- The Food and Drug Administration on Wednesday approved the first treatment for the Ebola virus, clearing an antibody drug cocktail that was shown in a landmark 2019 study to reduce the risk of dying from the lethal and feared infectious disease.
- U.S. government researchers, working together with international aid groups and investigators from the Democratic Republic of Congo, tested the drug alongside three other antiviral treatments in the trial, which was conducted last year during the recent Ebola virus outbreak in the central African country.
- The drug, now dubbed Inmazeb, was developed by New York biotech Regeneron in response to a different Ebola outbreak that spread virulently throughout several West African nations between 2014 and 2016. But, in a twist of fate, that outbreak was checked before the company's treatment could be tested in a clinical trial.
Regeneron scientists are months into day-and-night work developing a drug for COVID-19, building on the years of research that led to Wednesday's approval for Inmazeb.
Both Inmazeb and REGN-COV2, the company's experimental coronavirus treatment, are infusions of synthetic antibodies, designed to mimic the immune defenders the body relies on to neutralize viruses and other pathogens. In the case of Inmazeb, the drug comprises three separate antibodies, while REGN-COV2 is a mixture of two.
The treatments are meant to grab an invading virus and block its protruding proteins from latching onto the body's cells. Combining several antibodies together, Regeneron has shown, can prevent viruses from eluding the antibodies' grasp.
In the Ebola study that proved Inmazeb's worth, fewer patients treated with Regeneron's drug died after 28 days than did among those given a control drug known as ZMapp. The percentage of patients on Imazeb who died, 34%, was lower than the percentage of those treated with an antibody from Ridgeback Biotherapeutics (35%) and those given remdesivir, an antiviral drug from Gilead that's now approved for emergency use against COVID-19 (53%).
With the approval, Inmazeb is the first treatment approved by the FDA for Ebola, joining a recently cleared vaccine from Merck & Co. Regulators in Europe have also approved an Ebola vaccine developed by Johnson & Johnson.
Together, the vaccines and Regeneron's drug give public health officials and physicians a much improved toolkit with which to contain and stop future outbreaks of Ebola virus disease. Ten outbreaks have been recorded by the World Health Organization since the virus was first identified in 1976. The most recent, in the Democratic Republic of Congo, was second only to the 2014-2016 West African outbreak in lethality, claiming more than 2,200 lives.
Regulators noted treatment with Inmazeb was associated with fever, chills, fast heart beat and breathing, but those are also symptoms of Ebola virus infection. Treatment should not be given concurrent to vaccination, as Regeneron's drug may interfere with the replication of a live vaccine virus, the FDA said.
Regeneron currently provides Inmazeb for use in the DRC under a compassionate use program. The company said it would work with non-governmental organizations and health agencies to ensure drug access in low- and middle-income countries.
The U.S. government has contracted with Regeneron for a supply of the drug over six years, agreeing to pay $10 million in 2021 and an average of $67 million per year through 2026.
Regeneron and the U.S. are also working together on REGN-COV2, which was recently used to treat President Donald Trump. Initial data suggest the antibody could help ease symptoms among people recently diagnosed with coronavirus disease, and may help to clear the virus faster.
The company has asked the FDA for an emergency authorization for REGN-COV2.
Editor's note: This story has been updated to include additional data from the Ebola trial testing Inmazeb, remdesivir and the molecule from Ridgeback Biotherpaeutics.