New published data shows that the monoclonal antibody combination therapy, REGN-EB3 developed by Regeneron Pharmaceuticals, and the monoclonal antibody Mab114 developed by the National Institutes of Health and licensed by Ridgeback Biotherapeutics, are superior to ZMapp in preventing death due to the Ebola virus.
The clinical trial was published in the New England of Medicine and showed REGN-EB3 had a mortality rate of 33.5%, Mab114 had a mortality rate of 35.1%, while ZMapp had a mortality rate of 51.3%.
The study was conducted in the Democratic Republic of Congo (DRC) during the Ebola virus outbreak that began in August of 2018. In total, 681 patients were involved in the trail and they received one of four treatments: ZMapp (control group), REGN-EB3 (triple monoclonal antibody therapy), Mab114 (single monoclonal antibody therapy), or remdesivir (antiviral agent).
The primary end point was death at 28 days and interim analysis of the data in August 2019 showed that both REGN-EB3 and Mab114 to be superior to the ZMapp and the trial was stopped. The interim data showed that death occurred in 79 of 154 (51.3%) in the ZMapp group, 52 of 155 (33.5%) in the REGN-EB3 group, 61 of 174 (35.1%) in the MAb114 group, and 93 of 175 (53.1%) patients in the remdesivir group.
Both REGN-EB3 and MAb114 have orphan drug designation.
In a news release by Regeneron, they stated, “We are committed to continuing to provide this important treatment to patients through the PALM trial extension trial and ‘compassionate use’ until the current outbreak ends. We are also working closely with the U.S. Food and Drug Administration to gain regulatory approval and with U.S. and global health authorities to determine appropriate stockpiling of REGN-EB3, as we believe our triple antibody approach may have particular utility for future outbreaks.”
The CEO of Ridgeback Biotherapeutics added, “This landmark study will permanently change the outlook for Ebola patients. Ebola is a disease that can be treated, especially if patients are treated early in the course of the disease. The PALM trial coordinators were able to accomplish a feat which many said could not be done – conduct a scientifically rigorous clinical trial in the midst of a complicated and ever-changing Ebola outbreak. The results published today demonstrate the incredibly robust impact that mAb114 has on this devastating and deadly disease.”
Ebola virus disease is a rare but often fatal illness. The virus is transmitted to humans from wild animals but can spread in the human population through human-to-human transmission. Two recent outbreaks, one in West Africa from 2014 to 2016 and one in DRC that is ongoing. Several treatments and vaccines are in development for this highly deadly condition.