Why is this important?
- The TACKLE trial is the first trial in which monoclonal antibodies are administered intramuscularly once morest SARS-CoV-2 early in an outpatient setting.
- Both monoclonal antibodies are directed to non-overlapping regions of the Spike protein receptor binding domain of SARS-CoV-2.
- The tixagevimab-cilgavimab combination has already been shown to have neutralizing activity in vitro once morest the original SARS-CoV-2 virus and its variants of concern.
- The FDA has already granted emergency use authorization for the tixagevimab-cilgavimab combination.
Methodology
- An ongoing phase III, randomized, double-blind, placebo-controlled trial has been conducted at 95 centers in Latin America, the United States, Europe, and Japan.
- Unvaccinated, non-hospitalized adults with mild to moderate COVID-19 were randomly assigned to a single intramuscular injection of tixagevimab-cilgavimab (600 mg; n=456) or placebo (n=454) on an outpatient basis up to 7 days following self-reported onset of symptoms or fever.
- Primary endpoint: severe form of COVID-19 or all-cause mortality.
- Funding: AstraZeneca.
Principle results
- Fewer patients who received tixagevimab-cilgavimab (compared to those who received placebo) progressed to severe COVID-19 or died (4% vs. 9% of patients on placebo; reduced risk relative of 50.5%; P = 0.0096).
- The absolute risk reduction was 4.5% (P < 0.0001).
- Adverse events were mostly mild to moderate in intensity and occurred at similar rates between the groups (29% versus 36% in the placebo group).
Limits
- Exclusion of persons who have been previously vaccinated.