ALBERT

Description: Introduction: Over half of patients with chronic myeloid leukemia (CML) in sustained deep molecular remission do not lose the major molecular response (MMR) after stopping treatment with tyrosine kinase inhibitors (TKI). This strategy is safe in controlled clinical trials, but there is scarce information on its applicability in the real-life setting. We aimed to assess if treatment cessation was feasible in clinical practice in a large nationwide series of CML patients from Spain. Methods: This retrospective study comprised a series of 236 patients in chronic-phase CML who discontinued TKI treatment outside of clinical trials between April 2009 and February 2018 in 33 Spanish institutions. Inclusion criteria were: a) TKI treatment duration 〉3 years; b) sustained MR4.5 in 〉4 consecutive determinations (one single point in MR4 was acceptable) during 〉2 years; c) molecular monitoring in a reference laboratory expressing the results on the International Scale (IS). Patients who had undergone allogeneic hematopoietic stem-cell transplantation were excluded. Molecular relapse was defined as consecutively detectable BCR-ABL1 transcripts showing a ≥1 log increase or loss of MMR in any single sample. Treatment-free remission (TFR) was estimated by the method of Kaplan-Meier and defined as the time from TKI discontinuation to the date of restarting therapy for any reason or, if treatment was not restarted, the date of last contact. Incidence of molecular relapse was calculated using the cumulative incidence function with resumption of TKI treatment in the absence of molecular relapse and death in MMR as competing events. Analysis of factors predicting molecular relapse was done by the method of Fine and Gray. Results: Table 1 shows the main characteristics of the series. Median follow-up from treatment discontinuation was 21.5 months, and 5 patients died in MMR due to CML unrelated causes. TKI therapy was reinitiated due to molecular relapse (MMR loss: n=52, increase 〉1 log in BCR-ABL transcript level at two consecutive assessments without losing MMR: n=12), patient preference (n=2), and severe withdrawal syndrome (n=1). One additional patient lost MMR after 20 months from treatment cessation but decided not to be retreated, with spontaneous recovery of MMR. The probability of TFR at 4 years was 64% (95% Confidence Interval [CI]: 55%-72%)(Figure 1). The cumulative incidence of molecular recurrence was 33% (95% CI: 26%-38%) at 3 years (Figure 2). Forty-nine relapses (75% of total) occurred in the first 6 months. The latest MMR loss was detected 30 months after treatment stop. One patient restarted treatment 44 months after TKI discontinuation due to ≥1 log increase in BCR-ABL1 transcripts in two consecutive samples without losing MMR. In univariate analysis, duration of TKI treatment of less than 5 years (P=0.005) and time in RM4.5 shorter than 4 years before TKI discontinuation (P=0.003) were both significantly associated with a higher incidence of molecular recurrence. No patient progressed to the advanced phases of CML. At the time of restarting treatment, the median BCR-ABL1 IS was 0.3%, with this value being 〉5% in only 7 instances. Most patients (81%) received the same TKI that they were taking before the trial of treatment cessation. Median follow-up after treatment resumption was 20 months. Among the 64 patients who restarted treatment due to molecular relapse, 46 of 52 cases regained MMR after a median time of 3 months, and 47 of 64 regained MR4.5 after a median time of 5 months. Response status at last control was: MR4.5 (n=196), MR4 (n=15), MMR (n=14), complete cytogenetic response (n=10), and other (n=1). Fifty-one patients (22%) developed musculoskeletal or joint pain after treatment cessation. In patients stopping imatinib, a significant increase in Hb levels, leukocyte counts, total lymphocyte counts, platelet counts, and cholesterol levels was observed. At 6 months, an increase in Hb level 〉2 g/dL was observed in 47% of patients with anemia. By contrast, nilotinib discontinuation was not followed by any relevant change in laboratory values. Conclusions: Our results confirm that treatment discontinuation is feasible and safe in clinical practice in Spain. Duration of TKI treatment of less than 5 years and a time in RM4.5 shorter than 4 years before TKI discontinuation were significantly associated with a higher incidence of molecular recurrence. Disclosures Hernandez Boluda: Incyte: Consultancy; Novartis: Consultancy. García Gutiérrez:Incyte: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Ferrer Marin:Incyte: Consultancy; Novartis: Consultancy, Research Funding. Cervantes:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Hospital Clinic Barcelona: Employment.

