Edinburgh Postnatal Depression Scale (EPDS) Total Score Remission and Number Needed to Treat (NNT) Outcomes in a Phase 3, Placebo-Controlled Trial of Zuranolone in Postpartum Depression (PPD)

Background: Zuranolone (SAGE-217) is an investigational, neuroactive steroid and GABAA receptor positive allosteric modulator evaluated in a Phase 3 trial in patients with PPD (NCT02978326). Zuranolone achieved the primary endpoint of a statistically significant reduction in depressive symptoms versus placebo at Day 15, assessed by the 17-item, clinician-reported Hamilton Rating Scale for Depression (HAMD-17). Post-hoc analyses examined patient-reported EPDS-remission and NNT outcomes at Day 45. These analyses primarily focused on the Day 45 timepoint, as patient-rated scales may require more time to observe changes in depressive symptoms relative to clinician-rated scales.

Methods: Women (n=151) ages 18-45, ≤6 months postpartum, with PPD and HAMD-17≥26, were randomized 1:1 to zuranolone:placebo for 14 days, with 4-weeks follow-up. Due to the lack of a unified EPDS-remission definition, three cutoff points were explored (EPDS total score < 7, < 10, or < 13). NNT was calculated using the proportion of EPDS remitters in each treatment arm.

Results: A significantly higher proportion of zuranolone-treated patients achieved EPDS-remission at Day 45 versus placebo for all three remission definitions ( < 7: 51% vs 22%, p=0.0005, NNT=4; < 10: 63% vs 38%, p=0.0026, NNT=4; < 13: 77% vs 55%, p=0.0140, NNT=5). At Day 15, no significant differences versus placebo were observed for the EPDS < 7 and < 10 remission definitions, but significance was observed for the least strict EPDS-remission definition < 13 (64% vs 45%, p=0.0405, NNT=6).

Conclusions: In this post-hoc analysis, zuranolone demonstrated significant reductions in patient-reported depressive symptoms in women with PPD at the end of trial follow-up. Single-digit NNTs support the robustness of the effect.