Long-term follow-up of patients with CLL treated with the selective Bruton's tyrosine kinase inhibitor ONO/GS-4059.

To the editor: The inhibitor of Bruton’s tyrosine kinase (BTK) ibrutinib has transformed the treatment of chronic lymphocytic leukemia (CLL); many patients with previously untreatable disease may now enter durable remissions.[1][1],[2][2] Nevertheless, the kinome of ibrutinib is broad, resulting