Description: INTRODUCTION: In patients with so called "late suboptimal responses" (patient with complete cytogenetic response (CCyR) without major molecular response (MMR) after 18 months of imatinib) , the role of dasatinib has not been evaluated. Dasatinib has unique immunomodulatory effects especially on the proliferation and activation of T- and NK-cells. Yet, how dasatinib affects the migration of lymphocytes is unknown. DASAPOST is the first clinical trial evaluating efficacy and safety of dasatinib in patients with late suboptimal response (now considered as ELN2013 as warning). Another aim is to correlate new immunological aspects related to dasatinib and its possible correlation with responses. METHODS: We are presenting results of first 18 patients enrolled in the phase II DASAPOST study (NCT01802450). Main inclusion criteria were patients treated with late suboptimal response by ELN09 (CCyR without MMR after 18 months of treatment. Sokal risk groups were (L/I/H) 22.5%, 50% and 22.5%. All BCR-ABL/ABL (IS) measurements were centralized in an EUTOS laboratory. An exhaustive lymphocyte migration study was done, including immunophenotipying pre and post samples (CD 45, CD3,CD8, CD16, CXCR3, CXCR4, CD56 and CCR7), migration assay (chemokines CXCL10, CCL19+CCL21 and CXCL12) and CXCL10 plasma concentration measured by ELISA. RESULTS: - Clinical: Median follow up was 288 days (100-380). Three out of 18 (16%) patients had discontinued dasatinib due to side effects (pancreatitis, pleural effusion and low grade, persistant side effects (fever, arthralgias, anemia and astenia). All patients have been evaluated at 3 months, 17 at 6 months and 11 at 12 months. Cumulative incidences by ITT of MMR by 3 and 6 months were 50% and 81%. Cumulative incidences by ITT of MR4.5 by 3 and 6 months were 18% and 25%, respectively. - Inmunological: Dasatinib intake induced a significant increase of NK-cells and decrease of percentage of T-cells. Further, it increased CD8+ T cells, while reducing the proportion of CD4+ T-cells among the total T-cells. With the first dose of dasatinib (to),the percentage of CCR7 was lower in CD4+ and CD8+ T-cells in the post-samples. Lymphocyte migration was studied with transwell assays. At t0, post-samples showed a reduced migratory capacity towards the chemokines CCL19 and CCL21 in both CD4+ and CD8+ T-cell subsets. Patients were classified as mobilizers (n=14) or non-mobilizers (n=3) depending on whether they experienced an increase in the absolute lymphocyte counts after the first intake of dasatinib or not, showing different lymphocyte distribution and migratory capacity. In order to study the long term effects of dasatinib, we calculated the fold change (FC) of absolute lymphocyte counts pre- and post-dasatinib intake. Patients were divided into two groups based on whether in the 3 months samples (t3) had a higher ("increase group") or a lower ("decrease group") FC compared with t0. The migratory capacity of these two groups was studied in basal conditions and towards CCL19+CCL21 or CXCL10. We found no differences in basal migration in the "increase "group, while, the basal migration in the "decrease" group was quite promoted at t0 and t3. Further, migration towards CCL19+21 in post-samples is even more inhibited in "increase" patients at t3, whereas in the "decrease" patients the inhibition is diminished. The patients were divided into two groups based on the achievement of MMR at t3. At t0 both patient groups had similar migratory capacity, however, at t3, responders maintained significantly impaired migratory capacity to CCL19+21, compared with non-responders. CONCLUSIONS: Our study shows, for the first time to our knowledge, that in patients treated with Imatinib and with late warning responses, switch to Dasatinib induced MMR in 83% of the patients, although 16% discontinued treatment because of toxicity. We reported for the first time that dasatinib has significant effects on lymphocyte migration, and these are associated with early