Shares of AstraZeneca dipped in trading after the company announced its COVID-19 antibody therapeutics failed to provide high levels of protection for individuals who have had contact with a symptomatic COVID-19 patient.
AstraZeneca said the Phase III STORM CHASER trial assessing AZD7442, a long-acting antibody (LAAB) combination, failed to meet the primary endpoint of post-exposure prevention of symptomatic COVID-19 compared to placebo. The failure marks a setback in the hunt for means other than vaccines to provide protection against the novel coronavirus and its variants. The STORM CHASER trial assessed AZD7442 in unvaccinated adults who had confirmed exposure to an individual infected with COVID-19 within an eight day period. Participants tested negative on the day AZD7442 was administered in order to exclude prior infection. Study data showed that AZD7442 reduced the risk of symptomatic COVID-19 by 33% compared to placebo. The results were not statistically significant.
The STORM CHASER data follows a rocky rollout for AstraZeneca’s COVID-19 vaccine, which has been plagued by concerns over blood-clotting issues. Yesterday the European Medicines Agency added another side effect warning to the vaccine, capillary leak syndrome, which causes plasma to leak into other parts of the body and can cause a sharp decline in blood pressure.