ABSTRACT
Background. SARS-CoV-2 continues to spread and the development of safe and effective therapeutics for the prevention of severe disease remains a priority. BRII-196 and BRII-198 are non-competing anti-SARS-CoV-2 mAbs with YTE triple amino acid substitution in Fc to extend half-life and reduce receptor binding, that are being studied for treatment of COVID-19 in the ACTIV-2 Trial, sponsored by NIAID and led by ACTG. Methods. ACTIV-2 evaluates safety/efficacy of investigational agents for treatment of non-hospitalized adults with mild-moderate COVID-19 under a randomized, blinded, controlled adaptive platform. BRII-196/BRII-198 (1000 mg each) as a single dose given as sequential infusions, or placebo to those at high risk of clinical progression (i.e., age ≥ 60 years or presence of other medical conditions) within 10 days of symptom onset and positive test for SARS-CoV-2. The primary endpoint was hospitalization and/or death through day 28. We report Phase 3 BRII-196/BRII-198 trial results per DSMB recommendation following an interim analysis. Results. Between January and July 2021, 837 participants (418 active, 419 placebo) from sites in the US (66%), Brazil, South Africa, Mexico, Argentina and the Philippines were randomized and received study product at time of emerging variants. Median age 49 years (Q1, Q3: 39, 58), 51% female, 17% Black/African-American and 49% Hispanic/Latino, with median 6 days from symptom onset. At interim analysis 71% and 97% had a day 28 and 7 visit, respectively. For all available data at interim review, BRII-196/BRII-198 compared to placebo had fewer hospitalizations (12 vs. 45) and deaths (1 vs. 9). At day 28 of follow-up, there was an estimated 78% reduction in hospitalization and/or death (2.4 vs. 11.1%), relative risk 0.22 (95% CI: 0.05, 0.86), P=0.00001 (nominal one-sided). Grade 3 or higher adverse events (AEs) were observed less frequently among BRII-196/BRII-198 participants than placebo (3.8% vs. 13.4%) with no severe infusion reactions or drug related serious AEs. Conclusion. BRII-196/BRII-198 was safe, well-tolerated, and demonstrated significant reduction compared to placebo in the risk of hospitalization and/or death among adults with mild-moderate COVID-19 at high risk for progression to severe disease.
ABSTRACT
Background: Patients with underlying medical conditions have a greater risk of developing severe COVID-19. Unlike vaccine-derived immunity which develops over time, administration of neutralizing monoclonal antibodies is an immediate, passive humoral immunotherapy, with the potential to reduce disease progression, emergency room visits, hospitalizations, and death. Methods: In this phase 3 portion of the BLAZE-1 trial, a high-risk ambulatory cohort of 1035 patients with mild-to-moderate COVID-19 were randomly assigned 1:1 to receive a single intravenous infusion of a neutralizing monoclonal antibody combination treatment consisting of 2800mg bamlanivimab+2800mg etesevimab together, or placebo, within 3 days of laboratory diagnosis. The primary outcome was overall patient clinical status, measured by the proportion of patients who experienced COVID-19-related hospitalization or death by any cause by Day 29. Results: 1035 patients were randomized and infused (mean age [SD];53.8 years [16.8], female (52%)). A 70% reduction in COVID-19-related hospitalization and death by any cause by Day 29 was observed in patients who received the bamlanivimab+etesevimab combination treatment (11/518 arm total) compared to those who received placebo (36/517 arm total) (Δ[95% CI]=-4.8[-7.4,-2.3])(p=0.0004). No deaths were observed among patients who received the combination treatment, 10 deaths were reported in the placebo group, at least 8 designated COVID-19-related. A significantly greater reduction in log10(viral load) from baseline at Day 7 was observed amongst patients who received bamlanivimab+etesevimab compared to placebo (Δ[95% CI]=-1.20[-1.46,-0.94])(p<0.00000001). The median time to sustained symptom resolution was shorter for those who received the combination treatment (days [95% CI]=8[7.0,8.0]) compared to those who received placebo (days [95% CI]=9[8.0,10.0])(p=0.007). Similar rates of adverse events were observed between placebo (60/517,11.6%) and combination treatment groups (69/518,13.3%). Conclusion: 2800mg bamlanivimab+2800mg etesevimab neutralizing monoclonal antibody combination therapy significantly reduced COVID-19- related hospitalizations and deaths amongst high-risk ambulatory patients and accelerated the decline in viral load and disease symptoms over time. This study confirms that early intervention with bamlanivimab + etesevimab greatly improves the clinical outcomes for high-risk ambulatory patients, and links reduction in nasopharyngeal viral load to clinically meaningful benefits.