The Board of Brii Biosciences Limited announced the topline results from a Phase 1 study evaluating the Company's long-acting, single-injection therapy, BRII-296, in the development for the treatment of postpartum depression ("PPD"). These data show that a single treatment via intramuscular ("IM") injection of 600 mg of BRII-296 achieved dose linearity, early drug absorption, gradual and extended-release profiles without the need for dose titration or tapering, providing confidence that this dose has potential to achieve clinical efficacy in the treatment of PPD. The selected dose regimen will be evaluated in a Phase 2 clinical trial that is expected to begin this year.

BRII-296 acts as a novel gamma-aminobutyric acid A receptor positive allosteric modulator with a unique long-acting formulation that does not require cessation of breastfeeding and enables the drug to be effective for weeks after the patient received the injection. It is designed to provide a rapid, profound and sustained reduction in depressive symptoms of PPD and may offer substantial and clinically meaningful advantages over the currently available treatment options for PPD. Data from healthy subjects in cohorts 1-15 were presented in a poster, titled Safety, Tolerability, and Pharmacokinetics of BRII-296, An Extended-Release Injectable Aqueous Suspension Formulation of Brexanolone in Healthy Adult Subjects, at the International Marcé Society Conference taking place in London, United Kingdom, from September 19 to 23, 2022.

The full Phase 1 dataset will be presented at a scientific conference later this year. The completed open-label, Phase 1, single ascending dose study assessed the safety, tolerability and pharmacokinetics of BRII-296 as a single-injection treatment option for PPD in 116 subjects enrolled across 16 cohorts. Three formulation concentrations (100 mg/mL, 200 mg/mL and 300 mg/mL) were administered via one or more IM injections to healthy adults at total dose levels of 30 mg, 75 mg, 100 mg, 200 mg, 300 mg and 600 mg.

In addition, oral prophylactic treatment, or local steroid administration with BRII-296 (Depo Medrol via co-injection or admix) were evaluated to manage local injection site reactions ("ISRs"). The local steroid administration was shown in the study to effectively manage ISRs. Of the 116 subjects, 98 subjects reported treatment emergent adverse events ("TEAEs"), with the majority considered drug-related and attributed to ISRs.

Most ISRs were mild to moderate in severity and none lead to premature discontinuation from the study. There was no life threatening TEAEs, TEAEs leading to premature discontinuation of study, serious adverse events, or deaths.