Tirabrutinib (also known as ONO-4059 or GS-4059), a second-generation, enhanced-selectivity Bruton's tyrosine kinase inhibitor that demonstrated antitumor activity in preclinical models. Tirabrutinib participated in phase I clinical trial in patients with relapsed or refractory B-cell malignancies, where it was well tolerated and showed promising efficacy. In addition, tirabrutinib is involved in phase II clinical trials to study safety and efficacy in adults with Active Sjogren's syndrome and in adults with chronic lymphocytic leukemia. Besides the drug was studied for the treatment of Waldenstrom's macroglobulinemia and patients with refractory pemphigus.