Paris (AFP) - For the first time since the west African Ebola outbreak began over a year ago, a clinical trial with a candidate treatment has yielded "encouraging" results, researchers announced Thursday.
The trial with 80 patients in Guinea resulted in fewer deaths and faster recovery rates, the French government and medical research agency Inserm said of tests with the Japanese-manufactured anti-viral drug favipiravir.
No scientific trial data has been made public, but the outcome was said to offer "hope" for tackling the haemorrhagic fever virus that has infected 22,495 people and killed 8,981 in the worst Ebola outbreak in history, according to the latest World Health Organization tally.
"Encouraging results of the trial... will be submitted shortly to a scientific journal for publication," Inserm said in a statement to AFP.
The French presidency said in a separate statement the trial showed "a reduction in the number of deaths among adults and teenagers, with slower virus multiplication. Recovery is accelerated".
- 'Important step forward' -
The head of France's Ebola Task Force, Jean-Francois Delfraissy, and Inserm head Yves Levy briefed President Francois Hollande and government officials on Wednesday, it added, and described the results as "an important step forward".
Inserm is in charge of the trial at a treatment centre in Gueckedou in the east of Guinea -- one of the three countries, with Liberia and Sierra Leone, hardest hit by the outbreak.
The trial, which started on December 17, was conducted with Guinean researchers and authorities, non-government organisations, the French Red Cross and aid group Doctors Without Borders (MSF).
It is the largest clinical trial yet with a candidate Ebola treatment, the French statement said.
Favipiravir, also known as Avigan, is developed by Toyama Chemical, a subsidiary of Fujifilm Holdings.
Inserm said the scientific results will be made public once they have been officially reviewed and validated by the scientific community, which could happen by month's end.
- Emergency treatment -
The drug has already been administered as an emergency treatment to patients evacuated from West Africa to Europe, though this was not part of an official trial.
It has commercial authorisation in Japan as a flu medicine, and large doses can be made quickly available -- an advantage over other experimental treatments, like ZMapp, of which stocks are limited.
The Japanese company said last year it had sufficient reserves for more than 20,000 people.
The Elysee said the results gave rise to "hope", but cautioned they have to be confirmed with a larger group of trial patients.
"These early results open new avenues for access to treatment in the fight against this disease," it said.
MSF said in December that "if favipiravir is shown to be safe and effective, it will be made accessible to Ebola patients in other Ebola treatment centres through advancing the trial to the next phase.
"This means that after approval from national authorities and independent ethics committees more Ebola positive patients in west Africa will be placed on the treatment."
There is as yet no licenced vaccine or treatment for Ebola.
The WHO gave the green light last August for experimental treatment to be used in the current crisis, and several candidate drugs are being fast-tracked through the normally years-long trial process.
Ebola, one of the deadliest viruses known to man, is spread through direct contact with the bodily fluids of an infected person showing symptoms such as fever or vomiting.
People caring for the sick or handling corpses are at highest risk, and the disease is best contained by limiting exposure through patient isolation and safe burials.
A sharp drop in new cases in recent weeks gave rise to optimism that the worst was over, but the WHO on Wednesday reported the first rise for 2015 in the weekly number of cases in all three countries.
A trial with another candidate treatment, brincidofovir, was halted in Liberia Tuesday.
The trial's funder, the Wellcome Trust research charity, cited dropping patient numbers and said there was "no realistic prospect of the trial enrolling sufficient patients to be able to reach a conclusion about the efficacy of the drug."
The first large-scale trials with two Ebola vaccines started in Liberia on Monday.