MMR and CMR in Chronic Phase Chronic Myeloid Leukemia Patients: Role of Sokal Score and Different Tyrosine Kinase Inhibitors On Time of Their Obtention, Maintenance and Failure-Free Survival

Abstract 4437 In order to describe the different treatments and factors involved in the first major molecular response (MMR) occurence in chronic phase CML, its maintenance, and its conversion to complete molecular response (CMR), we analyzed 211 CML patients [124 males and 87 females; median age: 50 years (17–81)] in first chronic phase who received tyrosine-kinase inhibitors (TKI) followed at our institution between 2001 and 2011. Among 196 patients evaluated for Sokal score, 79 (40%) were low, 82 (42%) were intermediate and 35 (18%) were high. According to hasford score (153 evaluated), 46% were low, 46% intermediate and 8% were high. First MMR was obtained in: 61% of patients after first line treatment [Imatinib, n=102; Imatinib+Peg-interferon, n=11; Dasatinib, n=10; Nilotinib, n=6]; 26% after second line [Imatinib, n=32; Dasatinib, n=11; Nilotinib, n=12] and 13% beyond second line [Imatinib, n=14; Dasatinib, n=7; Nilotinib, n=6]. The median time of MMR obtention was 15 months (2.5–94) after Imatinib, 6.4 months (3–24) after Imatinib+Peg-interferon, and it was significantly shorter after both Dasatinib [HR=2.6 (1.7–3.9), p st , 2 nd line or beyond, showed an independent significant faster time to MMR, as well as patients with low sokal score. Conversion to CMR was significantly faster only in Dasatinib patients and slower in patients with intermediate and high sokalscore. Treatment discontinuation did not have a benefit in terms of FFS while patients on TKI therapy seem to have better result. Disclosures: Nicolini: Novartis, Bristol Myers-Squibb, Pfizer, ARIAD, and Teva: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding.