Scientists trialling new Ebola treatments in the Democratic Republic of Congo have found two drugs make a remarkable difference to survival rates.
In a randomised trial of around 700 patients with the disease – currently seeing its second deadliest outbreak ever – two of the four drugs being tested emerged as more effective than others at treating it.
The two drugs, REGN-EB3 developed by Regeneron Pharmaceuticals and mAb114 by NIH researchers, are antibodies that work by blocking the virus.
The preliminary findings prompted an early halt to the major study on the drugs and a decision to prioritise their use in the DRC, where a year-long outbreak has killed more than 1,800 people.
The early results mark “some very good news,” said Dr Anthony Fauci of the US National Institutes of Health, which helped fund the study. With these drugs, “we may be able to improve the survival of people with Ebola”.
It is not yet clear which of several potential treatments are best for those who have already fallen sick. During the West Africa Ebola epidemic between 2014 and 2016, studies hinted that another antibody mixture named ZMapp worked, but not clear proof.
On Friday, independent monitors of the trial reviewed preliminary results for 499 patients and found enough difference to call it to an early halt. The panel determined that the Regeneron compound was working better than the others, and the NIH antibody wasn’t far behind, Dr Fauci said.
NIH said 49 per cent of the patients on ZMapp and 53 per cent on Remdesivir died in the study. In comparison, 29 per cent of the patients on REGN-EB3 and 34 per cent on mAb114.
More striking still, when patients sought care early, before too much of the virus was in their bloodstream, the mortality rate dropped to just 6 per cent with the Regeneron drug and 11 per cent with the NIH compound, compared to about 24 per cent for ZMapp.
Next, researchers will conduct further studies to find out exactly how well the two drugs work.
In July, the World Health Organisation declared a public health emergency of international concern in the DRC as the crisis worsened.
The emergency declaration is one of the most serious actions available to the WHO. Previous emergency declarations have focused on the emergence of Zika in the Americas, the swine flu pandemic and polio.
The most recent of those occasions was the major Ebola outbreak in West Africa between 2014 and 16, which killed more than 11,000 people.
The NIH, DRC health authorities and the WHO hailed the "extraordinary team of individuals who have worked under extremely difficult conditions to carry out this study," as well as the patients and their families.
"It is through this type of rapidly implemented, rigorous research that we can quickly and definitively identify the best treatments and incorporate them into the Ebola outbreak response," they said.