Efficacy and safety of tixagevimab‐cilgavimab versus SARS‐CoV‐2 breakthrough infection in the hematological conditions

Abstract

AbstractBackgroundManaging SARS‐CoV‐2 infection in frail and immunosuppressed patients still represents an open challenge, but, starting from the phase 3 PROVENT study, prophylaxis with tixagevimab‐cilgavimab has improved the approach in this category of patients, guaranteeing a better outcome and inferior mortality. Real‐life data in a heterogeneous cohort are few.MethodsThe aim of this study is to evaluate the benefit of prophylaxis with tixagevimab‐cilgavimab in a cohort of 202 patients affected by different hematological diseases (lymphoproliferative, myeloproliferative, autoimmune, patients recently receiving a bone marrow transplant), active (with ongoing treatment), or in watch‐and‐wait strategy, followed in our center, during a median follow‐up of 249 (45‐325) days.ResultsAn incidence of 44 breakthrough infections (21.8%) is reported, with no treatment‐related adverse effects. Age ≥70 years, ongoing treatment (above all with monoclonal antibodies), baseline lymphoproliferative disorders, and prior virus exposure are identified as risk factors related to subsequent infection (p < 0.05). Moreover, the incidence is higher in low/nonresponse to prior vaccination (p = .002). Patients treated with tixagevimab‐cilgavimab had a mild course of the infection and a reduction of the duration compared with preprophylaxis infection (11 vs. 15 days, p < .001). The concurrent treatment with anti‐CD20 monoclonal antibodies and B–non‐Hodgkin lymphoma still confers a higher duration of infection despite prophylaxis. No deaths attributable to the infection occurred.ConclusionProphylaxis treatment seems to be a valid and safe strategy, although not preventing breakthrough infection, but the severe complications associated with the infection and the possible delays in administering lifesaving therapies from long positivity.