Efficacy of entospletinib+obinutuzumab was analyzed in the 21 patients with CLL, of which 17 received entospletinib at RP2D (400 mg twice daily). Patients with CLL had a median age of 66 years. Thirteen patients (62%) had TP53 aberration (n=9), complex karyotype (n=6), or NOTCH1 or SF3B1 mutation..Among the 21 efficacy-evaluable participants with CLL, the ORR was 67% (95%CI, 43–85%). Three patients (14%, 95%CI 3–36%) achieved a CR, and 11 patients (53%) had a partial response (PR)...Thus, the combination of entospletinib and obinutuzumab shows an acceptable safety profile.