(Adds AstraZeneca comment, Moderna comment, byline)
By Deena Beasley
Sept 8 (Reuters) - AstraZeneca Plc on Tuesday said
it has paused a late-stage trial of one of the leading COVID-19
vaccine candidates after an unexplained illness in a study
participant.
"Our standard review process was triggered and we
voluntarily paused vaccination to allow review of safety data by
an independent committee," company spokeswoman Michele Meixell
said in an emailed statement.
The study is testing a COVID-19 vaccine being developed by
AstraZeneca and University of Oxford researchers at various
sites, including the United Kingdom, where the illness was
reported.
The nature of the case and when it happened were not
detailed, although the participant is expected to recover,
according to Stat News, which first reported the trial was
halted due to a "suspected serious adverse reaction." The U.S.
Food and Drug Administration defines that as an adverse event in
which evidence suggests a possible relationship to the drug
being tested.
The suspension of the trial has impacted other AstraZeneca
vaccine trials - as well as clinical trials being conducted by
other vaccine makers, which are looking for signs of similar
reactions, Stat said.
The U.S. National Institutes of Health, which is providing
funding for AstraZeneca's trial, declined to comment.
AstraZeneca's statement said that "in large trials,
illnesses will happen by chance but must be independently
reviewed to check this carefully."
Shares of AstraZeneca fell more than 8% in after-hours U.S.
trading, while shares of rival vaccine developers rose. Moderna
Inc was up more than 4% and Pfizer Inc rose
less than 1%.
Moderna, in an emailed statement, said it was "not aware of
any impact" to its ongoing COVID-19 vaccine study at this time.
Nine leading U.S. and European vaccine developers pledged on
Tuesday to uphold scientific safety and efficacy standards for
their experimental vaccines despite the urgency to contain the
coronavirus pandemic.
The companies, including AstraZeneca, Moderna, and Pfizer
issued what they called a "historic pledge" after a rise in
concern that safety standards might slip in the face of
political pressure to rush out a vaccine.
The companies said they would "uphold the integrity of the
scientific process as they work towards potential global
regulatory filings and approvals of the first COVID-19
vaccines."
The other signatories were Johnson & Johnson, Merck
& Co, GlaxoSmithKline, Novavax Inc,
Sanofi and BioNTech.
(Reporting By Peter Henderson
Editing by Bill Berkrot and Aurora Ellis)
Glaxosmithkline (GSK)
Astrazeneca (AZN)