Limited BA.5 neutralization by pre-exposure prophylaxis with tixagevimab/cilgavimab in CAR-T treated people (preprint)

CAR T-cell recipients experience profound B-cell aplasia and hypogammaglobulinemia, being unable to mount any humoral response and at higher risk for severe COVID-19. Tixagevimab/cilgavimab has been approved for COVID-19 pre-exposure prophylaxis (PrEP) in immunocompromised people. 150/150 mg of tixagevimab/cilgavimab does not adequately neutralize against Omicron BA.5 and these results support recommendations on dose increase to 300/300 mg for prophylaxis in order to enhance effectiveness probability, until the European regulatory agency makes a decision on the usability of this compound as the FDA has already done