Scientists and doctors in the Democratic Republic of Congo are doing a clinical trial of new drugs to try to combat a year-long Ebola outbreak. The trial’s cosponsors at the World Health Organization and the National Institutes of Health declared that two of the experimental treatments has appeared to dramatically boost survival rates.
Though an experimental vaccine previously had been shown to shield people from catching Ebola, this news marks a first for people who already have been infected. “From now on, we will no longer say that Ebola is incurable,” said Jean-Jacques Muyembe, Director General of the Institute National de Recherche Biomedicale in the DRC, which has overseen the trial’s operations on the ground.
However, starting last November, patients in four treatment centers in the country’s east, were randomly assigned to receive one of four investigational therapies either an antiviral drug called remdesivir or one of three drugs that use monoclonal antibodies. Scientists concocted these big, Y-shaped proteins to recognize the specific shapes of invading bacteria and viruses and then recruit immune cells to attack those pathogens.
One of these, a drug known as ZMapp, is presently considered the standard of care during Ebola outbreaks. It had been tested and used during the devastating Ebola epidemic in West Africa in 2014. The goal was to check if those other drugs could outperform it. But preliminary data from the first 681 patients (out of a planned 725) showed very strong results that the trial has now been stopped.
Patients who received Zmapp in the four trial centers experienced an overall mortality rate of 49 percent, as per Anthony Fauci, Director of the NIH’s National Institute of Allergy and Infectious Diseases. (Mortality rates are in excess of 75 percent for infected individuals that don’t seek any form of treatment.) The monoclonal antibody cocktail produced by a company called Regeneron Pharmaceuticals had the biggest impact on lowering death rates, down to 29 percent, while NIAID’s monoclonal antibody, known as mAb114, had a mortality rate of 34 percent.
The results were most striking for patients which received treatments soon after becoming sick, when their viral loads were still low death rates dropped to 11 percent with mAb114 and just 6 percent with Regeneron’s drug, compared with 24 percent with ZMapp and 33 percent with Remdesivir.
Drugs which are based on monoclonal antibodies have become a mainstay of modern medicine fending off a variety of diseases from cancer to lupus. However, it takes many years of painstaking reverse-engineering to make them. Zmapp, for example, was developed by infecting mice with Ebola and then collecting the antibodies the mice produced against the virus. Those antibodies then had to be further engineered to look more like a human antibody, so as not to provoke an immune reaction.
An even better solution, some have posited, will be to mine the serum of Ebola survivors and harvest the DNA from the white blood cells that make antibodies. It would yield a set of genetic instructions for making antibodies with a proven track record against the Ebola virus. That’s what the NIH’s mAb114 is an antibody isolated from the blood of a survivor of a 1995 outbreak in Kikwit, DRC.
Now with the WHO’s announcement a new trial will kick off, directly comparing Regeneron to mAb114, which is being produced by a Florida-based company called Ridgeback Biotherapeutics. All Ebola treatment units in the outbreak zone will only administer the two most effective monoclonal antibody drugs, as per the WHO’s Director of Health Emergencies, Mike Ryan.
Ryan said, “Today’s news puts us one more step to saving more lives. The success is clear. But there’s also a tragedy linked to the success. The tragedy is that not enough people are being treated. We are still seeing too many people staying away from treatment centers, people not being found in time to benefit from these therapies.”
Source- Wired
