Monoclonal Antibody Infusions for Outpatient Management of Mild-Moderate COVID-19.

Background: The COVID-19 pandemic has led to a rapid, exponential increase in hospitalizations and morbidity/mortality. In November 2020, the Food and Drug Administration (FDA) issued Emergency Use Authorizations (EUAs) permitting administration of the first monoclonal antibodies (mAb) for outpatient treatment of COVID-19. Early data showed a reduction in COVID-19-related hospitalizations with few adverse events. However, since these treatments are only authorized under an EUA, real-world data are minimal.

Objective: To assess efficacy and safety of mAbs in a veteran population.

Methods: This retrospective study analyzed veterans at the Ralph H. Johnson Veterans Affairs Health Care System with mild-moderate COVID-19 and screened for mAb eligibility between December 1, 2020, and October 31, 2021. The primary outcome was hospitalizations and/or emergency department (ED) visits within 30 days. Secondary outcomes included 30-day mortality and post-COVID-19 conditions. Adverse events were also evaluated. Outcomes were compared between mAb-treated patients and eligible veterans who were not treated.

Results: There were 296 and 275 veterans in the mAb and control groups, respectively. No statistically significant difference was found for the primary outcome overall (25.7% vs 25.1%; P = 0.87), nor for COVID-19-related return visits or hospitalizations (13.9% v. 16%; P = 0.4). However, the mAb group had more return ED visits (P = 0.35), and the control group had significantly more hospitalizations (P = 0.02). Vaccinated veterans who received an mAb had fewer return visits and hospitalizations (P = 0.01). More mAb-treated veterans experienced post-COVID-19 conditions. No difference in mortality was found. Four nonsevere adverse events occurred after the mAb therapy.

Conclusion and relevance: Overall, the mAbs appeared safe and effective. Sicker, higher-risk mAb-treated veterans faired similarly to less-sick, high-risk veterans not treated. Those who were vaccinated seemed to benefit the most from mAb therapy. Future prospective studies with more matched groups are needed to assess full benefits and risks of mAbs shown to neutralize the predominant variants.