AstraZeneca Antibody Cocktail Fails to Prevent Covid-19 in Trial. Here's the Good News.

AstraZeneca’s antibody treatment failed to show evidence it prevents Covid-19 symptoms in people exposed to the coronavirus that causes the disease in a Phase 3 trial, the company said on Tuesday.

The U.K.-Swedish drug company said its long-acting antibody combination—AZD7442—reduced the risk of unvaccinated adults developing symptomatic Covid-19 by 33% compared with the placebo, which “was not statistically significant.”

The trial included 1,121 people and explored whether the antibody drug could prevent Covid-19 symptoms in those who had been recently exposed to the SARS-CoV-2 virus.

Aside from its vaccine, AstraZeneca has also developed an antibody treatment—a combination of two drugs derived from cells donated by convalescent Covid-19 patients—in the hope it could be used by those unable to be vaccinated or who have an inadequate response to vaccination.

Morgan Stanley said in a December note the treatment could increase 2021 earnings by 30%—$3 billion—if developed successfully. So, these latest trial results must be considered a blow for the company, but there is good news and still hope the treatment could be a success.

Read:AstraZeneca, Pfizer Vaccines Offer Strong Protection From Delta Variant

The antibody cocktail showed more encouraging results when given to participants who recorded a negative polymerase chain reaction test result at the time of dosing, suggesting it may be effective on people not already infected.

In those testing negative before receiving the treatment, the risk of developing Covid-19 symptoms more than seven days after dosing was cut by 92%.

“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 AstraZeneca’s executive vice president of biopharmaceuticals research and development Mene Pangalos

The results suggest AZD7442 “may be useful in preventing symptomatic Covid-19 in individuals not already infected,” according to the trial’s principal investigator, Myron Levin, professor of pediatrics and medicine at University of Colorado School of Medicine. 

A number of trials to discover whether the treatment could be effective are ongoing, including a pre-exposure study and one looking at prevention of more severe disease.

Read:The Delta Virus Variant Has the World on Edge. What to Know.

In October 2020, the U.S. government awarded AstraZeneca $486 million to develop and secure 100,000 doses of its AZD7442 treatment. In March, AstraZeneca said it had reached an agreement with the U.S. government to supply up to 500,000 additional doses for $205 million, provided it receives emergency-use authorization from the U.S. Food and Drug Administration. The drug company said on Tuesday that discussions with the U.S. government over the next steps were ongoing.

Looking ahead. After an encouraging deal with the U.S. government over the treatment, the trial results revealed on Tuesday are certainly disappointing. The stock appeared largely unaffected, though, enjoying modest gains of 0.6% into afternoon London trading. 

Bryan Garnier analysts said AstraZeneca has “high hopes” for its antibody treatment and noted that two further studies could still show how it could be used. They maintained a conviction buy rating on the stock and said no sales for the drug were included in its model.

While the global vaccination rollout appears to be going well, antibody treatments could yet still be useful. There is still hope AstraZeneca’s cocktail could have a place in the fight against the virus if ongoing trials prove more positive—and it could also help the stock.

Write to Callum Keown at [email protected]