High-risk people such as cancer patients may need drugs like monoclonal antibodies that can neutralize the virus and mimic the necessary immune response to avoid infection.
AstraZeneca Plc’s Covid-19 antibody cocktail has proved effective against variants of the virus in early testing, a potentially key development for vulnerable populations unable to receive vaccines.
The combination of monoclonal antibodies taken from Covid-19 convalescent patients held up against new strains first identified in the UK and South Africa in extensive laboratory testing, Mark Esser, Astra’s head of microbial sciences, said in an interview. The news is particularly helpful as the company grapples with slower trial recruitment in light of the success of vaccines.
While vaccines can protect the general population from disease, not everyone’s immune system can respond adequately. High-risk people such as cancer patients may need drugs like monoclonal antibodies that can neutralize the virus and mimic the necessary immune response to avoid infection. Astra is running five advanced-stage trials of its antibodies, looking at both prevention and treatment.
Astra had originally planned to target the elderly with the antibodies because that population doesn’t usually respond as well to flu vaccines, but a better-than-expected reaction from older adults to the Covid shots has forced the company to focus more on high-risk individuals, with the first data expected by summer, Esser said.
The strong rollout in the U.S. and U.K. “has slowed us down a little bit. That’s a good problem to have,” said Esser. “The other challenge is people that have already enrolled in our studies are dropping out to get vaccinated.”
The company has recruited about 3,000 of a target 5,000 participants in a trial looking at prevention, and half of a 1,125-person study examining the impact of the antibodies after someone has been exposed to the virus in settings such as nursing homes. The three other trials looking at treatment of the disease include both inpatient and outpatient Covid-19 cases.
The U.K. pharmaceutical giant agreed last year to supply as many as 100,000 doses of the antibodies to the U.S. starting at the end of 2020, with an option to acquire one million more in 2021. Those won’t now be delivered until the company has results, according to an Astra spokesman. The U.K. also agreed to buy one million doses in December.
Although vaccine output can be scaled up more easily, it’s only possible to produce several million doses of the monoclonal antibodies annually, according to Esser. This means demand for the drugs could considerably outstrip supply if they’re shown to work.
Other companies are also working on similar projects. A neutralizing antibody from Eli Lilly and Co. was granted emergency approval in the U.S in November as a treatment for patients at high risk of progressing from a mild to severe case or hospitalization. Lilly also teamed up with GlaxoSmithKline Plc and partner Vir Biotechnology Inc. last month to test a combination of their antibodies as the virus variants present a new threat.
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