfere with the maternal-infant bond, and some women "may experience thoughts about harming themselves or harming their child," said Tiffany Farchione, MD, acting director of the Division of Psychiatry Products in the FDA's Center for Drug Evaluation and Research,in a statement.
"This approval marks the first time a drug has been specifically approved to treat postpartum depression, providing an important new treatment option," Farchione said
Brexanolone's mechanism of action is different from that of currently available antidepressants. It is chemically identical to endogenous allopregnanolone, a hormone that decreases after childbirth. Brexanolone acts as a positive allosteric modulator of gamma-aminobutyric acid-A (GABAA) receptors, which become dysregulated in the postpartum period.
The FDA gave brexanolone priority review and it was also designated as a breakthrough therapy. But the approval date was extended by 3 months to give the agency and Sage Therapeutics time to work out the details of the Risk Evaluation and MitigationStrategy (REMS) that had beenrecommended by FDA advisersin November.
At the time, a joint panel of the FDA's Psychopharmacologic Drugs Advisory Committee and Drug Safety and Risk Management Advisory Committee voted 17-1 that brexanolone's benefits outweighed its risks, but recommended that the drug have a REMS that included elements to assure safe use.
"Because of concerns about serious risks, including excessive sedation or sudden loss of consciousness during administration, Zulresso has been approved with a Risk Evaluation and Mitigation Strategy and is only available to patients through a restricted distribution program at certified health care facilities where the health care provider can carefully monitor the patient," Farchione said.
Patients must have continuous pulse oximetry monitoring during the whole 60-hour infusion and must be accompanied during interactions by their child(ren) while receiving the infusion, the FDA said.
REMS also requires that patients be enrolled in the program before receiving Zulresso.
Brexanolone will carry a boxed warning, and patients will be counseled on the risks and told that they must be monitored at a healthcare facility for the entire infusion. The agency said that patients should not drive, operate machinery, or do other dangerous activities "until feelings of sleepiness from the treatment have completely gone away."
Intwo placebo-controlled studies, brexanolone demonstrated superiority to placebo in improvement of depressive symptoms at the end of the first infusion. One study included patients with severe postpartum depression (PPD) and the other enrolled patients with moderate PPD.
The agency recommended that clinicians discontinue brexanolone in patients whose PPD becomes worse or who experience emergent suicidal thoughts and behaviors.
The Centers for Disease Control and Preventionestimatesthat 1 in 9 women and possibly as many as 1 in 5 experience PPD. Generally, the condition has been treated with counseling and/or antidepressants, according to theNational Institute of Mental Health.