The National Institutes of Health (NIH) has halted a clinical assessment of two Brii Biosciences antibodies in hospitalized COVID-19 patients for futility. Brii’s BRII-196 and BRII-198 became the latest anti-SARS-CoV-2 antibodies to fail to improve outcomes in hospitalized individuals but remain in development in ambulatory patients.
Improving on the efficacy of dexamethasone and remdesivir in hospitalized COVID-19 patients has proven to be beyond many anti-SARS-CoV-2 antibodies. Regeneron cleared a phase 3 futility analysis in hospitalized COVID-19 patients requiring low-flow oxygen late last year, but the NIH has chalked up a clean sweep of failures in its assessments of anti-SARS-CoV-2 antibodies in hospitalized patients.
Having stopped a sub-study assessing Eli Lilly’s bamlanivimab last year, the NIH this week pulled the plug on sub-studies set up to test drugs from Brii and the Vir Biotechnology-GlaxoSmithKline alliance. The Brii and Vir-GSK sub-studies were both stopped for futility.
Brii derived BRII-196 and BRII-198 from the plasma of recovered COVID-19 patients. The antibodies were chosen, in part, because they target non-overlapping epitope binding regions, reducing the risk the combination will be rendered ineffective by coronavirus variants. Brii engineered the antibodies to reduce the risk of antibody-dependent enhancement and prolong the plasma half-lives.
The NIH randomized 343 hospitalized COVID-19 patients to receive either Brii’s antibody cocktail or placebo on top of standard of care. As in other ACTIV-3 sub-studies, the efficacy of Brii’s antibodies was assessed in terms of their effect on the clinical status of participants after five days. Neither the NIH nor Brii have shared data from the trial but they have revealed that the antibodies missed the criteria for continued enrollment.
With antibodies from Brii and Vir-GSK failing this week, the NIH’s ACTIV-3 trial is now only assessing AstraZeneca’s long-acting antibody combination AZD7442. The AZD7442 sub-study is yet to reach the interim review, which takes place when investigators have enrolled around 300 subjects.
ACTIV-2 has a busier roster of sub-studies. That NIH trial is assessing the use of anti-SARS-CoV-2 antibodies, including BRII-196 and BRII-198, and other COVID-19 candidates in ambulatory patients. In a statement, Brii CEO Zhi Hong said the company remains “committed to investigating this antibody combination in ambulatory COVID-19” and continues “to feel confident in this therapy and its antiviral activity against the newly emerging variants.”