Regeneron’s FDA Success with Ebola Treating Antibody Cocktail, Inmazeb, Bodes Well for its COVID-19 Candidate

By Daniel Ojeda, Ph.D.

On October 14th, 2020, Regeneron Pharmaceuticals, Inc., announced Inmazeb had become the first FDA-approved therapy to treat Zaire ebolavirus in adult and pediatric patients. Inmazeb showed to be more effective at reducing mortality than other experimental treatments, ZMapp, and remdesivir.

Inmazeb (REGN-EB3) is an antibody cocktail consisting of three separate monoclonal antibodies (atoltivimab, maftivimab, and odesivimab). These antibodies bind to the ebolavirus glycoprotein that infects the host cells. As a result, Inmazeb mitigates the infection and/or recruit immune cells to target infected cells.

Inmazeb was developed using VelociSuite technologies. This is the same technology used to develop the antibody cocktail currently in clinical trials to treat COVID-19. This approval is an important proof of concept for this technology and could allow Regeneron to confidently pursue their COVID-19 candidate and also produce therapies for other emerging infectious diseases.

“Decades of investment in our VelociSuite® rapid response technologies, the dedication of world-class scientists, and the courageous contributions of healthcare providers and patients, together with remarkable cooperation between leading international health organizations and governments, have led to this important moment,” stated George D. Yancopoulos, M.D., Ph.D., President and Chief Scientific Officer of Regeneron. “As we apply the same sophisticated technologies and manufacturing capabilities against COVID-19, we hope this will be one of many demonstrations of how the power of science can be successfully deployed against dangerous infectious diseases.”

Ebolavirus

Ebola virus disease (EVD) is a very deadly disease with a mortality rate between 25%-90% in past outbreaks. This disease is caused by the Zaire ebolavirus, which can be transmitted to humans from wild animals, such as bats, porcupines, and non-human primates. The symptoms include fever, diarrhea, vomiting, severe pain, and unexplained hemorrhaging, bleeding, or bruising. Human to human transmission occurs via direct contact with the blood and bodily fluids of infected people and contact with materials and surfaces contaminated with these fluids.

The 2014-2016 outbreak in West Africa was the largest outbreak recorded since the virus was discovered in 1976. Additionally, on June 1st, 2020, a new outbreak was declared in the Democratic Republic of the Congo, making the approval of Inmazeb even more crucial.

PALM Trial

The clinical trial to determine the safety and efficacy of Inmazeb was known as PAmoja TuLinde Maisha (PALM). It was a 681-patient, randomized, multicenter, controlled trial initiated in 2018 in the Democratic Republic of Congo (DRC). PALM was co-sponsored by the WHO, the National Institutes of Health (NIH), and the Institut National de Recherche Biomédicale (INRB) in the DRC. The trial was stopped early after results showed higher efficacy of Inmazeb compared to ZMapp, another antibody cocktail, and remdesivir, a nucleotide analog that interferes with viral replication.

The most common side effects observed in at least 10% of the patients were chills, an increase in fever, tachycardia, rapid breathing, vomiting, diarrhea, and others. Only chills were more frequent in Inmazeb treated patients than ZMapp patients.

Power of Public-Private Partnerships

In July 2020, Regeneron announced an agreement with the Biomedical Advanced Research and Development Authority (BARDA) to provide an established number of doses during the next six years to building national preparedness for public health emergencies. That agreement was contingent on FDA approval. Now, Regeneron is set to receive $10 million next year in compensations and $67 million per year on average over the next five years. Additionally, with BARDA’s support, Regeneron will continue to provide Inmazeb for free in response to outbreaks in the DRC. To ensure continued access to the therapy in low- and middle-income countries, Regeneron is also working with non-governmental organizations and public health agencies.

Gary Disbrow, the Acting Director of BARDA, said, “Since 2015, BARDA has partnered with Regeneron to develop a life-saving treatment for Ebola Zaire. The Food and Drug Administration’s approval of Inmazeb shows the power of public-private partnerships to bring forward these critical treatments and improve global public health”.

Related Article: GSK, Vir Collaboration Drives Advanced Clinical Trial for Novel COVID-19 Antibody Forward

References

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829775/#:~:text=Ebolavirus%20(EBOV)%20is%20a%20highly,and%20catalysis%20of%20membrane%20fusion.
2. https://investor.regeneron.com/news-releases/news-release-details/regenerons-antibody-cocktail-regn-eb3-inmazebr-first-fda
3. https://www.cdc.gov/vhf/ebola/outbreaks/drc/2020-june.html
4. https://www.who.int/health-topics/ebola/#tab=tab_1
5. https://www.sciencedirect.com/topics/immunology-and-microbiology/zmapp
6. https://www.gilead.com/purpose/advancing-global-health/covid-19/about-veklury-remdesivir
7. https://investor.regeneron.com/news-releases/news-release-details/barda-procures-regenerons-regn-eb3-investigational-ebola

Author

Daniel Ojeda