By Akane Otani and Bill Berkrot
Aug 4 Hopes of finding a treatment for the
deadly Ebola virus shifted on Monday to a small California-based
biotech company whose experimental drug has been used to treat
two American missionary workers.
The drug, developed by Mapp Biopharmaceutical Inc, was used
to treat two aid workers, one from the Samaritan's Purse group
and the other from Christian mission group SIM USA, who were
exposed to the disease in Liberia, according to a U.S.
government health official.
The official said the treatment was administered in Liberia.
One of the aid workers, Dr Kent Brantly, returned to the
United States on Saturday for medical care, and his colleague
Nancy Writebol is due to fly back to the country via medical
aircraft on Tuesday.
Samaritan's Purse said both the aid workers received the
experimental treatment while in Liberia.
News of the treatment, first reported by CNN, punctured a
share price rally in Canada's Tekmira Pharmaceuticals,
whose own experimental Ebola treatment had progressed to human
trials. The severity of the current outbreak in Africa, in which
more than 800 people have died, has raised investor expectations
that Tekmira's treatment might move more quickly toward
The treatment developed by Mapp, called ZMapp, had only been
tested in monkeys. Treatment with experimental drugs that have
not gone through the customary series of clinical trials in
humans to determine safety and efficacy is highly unusual.
Officials at Mapp, a privately held company based in San
Diego, did not respond to requests for comment.
The U.S. Food and Drug Administration said that in the past
it has granted access to drugs not yet tested in humans
depending on an individual patient's situation. It would not
comment on whether it had granted such access to the Mapp drug
in the case of the two American aid workers.
Tekmira was one of a few companies with an Ebola treatment
advanced enough to be tested on people. On July 3, the FDA
placed a hold on a clinical trial for the Tekmira drug due to
safety concerns, after having granted a fast-track designation
to the drug in March.
Shares in Tekmira had climbed 70 percent in the past three
weeks as concerns over the Ebola outbreak mounted, including an
18 percent spike early on Monday. But the news on Monday about
the Mapp treatment led to a sharp reversal, and Tekmira shares
closed down 7 percent by the end of the day on its highest ever
Tekmira's drug, TKM-Ebola, has not been given to "anyone
else infected in the current outbreak, and has not been given to
anyone outside of our Phase I trials," Canadian Press cited
Tekmira as saying in an email.
The CNN report said that Brantly improved dramatically
within an hour of receiving the Mapp drug.
Leaf Biopharmaceutical, which is affiliated with Mapp and
holds the commercial license to ZMapp, also did not respond to
calls or emails seeking comment on use of the treatment.
Mapp was part of a consortium of 15 research outfits that in
March won a five-year grant from the National Institutes of
Health worth up to $28 million to find a treatment for Ebola.
(Additional reporting by Toni Clarke in Washington; Editing by
Leslie Adler and Grant McCool)