AstraZeneca PLC’s coronavirus antibody treatment failed in late-stage clinical trials to achieve its primary goal of preventing symptomatic Covid-19 in people recently exposed to the virus, the latest disappointment in a broader search for reliable post-infection therapies.
A single dose of the AZD7442 long-acting antibody treatment wasn’t statistically more effective than a placebo in preventing symptomatic Covid-19 in the trial of 1,121 people in the U.K. and U.S., AstraZeneca said Tuesday. The antibody treatment is separate from AstraZeneca’s widely used Covid-19 vaccine developed in partnership with the University of Oxford.
The trial failure is a major setback for hopes by AstraZeneca and the U.S. of using the drug to treat individuals infected with Covid-19. The drugmaker had received support from the U.S. government potentially exceeding $700 million to develop the treatment and, if successful, to supply hundreds of thousands of doses.
But the results did show potential promise in helping reduce the chances of illness from potential infection in the first place. In a parallel analysis of the same AZD7442 phase-three trial data, the antibody combination showed to be 73% effective in reducing the risk of symptomatic Covid-19 in people who tested negative for evidence of the virus at the time they were dosed with the drug. Though the primary goal was preventing symptomatic Covid-19 after confirmed exposure with an infected person, the company said the treatment could find use in people who aren’t well protected by the range of Covid-19 vaccines, or who are unable or unwilling to take a vaccine.
However, the increasingly broad availability and efficacy of vaccines—with more under development—along with the expected high cost of antibody treatments are likely to limit the demand for vaccine alternatives as a preventive tool.