response. Disclosures García-Gutierrez: Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Casado:Pfizer: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Sánchez-Guijo:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Ariad: Consultancy, Speakers Bureau. Boque:Celgene: Honoraria; BMS: Honoraria; Novartis: Honoraria. Muñoz-Calleja:BMS: Research Funding. Steegmann:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau; Ariad: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Description: Background: Current European LeukemiaNet (ELN) recommendations (ELN 2013) endorse closely monitoring, due to risk of failure, for patients with so called late warning response (patients with complete cytogenetic response without major molecular response after 12 months of treatment). In this situation, for patients initially treated with imatinib, previous studies have shown a benefit of treatment change to nilotinib in terms of the achievement of deeper molecular responses. However, the role of treatment change to dasatinib in this group of patients have not been evaluated. DASAPOST is the first clinical trial evaluating efficacy and safety of dasatinib in patients with late warning responses. Methods: We are presenting results of the 18 patients enrolled in the phase II, open, multicenter DASAPOST study (NCT01802450). Main inclusion criteria were patients previously treated with imatinib with late suboptimal response by ELN2009 (CCyR without MMR after 18 months of treatment). The primary end point was rate of MMR by 6 moths after treatment change to dasatinib. Secondary end points were rate of MMR by 12 months, rate of deep molecular responses, progression free survival and safety of treatment change. Results were expressed as the proportion of patients who achieved molecular responses in the intention-to-treat (ITT) population, considering as failure if the evaluation was not performed in a specific time point. All BCR-ABL/ABL (IS) measurements were centralized in an EUTOS laboratory. Results: From April 2013 to May 2015, 18 patients were enrolled in 12 Spanish centers. Median age was 59 years (39-77). The ratio of men to women was 13/5, and the risk groups according to Sokal Score were 48%, 30% and 22% for low, intermediate and high risk, respectively. Median time from diagnosis to treatment change to dasatinib was 2.6 years (1.6-23) and median time while on imatinib to achieve CCyR 1.4 years (0.2-12). Median exposure to imatinib was 2.4 years (1.6-14). Seventy-two percent of the patients achieved MMR by 6 months (primary endpoint). Rates of MMR and deeper molecular responses at different time points are shown in table 1. Of interest 9/18 patients (50%) achieved MR4 by 12 months. Treatment change to dasatinib was safe, with only 3 study discontinuations (16%), due to adverse events (AE) and 4 serious AE (congestive heart failure, acute gastroenteritis, pyelonephritis and pancreatitis (only congestive heart failure was related to dasatinib). Most commonly reported (〉5%) drug-related AEs are shown in table 1. Conclusions: Our study shows, for the first time, that in patients treated with imatinib and with late warning responses, switching to Dasatinib induced MMR in 2 out every 3 patients, and MR4 in half of the patients by 6 months, with a good safety profile. Table 1 Most commonly reported (〉5%) drug-related AEs Table 1. Most commonly reported (〉5%) drug-related AEs Table Table. Disclosures García-Gutierrez: Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Casado:Ariad: Honoraria; Pfizer: Honoraria; Novartis: Honoraria; BMS: Honoraria. Sánchez-Guijo:Pfizer: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Bristol-Myers-Squib: Consultancy, Honoraria. Martinez-Lopez:BMS: Research Funding. Steegmann:Ariad: Honoraria, Other: Research funding for the Spanish CML Group; Pfizer: Honoraria, Other: Research funding for the Spanish CML Group; BMS: Honoraria, Other: Research funding for the Spanish CML Group; Novartis: Honoraria, Other: Research funding for the Spanish CML Group.

