Randomized Phase 2 Trial: Extended-Release Ketamine Tablets Reduce Depression Scores in Treatment-Resistant Depression Without Significant Adverse Effects – Nat Med

Study Design and Population: This phase 2 multicenter, randomized, placebo-controlled trial evaluated the efficacy and safety of extended-release ketamine tablets (R-107) in adults with treatment-resistant depression (TRD). A total of 231 patients underwent an initial open-label phase where they received 120 mg of R-107 daily for 5 days. Responders, defined by a ≥50% reduction in Montgomery–Åsberg Depression Rating Scale (MADRS) scores, were randomized to receive one of four doses of R-107 (30, 60, 120, or 180 mg) or placebo twice weekly for 12 weeks.

Main Findings: The primary endpoint, change in MADRS score at week 13, showed a significant reduction of 6.1 points in the 180 mg R-107 group compared to placebo (P = 0.019). This dose also had the lowest relapse rate (42.9%) compared to 70.6% for placebo. Secondary outcomes, including response and remission rates, were generally higher for active treatment arms but reached statistical significance only in the 120 mg dose group for treatment response. The treatment was well-tolerated, with no significant increases in blood pressure or sedation.

Implications for Practice: Extended-release ketamine tablets could be a promising treatment for TRD, offering significant symptom improvement with minimal adverse effects, particularly at higher doses. The favorable safety profile and potential for at-home administration make this formulation a convenient option for wider use, though further research is needed to confirm these findings in broader populations.

Reference: Glue, P. et al. (2024). Extended-release ketamine tablets for treatment-resistant depression: A randomized placebo-controlled phase 2 trial. Nature Medicine, 30(7), 2004–2009. DOI: 10.1038/s41591-024-03063-x.