1117. COVID-19 Monoclonal Antibodies: A Single Center Real World Experience

Abstract Background COVID-19 monoclonal antibodies (mAb) have been shown to reduce risk of ED visit and hospitalization when administered early in disease course. However, there has been little data evaluating the challenges and barriers to delivering an outpatient mAb infusion. Methods This was a retrospective cohort review of patients referred 12/7/20-5/20/21 to evaluate factors associated with selection and treatment with mAb. Inclusion criteria included symptom onset within 10 days of referral, high-risk for severe disease, not hospitalized or meeting hospitalization criteria, and followed by in-network primary care provider. We collected data on demographics, high risk comorbidities, illness course, infusion selection, and adverse events. Using unadjusted regression models, we estimated effect sizes (mean difference or percentage point difference) and 95% confidence intervals to estimate baseline factors associated with infusion. Results Of the 230 eligible subjects, 179 (78%) were selected for mAb treatment and 119 (66%) were infused. Those with a Social Vulnerability Index > 0.5 were more likely to be selected (86% vs 71%) but among those selected were less likely to be infused (59% vs 74%). Other predictors for selection (Fig 1) included Spanish language preference, 3+ symptoms at the time of referral, shortness of breath, headache, immunosuppressive medications, and chronic respiratory disease. Predictors of mAb infusion (Fig 2) included 3+ symptoms at time of referral, diarrhea, myalgias, male gender, being employed, and history of chronic kidney or respiratory disease. Time of onset of symptoms-to-referral was < 5 days and test-to-referral was 2-3 days (Fig 3). 60 subjects were selected but not infused. 19 (32%) were not infused due to becoming ineligible after referral. Reasons for ineligibility included clinical decompensation or passing eligibility window. 39 (65%) were not infused due to refusal after selection. Most common reasons for refusal included feeling better (12, 20%), concerns about mAb (6, 10%), and lack of caregiver for a family member (4, 7%). Figure 1.Predictors of Selection for mAb InfusionFigure 2.Predictors of mAb Infusion After SelectionFigure 3.Days of Symptoms to Testing and Referral Conclusion Our study identified factors that impact selection and infusion of mAb in a real-world setting. This can help address potential barriers in operationalizing the administration of COVID-19 mAb in the future. Disclosures All Authors: No reported disclosures.