# Safety and efficacy of zuranolone in Japanese adults with major depressive disorder: An open‐label, repeated‐treatment part of a Phase 3 clinical trial

## TL;DR

This study evaluated the safety and effectiveness of repeated zuranolone treatment for depression in Japanese adults, finding no new safety issues and consistent improvement in depression scores.

## Contribution

The study provides new evidence on the safety and efficacy of repeated zuranolone treatment cycles in Japanese patients with major depressive disorder.

## Key findings

- Zuranolone consistently reduced depression scores across six treatment cycles without new safety signals.
- Common side effects included somnolence and dizziness, with no signs of drug dependence or withdrawal.
- Improvement in depression scores was observed within 8 to 15 days of treatment initiation in all cycles.

## Abstract

To evaluate the safety and tolerability of repeating 14‐day treatment with zuranolone (30 mg) followed by a 6‐week follow‐up period (one treatment cycle) for a maximum of six treatment cycles in Japanese participants with major depressive disorder.

This multicenter Phase 3 study was conducted in two parts (70 sites; Japan). Part B was an open‐label study for participants who completed the initial double‐blind study (Part A; zuranolone vs. placebo) in which all eligible participants received zuranolone regardless of their assignments in Part A. Endpoints included treatment‐emergent adverse events (TEAEs) and efficacy using the 17‐item Hamilton Depression Rating Scale (HAMD‐17).

A total of 271, 213, 170, 147, 126, and 99 participants were evaluated in Cycles 1–6, respectively. TEAEs occurring in ≥5% of participants were somnolence and dizziness during the treatment period and nasopharyngitis during the follow‐up period, and no new safety signals were observed with increased numbers of treatment cycles. Additionally, no TEAEs suggestive of drug dependence or withdrawal symptoms were identified. The HAMD‐17 total score decreased by 8 and 15 days after the initiation of zuranolone in all six cycles, and there were no meaningful differences in the HAMD‐17 total score reduction across treatment cycles.

In this open‐label part of the Phase 3 study in Japan, zuranolone decreased the HAMD‐17 total scores from baseline over 15 days during repeated treatment cycles in patients with major depressive disorder, without any new safety signals.