A new oral antidepressant that targets the gamma-aminobutyric acid type A (GABAA) receptors in the brain has been found to achieve a reduction in symptoms in adult patients with moderate to severe major depressive disorder, with no serious safety signals, results of a double-blind, phase 2 trial show.
The study involved 89 participants with major depression, excluding those with a history of treatment-resistant depression, who were randomized either to a once-daily dose of 30 mg of, a synthetic neurosteroid that acts as a positive allosteric modulator of GABAA receptors, or placebo for 14 days. Thirty-six of the 45 patients in the SAGE-217 group were black, as were 28 of the 44 patients in the placebo group, reported , of Sage Therapeutics and coauthors. Their study was published in the New England Journal of Medicine.
“One hypothesis for the mechanism of depression implicates deficits in gamma-aminobutyric acid and downstream alterations in monoaminergic neurotransmission,” wrote Dr. Gunduz-Bruce and coauthors. “Preclinical studies have shown that the naturally occurring neurosteroid allopregnanolone is a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors that affects both phasic and tonic inhibition of neurons.”
At day 15 of the study, there was a significantly greater mean change from baseline inscores in the treatment group, compared with the placebo group (–17.4 vs. –10.3, P less than .001), and 79% of participants in the treatment arm showed a greater than 50% reduction in depression scores, compared with 41% of the placebo group.
At day 28, 62% of the treatment group and 46% of the placebo group had a reduction of more than 50% from baseline depression scores.
No serious or severe adverse events were seen in either group, and the most common adverse events in the SAGE-217 group included headache (18%), dizziness (11%), and nausea (11%). One patient in the treatment arm also reported euphoria.
The authors commented that somnolence and sedation were expected adverse events, based on the pharmacological properties of SAGE-217.
Six patients in the treatment arm also had dose reductions as a result of adverse events. Two patients in the SAGE-217 arm stopped treatment because they met prespecified criteria for discontinuation; the investigators reported nausea, dizziness, and headache in one patient, and increased levels of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase in the other. However, the second patient had shown mildly elevated values of these at baseline, was asymptomatic throughout the trial, and the patient’s values returned to baseline or near-baseline after stopping treatment.
About one-quarter of both the SAGE-217 and placebo groups were receiving antidepressant treatment at baseline (27% and 23% respectively), with the duration of prior treatment ranging from 2 to 48 months. Investigators also gave three patients in the treatment arm and 11 in the placebo arm concomitant antidepressants during the follow-up period.
The small sample size and limited racial diversity among the participants were cited as limitations.
The study was supported by SAGE-217 manufacturer Sage Therapeutics. Ten authors were employees or directors of Sage Therapeutics, with stock options and patent interests. Three authors declared grants, personal fees, or advisory board positions with the pharmaceutical sector, including from Sage, and one also declared interest in a range of patents outside the study. One author had no disclosures.
SOURCE: Gunduz-Bruce H et al. N Engl J Med. 2019 Sep 5;381:903-11. .