EVUSHELD EFFICACY AND SAFETY IN AUTOIMMUNE RHEUMATIC DISEASES TREATED BY RITUXIMAB: A PROSPECTIVE OBSERVATIONAL TRIAL

Abstract

Background: B cell depleting therapy (rituximab) results in impaired ability to mount a humoral immune response. Evusheld, tixagevimab 150mg co-packaged with cilgavimab 150mg, is a passive vaccine against SARS-CoV-2. Objective: Evaluate prospectively the efficacy and safety of Evusheld vaccine for preventing or mitigating SARS-COV2 infection in patients with autoimmune rheumatic diseases (AIRD) treated with rituximab. Methods: We compared patients treated with rituximab, who agreed to receive Evusheld, to patients who refused. The primary outcome was the risk of severe COVID19 infection from omicron variant. Results: 45 AIRD patients in the intervention group and 26 in the control group, were recruited. There was no difference between the groups with regard to sex, age, years of rituximab treatment, previous mRNA vaccination and serum immunoglobulins level. No difference in the infection rate was found between intervention group and control group (21 (49%) versus 12 (48%). Four patients had a severe infection, 3 in the control group and 1 in the intervention group. Evusheld reduced the risk for severe infection by 94% (HR 0.06, 95% CI 0.01-0.76, p-value 0.017). No adverse events were reported. Conclusions: Evusheld decreased the risk for severe COVID19 infection in patients with AIRD treated with rituximab in a period in which Omicron BA.5, BQ1 and BQ.1.1 variants were prevalent in Israel, with a favorable safety profile.