ABSTRACT
Background. Sotrovimab (VIR-7831) is an engineered human monoclonal antibody targeting a conserved region of the SARS-CoV-2 spike protein;it has been shown to have a favorable safety profile and be effective for early treatment of highrisk COVID-19 patients. The COMET-TAIL phase 3 study evaluated sotrovimab administered intravenously (IV) or intramuscularly (IM) for the treatment of participants with mild to moderate COVID-19 who are at high risk of disease progression. Methods. Between June to August 2021, 973 participants were randomized and received sotrovimab by 500 mg IV infusion or by 500 or 250 mg IM injection. Deep sequencing of the spike gene was performed on nasopharyngeal samples. Baseline (BL;Day 1 or Day 3), post-BL (Day 5 or later), treatment-emergent (TE) substitutions at sotrovimab epitope positions, and presence of variants of concern/interest (VOC/ VOI), were evaluated at a >=5% allelic frequency. Phenotypic analyses were conducted using a pseudotyped virus assay. Results. Sequences were available from 764 participants (500 mg IV: 314/393;500 mg IM: 302/387;250 mg IM: 148/193). Consistent with VOC circulation during enrollment, the Delta variant was detected in 88.2% (674/764) of participants. Alpha and Mu variants were also seen at >2% prevalence. Of the 764 participants, 26 met the primary endpoint for clinical progression to hospitalization >24 hours or death due to any cause through day 29 and were infected with Delta (500 mg IV: 4;500 mg IM: 9;250 mg IM: 11), Alpha (500 mg IM: 1), or Mu (500 mg IV: 1) variants. Substitutions at sotrovimab epitope positions were similar across arms and were detected in 82/764 (10.7%) participants at any visit (500 mg IV: 42/314;500 mg IM: 27/302;250 mg IM: 13/148). Of these, 2 participants experienced clinical progression: 1 participant infected with the Mu variant (500 mg IV) carried the characteristic R346K substitution at BL;1 participant infected with the Delta variant (500 mg IM) had P337L and E340K substitutions detected at Day 3 and P337L was enriched at Day 8. The predominant TE epitope substitutions included P337L and E340A/K/V, which confer reduced susceptibility to sotrovimab in vitro. Conclusion. Overall, TE epitope substitutions were not associated with clinical progression.
ABSTRACT
Background. COVID-19 disproportionately results in hospitalization and death in older patients and those with underlying comorbidities. Sotrovimab is a pan-sarbecovirus monoclonal antibody that binds a highly conserved epitope of the SARSCoV-2 receptor binding domain and has an Fc modification that increases half-life. Sotrovimab retains activity against UK, S. Africa, Brazil, India, New York and California variants in vitro. Objectives. To evaluate the efficacy and safety of treatment with sotrovimab in high-risk, non-hospitalized patients with mild/moderate COVID-19, as part of the COMET-ICE clinical trial. Methods. Multicenter, double-blind, phase 3 trial in non-hospitalized patients with symptomatic COVID-19 and ≥1 risk factor for disease progression were randomized 1:1 to an IV infusion of sotrovimab 500 mg or placebo. The primary efficacy endpoint was the proportion of patients with COVID-19 progression, defined as hospitalization > 24 hours or death, due to any cause, ≤29 days of randomization. Results. The study met the pre-defined primary efficacy endpoint in a preplanned interim analysis: the risk of COVID-19 progression was significantly reduced by 85% (97.24% CI, 44% to 96%;P = 0.002) in 583 patients. In the final intention-to-treat analysis (N = 1057), the adjusted relative risk reduction was 79% (95% CI, 50% to 91%;p< 0.001) through Day 29 in recipients of sotrovimab (n=528) vs. placebo (n=529). Treatment with sotrovimab (ITT) resulted in a numerical reduction in the need for ER visits for illness management, hospitalization for acute illness management (any duration) or death (any cause) compared to placebo. No participants on sotrovimab required ICU admission, compared to 9 participants on placebo, of whom 4 participants required mechanical ventilation. No participants who received sotrovimab died, compared to 4 participants on placebo. The incidence of adverse events was similar between treatment arms and SAEs were numerically more common in the placebo arm. Conclusion. Treatment with sotrovimab 500 mg IV resulted in a clinically and statistically significant reduction in progression of COVID-19 to hospitalization or death in patients with mild/moderate disease and was well-tolerated.