Crossover for pts meeting ELN 2013 failure criteria DAS vs IMA in pts with CML-CP who have not achieved an optimal response to 3 mo of IMA therapy: DASCERN Cortes (Abstract # 788) Oral Objectives To evaluate early switch to DAS vs remaining on IMA in pts with CML-CP who have not achieved an optimal response (ie, BCR-ABL1IS ≤ 10%) with 3 mo of 1L IMA treatment DAS 100 mg QD (n = 174) R (2:1) IMA ≥ 400 mg QD or BID (n = 86) Pts with CML-CP Received 1L IMA 400 mg QD Achieved CHR but BCR-ABL1IS > 10% at 3 mo Crossover for pts meeting ELN 2013 failure criteria F/up up to 6 mo after LPFV Methods Primary endpoint: MMR rate at 12 mo after day 1 initiation of 1L IMA (i.e., 9 mo after randomization) Results 78% male; 73% Asian; median age, 37 y; minimum f/up, ≥ 12 mo At the time of analysis, 84% of pts were continuing in the study; 42 (49%) of IMA-randomized pts had crossed over to DAS MMR rate at 12 mo was higher with DAS vs IMA 100 P=0.005 DAS (n=174) IMA (n=86) 29% 13% 90 80 70 60 50 40 30 20 10 MMR at 12 months MMR, % (95% CI) MMR at 12 mo 1L, frontline; BID, twice daily; CML, chronic myeloid leukemia; CP, chronic phase; DAS, dasatinib; ELN, European LeukemiaNet; f/up, follow-up; IMA, imatinib; IS, International Scale; MMR, major molecular response (BCR-ABL1IS ≤ 0.1%); LPFV, last patient first visit; pt, patient; QD, once daily.

DAS vs IMA in pts with CML-CP who have not achieved an optimal response to 3 mo of IMA therapy: DASCERN Cortes (Abstract # 788) Oral Results (cont) Median time to MMR with DAS vs IMA: 14 vs 20 mo Rate of MR4.5 at 12 mo: 5% with DAS vs 2% with IMA No differences between DAS and IMA were seen in PFS (96.9% vs 97.6%) or OS (98.8% for both) No new safety signals were seen with DAS or IMA, and early switch to DAS did not increase toxicity rates Rates of treatment-emergent pleural effusion were 5% in DAS-randomized pts (1 case was grade 3) and 7% in IMA-randomized pts who crossed over to DAS (1 case was grade 4 and the pt discontinued from the study) Time to MMR 1.0 0.8 0.6 0.4 0.2 3 6 9 12 15 18 21 24 30 36 42 48 54 Pts at risk Time Since Randomization (mo) Probability of MMR DAS IMA 172 86 156 82 128 75 107 67 79 58 59 45 35 32 22 28 20 14 7 2 1 Authors Conclusions In pts with suboptimal responses to IMA at 3 mo, switching to DAS provided a significantly higher rate of MMR at 12 mo vs remaining on IMA Longer f/up is needed to evaluate the impact of early switch on PFS, OS, and deep molecular responses CML, chronic myeloid leukemia; CP, chronic phase; DAS, dasatinib; f/up, follow-up; IMA, imatinib; IS, International Scale; MMR, major molecular response (BCR-ABL1IS ≤ 0.1%); MR4.5, BCR-ABL1IS ≤ 0.0032%; OS, overall survival; PFS, progression-free survival; pt, patient.