Novel neurosteroid therapeutics for post-partum depression: perspectives on clinical trials, program development, active research, and future directions.

This article reviews novel neurosteroid therapeutics for post-partum depression, with a focus on their development, clinical trial data, current practices, and future directions in this exciting field. We discuss the clinical impact of brexanolone and several other neurosteroids, particularly as they relate to the treatment of postpartum depression (PPD) and major depressive disorders outside of the perinatal period. There has been increasing interest in GABA signaling and modulation as it pertains to the development of altered circuity and depressive states. This scientific underpinning served as the rationale for the initial development of brexanolone. We review the clinical trials supporting its Food and Drug Administration (FDA) approval as the first rapidly acting antidepressant specific for PPD, and the subsequent development of a clinical brexanolone program at an academic medical center, highlighting new research and data from that site as well as the challenges with the delivery of this I.V. drug. In addition to the GABA signaling hypothesis, we discuss the new evidence demonstrating that brexanolone inhibits inflammatory signaling post-infusion, suggesting that inflammatory signaling may contribute to the etiology of PPD. Finally, we describe new and future directions in neurosteroid therapeutics, including the development of an oral agent, zuranolone, and the IV and oral formulations of ganaxolone. Ultimately, the hope is that these novel neurosteroid therapeutics will provide fast-acting treatment for these impairing disorders and improve our understanding of the underlying mechanisms of depressive disorders.

Brexanolone therapeutics in post-partum depression involves inhibition of systemic inflammatory pathways.

BACKGROUND: Brexanolone has rapid, long-lasting, and remarkable efficacy in the treatment of post-partum depression (PPD). We test the hypothesis that brexanolone inhibits proinflammatory modulators and macrophage activation in PPD patients, which may promote clinical recovery. METHODS: PPD patients (N = 18) provided blood samples before and after brexanolone infusion according to the FDA-approved protocol. Patients were unresponsive to prior treatment before brexanolone therapy. Serum was collected to determine neurosteroid levels and whole blood cell lysates were examined for inflammatory markers and in vitro responses to the inflammatory activators lipopolysaccharide (LPS) and imiquimod (IMQ). FINDINGS: Brexanolone infusion altered multiple neuroactive steroid levels (N = 15-18), reduced levels of inflammatory mediators (N = 11) and inhibited their response to inflammatory immune activators (N = 9-11). Specifically, brexanolone infusion reduced whole blood cell tumor necrosis factor-α (TNF-α, p = 0.003), and interleukin-6 (IL-6, p = 0.04) and these effects were correlated with HAM-D score improvement (TNF-α, p = 0.049; IL-6, p = 0.02). Furthermore, brexanolone infusion prevented LPS and IMQ-induced elevation of TNF-α (LPS: p = 0.02; IMQ: p = 0.01), IL-1ß (LPS: p = 0.006; IMQ: p = 0.02) and IL-6 (LPS: p = 0.009; IMQ: p = 0.01), indicating inhibition of toll-like receptor (TLR)4 and TLR7 responses. Finally, inhibition of TNF-α, IL-1ß and IL-6 responses to both LPS and IMQ were correlated with HAM-D score improvements (p < 0.05). INTERPRETATION: Brexanolone actions involve inhibition of inflammatory mediator production and inhibition of inflammatory responses to TLR4 and TLR7 activators. The data suggest that inflammation plays a role in post-partum depression and that inhibition of inflammatory pathways contributes to the therapeutic efficacy of brexanolone. FUNDING: The Foundation of Hope, Raleigh, NC and UNC School of Medicine, Chapel Hill.

A Brexanolone Treatment Program at an Academic Medical Center: Patient Selection, 90-Day Posttreatment Outcomes, and Lessons Learned.

BACKGROUND: Brexanolone is the first U.S. Food and Drug Administration-approved drug for the treatment of postpartum depression. Brexanolone is a positive allosteric modulator of the GABAA receptor and is given over 60 hours by infusion in a medical setting. This drug has been shown to be effective at significantly reducing Hamilton Rating Scale for Depression scores at 60 hours and 30 days after infusion; however, data beyond 30 days have not yet been available. There have been limited clinical programs able to offer brexanolone owing to the complexity of setting up this treatment in a medical setting. PURPOSE: This study sought to obtain follow-up data from 16 patients who received a brexanolone infusion at UNC Hospitals in Chapel Hill, NC, between October 2019 and December 2020 and were beyond the 30-day postinfusion time point. We describe the methods used to successfully implement this treatment program in an academic medical center and discuss associated challenges and lessons learned with patient selection and process improvements. METHODS: Hamilton Rating Scale for Depression scores were collected before and after infusion from 16 patients who received a brexanolone infusion at UNC. Patients were subsequently contacted for a follow-up interview to obtain Hamilton Rating Scale for Depression scores and complete a semistructured interview at least 30 days past treatment end (between 3 and 16 months after infusion). RESULTS: All 16 patients had a significant reduction in Hamilton Rating Scale for Depression scores at 60 hours, scores dropping on average from 23.9 (standard deviation = 2.6) to 7.6 (standard deviation = 2.9). Eleven of 16 patients consented to provide follow-up data. Follow-up Hamilton Rating Scale for Depression scores remained lower than postinfusion at an average of 6.7 points (standard deviation = 5.1). CONCLUSION: With a strategic cross-disciplinary approach, a Clinical Brexanolone Treatment Program was established at UNC Hospitals in 2019. Sixteen patients have been treated in the program, and 11 participated in a follow-up interview. All 11 patients gave very positive feedback about their treatment. Our program has found brexanolone to be a useful clinical tool in treating women with significant symptoms of postpartum depression.