SIMPLICITY (NCT01244750) is an observational study exploring tyrosine kinase inhibitor (TKI) use and management patterns in patients with chronic phase-chronic myeloid leukemia in the US and Europe in routine clinical practice. Herein we describe interruptions, discontinuations and switching of TKI therapy during the initial 2 years of treatment among 1121 patients prospectively enrolled between October 1, 2010 and March 7, 2017. Patient characteristics were broadly similar between the imatinib (n = 370), dasatinib (n = 376), and nilotinib (n = 375) cohorts. Treatment interruptions occurred in 16.4% (year 1) and 4.0% (year 2) of patients, mainly attributed to hematologic intolerances. Treatment discontinuations occurred in 21.8% (year 1) and 10.2% (year 2) of patients, with the highest rate within the first 3 months for intolerance. Switching of TKI was seen in 17.8% (year 1) and 9.5% (year 2) of patients. Significant associations were found between TKI switching and female gender (year 1), age ≥65 years at diagnosis (year 2) and treatment with imatinib (year 2). Intolerance was the most common reason given for patients discontinuing and for switching TKI therapy; however resistance was also cited. Lack of response monitoring in routine clinical practice may have resulted in lower identification of resistance in this dataset. Data from SIMPLICITY suggest that, in routine clinical practice, intolerance and resistance to TKIs influence decisions to change treatment. Changes in TKI therapy are frequent, with nearly a third of patients discontinuing their first-line TKI.

PATRONES DE CAMBIO DE LOS INHIBIDORES DE LA TIROSINA CINASA BCR-ABL1 EN PACIENTES CON LMC EN FASE CRONICA EN LA PRACTICA CLINICA RUTINARIA ESTUDIO SIMPLICITY

Introduction: Data on clinical response and factors associated with response in CP-CML outside clinical trials are limited.SIMPLICITY (NCT01244750) is an ongoing observational study of CP-CML pts in routine clinical practice receiving first-line (1L) imatinib (IM), dasatinib (DAS) or nilotinib (NIL) in the US and Europe. This analysis aims to describe the factors associated with achievement of complete CyR (CCyR) and major MR (MMR).

Achieving successful outcomes in chronic phase-chronic myeloid leukemia (CP-CML) requires careful monitoring of cytogenetic/molecular responses (CyR/MR). SIMPLICITY (NCT01244750) is an observational study exploring tyrosine kinase inhibitor use and management patterns in patients with CP-CML receiving first-line imatinib (n = 416), dasatinib (n = 418) or nilotinib (n = 408) in the US and 6 European countries in routine clinical practice. Twelve-month follow-up data of 1242 prospective patients (enrolled October 01 2010-September 02 2015) are reported. 81% of patients had baseline comorbidities. Treatment selection was based on perceived efficacy over patient comorbidity profile. There was a predominance of imatinib-treated patients enrolled earlier in the study, with subsequent shift toward dasatinib- and nilotinib-treated patients by 2013/2014. Monitoring for either CyR/MR improved over time and was documented for 36%, 82%, and 95% of patients by 3, 6, and 12 months, respectively; 5% had no documentation of CyR/MR monitoring during the first year of therapy. Documentation of MR/CyR testing was higher in Europe than the US (P < .001) and at academic versus community practices (P = .001). Age <65 years, patients being followed at sites within Europe, those followed at academic centers and patients no longer on first-line therapy were more likely to be monitored by 12 months. SIMPLICITY demonstrates that the NCCN and ELN recommendations on response monitoring have not been consistently translated into routine clinical practice. In the absence of appropriate monitoring practices, clinical response to TKI therapy cannot be established, any needed changes to treatment strategy will thus not be implemented, and long-term patient outcomes are likely to be impacted.

