Antibody combo of Tixagevimab and Cilgavimab effectively prevents COVID-19: NEJM

UK: Single dose of AZD7442 (Tixagevimab-Cilgavimab) is effective for COVID-19 prevention sans any evident safety concerns. Further administration of Monoclonal antibody combination tixagevimab-cilgavimab (Evusheld) maintained efficacy up to 6 months in high risk of COVID-19 patients, showed PROVENT trial.

The study has been published in the New England Journal of Medicine. 

The study showed the incidences of symptomatic RT-PCR–positive SARS-CoV-2 infection and severe disease among infected participants to be lower in the AZD7442 group than in the placebo group, and there were no evident safety concerns.

The monoclonal-antibody combination AZD7442 is comprised of two monoclonal neutralizing antibodies, tixagevimab and cilgavimab that are derived from isolated B cells obtained from persons infected with SARS-CoV-2. They have an extended half-life and have been shown to have prophylactic and therapeutic effects in animal models. In humans, pharmacokinetic data indicate that AZD7442 has an extended half-life of approximately 90 days.

In the study, Myron J. Levin, and colleagues reported results from the ongoing, phase 3 PROVENT trial, which evaluated AZD7442 for the prevention of symptomatic and severe Covid-19 in adults. 

The trial enrolled adults (≥18 years of age) who had an increased risk of an inadequate response to vaccination against coronavirus disease 2019 (Covid-19), an increased risk of exposure to SARS-CoV-2, or both. They were randomly assigned in a ratio of 2:1 to receive a single dose (two consecutive intramuscular injections, one containing tixagevimab and the other containing cilgavimab) of either 300 mg of AZD7442 or saline placebo. They were followed up to 183 days in the primary analysis. 

The incidence of adverse events after a single dose of AZD7442 was the primary safety endpoint. The primary efficacy endpoint was symptomatic Covid-19 occurring after administration of AZD7442 or placebo and on or before day 183. SARS-CoV-2 infection  was confirmed by means of reverse-transcriptase–polymerase-chain-reaction assay.