First effective Ebola treatment a step closer after breakthrough trial

Clinical trials of four experimental treatments for Ebola in the Congo have been halted early after two of the drugs showed compelling benefits in a breakthrough against the deadly virus.

In an extension of the original study patients have immediately been switched to receive either Regeneron’s REGN-EB3 or Ridgeback’s mAb114 after they were found to block the virus’ progression.

The two monoclonal antibodies outperformed Mapp’s ZMapp and Gilead’s remdesivir in the trial, with REGN-EB3 eliciting the lowest overall death rate – at 29% – while mAb114 achieved a mortality rate of 34%.

Initially, the Ebola trial, which began in November 2018, involved three drugs – mAb114, remdesivir and ZMapp. The World Health Organization (WHO) then assessed all preclinical and clinical data on all available investigational products, and recommended the addition of REGN-EB3 as a fourth treatment.

The Pamoja Tulinde Maisha (PALM [together save lives) randomised, controlled trial was run in the Democratic Republic of the Congo (DRC) as part of the emergency response to an ongoing Ebola outbreak in the country’s North Kivu and Ituri Provinces.

The trial’s independent data and safety monitoring board (DSMB) and the study leadership decided preliminary analysis of the existing data was compelling enough to halt the original trial and focus on the two successful candidates.

The study was co-sponsored and funded by the INRB and the National Institute of Allergy and Infectious Diseases (NIAID) of the NH, and carried out by an international research consortium coordinated by the WHO.

Neil Stahl, executive vice president of research and development at Regeneron, said: “The Regeneron team worked tirelessly to discover, develop and produce REGN-EB3 in record time utilising our VelocImmune-based technologies.

“We are moved to know our therapy is helping save the lives of people facing this deadly infectious disease. We look forward to reviewing the trial data and are working with governments and other collaborators, including BARDA (Biomedical Advanced Research and Development Authority), to make REGN-EB3 available for the current outbreak and future use.”

The other successful investigational drug, mAb114, was developed by the US National Institutes of Health (NIH), which isolate an antibody retained by a human Ebola survivor and licensed it to Ridgeback for further development in 2018.

Wendy Holman, CEO and co-founder of Ridgeback Biotherapeutics, said: “I am very proud of what the Ridgeback team has accomplished in less than a year and we will continue to concentrate on ensuring that mAb114 is available to respond to the current and any future outbreaks.”

The complete results will be submitted for publication in the peer-reviewed medical literature as soon as possible.