Understand time to and reasons for discontinuation or switching of imatinib in pts with CP-CML (≥12 months follow-up) in routine clinical practice. SIMPLICITY (NCT01244750) is an ongoing study of pts receiving first-line imatinib prior to 2010 (retrospective) or first-line imatinib, dasatinib or nilotinib since 2010 (prospective) in the US and Europe. 252 retrospective (median follow-up: 60 months) and 405 prospective (median follow-up: 37 months) imatinib pts were included. In the retrospective and prospective cohorts, 17.9% and 17.0% of pts had a treatment interruption, and 14.3% and 29.9% discontinued imatinib (regional differences were noted and will be presented). Median time to first discontinuation was 5.3 months (retrospective) and 4.4 months (prospective). The most common reason for discontinuation was intolerance (64.7% retrospective and 61.7% prospective). Types of intolerance (MedDRA) differed: retrospective – blood/lymphatic system (36.4%) and GI disorders (27.3%); prospective – skin/subcutaneous tissue (28.2%) and GI disorders (26.8%). Discontinuations due to primary resistance were lower in the retrospective cohort (8.8% vs. 15.7%). Fewer pts in the retrospective cohort switched to second-line TKI; 9.1% (47.8% dasatinib, 52.2% nilotinib) compared with 25.2% (62.7% dasatinib, 36.3% nilotinib) in the prospective cohort. Median time to switch was 7.7 months (retrospective) and 4.5 months (prospective). 69.6% (retrospective) and 61.6% (prospective) of pts switched owing to intolerance. Similar intolerances led to discontinuation or switching, although in retrospective pts, GI disorders caused more pts to switch (37.5% vs 27.9%). The proportion of pts with treatment interruptions was similar between cohorts; however, twice as many pts discontinued imatinib, and more switched to second-line TKI, in the prospective vs. retrospective cohort, perhaps due to treatment landscape changes. Intolerance was the primary reason for discontinuation, including switching. These findings suggest intolerance remains an issue and highlights the need for effective management of adverse events as well as second-generation treatment options.

National and regional population-based registries are, provided diagnostic accuracy and full coverage of the target population, indispensible tools for epidemiological research. CML registries with a more comprehensive reporting may also provide complementary data on treatment outcome to those obtained from clinical trials. Reports from several European CML registries consistently show a crude annual incidence of 0.7–1.3/100,000, median age at diagnosis of 56–60 years and a male/female ratio of 1.2–1.7. The incidence of CML has been stable over time. Worldwide, variations in reported incidence of CML may be due to methodological issues, but a true difference between different geographical areas and/or ethnical subgroups cannot be excluded. The prevalence of CML is less well known but has been estimated to 10–12/100,000 inhabitants with a steady increase due to the dramatic improvement in survival of these patients. In recent population-based studies, CML patients have an overall survival that is comparable to that shown in large clinical trials, though relative survival in patients >70 years is still decreased. The importance of socioeconomic factors and health-care setting for outcome, a possible increased risk of secondary cancer in CML and possible long-term adverse off-target effects related to the use of tyrosine kinase inhibitors, are areas of ongoing epidemiological research.

Background: We analyzed the cost-effectiveness of treating incident chronic myeloid leukemia in chronic phase (CML-CP) with generic imatinib when it becomes available in United States in 2016. In the year following generic entry, imatinib's price is expected to drop 70% to 90%. We hypothesized that initiating treatment with generic imatinib in these patients and then switching to the other tyrosine-kinase inhibitors (TKIs), dasatinib or nilotinib, because of intolerance or lack of effectiveness ("imatinib-first") would be cost-effective compared with the current standard of care: "physicians' choice" of initiating treatment with any one of the three TKIs.Methods: We constructed Markov models to compare the five-year cost-effectiveness of imatinib-first vs physician's choice from a US commercial payer perspective, assuming 3% annual discounting ($US 2013). The models' clinical endpoint was five-year overall survival taken from a systematic review of clinical trial results. Per-person spending on incident CML-CP treatment overall care components was estimated using Truven's MarketScan claims data. The main outcome of the models was cost per quality-adjusted life-year (QALY). We interpreted outcomes based on a willingness-to-pay threshold of $100 000/QALY. A panel of European LeukemiaNet experts oversaw the study's conduct.Results: Both strategies met the threshold. Imatinib-first ($277 401, 3.87 QALYs) offered patients a 0.10 decrement in QALYs at a savings of $88 343 over five years to payers compared with physician's choice ($365 744, 3.97 QALYs). The imatinibfirst incremental cost-effectiveness ratio was approximately $883 730/QALY. The results were robust to multiple sensitivity analyses.Conclusion: When imatinib loses patent protection and its price declines, its use will be the cost-effective initial treatment strategy for CML-CP.