Description: Patients with essential thrombocythemia (ET) and polycythemia vera (PV) have an increased incidence of acute myeloid leukemia and new nonhematologic malignancies compared with the general population. However, information on the factors determining the risk for such complications is limited. In the present study, we investigated whether constitutional genetic variations in DNA repair predispose to leukemic transformation and new nonmyeloid neoplasias in patients with ET and PV. Case-control studies for predisposition to both types of malignancies were nested in a cohort of 422 subjects diagnosed with ET or PV during the period 1973-2010 in several institutions in Spain. A total of 64 incidence cases of leukemia and 50 cases of primary nonmyeloid cancers were accrued. At conditional regression analysis, the Gln/Gln genotype in the XPD codon 751 showed the strongest association with both leukemic transformation (odds ratio [OR] = 4.9; 95% confidence interval [95% CI], 2.0-12) and development of nonmyeloid malignancies (OR = 4.2; 95% CI, 1.5-12). Additional predictive factors were exposure to cytoreductive agents for leukemic transformation (OR = 3.5; 95% CI, 2.0-6.2) and age for nonmyeloid malignancies (OR = 2.0; 95% CI, 1.4-2.8). These findings provide further evidence about the contribution of inherited genetic variations to the pathogenesis and clinical course of myeloproliferative neoplasms.

Description: Key Points In a 3-year follow-up of the DASatinib versus Imatinib Study In treatment-Naive CML patients trial, first-line dasatinib resulted in faster and deeper responses compared with imatinib. Deeper responses at 3, 6, and 12 months were associated with better 3-year progression-free survival and overall survival.

Description: Introduction: Transformation to secondary myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PV) and essential thrombocythemia (ET), the two more indolent Ph-negative myeloproliferative neoplasms (MPN). Once transformed, survival is remarkably shorted. Chronic inflammation plays a critical role in the progression of MPN, driving clonal expansion toward end stage disease. Importantly, MPN are characterized by the production of inflammatory cytokines, by both malignant and non-malignant clone. Inflammation and cancer share a common pathway, i.e. NF-κB. Interestingly, miR-146a regulates TLR/NF-κB pathway through the inhibition of its targets, IRAK1 and TRAF6, decreasing the production of cytokines. Based on: i) miR-146a-/- mice develop an MF-like phenotype with aging; and ii) miR-146a polymorphism (miRSNPs) rs2431697, influences its expression levels (50% decrease in TT individuals); we hypothesized that lower miR-146a-5p levels associated to this miRSNPs may result in high risk to develop MF. Objective: To evaluate the association of rs2431697 with MF transformation and to study the molecular mechanisms beyond this association. Methods: We genotyped rs2431697 in 938 patients (312 MF, 299 PV, and 327 ET) recruited from 13 tertiary Spanish institutions belonging to GEMFIN and 600 controls. The levels of miR-146a and IRAK1 were evaluated by qRT-PCR in total blood RNA of homozygous patients (TT=30, CC=25) with PV or ET and in healthy subjects (TT=7, CC=7). In miR-146a-/- mice, 2 and 9 months old, we evaluated spleen size and cellularity: degree of fibrosis in bone marrow (H&E and silver staining); and STAT3 and pSTAT3 in granulocytic lysates by western blot. Results: Association analysis, taken controls as reference, showed that TT genotype (associated in the literature with low levels of mir-146a) is associated to MF with an OR of 1.36 (1.01-1.82, p=0.04). Among MF patients, the subgroup with the greatest differences was the one of secondary MF (OR = 1.47, CI: 0.98-2.20) (Table 1 a,b). Next, we compared the genetic frequencies of rs2431697 SNPs between the secondary MF patients and the population in risk. Confirming our hypothesis, we observed an enrichment of TT genotype in the post-PV/TE MF group (n=132) compared to the PV+TE group (n=626) (OR=1.51; p

