A few weeks ago, Biogen and Sage Therapeutics announced that they have completed a rolling submission to the FDA of a New Drug Application (NDA) for zuranolone for the treatment of major depressive disorder (MDD) and postpartum depression (PPD). The investigational drug is being evaluated as a rapid-acting, once-daily, 14-day oral short course therapy for adult patients with MDD and PPD.

Zuranolone is similar to brexanolone, which was approved in 2019 by the FDA for the treatment of PPD, and is a neuroactive steroid with a novel mechanism of action as a positive allosteric modulator of GABA-A receptors.  

Data from the Phase 3 SKYLARk study demonstrated that a 15-day course of zuranolone was superior to placebo in women with severe PPD. By day 3, women receiving zuranolone experienced a greater reduction in HAM-D scores than women receiving placebo (mean reduction, 9.5 vs