S292: nirmatrelvir/ritonavir in covid-19 patients with haematological malignancies: a report fromthe epicovideha registry

Background: Nirmatrelvir/ritonavir treatment decreases the hospitalisation rate in immunocompetent patients with COVID-19, but data on efficacy in patients with haematological malignancy are scarce. Here, we describe the outcome of nirmatrelvir/ritonavir treatment in a large cohort of the latter patients. Aims: We aime to discover factors associated with mortality in patients receiving nirmatrelvir/ritonavir for the COVID-19 treatment. Methods: This is a retrospective cohort study from the multicentre EPICOVIDEHA registry on patients with haematological malignancy, who were diagnosed with COVID-19 between January and September 2022. Patients receiving nirmatrelvir/ritonavir were compared to those who did not. A logistic regression was run to determine factors associated with nirmatrelvir/ritonavir administration in our sample. Additionally, a Cox regression was modelled to detect factors associated with mortality. Results: A total of 1859 patients were analysed, 117 (6%) were treated with nirmatrelvir/ritonavir, 1742 (94%) were treated otherwise. Of 117 patients receiving nirmatrelvir/ritonavir, 80% had received ≥1 anti-SARS-CoV-2 vaccine dose before COVID-19 onset, versus 74% in patients with no nirmatrelvir/ritonavir (p=0.003). Nirmatrelvir/ritonavir recipients were more likely to have received a 2nd vaccine booster than patients without (13% versus 7%, p=0.04), 5% were admitted to ICU, less than patients not receiving nirmatrelvir/ritonavir (12%, p=0.021). Nirmatrelvir/ritonavir treatment was associated with the presence of extrapulmonary symptoms at COVID-19 onset, for example anosmia, fever, rhinitis, or sinusitis (aOR 2.509, 95%CI 1.448-4.347) and 2nd vaccine booster (aOR 3.624, 95%CI 1.619-8.109). Chronic pulmonary disease (aOR 0.261, 95%CI 0.093-0.732) and obesity (aOR 0.105, 95%CI 0.014-0.776) were not associated with nirmatrelvir/ritonavir use. Overall mortality rate was 11%, and COVID-19 attributable mortality was 9%. In patients treated with nirmatrelvir/ritonavir the mortality rate was 7%, significantly lower than in patients with SARS-CoV-2 directed treatment other than nirmatrelvir/ritonavir (15%, p=0.023). No other factor was observed explaining the mortality difference. Summary/Conclusion: Haematological malignancy patients were more likely to receive nirmatrelvir/ritonavir when reporting extrapulmonary symptoms or 2nd vaccine booster at COVID-19 onset, as opposed to chronic pulmonary disease and obesity. The mortality rate in patients treated with nirmatrelvir/ritonavir was significantly lower than in patients with targeted drugs other than nirmatrelvir/ritonavir. Keywords: Hematological malignancy, Immune deficiency, COVID-19, Infection