Description: Abstract 1675 Background: In the randomized phase 3 DASISION trial in patients (pts) with newly diagnosed CML-CP, dasatinib 100 mg once daily (QD) demonstrated improved efficacy over imatinib 400 mg QD and an acceptable tolerability profile (NEJM 2010 362 2260). At 3 years (y) pts achieved high rates of progression free survival (PFS) (91% both arms) and overall survival (OS) (94%, dasatinib; 93%, imatinib). Compared with pts receiving imatinib, pts receiving dasatinib achieved higher rates of cytogenetic and molecular responses, shorter time to responses, and fewer transformations to accelerated/blast phase (AP/BP) (JCO 2012 30 6504). Marin et al reported that BCR-ABL levels at 3 and 6 months (mo) with imatinib were significantly correlated with 8-y PFS and OS (JCO 2012 30 232), and Hanfstein et al proposed BCR-ABL levels of 10% at 3 mo and 1% at 6 mo as clinically important landmarks correlated with 5-y PFS and OS (Leukemia 2012 Epub). The aim of this exploratory analysis was to investigate the impact of early molecular and cytogenetic response on the outcome of pts enrolled in the DASISION trial. Methods: Pts with CML-CP were randomized to receive dasatinib 100 mg QD (n=259) or imatinib 400 mg QD (n=260). Methods have been previously reported (NEJM 2010 362 2260). PFS and OS rates were obtained from Kaplan-Meier estimates. Qualifying events for PFS included: increasing white blood cells, loss of complete hematologic response or major cytogenetic response, transformation to AP/BP, or death. Results: More dasatinib v imatinib pts achieved a partial cytogenetic response (PCyR) or complete CyR (CCyR) at 3 mo (81% v 67%) and at 6 mo (91% v 81%). Significantly higher rates of 3-y PFS were observed in pts with PCyR/CCyR at 3 mo (P10% at 3 mo and ≤10% at 6 mo transformed. Conclusions: More pts treated with dasatinib achieved a faster, deeper cytogenetic and molecular response, which was associated with better 3-y outcomes and lower risk of transformation to AP/BP. The clinical importance of achieving deeper levels of cytogenetic response (CCyR) at 6 mo will be presented. Early response landmarks may identify pts at higher risk for transformation, poor outcome, and those who may benefit from alternate treatments to improve responses and thereby minimize exposure to risk over time. More pts starting on imatinib compared with dasatinib transformed to AP/BP than those receiving dasatinib. These exploratory data highlight the clinical importance of a fast and deep response, with the potential to reduce the risk of transformation and improve long-term outcomes. OS data at 3 y in DASISION are immature and longer-term follow up is planned. Disclosures: Saglio: Bristol-Myers Squibb: Consultancy, Speakers Bureau. Kantarjian:Bristol-Myers Squibb: Research Funding. Shah:Novartis: Consultancy; Bristol-Myers Squibb, Ariad: Consultancy, Research Funding. Jabbour:Bristol-Myers Squibb, Novartis: Honoraria; Pfizer: Consultancy. Quintas-Cardama:Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Steegmann:Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau. Boqué:Novartis: Consultancy; Bristol-Myers Squibb: Consultancy. Chuah:Novartis, Bristol-Myers Squibb: Honoraria. Pavlovsky:Bristol-Myers Squibb: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau. Mayer:Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Ukropec:Bristol-Myers Squibb: Employment. Wildgust:Bristol-Myers Squibb: Employment, Equity Ownership. Hochhaus:Pfizer, ARIAD, Bristol-Myers Squibb, Novartis: Research Funding; Pfizer, ARIAD, Bristol-Myers Squibb, MSD, Novartis: Consultancy.

