Ebola: new drugs show promise, but we’re not out of the woods yet

I’m encouraged to hear that two new drugs to treat Ebola are showing promise, but the process of testing them has been fraught with difficulty – and bloodshed.  Nature reports:

The race to develop treatments for Ebola has accelerated since the largest epidemic in history devastated West Africa between 2014 and 2016. Scientists responding to the ongoing outbreak in the Democratic Republic of the Congo (DRC) have enrolled more than 500 participants in an unprecedented study of experimental drugs, vaccinated nearly 170,000 people, and sequenced the genomes of more than 270 Ebola samples collected from the sick.

. . .

Working in a conflict zone has forced researchers to adapt and persevere to an extraordinary degree. They have learnt how to conduct rigorous studies in areas where killings, abductions and arson are commonplace, and where Ebola responders have come under repeated attack.

. . .

Every aspect of the outbreak is affected by the area’s long history of conflict and trauma. Residents have endured more than two decades of terror from armed groups, along with resource exploitation, political instability and neglect from the world at large. That has bred distrust of authorities — including foreign health workers — and conspiracy theories about why Ebola is thriving. One popular rumour alleges that Ebola responders inject people with deadly substances at treatment centres and vaccination sites.

These false ideas have fostered nearly 200 attacks on Ebola responders and treatment centres so far this year, according to the WHO. Seven people have been killed and 58 injured.

To adapt to the conflict, clinical researchers at an Ebola centre in Beni operated by the French medical charity ALIMA give mobile phones to patients who check out of the clinic. This allows them to stay in touch about lingering symptoms, even if violence makes it impossible to keep follow-up appointments. Many people use the service as an emergency helpline, says Émilie Gaudin, a support officer at ALIMA. “Sometimes a patient calls us and says, ‘People want to kill me,’ or ‘I want to kill myself.’”

Despite this difficult environment, the drug trial is nearing completion. Researchers are 14 people shy of their goal of enrolling 545 participants, a threshold that should allow them to draw strong conclusions about the drugs’ efficacy. But there are already hints that the treatments are working. The mortality rate at Ebola treatment centres, where all patients receive one of the experimental drugs, is 35–40% — compared with 67% overall in this outbreak. The latter figure reflects the large number of people who have died at home or in facilities that aren’t equipped to treat Ebola.

Violence has also hampered vaccination efforts. A few months ago, Diallo Abdourahamane, the WHO’s Ebola vaccine coordinator, heard about a man in the town of Katwa who his team had immunized with an experimental Ebola vaccine made by the pharmaceutical company Merck. The man had told sceptical onlookers that the vaccine would protect against the disease. “But after the team left,” Abdourahamane says, “the neighbours came and surrounded him at night. They said ‘You are the one helping to bring Ebola to our area’ — and they killed him.”

There’s more at the link.

Two new drugs have shown promise in the trials, provided they’re administered as soon as possible after infection.  That, in itself, is a problem, as many Congolese are deathly afraid of being identified as Ebola carriers.  They’d rather wait at home, hoping against hope that they have flu or something simple, rather than the deadlier disease;  so by the time they’re brought to a treatment center and diagnosed, it may be too late for the new drugs to have their desired effect.  Even so, the results hold out hope.

The survival rate for people who received either drug shortly after infection, when levels of the virus in their blood were low, was 90%.

. . .

One of the drugs, REGN-EB3, is a cocktail of three monoclonal antibodies against Ebola made by Regeneron Pharmaceuticals of Tarrytown, New York. The second, mAB114, is derived from a single antibody recovered from the blood of a person who survived Ebola in the DRC in 1995 , and was developed by the US National Institute of Allergy and Infectious Diseases (NIAID).

Both drugs outperformed two other experimental treatments in the unprecedented multi-drug clinical trial in the DRC, the World Health Organization, INRB and NIAID said in a joint statement on 12 August. Preliminary data from the first 499 people enrolled in the study show that 29% of people given REGN-EB3 died, compared with 34% of those who received mAb114.

Again, more at the link.

I’ll be holding thumbs that further tests, and possibly further refinement of the two drugs, will lead to an even greater reduction in the death rate.  If an effective treatment for Ebola becomes available, it’ll be a huge relief to countries like ours, that up until now have been faced with the possibility of an untreatable, almost invariably fatal disease showing up without warning in our major urban centers.  We’ve had no answer to that before now.  Here’s hoping the new drugs will provide one.

Peter