The U.S. Department of Health and Human Services (HHS) plans to allocate to states and territories initial doses of Regeneron Pharmaceuticals' investigational monoclonal antibody therapeutic, casirivimab and imdevimab, for treatment of non-hospitalized patients with mild or moderate confirmed cases of COVID-19 at high risk of hospitalization.
The move follows the U.S. Food and Drug Administration’s decision November 21 to grant emergency use authorization (EUA) for the treatment.
The medicine is a combination of two virus-neutralizing monoclonal antibodies. Monoclonal antibodies, which mimic the human immune system, are produced outside of the body by a single clone of cells or a cell line with identical antibody molecules and then delivered to patients by injection or infusion. The antibodies bind to certain proteins of a virus, reducing the ability of the virus to infect human cells.
In a clinical trial of patients with COVID-19, casirivimab and imdevimab, administered together, were shown to reduce COVID-19-related hospitalization or emergency room visits in patients at high risk for disease progression within 28 days after treatment, compared to a placebo. The safety and effectiveness of this investigational therapy for use in the treatment of COVID-19 continues to be evaluated.
In July, the federal government announced federal funding to support large-scale manufacturing of casirivimab and imdevimab with approximately 300,000 doses of the medicine expected to result from the project.
HHS said it will use a data-driven system to ensure fair and equitable distribution of these new products. Beginning immediately, weekly allocations to state and territorial health departments will be proportionally based on confirmed COVID-19 cases in each state and territory over the previous seven days, based on data hospitals and state health departments enter into an HHS data collection platform.
The intravenous administration of therapeutics to non-hospitalized patients with confirmed mild to moderate COVID-19 presents unique challenges. To accommodate IV infusions, outpatient facilities must have appropriate healthcare staffing, training and equipment, the FDA said.
The infusion process takes approximately one hour and may be followed by an observation period. Under the EUA, casirivimab and imdevimab must be administered together and in settings where healthcare providers have immediate access to medications to treat a severe infusion reaction, such as anaphylaxis, and the ability to activate the emergency medical system (EMS), as necessary. Facilities also must have space available to administer the medication in a manner that minimizes infection transmission.
Regeneron developed casirivimab and imdevimab with preclinical and clinical development support through an agreement with the Biomedical Advanced Research and Development Authority (BARDA), part of the HHS Office of the Assistant Secretary for Preparedness and Response. Regeneron used the same proprietary technology platforms and cocktail approach to develop a novel triple antibody treatment for Ebola that is now under regulatory review by the FDA.
