Treatment benefit clear in less than 3 days, lasts at least a month.
The group with moderate PPD (study 202C) included 104 women. HAM-D total score from baseline of 14.2 points at 60 hours in the brexanolone 90 mg/kg/hour group compared with a 12.0-point reduction in the group who received the placebo (P=0.0160).
Statistical significance was first observed at hour 48 and sustained through day 7, and the mean reduction from baseline in HAM-D score seen at hour 60 in the brexanolone group was maintained at day 30. Clinical Global Impression-Improvement (CGI-I) scales also improved in brexanolone patients (P=0.0005 versus placebo).
The severe PPD group (study 202B) included 122 patients. At hour 60, the 90-μg/kg/hour group showed a mean reduction in HAM-D total score of 17.7 points from baseline compared with 14.0 points with placebo (P=0.0252). Treatment with 60 μg/kg/hour brexanolone produced a significant mean reduction in HAM-D total score of 19.9 points versus placebo (P=0.0013). In the brexanolone groups, reductions in HAM-D total score were first observed at 48 hours, and the effect at 60 hours was maintained at the 30-day follow-up. Additionally, there were significant improvements in the CGI-I at hour 60 at both doses relative to placebo.
Study authors offered no explanation for the numerically greater response with the lower brexanolone dose. Although HAM-D reductions with the higher dose were significantly greater than with placebo at the 60-hour and 30-day points, it showed no advantage at any other evaluation. The lower dose, on the other hand, was consistently superior to placebo. The high dose also did not produce greater rates of HAM-D remission (score of 7 or less) versus placebo, whereas the 60-μg/kg/hour dose did.
Brexanolone was well-tolerated, with common adverse events including headache, dizziness, and somnolence. One patient in each group had a serious adverse event. Neither required hospitalization.