Regeneron Earns First-Ever FDA Approval For Ebola Treatment

The U.S. Food and Drug Administration (FDA) announced on October 14 that it has approved Inmazeb, an antibody cocktail designed to treat the Ebola virus. The drug, which is a mixture of three monoclonal antibodies administered via injection, is the first FDA-approved treatment for the virus.

“Today’s action demonstrates the FDA’s ongoing commitment to responding to public health threats—both domestically and abroad—on the basis of science and data,” said FDA Commissioner Stephen M. Hahn, MD, in a news release.

Inmazeb is manufactured by Regeneron, the same company behind the antibody cocktail aimed at treating COVID-19.

“We are incredibly proud that the FDA has approved Inmazeb, which is also known as REGN-EB3,” George D. Yancopoulos, MD, PhD, President and Chief Scientific Officer of Regeneron said in a news release for the company. “This is the first time the FDA has approved a treatment specifically for Ebola, which has caused a number of deadly outbreaks.”

According to the World Health Organization (WHO) the average Ebola virus disease (EVD) case fatality rate is around 50%. In the past, case fatality rates have varied from 25 to 90%. The most recent Ebola virus outbreak began in June in the Democratic Republic of the Congo and, as of September, 110 cases, including 47 deaths, have been reported as a result. Ebola made headlines in the U.S. in 2014, when only four cases were diagnosed in the country.

“The approval of Inmazeb is not only a big deal, it is the approach to prevent future Ebola pandemic worldwide,” Anton Bizzell, MD, CEO and President of The Bizzell Group, tells Verywell.

Inmazeb, which is a three-part combination of atoltivimab, maftivimab, and odesivimab-ebgn antibodies was evaluated in 382 adult and pediatric patients who were confirmed to have Ebola virus.

“Inmazeb targets the glycoprotein that is on the surface of Ebola virus,” the FDA release says.

Typically, glycoprotein would attach to a cell receptor in humans, allowing the virus to enter the body. But Inmazeb's antibodies bind to glycoprotein, preventing it from attaching to the receptor and infiltrating the cell.

Are There Any Side Effects?

According to the FDA, the most common symptoms participants experienced while receiving Inmazeb during clinical trials included fever, chills, tachycardia (fast heart rate), tachypnea (fast breathing), and vomiting; however, these are also common symptoms of Ebola virus infection. 

What Has Past Treatment Been Like?

Prior to an FDA-approved antiviral drug, Ebola virus symptoms were treated as they appeared, according to the CDC. Treatments included:

• Intravenous fluids and electrolytes
• Oxygen therapy
• Medication to support blood pressure
• Medication to reduce vomiting and diarrhea
• Medication to manage fever and pain

“The mainstay of treatment for Ebola is supportive care,” Soma Mandal, MD, a board-certified internist at Summit Medical Group in Berkeley Heights, New Jersey, tells Verywell. “This is to maintain adequate cardiorespiratory and renal function. Continuous monitoring of vital signs and respiratory support may be needed.”  

WHO allowed for compassionate use of experimental antiviral treatments during the outbreak in West Africa in 2014.

In December 2019, the FDA gave the green light to Ervebo, the first FDA-approved vaccine for the prevention of Ebola virus disease.

“While the risk of Ebola virus disease in the U.S. remains low, the U.S. government remains deeply committed to fighting devastating Ebola outbreaks in Africa, including the current outbreak in the Democratic Republic of the Congo,” Anna Abram, FDA Deputy Commissioner for Policy, Legislation, and International Affairs said in a news release at the time.