* CEO confirms timeline, contingent on safety board ruling
* Says case of transverse myelitis has yet to be confirmed
* Says up to 60,000 set to take part in trial programme
* Trials not smaller than the norm for vaccines, CEO says
* Transverse myelitis cases rare, link to vaccines unclear
(Adds details on suspected condition)
By John Miller and Ludwig Burger
ZURICH/FRANKFURT, Sept 10 (Reuters) - AstraZeneca should
still know by year-end whether its experimental vaccine protects
people against coronavirus, as long as it is cleared to resume
trials soon, its chief executive said on Thursday amid doubts
over its rollout.
Governments desperate to put an end to the COVID-19 pandemic
which has caused more than 900,000 deaths and huge economic and
social disruption during 2020 are pinning their hopes on a
vaccine.
However British drugmaker AstraZeneca suspended late-stage
trials on its potential vaccine this week after an illness in a
participant in Britain who was reported to be suffering from
symptoms associated with transverse myelitis, a rare spinal
inflammatory disorder.
The World Health Organization (WHO) has flagged the
AstraZeneca vaccine, which is being developed with the
University of Oxford, as the most promising for coronavirus.
CEO Pascal Soriot said during an online event on Thursday
that AstraZeneca did not yet know the diagnosis of the
participant who was ill, adding that it was not clear if the
volunteer had transverse myelitis and more tests were needed.
The diagnosis would be submitted to an independent safety
committee and this would usually then say whether trials can be
resumed, Soriot said, adding it was usual for such pauses.
"It's very common, actually, and many experts will tell you
this," Soriot said, adding: "The difference with other vaccine
trials is, the whole world is not watching them, of course. They
stop, they study, and they restart."
Shares in AstraZeneca fell on Wednesday after the trial halt
raised doubts about the timeline for the vaccine's rollout.
AstraZeneca would supply vaccines to countries at the same
time to ensure a fair and equitable distribution, Soriot said,
reiterating that the company was close to having capacity to
produce 3 billion doses at sites set up around the world to
prevent governments from restricting distribution.
With up to 60,000 people set to participate in the study
programme, AstraZeneca's CEO said the volume was typical of
vaccine trials and large enough to spot rare side effects.
"With this you are going to pick up very rare events." he
said, adding that a planned staggered launch, prioritising
at-risk groups, would provide further assurance for the masses
that are set to be covered by government plans at a later stage.
Serum Institute of India, one of AstraZeneca's
development and production partners, said on Thursday it was
joining the suspension, backtracking on remarks that it did not
face any issues.
'DIFFICULT TO BE SURE'
Transverse myelitis cases after a vaccination have been
documented before, but concrete links between the condition and
vaccinations have not been established, experts said.
The U.S.-based Mayo Clinic concludes that the association so
far is not strong enough to warrant limiting any vaccine.
A 2009 review in the journal Lupus of nearly 40 years of
English-language publications found 37 cases of transverse
myelitis associated with hepatitis B vaccines,
measles-mumps-rubella, diphtheria-tetanus-pertussis and others.
The vaccines remained on the market, Stephen Evans, a
professor of pharmacoepidemiology at the London School of
Hygiene and Tropical Medicine, said.
Linking such an autoimmune response to a single factor like
a vaccine is problematic, he said, given the number of
immunological, hormonal or environmental factors at play.
"It's terribly difficult to be sure," Evans said.
RBC Capital Markets analyst Bryan Abrahams cautioned the
trial participant's condition must be thoroughly investigated.
"Even a single case could possibly imply a rate or
association higher in the study than what is normally observed
sporadically" he wrote to investors, adding a one in 10,000
risk, if confirmed, would likely be unacceptable.
BioNTech, among the frontrunners in the vaccine
race with partner Pfizer, echoed remarks by Soriot that
clinical halts are a common feature of immunisation trials.
"Safety is a top priority," its CEO Ugur Sahin told Reuters.
(Additional reporting by Patricia Weiss and Josephine Mason;
Editing by Alexander Smith)
Astrazeneca (AZN)