The current Ebola outbreak in the Democratic Republic of Congo (DRC) has been ravaging the country for over a year and is the second-largest Ebola outbreak in history, with more than 2,800 cases reported.
While there are currently no therapeutic options for Ebola, preliminary data from a clinical trial in the DRC that compared four drugs for the treatment of Ebola showed promising results.
Ebola treatment outlook
Regeneron Pharmaceuticals’ REGN-EB3 and Ridgeback Therapeutic’s mAb114 were able to reduce Ebola mortality rates to 29% and 32%, respectively. Given that the current outbreak has had a fatality rate of nearly 67%, GlobalData believes these two new therapies show high promise that Ebola will soon be a treatable disease, and could also help contain the spread of outbreaks.
The PALM study, sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) and the World Health Organisation (WHO), also included Mapp Biopharmaceutical’s ZMapp and Gilead’s remdesivir.
Both drugs showed significantly lower survival rates, at 49% for ZMapp and 53% for remdesivir. Although 700 patients in DRC Ebola hotspots have been tested in the study, preliminary results from 499 patients were so promising that the study was terminated early and patients who received ZMapp and remdesivir will now be treated with REGN-EB3 or mAb114.
REGN-EB3 is a mixture of three monoclonal antibodies (atoltivimab, maftivimab, and odesivimab) generated in mice, while mAb114, which was initially developed by the NIAID, is a monoclonal antibody derived from an antibody of an earlier Ebola outbreak survivor. Survival rates were even higher among patients with low levels of virus in their blood, at 94% for REGN-EB3 and 89% for mAb114. ZMapp, a mixture of three monoclonal antibodies (cosfroviximab, larcaviximab, and porgaviximab), was initially the most promising drug and was competing with REGN-EB3, mAb114, and Gilead’s antiviral remdesivir, an ribonucleic acid (RNA) polymerase inhibitor.
With Merck’s V920 (VSV-EBOV), an effective vaccine for Ebola is available that will likely receive FDA approval, but a military conflict and mistrust of foreign medical workers in the DRC has made wide distribution of the vaccine and containment of the outbreak very difficult.
With new treatment options available, hopes are high that Ebola outbreaks will see easier, more rapid containment, thus reducing the morbidity and mortality associated with Ebola.
Storage, maintenance and distribution
Key opinion leaders interviewed by GlobalData were hopeful that a vaccine would ease Ebola containment; provided therapeutics do not face the same problems as the vaccines, such as distribution difficulties in the conflict zones and supply shortages. Since these therapies are biologicals like vaccines, the problems of storage, cold chain maintenance, and safe administration conditions will likely continue to persist. However, these treatment options are expected to reduce the spread of Ebola to neighbouring countries, where vaccination has not been implemented, thereby reducing the fear of Ebola reaching densely populated areas and epidemic proportions.
GlobalData (2019). Expert Insight: With an Effective Experimental Vaccine on Hand, Why Is Ebola Containment Proving so Difficult? July 2019, GDHC2559EI
GlobalData (2019). Expert Insight: Highlights from an Exciting Year of Vaccine Development and Commercialization, February 2019, GDHC2248EI