AstraZeneca’s Covid-19 antibody treatment failed to meet its main targets in its latest trial, while showing it could prevent people exposed to the virus from developing the disease if given early enough.
The phase 3 trial of the AZD7442 treatment found that it was not significantly more effective than placebo. Out of 1,121 participants who had had contact with an infected person, 23 on the drug developed symptomatic Covid-19, compared with 17 on placebo.
The treatment is separate from the company’s vaccines, which are being used worldwide to protect against coronavirus.
AstraZeneca has agreed to supply up to 700,000 doses of the antibody treatment to the US government, worth up to $726m.
However, the AZD7442 results were more encouraging when the drug was given to patients who had not yet tested positive for the virus, reducing the risk of developing the condition by 73 per cent.
“While this trial did not meet the primary endpoint against symptomatic illness, we are encouraged by the protection seen in the PCR-negative participants following treatment with AZD7442,” said Mene Pangalos, executive vice-president of biopharmaceuticals research and development at AstraZeneca.
The treatment is in several late-stage trials with a combined 9,000 participants. Myron Levin, a professor at the University of Colorado School of Medicine, and principal investigator on the trial, said another trial called Provent would give more data on this patient population.
“While Covid-19 vaccination efforts have been successful, there is still a significant need for prevention and treatment options for certain populations, including those unable to be vaccinated or those who may have an inadequate response to vaccination,” the professor said.
Latest coronavirus news
Follow FT’s live coverage and analysis of the global pandemic and the rapidly evolving economic crisis here.
Antibody treatments from companies including Regeneron and Eli Lilly have been used to bolster the immune response of patients with Covid-19. Former US President Donald Trump was among the recipients of the Regeneron treatment.
But they could also be given prophylactically to people who might develop the disease. In a trial of residents and staff at long-term care facilities, Eli Lilly’s antibody bamlanivimab reduced the risk of infection by 80 per cent in participants who tested negative.
The search for drugs to treat Covid-19 has been less fruitful than the rapid development of many vaccines against the disease, with doubts about how well the antiviral remdesivir works.
Antibody treatments have been one bright spot but they are difficult to administer early enough in the course of the disease to make a difference. With widespread vaccination in the west, demand for these treatments is likely to fall — and they are often too expensive for developing countries.