US firm announces clinical trial of first U.S. Covid-19 antibody cocktail

NEW YORK – Regeneron Pharmaceuticals announced in a press release on June 11 that the first U.S. clinical trial of REGN-COV2, its investigational dual antibody cocktail for the prevention and treatment of COVID-19, began on June 10. Greek-American George D. Yancopoulos, MD, Ph.D., Co-Founder, President, and Chief Scientific Officer of Regeneron, had told The National Herald in an interview in March about the effort to develop the antibody cocktail, noting then that trials could begin as early as June.

According to the press release, the REGN-COV2 clinical program will consist of four separate study populations: hospitalized COVID-19 patients, non-hospitalized symptomatic COVID-19 patients, uninfected people in groups that are at high risk of exposure (such as healthcare workers or first responders) and uninfected people with close exposure to a COVID-19 patient (such as the patient’s housemate). The placebo-controlled trials will be conducted at multiple sites.

“We have created a unique anti-viral antibody cocktail with the potential both to prevent and treat infection and also to preempt viral ‘escape,’ a critical precaution in the midst of an ongoing global pandemic,” said Dr. Yancopoulos said in the press release. “REGN-COV2 could have a major impact on public health by slowing the spread of the virus and providing a needed treatment for those already sick – and could be available much sooner than a vaccine. The antibody cocktail approach may also have long-term utility for elderly and immuno-compromised patients, who often do not respond well to vaccines. Ultimately, the world needs multiple solutions for COVID-19, and the innovative biopharma industry is collectively working hard to help as many people as possible with a variety of complementary approaches.”

Regeneron used the same “rapid response” capabilities and cocktail approach to developing REGN-EB3, a novel triple antibody treatment for Ebola that is now under regulatory review by the U.S. Food and Drug Administration (FDA). REGN-COV2’s preclinical development and preclinical/clinical manufacturing has been funded in part with federal funds from the Biomedical Advanced Research and Development Authority (BARDA), part of the office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services.

The first two adaptive Phase 1/2/3 studies are evaluating REGN-COV2 (REGN10933+REGN10987) as a treatment for hospitalized and non-hospitalized patients with COVID-19. The Phase 1 portion will focus on virologic and safety endpoints, and the Phase 2 portion will focus on virologic and clinical endpoints. Data from Phase 1 and Phase 2 studies will be used to refine the endpoints and determine the size for the Phase 3 studies.

“We are particularly excited to begin studies of REGN-COV2, which is a novel antibody cocktail targeted specifically against SARS-CoV-2,” said trial investigator Dr. Suraj Saggar, Chief of Infectious Disease at Holy Name Medical Center in Teaneck, NJ. “Over the last long months, we have learned that repurposing existing medicines, unfortunately, does not offer a broadly effective solution for COVID-19. For this reason, we need to investigate custom-designed approaches like REGN-COV2. The first studies will evaluate if REGN-COV2 can improve disease outcomes in both hospitalized and non-hospitalized patients with COVID-19.”

About Regeneron’s Anti-Viral Antibodies

When faced with a harmful pathogen, such as a virus or bacteria, the human immune system typically produces antibodies to fight the invader. Specifically, the immune system produces “anti-viral” antibodies that recognize, bind, and kill or neutralize the virus. Vaccination involves injecting a dead or weakened virus, or a critical small piece of a virus, to induce this protective immune response, resulting in the same antibodies the immune system would typically make in a person who actually had the infectious disease.

Regeneron’s core technologies allow for the rapid and efficient generation of these protective anti-viral antibodies outside of the body, derived from either genetically-humanized mice or convalescent humans. The resulting antibodies correspond to the most potent of anti-viral antibodies that could be elicited by a vaccine or through exposure to a pathogen. These antibodies can be delivered to people via injection, providing “passive immunity” and protection from the disease immediately, though they must be re-administered to remain effective over time. These antibodies can also treat an existing infection, unlike vaccines which can only be used preventatively.

The concept that drug cocktails can prevent viral escape has previously been demonstrated for traditional antiviral drugs used to treat HIV and other viruses. In the upcoming Science publications, Regeneron scientists report the fundamental realization that this can also be true for antibody-based therapies. Regeneron’s preclinical studies demonstrate that, in the setting of a single therapeutic antibody that blocks the ability of a virus to infect healthy cells, spontaneously arising mutant forms of the virus are able to “escape” or evade the antibody’s blocking action. These mutants are then “selected” (i.e., are able to survive and proliferate despite the single antibody treatment) and may ultimately become the dominant strain of the virus. Regeneron, therefore, pursues a multi-antibody cocktail approach designed to decrease the potential for the virus to escape.

Regeneron has developed additional technologies that allow for the large-scale manufacturing and purification of these anti-viral antibodies, potentially allowing many people to be granted immunity before vaccines become widely available.

More information about Regeneron is available online: regeneron.com.