Dual combined antiviral treatment with remdesivir and nirmatrelvir/ritonavir in patients with impaired humoral immunity and persistent SARS-CoV-2 infection

Despite global vaccination efforts, immunocompromized patients remain at high risk for COVID-19-associated morbidity. In particular, patients with impaired humoral immunity have shown a high risk of persistent infection. We report a case series of adult patients with B cell malignancies and/or undergoing B cell targeting therapies with persisting SARS-CoV-2 infection and treated with a combination antiviral therapy of remdesivir and nirmatrelvir/ritonavir, in three Italian tertiary academic hospitals. A total of 14 patients with impaired adaptive humoral immunity and prolonged SARS-CoV-2 infection were treated with the dual antiviral therapy. The median age was 60 (IQR 56-68) years, and 11 were male. Twelve patients had B cell lymphoma, one patient had chronic lymphocytic leukemia and one patient had multiple sclerosis. Thirteen out of 14 patients had received prior B cell-targeting therapies, consisting of anti-CD20 monoclonal antibodies in 11 patients, and chimeric antigen receptor T therapy in 2 patients. The median time between diagnosis and therapy start was 42.0 (IQR 35-46) days. Seven patients had mild, 6 moderate and one severe disease. Nine patients had signs of interstitial pneumonitis on chest computed tomography scans before treatment. The median duration of nirmatrelvir/ritonavir and remdesivir combination therapy was 10 days. All patients showed resolution of COVID-19-related symptoms after a median of 6 (IQR 4-11) days and viral clearance after 9 (IQR 5-11) days. Combination therapy with remdesivir and nirmatrelvir/ritonavir is a promising treatment option for persistent COVID-19 in immunocompromized patients with humoral immunity impairment, worthy of prospective comparative trials.