Ibrutinib antagonizes rituximab-dependent NK cell–mediated cytotoxicity

To the editor: Ibrutinib is an irreversible inhibitor of Bruton’s tyrosine kinase (BTK) with promising activity in CD20+ B-cell malignancies including recent US Food and Drug Administration approval in mantle cell lymphoma.[1][1] Given the homology between BTK and interleukin-2 inducible tyrosine