Pb2586: passive preexposure immunization by tixagevimab/cilgavimab in covid 19 infected hematological malignancy of epicovidhea survey

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: Some literature publications and review showed that in active haematologic malignancy (HM) the overall seropositivity rates following SarS cov 2 vaccine dose is inferior than healthy population, requiring, however for some of those patients, the hospitalization for critical complications until death. Severe breakthrough Covid infection after vaccination in HM patients were reported in literature, demonstring how the mortality is significantly lower than in the pre-vaccination era, but breakthrough COVID19 in HM is still associated with considerable mortality. In HM is necessary a strategy to reduce the risk of severe covid 19 due to alterated humoral response associated with low or absent seroconversion post vaccination. One way is the passive immunitation with monoclonal antibodies (MA). Aims: Few studies in real world analized the efficacy of MA tixagevimab- cilgavimab [authorized in 2022 by FDA(Food and Drug Administration), EUA(Emergency Use Authotization), EMA (European Medicines Agency] in preexposure intramuscular treatment in haematologic malignancies with immunodeficiency in preventing Sars-coV2 and related complications, hospitalization in HM patients. Methods: We collected,from March1st 2022, until november 1st 2022, in EPICOVIDEHA survey (www.clinicaltrials.gov; National 274 Clinical Trials identifier NCT04733729 an international open web-based registry for patients with HM infected with SARS-CoV-2) all hematological patients infected by Sars-Cov 19 despite vaccinations and treatment with a first dose prophylactic monoclonal antibodies (150 mg of tixagevimab plus 150 mg of cilgavimab adminstred as consecutive intramuscolar injections). We conducted this study in an international registry (EPICOVIDHEA) to determine the protection by severe covid 19 disease in a cohort of patients with an active HM treated with tixagevimab and cilgavimab. Results: Among the 8125 patients with HM and COVID-19 registered between March 2020 and November 2022, 47 had received prophylaxis with tixagevimab/cilgavimab. Lymphoproliferative disorders (44/47, 93.6%) were the main underlying HM. SARS-CoV-2 strains were genotyped in 7 (14.9%) cases only, and all belonged to the omicron variant. Forty (85.1%) patients had received vaccinations prior to tixagevimab/cilgavimab, the majority of them with at least two doses. Eleven (23.4%) patients had a mild SARS-CoV-2 infection, 21 (44.7%) a moderate infection, while 8 (17.0%) had severe infection and 2 (4.3%) critical. Thirty-six (76.6%) patients were treated, either with monoclonal antibodies, antivirals, corticosteroids, or with combination schemes. Overall, 37 patients were monitored at home or treated as outpatients, while 10 (21.3%) were admitted to a hospital. Among these, two (4.3%) were transferred to intensive care unit (ICU) and one (2.1%) of them died. Summary/Conclusion: Our study is limited by the fact that is a survey and not a case control study, however, in conclusion we report the interesting reduction risk of covid complications and mortality in HM patients treated with prophylactic Evusheld (tixagevimab and cilgavimab), analized in EPICOVIDEHA survey. Keywords: COVID-19