Monoclonal antibody treatment highly effective at reducing COVID-19 hospitalizations

Researchers believe treatment could remain effective against future variants of concern

SEATTLE — October 27, 2021 — Researchers today published interim results in The New England Journal of Medicine from a Phase 3 study of the COVID-19 monoclonal antibody treatment sotrovimab, sponsored by Vir Biotechnology and GlaxoSmithKline. The study found that compared to the placebo group, COVID-19 patients who received sotrovimab had a significantly reduced risk of hospitalization or death and that the treatment, which was administered by intravenous infusion on an outpatient basis, was safe.

Of the 583 study participants included in this analysis, three participants who received sotrovimab and 21 participants in the placebo group experienced disease progression that led to hospitalization or death, representing a risk reduction of 85% in people with COVID-19 who received the monoclonal antibody treatment. Among the participants who were hospitalized, five participants were admitted to intensive care units and one participant died, all of whom were in the placebo group.

These results are part of an interim analysis of the COMET-ICE Trial, a randomized, placebo-controlled, double-blinded, multicenter trial that enrolled participants across 37 sites in four countries, including at the COVID-19 Clinical Research Center (CCRC) at Fred Hutchinson Cancer Research Center. Final study results were announced by the companies in June 2021.

Fred Hutch scientists at the CCRC, which opened in October 2020, have collaborated with health care providers, research institutes, the biotech and pharmaceutical industries and volunteer study participants to study the safety and efficacy of five potential COVID-19 treatments. These studies focused on understanding whether providing outpatient treatment early in the course of COVID-19 infection could reduce severe disease, hospitalization and long-lasting symptoms.

“We’ve lost more than four million people globally to COVID-19, and many more have experienced serious illness, so it’s clear that we need multiple strategies to control the pandemic,” said Dr. Adrienne Shapiro, a physician-researcher at Fred Hutch and UW Medicine, and the corresponding author of the study. “Effective vaccines are the foundation for prevention and curbing the epidemic, but COVID-19 treatments are still needed for people who are immunocompromised or for people who don’t have access to COVID vaccines yet.”

The study authors pointed out that sotrovimab, a monoclonal antibody treatment that targets a highly conserved epitope of the virus, could be more effective at blocking variants of the SARS-CoV-2 virus because this region of the virus doesn’t appear to mutate as rapidly as other parts of the virus. In lab studies, sotrovimab was effective against Delta and all other circulating variants of concern. Based on the science of how this antibody treatment was identified, study authors hypothesized that sotrovimab could remain effective even if the virus continues to evolve and create new variants of concern.

“These results are possible because of cooperation among scientists at numerous trial sites across four counties and thanks to the participants, including those here in Seattle, who volunteered to help move the science forward,” said Dr. Rachel Bender Ignacio, a physician-scientist at Fred Hutch and UW Medicine, and the medical director of the COVID-19 Clinical Research Center at Fred Hutch. “We’ve been honored to play a part in better understanding ways to help people with COVID-19 heal more quickly and hopefully minimize spread of the virus.”

To qualify for study enrollment, participants were required to have a positive COVID-19 test, be within five days of the onset of COVID-19 symptoms and have at least one risk factor for developing a more serious course of illness. Risk factors were defined as being 55 years of age or older or having at least one of the following health conditions: diabetes for which medication was warranted, obesity, chronic kidney disease, congestive heart failure, chronic obstructive pulmonary disease or moderate to severe asthma.

The study was initiated before COVID vaccines were widely available in the U.S. Early treatments that can prevent hospitalization for COVID-19 continue to be important for people who are not yet vaccinated and for those who are immunocompromised such as cancer patients, bone marrow transplant recipients and people who take immunosuppressive medicines. When used in tandem with vaccines and non-pharmaceutical interventions, treatments for COVID-19 could reduce the overall spread and burden of COVID-19 disease.

“As long as people are getting COVID-19, there is a need for effective treatment to prevent serious illness and death,” said Dr. Shapiro. “Based on these efficacy results, we are excited for the potential of sotrovimab—which now has emergency use authorization from the FDA—to reduce hospitalizations and thus relieve the burden of hospital crowding, another serious consequence of the COVID-19 pandemic.”

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Media Contact:
Claire Hudson

At Fred Hutchinson Cancer Research Center, home to three Nobel laureates, interdisciplinary teams of world-renowned scientists seek new and innovative ways to prevent, diagnose and treat cancer, HIV/AIDS and other life-threatening diseases. Fred Hutch’s pioneering work in bone marrow transplantation led to the development of immunotherapy, which harnesses the power of the immune system to treat cancer. An independent, nonprofit research institute based in Seattle, Fred Hutch houses the nation’s first cancer prevention research program, as well as the clinical coordinating center of the Women’s Health Initiative and the international headquarters of the HIV Vaccine Trials Network and COVID-19 Prevention Network.


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