Vir Biotechnology and GlaxoSmithKline dosed the first patient last week in a Phase II/III clinical trial of VIR-7831, a fully human monoclonal antibody against COVID-19. The trial is evaluating the therapy as early treatment for COVID-19 patients at high risk of hospitalization.
They now join a number of other companies, including Regeneron Pharmaceuticals, in testing monoclonal antibodies against COVID-19. Regeneron, with the U.S. National Institute of Allergy and Infectious Diseases (NIAID), launched their Phase III trial of REGN-COV2, a two-antibody cocktail against SARS-CoV-2, in late July.
This is different than the convalescent plasma treatment that recently received Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration. Convalescent plasma antibody therapy takes blood plasma collected from patients who have recovered from COVID-19, using their antibodies against the virus as treatment.
In monoclonal antibody therapy, companies isolate antibodies from immune cells and screen them for their affinity for the SARS-CoV-2 virus and concentrate them into a therapeutic. Although not a vaccine, they are believed to offer a potential resistance and effectiveness against infections for a limited period of time, perhaps up to three months.
The Vir-GSK COMET-ICE study plans to enroll about 1,300 patients globally who have early symptoms of infection. The goal is to evaluate VIR-7831, a single-dose monoclonal antibody, to see if it can prevent hospitalization from the disease. They expect results before the end of the year with complete data in the first quarter of 2021, and possibly early access to treatment in the first half of 2021.
“Treating those with early COVID-19 disease so that it doesn’t become worse is critical both for the patients and for society,” said George Scangos, chief executive officer of Vir. “Hospital systems are overwhelmed worldwide, with new infections continuing to strain already limited resources. This study is designed to demonstrate whether VIR-7831 can significantly reduce the need for hospitalization in high-risk individuals, such as the elderly or those with pre-existing conditions such as lung or heart disease.”
Preclinical studies with VIR-7831 show affinity for the SARS-CoV-2 spike (S) protein and demonstrated high potency in neutralizing the virus. This at least suggests a high barrier to resistance and an ability the recruit immune cells to kill already infected cells. The antibody has also been designed to improve the antibody’s availability to the lungs.
COMET-ICE has two parts. The first will act as the first-in-human evaluation for safety and dosing. It will test the safety and tolerability of a single 500mg intravenous (IV) infusion of VIR-7831 compared to placebo over a 14-day period in non-hospitalized patients. It hopes to recruit 20 patients across the U.S.
After the first part is completed, the Expansion phase will determine whether it reduces the need for hospitalization. It will test the safety and efficacy of a single IV infusion of VIR-7831 or placebo in about 1,300 non-hospitalized patients around the world. The primary efficacy endpoint is percentage of patients with mild or moderate COVID-19 who worsen, as defined as the need for hospitalization or death, within 29 days of randomization.
The COMET clinical development program has two more planned trials, one for severely ill hospitalized patients and another for prophylaxis of symptomatic infection.
The companies also have another potential antibody, VIR-7832, which is similar to VIR-7831, but might act as a therapeutic or potentially prophylactic T-cell vaccine.
“Monoclonal antibodies directed against the SARS-CoV-2 virus could provide an effective and immediate immune response to COVID-19, bypassing the need for our body to produce its own antibodies, which is particularly important in the absence of an effective vaccine,” said Hal Barron, chief scientific officer and president R&D, for GSK. “This study will assess the ability of VIR-7831 to prevent high-risk individuals from progressing to severe disease, and in future studies we will also test the antibody’s ability to prevent infection in high-risk patients and to reduce disease severity in patients who are already hospitalized.”