Using Matching-Adjusted Indirect Comparisons and Network Meta-analyses to Compare Efficacy of Brexanolone Injection with Selective Serotonin Reuptake Inhibitors for Treating Postpartum Depression.

BACKGROUND

Brexanolone injection, the first therapy approved by the US FDA for the treatment of postpartum depression (PPD) in adults, has been shown to produce a significantly greater decrease in the Hamilton Rating Scale for Depression (HAM-D) total score than placebo in randomised controlled trials (RCTs) of women with PPD.

OBJECTIVES

Given the rapid effect of brexanolone injection (within 60 h) sustained throughout the length of the trials (30 days), we sought to compare its efficacy data against selective serotonin reuptake inhibitors (SSRIs), the class of antidepressants most commonly prescribed for PPD, using HAM-D and Edinburgh Postnatal Depression Scale (EPDS) outcomes from currently available RCTs.

METHODS

We extracted data from 26 studies identified in a systematic literature review of pharmacological and pharmacological/nonpharmacological combination therapies in PPD. Six studies were suitable to form evidence networks through which to perform indirect treatment comparisons (ITCs) of HAM-D and EPDS outcomes between brexanolone and SSRIs. Having assessed the comparability and suitability of the available evidence for analysis, we discovered significant heterogeneity in the study designs, most notably in the placebo arms of the trials. We therefore conducted matching-adjusted indirect comparisons (MAICs) between brexanolone and the placebo arms of comparator studies, subsequently using the MAIC results of brexanolone versus placebo, and results for SSRIs versus placebo, to form ITCs of brexanolone versus SSRIs at three separate time points-day 3, week 4 and last observation. ITCs were calculated as the differences in change from baseline (CFB) in HAM-D and, separately, CFB in EPDS, between treatments, and reported with 95% confidence intervals (CIs).

RESULTS

For all time points, MAICs showed larger differences in CFB for brexanolone compared with SSRIs. Differences (95% CIs) between brexanolone and SSRIs were 12.79 (8.04-17.53) [day 3], 5.87 (- 1.62 to 13.37) [week 4] and 0.97 (- 6.35 to 8.30) [last observation] for the HAM-D. For the EPDS, the differences in CFB were 7.98 (5.32-10.64) [day 3], 6.35 (3.13-9.57) [week 4] and 4.05 (0.79-7.31) [last observation]. Other analytical approaches are also presented to demonstrate the similarity of results, using a network meta-analysis approach, and the importance of using the MAIC method to control for the important heterogeneity between placebo arms.

CONCLUSIONS

Acknowledging the limitations of ITCs and this evidence base, when compared with SSRIs, these analyses suggest that brexanolone demonstrated larger differences in CFB for both patient- and clinician-reported PPD outcomes and at all investigated time points after adjusting for differences between placebos in the included studies.