Compassionate Use of REGEN-COV ® in Patients with COVID-19 and Immunodeficiency-Associated Antibody Disorders

Clin Infect Dis. 2021 Dec 31;ciab1059. doi: 10.1093/cid/ciab1059. Online ahead of print.


Background: Patients with immunodeficiency-associated antibody disorders are at a higher risk of prolonged/persistent COVID-19 infection, having no viable treatment options.

Methods: A retrospective analysis of patients with primary and/or secondary immunodeficiency-associated antibody disorders who received casirivimab and imdevimab (REGEN-COV ®) under emergency compassionate use.

Objectives: describe safety and response to REGEN-COV, focusing on the subset of patients who had COVID-19 duration ≥21 days before treatment.

Results: Quantitative (change in oxygenation status and/or viral load) and/or qualitative (physician-reported clinical status) patient outcomes data are reported from 64 patients who received REGEN-COV. Improvement in ≥1 outcome was observed in 90.6% of the overall patient group. Thirty-seven of these had COVID-19 duration ≥21 days before treatment; median time from diagnosis to REGEN-COV was 60.5 days. Of the 29 patients with COVID-19 duration ≥21 days before treatment and available outcome data, 96.6% showed improvement in ≥1 outcome. In the 14 patients with post-treatment RT-PCR results available, 11 (78.6%) reported a negative RT-PCR following treatment, with 5 (45.5%) reporting a negative RT-PCR within 5 days and 8 (72.7%) within 21 days of treatment. Ten of 85 patients (11.8%) experienced serious adverse events, only one was an infusion-related reaction, possibly related to REGEN-COV. Two deaths were reported, neither were attributed to REGEN-COV.

Conclusions: In this retrospective analysis of immunodeficient patients granted REGEN-COV under the compassionate use program, REGEN-COV treatment was associated with rapid viral clearance and clinical improvement in patients with long-standing COVID-19. Adverse events were consistent with COVID-19 and its associated complications, and due to patients' concurrent medical conditions.

Keywords: B-cell deficiency; COVID-19; antibody deficiency; compassionate use; monoclonal antibody.