Description: BACKGROUND: Despite the excellent prognostic of chronic myeloid leukemia (CML) patients since the introduction of tyrosine kinase inhibitors (TKIs), approximately 50% of patients that are treated with TKIs will discontinue first line treatment due to lack of efficacy or intolerance. Once patients need a second line treatment, a considerable proportion of patients will need third or even fourth line therapy during further evolution. At this moment, there is a lack of data about real benefit of this group of patients. We have recently published our experience of 30 CML patients treated with bosutinib in 4th line. We present an update of the study where we have increased the number of patients, and the follow-up. The aim of this study is to present safety and efficacy data CML chronic phase patients treated with bosutinib in 4th line. METHODS: We have collected data from 59 CML patients treated with bosutinib in 4th line after resistance or intolerance to IM, NI and DA. 51 patients have been treated under the Spanish compassionate use program (36 centers) and 10 patients were treated in a single institution from United Kingdom. Median age of patients at diagnosis was 53 years. The percentage of low, intermediate and high risk Sokal groups were 47%, 37% and 16%. Median time TKIs exposure before bosutinib was 9 years. The most common indication (30/59) was intolerant to DA and NI. Patients' dispositions and main line characteristics are shown in table 1. RESULTS: Median follow-up was 14.3 months. All patients started bosutinib at 500mg/d, median dose of was 450mg/d. Overall probabilities to either achieve or maintain previous response were 96% (57/59), 62% (37/59), 40% (24/59) and 17% (10/59) for complete hematological response (CHR), complete cytogenetic response (CCyR), major molecular response (MMR) and MR4.5 respectively. However, probabilities to obtain responses (in patients without response evaluated at baseline) were 27% (7/26), 26% (12/45) and 12% (7/55) for CCyR, MMR and MR4.5. As expected, probabilities to obtain CCyR were lower for patients resistant to DA and NI patients than for patients intolerant to DA and NI (8% VS 44%). Event free survival (EFS) and progression free survival (PFS) probabilities were 50% and 83% by 27 month. Treatment was discontinued in 20/58 (34%), most frequent reasons being adverse events 9/59(15%), lack of efficacy 5/59 (8.5%), disease progression 2/59 (3.4%) and death 1/59 (1.7%). Two patients discontinued due to stem cell transplantation. The adverse events that led to treatment discontinuation were pleural effusion (3), diarrhea (2), rash, renal impairment, auricular fibrillation and liver enzyme elevation one patient each. Overall, bosutinib was well tolerated. Grade 3-4 hematological toxicities were 3%, 6% and 6% for anemia, thromboctytopenia and neutropenia. Most common non hematological side effects were diarrhea (39%, nauseas 13% and liver alterations 14% and pleural effusion 14%. CONCLUSIONS: Little is known about the therapeutic role of Bosutinib in 4th line. The series presented here is, to our knowledge, the largest being presented. Bosutinib seems to be an appropriate treatment option for patients resistant or intolerant to three prior TKIs. Table 1. IM+NI-I+DA-R (N=4) IM+NI-R+DA-R (N=18) IM+NI-I+DA-I (N=30) IM+NI-R+DA-I (N=7) Total (N=59) Sex, N (%) Male 2 (50) 11 (61.1) 16 (53.3) 2 (28.6) 31 (52.5) Median age of diagnosis, yr (range) 57.32 (50-64) 49.19 (23-73) 54.95 (21-89) 48.87 (26-68) 53.15 (21-89) Median age of Bosutinib initiation, yr (range) 69.13 (61-70) 62.27 (39-79) 64.85 (25-90) 64.79(35-74) 63.7 (25-9) Median follow up, months (range) 18.5(7.8-34.1) 8.4(1.22-36.1) 16.3(0.5-34.7) 23.4(3.3-28.9) 14.3(0.7-36.1) SOKAL Index at diagnosis, N (%) High 2(50.0) 4 (23.5) 1 (4.3) 1 (20) 8 (16.3) Intermediate 1 (25.0) 5 (29.4) 10(43.5) 2 (40) 18 (36.7) Low 1 (25.0) 8 (47.1) 12 (52.2) 2 (40) 23 (46.9) Median Time from first TKI to BOS, (yr, range) 10.3 (4.8-11.9) 9.3 (2.0-11.4) 8.8 (0.7-13.6) 8.2 (5.1-12.3) 8.8 (0.7-13.6) Median duration of prior therapy, months (range) Imatinib 38.8 (11.8-69.8) 32.6 (6.3-96.8) 26.2 (1.6-102.6) 23.1 (8.3-66.8) 28.8 (1.6-102.6) Dasatinib 