The test bench drug was a long-acting antibody combination, AZD7442. However, the pharmaceutical company AstraZeneca said that the ‘Storm Chaser’ study did not reach the main goal: the primary endpoint of symptomatic post-exposure prevention of Covid-19, compared to placebo. In the overall study population, AZD7442 reduced the risk of developing symptomatic Covid-19 by 33% compared to placebo. Which was not statistically significant, was explained by taking stock of the trial that involved unvaccinated adults aged 18 and over with confirmed exposure to a case of Sars-CoV-2 in the past 8 days.
But Myron Levin, University of Colorado School of Medicine (USA), principal investigator on the study, said the Storm Chaser findings suggested that AZD7442 may be useful in preventing Covid-19 symptoms in individuals not already infected. . Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, said that although the study did not meet the primary endpoint against symptomatic disease, it is encouraged by the protection seen in PCR-negative participants after treatment with the combination.
Storm Chaser is a Phase III, randomized, double-blind, placebo-controlled, multicenter study evaluating the safety and efficacy of a single 300 mg dose of AZD7442 versus placebo for post-exposure prevention of Covid-19. The trial was conducted at 59 sites in Great Britain and the United States. A total of 1,121 participants were randomized to receive a single intramuscular dose of the antibody combination (749 people) or a placebo (372). AZD7442 is a combination of two Laab antibodies (Long Acting AntiBody): tixagevimab (AZD8895) and cilgavimab (AZD1061), derived from B cells donated by patients recovering after infection with the Sars-CoV-2 virus.