Three trials of experimental Ebola drugs will start next month at treatment centres run by the volunteer doctors of Médecins Sans Frontières in west Africa.

The trials are unprecedented because they are being run during an epidemic and the drugs have not been through the conventional process of clinical trials in animals and healthy humans before being given to people who are sick. Also, drugs will not be withheld from a control group.

The trials have been set up with extraordinary speed in the hope that the drugs will cut the 70% death rate from the disease in west Africa. More than 5,000 people have died since the outbreak began in December.

The announcement came as Liberia’s president said enough progress had been made to allow her to lift the state of emergency imposed across the country, but cautioned that the outbreak was not over. Though there have been fewer cases reported in the capital, Freetown, the virus has spread to new areas. Schools will remain closed until further notice.

MSF and its partners in the trials, who include academics, pharmaceutical companies and the World Health Organisation, have agreed to run two trials in Guinea, one of which will investigate the use of blood products from people who have survived Ebola.

The first patients will be treated next month and by February scientists expect to have some idea as to whether the drugs have any effect. The test will be whether more patients survive over a 14-day period than have done until now in that particular treatment centre. There is a chance that death rates could go up. If so, the drug will be immediately dropped.

ZMapp, the drug given to some of the foreign health workers who were infected earlier in the epidemic, is not among those being trialled at this stage because it takes too long to produce. The drugs to be tested were chosen because there is some promising data either in Ebola or other viral infections, they can be produced in sufficient quantities and they are not prohibitively expensive – which may be another barrier to ZMapp.

Oxford University scientists will lead a third trial, the location of which is still to be decided, funded by the Wellcome Trust. They will test the antiviral drug brincidofovir, made by Chimerix of Durham, North Carolina. It has shown an effect against the Ebola virus in the lab but has not been tried in animals. However, there is good evidence of its safety in humans from trials against other viruses, and it is easy to take as it is in pill form. Up to 140 patients will be involved.

Facebook Twitter Pinterest Sierra Leone health workers remove a corpse from a house in Freetown. Photograph: Francisco Leong/AFP/Getty Images

The French National Institute of Health and Medical Research (Inserm) will lead a trial in Guéckédou, Guinea, investigating a second antiviral drug called favipiravir, developed by Toyama Chemical of Japan and used against influenza. Positive results of tests in animals against Ebola were published in February.

The second trial in Guinea, in the capital, Conakry, will look at the effect of giving patients blood and plasma containing antibodies from people who have recovered from the disease. It will be led by the Antwerp Institute of Tropical Medicine (ITM).

“This is an unprecedented international partnership which represents hope for patients to finally get a real treatment against a disease that today kills between 50 and 80% of those infected,” said Dr Annick Antierens, of MSF. “As one of the principal providers of medical care to Ebola patients in west Africa, MSF is taking part in these accelerated clinical trials to give people affected by the current outbreak a better chance of survival.”

The trials will not compare one group of people receiving the drug with another group of people who do not. Although that is how drug trials are usually run under normal conditions, many did not believe it would be ethical or practical to withhold a drug that might help in an epidemic where most patients die, so all patients who want to take part will get the treatment.

“There is a great need for these trials,” said Prof Peter Horby, the chief investigator of the Oxford trial run by the International Severe Acute Respiratory and Emerging Infection Consortium (Isaric). “This is tragedy for individuals and communities. We need to do everything we can to offer hope to these communities.”

He said there was also a scientific imperative, because the only way to get information on what works was to test the drugs in an epidemic. “Everyone has gone beyond their comfort zone,” he said.

Prof Denis Malvy, who will lead the Inserm trial in Guinea, said those involved in the three trials would work closely together so they could learn from each other’s experiences and adapt what they were doing. The Inserm trial, which will aim to treat 200 patients, will analyse the results after every 20th patient, he said, “to ensure the drug provides benefits and not detrimental effects. The trial will be stopped prematurely if the mortality rate is under 40%.”

Blood plasma has been tried in the past against Ebola. It has been safely used against other infectious diseases, said Johan van Griensven, of ITM.

“We want to find out whether it works for Ebola, whether it is safe and whether it can be scaled up to reduce the number of deaths in the current outbreak,” he said. “Close communication with people who recovered from Ebola, and the community at large, will be vital for a successful trial. We hope that recovered patients donating blood and plasma to help sick people could reduce fear of the disease and reduce stigmatisation of those who survived.”

The trials are set up in a way that if one drug fails, another contender can be introduced from a list of possibilities drawn up by the WHO. They can also be adapted so that drugs that appear to be having some effect can be compared with each other. MSF said it was crucial that if a drug worked, the patients in the treatment centre could continue to get it. “There is no stop,” said Antierens.