Salt Lake City-based Lipocine Inc. (Nasdaq: LPCN) has initiated BLOOM, a second Phase III study of LPCN 1154 (oral brexanolone, proposed brand name Brlizio) for severe postpartum depression (PPD), after its first Phase III trial missed its primary endpoint earlier this year. The decision to run a second pivotal study rather than abandon the program rests on post hoc efficacy signals and site-level data anomalies that the company argues may have obscured a treatment effect in the failed study.
The prior Phase III trial, which enrolled 90 patients, did not show a statistically significant reduction from baseline in the 17-item Hamilton Depression Rating Scale (HAM-D17) total score at hour 60 compared to placebo in the full analysis set. Post hoc analyses identified anomalies at one high-enrolling site, including an absence of detectable study drug in blood samples from approximately 40% of LPCN 1154-treated participants there. Excluding that site, Lipocine said the drug produced rapid and sustained improvement in depressive symptoms. The company has applied for Breakthrough Therapy and Fast Track designations based on these exploratory findings, though FDA feedback on those applications has not been disclosed.
The placebo-controlled outpatient study will enroll approximately 120 participants with severe PPD, using the same 48-hour dosing regimen and HAM-D17 primary endpoint as the prior trial. Protocol changes include third-party site selection support, centralized rating for screening and eligibility, geographic diversification, participation by academic sites, and prespecified sensitivity analyses covering outlier sites and pharmacokinetic data. Measures to reduce placebo response — a persistent challenge in PPD trials — include fewer rating scales, reduced participant contact with site staff, and standardized education about study procedures. First participant dosing is expected in early Q4 2026.
LPCN 1154 is an oral formulation of brexanolone, a positive allosteric modulator of GABA-A receptors that is chemically identical to the endogenous neuroactive steroid allopregnanolone. The 48-hour at-home oral regimen is intended to distinguish it from Sage Therapeutics and Biogen's Zurzuvae (zuranolone), the only currently approved oral PPD therapy, which is taken once daily for 14 days and carries a boxed warning for driving impairment. Intravenous brexanolone (Zulresso) was withdrawn from the US market at the sponsor's request in April 2025. Reunion Neuroscience's luvesilocin, a subcutaneous prodrug with FDA Breakthrough Therapy Designation for PPD, is advancing toward a pivotal Phase III trial.