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 Faced with a disease with a death rate of between 40 and 90 percent,
randomized controlled trials (RCTs) -- where patients are assigned
to get either the drug or a dummy pill -- would be unfair and
ethically unacceptable, according to the disease specialists from
Europe, Africa and the United States.
"We accept that RCTs can generate strong evidence in ordinary
circumstances; not, however, in the midst of the worst Ebola
epidemic in history," experts including David Heymann, head of the
Chatham House Center on Global Health Security, wrote in a letter to
the Lancet medical journal.
Some trials of potential Ebola treatments or vaccines in West Africa
have just begun, or are due to start in the coming months, and the
World Health Organization (WHO) has said it hopes some medicines may
start to be deployed in the West Africa outbreak early next year.
A different group of disease experts last month argued in a letter
to the Journal of the American Medical Association that experimental
Ebola drugs were best tested in normal RCTs.
A similar debate is going on in the field of cancer drugs, where
researchers increasingly question whether randomization -- where
some patients are given a treatment and others get a "control"
substance for comparison -- makes sense in patients with an
incurable disease.
In cancer, new trial designs are being pioneered that allow faster
testing on experimental medicines in smaller, more targeted groups,
potentially shaving major costs and significant time off the usual
drug development process.
The Ebola expert group writing in the Lancet -- which also included
Peter Piot, a professor and director at the London School of
Tropical Medicine who was one of the discoverers of Ebola --
stressed that "the urgent need is to establish whether new
investigational drugs offer survival benefits" and therefore which,
if any, should be recommended by the WHO to save lives.
"We have innovative but proven trial designs for doing exactly
that," they wrote. "We should be using them, rather than doggedly
insisting on gold standards that were developed for different
settings and purposes."
The Ebola epidemic has infected almost 8,400 people so far and
killed more than 4,000 of them, mainly in Guinea, Sierra Leone and
Liberia.
One potential drug trial design that would avoid using placebos
would be to test two experimental drugs at the same time by giving
one to one group and another to a separate group.
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"In cancers with a poor prognosis for which there are no good
treatments, evidence from studies without a control group can be
accepted as sufficient for deployment, and even for licensing by
regulators, with fuller analysis following later," the experts
wrote.
"There is no need for rules to be bent or corners to be cut: the
necessary procedures already exist, and are used."
The WHO has approved the use of experimental drugs for Ebola in the
hope they might help some people infected in the outbreak which has
been raging since March.
Several patients have already been given experimental drugs
including ZMapp, made by Mapp Biopharmaceutical in the United
States, TKM-Ebola made by Canada's Tekmira, and brincidofovir, made
by the U.S. company Chimerix.
But since only a tiny number of patients have been treated and some
of those treated died and some survived, doctors don't know for sure
if they work.
In the letter to JAMA, disease experts argued that conducting RCTs
was the only way to "maximize lives saved in the present epidemic
and ensure knowledge gains for the next".
Heymann, Piot and 15 other signatories to the Lancet letter said:
"We disagree".
"No one insisted that western medical workers offered ZMapp and
other investigational products were randomized to receive the drug
or conventional care plus a placebo," they wrote.
"None of us would consent to be randomized in such circumstances."
(Editing by Ben Hirschler and Sonya Hepinstall)
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