Cilgavimab

AstraZeneca on Thursday said the long-acting antibody sipavibart significantly reduced the incidence of symptomatic COVID-19 compared with placebo or its predecessor antibody cocktail Evusheld (tixagevimab/cilgavimab) in a Phase III pre-exposure prophylaxis study involving immunocompromised individuals — a population that accounts for nearly a quarter of cases with worse outcomes.With the positive readout, Astrazeneca is poised to compete against Invivyd's Pemgarda (pemivibart), which recently secured an emergency-use authorisation (EUA) in the US for pre-exposure COVID-19 prophylaxis of immunocompromised patients.“Immunocompromised patients currently have limited or no options for COVID-19 protection…despite often being fully vaccinated,” noted Iskra Reic, EVP of vaccines and immune therapies at AstraZeneca, adding that “sipavibart has the potential to prevent COVID-19” in this vulnerable population.The SUPERNOVA trial randomised 3335 immunocompromised participants to receive either a single 300mg intramuscular dose of sipavibart or a comparator consisting of placebo or Evusheld. The participants included individuals aged 12 years and above, at risk of not adequately responding to active immunisation and at high risk for developing severe COVID-19.Superior protection across variantsTop-line results showed sipavibart met the study’s dual primary endpoints — reducing the risk of symptomatic disease from any SARS-CoV-2 variant and the risk of infections from variants not harbouring the F456L mutation, relative to the comparator. AstraZeneca noted that the protection offered by sipavibart was consistent across the evolving variant landscape throughout the study.In terms of safety, the antibody was well tolerated, with a comparable adverse-event profile between the sipavibart and control arms. Detailed findings will be unveiled at a forthcoming medical conference.AstraZeneca’s Evusheld lost its EUA for pre-exposure prophylaxis in the US early last year, after failing to neutralise circulating SARS-CoV-2 variants in vitro. The drugmaker now intends to engage with regulators to outline the approval process for sipavibart, looking to regain its position in the COVID-19 prophylactics market.