Neutralizing monoclonal antibodies in haematological patients paucisymptomatic for COVID-19: The GIMEMA EMATO-0321 study

COVID-19 continues to be a relevant issue among patients with haematological malignancies (HM). Vaccines are frequently not effective in subjects on active treatment. In this multicentre retrospective study of Gruppo Italiano Malattie EMatologiche dell'Adulto (GIMEMA), we collected data from 91 paucisymptomatic HM patients treated with anti-spike neutralizing monoclonal antibodies (nMoAbs) to determine time to viral clearance, referencing it to the expected value of 28 days from an historical group of untreated paucisymptomatic patients. Secondary endpoints included rate of hospitalization, intensive care unit (ICU) admission, COVID-19 related death and safety. SARS-CoV-2 molecular swab negativity was obtained in 86 patients (95%), with a median time of 18 days (IQR 13-26; p < 0.0001). We did not find significant variations according to age, diagnosis, treatment type, vaccination status or nMoAbs type. Rate of hospitalization due to COVID-19 progression was 12% (11/91), with 2 patients (2.2%) requiring ICU admission. With a median follow-up of 2.33 months, the overall mortality was 5.5% (5/91), with 3 deaths due to COVID-19. Side effects were rare and self-limiting. Our data suggest that nMoAbs can limit the detrimental effect of immunosuppressive treatments on COVID-19 clinical progression and time to viral clearance. The original trial was registered at as #NCT04932967.