Successful early use of anti‐SARS‐CoV‐2 monoclonal neutralizing antibodies in SARS‐CoV‐2 infected hematological patients – A Czech multicenter experience

COVID‐19 significantly impairs survival rates among hematological patients when compared to the general population. Our prospective multicentre project analyzed early administration of anti‐SARS‐CoV‐2 spike protein neutralizing monoclonal antibodies (NmAbs) – bamlanivimab (72%) and casirivimab/imdevimab (28%) – efficacy among hematological patients with early‐stage COVID‐19. Mortality rate was compared to a control cohort of 575 SARS‐CoV‐2 positive hematological patients untreated with any specific anti‐COVID‐19 therapy. 88 hematological patients with lymphomas, acute leukemias, and myeloma as their most frequent underlying diagnoses (72%) were evaluated with a 97 days median follow‐up after NmAb administration. One third of patients (32%) were treated with an anti‐CD20 monoclonal antibody before COVID‐19 diagnosis. Median time between first COVID‐19 symptom and NmAb administration was 2 days. When administering NmAb, 29%, 57%, 11%, 2%, and 1% of our patients had asymptomatic, mild, moderate, severe, and critical degrees of COVID‐19, respectively. 80% of baseline asymptomatic patients remained asymptomatic following NmAb administration. Median duration of COVID‐19 symptoms after NmAb administration was 2.5 days. Progression to severe/critical COVID‐19 occurred among a total of 17% (15/88) of our cases and numerically higher with bamlanivimab versus casirivimab/imdevimab (21% vs. 8%; p = 0.215), and myelomas (29%), lymphomas (17%) and acute leukemias (18%), respectively. During final follow‐up, nine deaths (10%) were recorded ‐ all after bamlanivimab (p = 0.056) with 8% attributed to COVID‐19. Regarding “remdesivir/convalescent plasma naïve” patients, COVID‐19 mortality rates were significantly lower in our NmAbs treated cohort compared to the control cohort of untreated SARS‐CoV‐2 positive hematological patients (6% vs. 16%, p = 0.020), respectively. Our study validated the safety and efficacy of NmAbs early use among hematological patients with newly diagnosed early‐stage COVID‐19 in terms of alleviating infection course and decreasing mortality. Results confirmed a more positive effect of a casirivimab/imdevimab combination versus bamlanivimab monotherapy.