The role of Bruton's kinase inhibitors (BTKi) in accelerated Chronic Lymphocytic Leukemia (a-CLL): a case of successful response to acalabrutinib.

Objectives: The use of Bruton's tyrosine kinase (BTK) inhibitors has changed the clinical history of patients with chronic lymphocytic leukemia (CLL) in both naïve and relapsed/refractory settings. "Accelerated" chronic lymphocytic leukemia (a-CLL) is a relatively rare form of CLL representing less than 1 % of all CLL cases. a-CLL patients usually have a more aggressive course and a reduced overall survival was reported with conventional chemo-immunotherapy approaches.

Methods: The role of Bruton Tyrosine Kinase-inhibitor, ibrutinib, in a-CLL is well established with encouraging preliminary results.

Results: We report a case of a-CLL-treated first-line with second-generation BTKi, acalabrutinib with a prompt clinical response. As known, it is the first literature report on acalabrutinib in a-CLL highlighting the role of second-generation BTKi also in this high-risk setting.

Conclusions: Target therapies (Bruton Kinase inhibitors and Bcl2 inhibitors) have improved the therapeutic landscape of CLL. The availability of therapeutic targets requires greater diagnostic accuracy to choose the most appropriate therapy for each patient.