LAUSR

and anemia (12%). The overall response rate (ORR) was 71% (12/17 pts) and median progression‐free survival (PFS) was not estimable across all cohorts; ORR in each subtype was 80% (4/5 pts) in DLBCL with 1 CR, 20% (1/5) in FL, and 100% in MCL with 2 CR, WM, and CLL. Interestingly, 4 pts with DLBCL who achieved objective responses had no CD79A/B, MYD88 and CARD11 mutations. Of note, CARD11 mutation was identified in one DLBCL pt who had disease progression. Furthermore, one CLL pt who had TP53 mutation, del 13q, and del 17p achieved PR and remained on therapy. The tendency of CXCL‐10 increase was observed in pts who achieved objective responses.Increases in Cmax and AUC were approximately dose‐proportional from 160 to 480 mg QD. The mean half‐life (t1/2) of ONO‐4059 was comparable across dose levels. Conclusions: MTD was not reached, and the safety profiles in Japanese pts with B‐NHL/CLL were similar to previous findings in the European Phase 1 study. ORR was observed in 71% of pts including 4 DLBCL with no mutations of CD79A/B, MYD88 and 1 CLL with TP53 mutation, del 13q and del 17p, that is promising data for future development. ONO‐4059 exhibited approximately dose‐proportional exposure, and there was little accumulation of exposure following multiple doses. Further investigation is warranted.