In this medical claims study including 62% of the US population, we observe fewer than 70,000 patients received monoclonal antibody treatments for COVID-19 between first FDA emergency use authorization and April 11, 2021. During this time period, over 20 million cases of COVID-19 were diagnosed, 2.5 million monoclonal antibody treatments were purchased by the US government, and nearly 1 million treatments were allocated to states.2
Our findings of low uptake of monoclonal antibody treatments contrast to prior reports of increased use of unauthorized therapies.6 Reasons for low uptake warrant future research and could reflect stockpiling of allocated treatments, limited distribution by health systems, barriers to patient access to treatments which require intravenous infusion, or hesitancy to adopt treatments by providers and patients. The initial authorization of monoclonal antibodies occurred on the cusp of the largest surge in COVID-19 infections and the initial COVID-19 vaccine rollout. If health systems lacked the capacity to immediately develop additional infrastructure for administering antibody treatments due to competing priorities, we would have expected to see gradual growth in the use of monoclonal antibodies; however, we find that antibody use declined throughout 2021.
Despite limitations of missing data, the observed demographic and insurer differences in the treated population compared to the study base highlight a possible disparity in access. As many patients receive a COVID-19 diagnosis outside of the health system, through government, school, workplace, and other testing sites, our study was unable to determine the symptomatic population who would have been potentially eligible for monoclonal antibody treatments. Furthermore, these testing sites may not be equipped to refer patients to receive monoclonal antibody treatments, particularly if they do not already have a usual source of healthcare.
The public interest would be well-served by improved transparency on the allocation and administration of monoclonal antibody treatments, including data necessary to assess equitable access to treatments.