21.5 (12.6-75) 21.8 (7.7-69) 31.4 (0.4-87.1) 23.7 (10.3-53.6) 23.44 (0.4-87.1) Nilotinib 19.1 (2.1-46.2) 16.7 (5-65.6) 8.9 (0.2-58.5) 30.9 (6.9-49.3) 14.3 (0.2-65.6) BOS: bosutinib, IM, imatinib; DA, dasatinib; NI, nilotinib, I: Intolerance, R: Resistant, Yr: year Disclosures García-Gutiérrez: Ariad: Consultancy; Pfizer: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Milojkovic:Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Ariad: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Boque:Novartis: Honoraria; BMS: Honoraria; Celgene: Honoraria. Casado:Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Jiménez:Pfizer: Consultancy, Honoraria. Giraldo:Pfizer: Consultancy. Steegmann:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau; Ariad: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Description: Second-generation TKIs have demonstrated efficacy and an acceptable tolerability in patients (pts) with chronic myeloid leukemia (CML); however, new data from so called “off target” side effects have been published. For example, serious concerns have been raised about cardiovascular (CV) events with ponatinib, and, in lesser degree with nilotinib (NI), impeding or difficulting the treatment in patients with previous CV risk factors. Besides, patients with previous history of pleural effusion or pulmonary hypertension should avoid dasatinib (DA) if possible. Bosutinib could be a good candidate for situations which preclude the use of other TKI’s. We have previously presented efficacy data of 29 patients treated with bosutinib in forth line. The aim of this study is to report safety data of heavily CML patients treated with bosutinib in 4th line. We have studied 30 pts previously treated with imatinib (IM), dasatinib and nilotinib and 5 pts previously treated with IM-DA or NI since 2012 under the Spanish Compassionate Use Program. Patient’s baseline characteristics and previous treatments are shown in table 1. We have classified patients in 2 groups regarding to investigator-driven cause of discontinuation: intolerant (INT) or resistant (RES). At the data cutoff on June 16, 2014, the median follow up was 11.47 months (range, 2.03-45.97 months). Median duration of BOS treatment across all cohorts was 9.23 months (range, 0.63-23.40 months). We observed no significant differences in terms of Index prognostic factors (Sokal, Hasford or Eutos), sex, median duration of TKIs treatment or comorbidities. However, patients with resistance where significantly older observed: 56 years vs. 67 years (p

Description: Background: The randomized, phase 3 DASISION trial demonstrated improved efficacy with dasatinib compared with imatinib in treatment-naïve CML-CP patients (pts). Dasatinib was also well tolerated, and demonstrated a faster response at 3 months. Here, we report the results of the final, 5-year analysis of DASISION. Methods: Pts with newly diagnosed CML-CP were randomized to receive dasatinib 100 mg once daily (n=259) or imatinib 400 mg once daily (n=260) as previously reported. The primary endpoint was confirmed complete cytogenetic response (cCCyR) by 12 months. Long-term efficacy and safety data from pts with the predefined minimum 5 years of study treatment are presented. Results: Sixty-one percent of dasatinib-treated pts and 63% of imatinib-treated pts were still on their initial study therapy at study end. Cytogenetic and molecular response rates continued to be higher for dasatinib compared with imatinib (intent-to-treat population). Specifically, the rate of cCCyR by 5 years was higher with dasatinib versus imatinib (83% vs 78%, P=.187), as were the rates of major molecular response (MMR; BCR-ABL ≤0.1%; 76% vs 64%, P=.002) and MR4.5 (BCR-ABL ≤0.0032% IS; 42% vs 33%, P=.025) by 5 years. Time to cCCyR (hazard ratio [95% confidence interval]=1.46 [1.20–1.77], P=.0001) and MMR (hazard ratio [95% confidence interval]=1.54 [1.25–1.89], P10% at 3 months, improved PFS, OS, and lower rates of transformation to AP/BP have been previously reported and were maintained at 5 years for dasatinib (PFS: 89% vs 72%, P=.0014; OS: 94% vs 81%, P=.0028; transformation n=6/198 [3%] vs n=5/37 [14%]) and imatinib (PFS: 93% vs 72%, P