--AstraZeneca said AZD7442 didn't meet primary target in a Phase 3 trial

--Drug didn't achieve a statistically significant prevention of symptomatic Covid-19 after exposure to the virus

--Company observed protection against virus in patients who tested negative in PCR test

By Adria Calatayud

AstraZeneca PLC said Tuesday that a Phase 3 trial to assess the safety and efficacy of a long-acting antibody combination, called AZD7442, for the prevention of symptomatic Covid-19 after exposure didn't meet the primary goal.

The Cambridge, U.K.-based pharmaceutical company said that AZD7442, developed with support from the U.S. government, reduced the risk of developing symptomatic Covid-19 in unvaccinated adults with confirmed exposure to a person with a case of the SARS-CoV-2 virus within the past eight days by 33% compared to a placebo, which wasn't statistically significant.

However, the drug reduced the risk of developing symptomatic Covid-19 by 73% in participants who tested negative in a polymerase chain reaction, or PCR, test at time of dosing, AstraZeneca said. In patients who were PCR negative, AZD7442 reduced the risk of developing symptomatic Covid-19 by 92% compared to a placebo more than seven days after dosing, and by 51% up to seven days after dosing, the company said.

Myron J. Levin, professor of Pediatrics and Medicine at the University of Colorado School of Medicine and principal investigator on the trial, said results from the study suggest that the drug might be useful in preventing symptoms in individuals not already infected.

The trial, which was conducted in the U.K. and the U.S. with 1,121 participants, showed that the drug was well-tolerated, AstraZeneca said. Full results from the trial will be submitted for publication in a peer-reviewed medical journal and presented at a forthcoming medical meeting, it said.

"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," AstraZeneca's BioPharmaceuticals R&D Executive Vice President Mene Pangalos said.

AZD7442 is a cocktail of tixagevimab and cilgavimab, two long-acting antibodies derived from cells donated by convalescent patients after being infected with the coronavirus that causes Covid-19. The drug was discovered by Vanderbilt University Medical Center and licensed to AstraZeneca in June 2020.

The drug is being tested in two additional Phase 3 trials for Covid-19 prevention and treatment. The company on April 30 said that it expected first data from the first of those trials, to evaluate the efficacy of the drug for treatment of Covid-19 in nonhospitalized patients, by the end of June.

First data from another AZD7442 trial to assess its safety and efficacy in adults who are at increased risk for coronavirus infection due to living or work situations, or who are at increased risk of responding inadequately to vaccines is expected in the second half of the year, AstraZeneca said.

The company in March said that it had extended an agreement with the U.S. government to supply up to 500,000 additional doses of AZD7442 for $205 million, taking the total potential U.S. supply to 700,000, contingent on AZD7442 receiving emergency-use authorization from the U.S. Food and Drug Administration.

Discussions with the U.S. government regarding next steps are continuing, AstraZeneca said.

The company, which has developed a Covid-19 vaccine in collaboration with the University of Oxford, has also evaluated the potential of some of its medicines to treat coronavirus infections, but those trials failed to meet their goals.

In November, AstraZeneca said that its Calquence oncology drug didn't meet the primary efficacy goal in Phase 2 trials. In April, the company said that a Phase 3 trial to assess the potential of its Farxiga diabetes drug to treat patients with Covid-19 at risk of developing serious complications didn't achieve statistical significance for its primary targets of prevention and recovery.

Write to Adria Calatayud at adria.calatayud@dowjones.com

(END) Dow Jones Newswires

06-15-21 0644ET