Introduction:SIMPLICITY (NCT01244750) is an ongoing observational study of CP-CML pts in routine clinical practice receiving first-line (1L) imatinib (IM) prior to 2010 (retrospective) or 1L IM, dasatinib (DAS) or nilotinib (NIL) since 2010 (prospective) in the US and Europe.

The EUTOS population-based registry includes data of all adult patients newly diagnosed with Ph+ and/or BCR-ABL1+ CML in 20 predefined countries and regions of Europe. Registration time ranged from 12 to 60 months between January 2008 and December 2013. Median age was 55 years and median observation time 29 months. 80% of patients were treated first-line with imatinib, and 17% with a second generation tyrosine kinase inhibitor, mostly according to European LeukemiaNet recommendations. After 12 months CCyR and MMR were achieved in 57 and 41% of patients, respectively. Patients with high EUTOS risk scores achieved CCyR and MMR significantly later than patients with low EUTOS risk. Probabilities of OS and PFS for all patients at 12, 24 and 30 months was 97%, 94% and 92%, and 95%, 92% and 90%, respectively. The new ELTS score was validated: the OS of patients differed significantly between the three risk groups. The probability of dying in remission was 1% after 24 months. The current management of patients with TKIs resulted in responses and outcomes in the range reported from clinical trials. These data from a large population-based, patient sample provides a solid benchmark for the evaluation of new treatment policies.

The European Treatment and Outcome Study (EUTOS) population-based registry includes data of all adult patients newly diagnosed with Philadelphia chromosome-positive and/or BCR-ABL1+ chronic myeloid leukemia (CML) in 20 predefined countries and regions of Europe. Registration time ranged from 12 to 60 months between January 2008 and December 2013. Median age was 55 years and median observation time was 29 months. Eighty percent of patients were treated first line with imatinib, and 17% with a second-generation tyrosine kinase inhibitor, mostly according to European LeukemiaNet recommendations. After 12 months, complete cytogenetic remission (CCyR) and major molecular response (MMR) were achieved in 57% and 41% of patients, respectively. Patients with high EUTOS risk scores achieved CCyR and MMR significantly later than patients with low EUTOS risk. Probabilities of overall survival (OS) and progression-free survival for all patients at 12, 24 and 30 months was 97%, 94% and 92%, and 95%, 92% and 90%, respectively. The new EUTOS long-term survival score was validated: the OS of patients differed significantly between the three risk groups. The probability of dying in remission was 1% after 24 months. The current management of patients with tyrosine kinase inhibitors resulted in responses and outcomes in the range reported from clinical trials. These data from a large population-based, patient sample provide a solid benchmark for the evaluation of new treatment policies.

Background and aimsThe simultaneous measurement of many proteins is now possible using multiplex assays. In this pilot study we investigated a total of 124 proteins in plasma from chronic myeloid leukemia (CML) patients with the purpose of identifying proteins that are differently expressed at diagnosis and after tyrosine kinase inhibitor (TKI) treatment initiation.MethodsSamples were taken from 14 CML patients at diagnosis and after three months of TKI treatment (imatinib or dasatinib). Samples were analyzed by Mesoscale Discovery, Myriad RBM MAP technology and Olink Proseek.ResultsMultiple plasma proteins were differentially expressed before and after initiation of TKI therapy. Protein patterns demonstrated a possible shift towards Th1-immunity and reduced angiogenic stimuli. Further, some plasma proteins were identified that can be of potential interest to study further for biologic, prognostic or therapeutic significance such as E-selectin, uPAR, growth hormone and carbonic anhydrase IX.ConclusionsPlasma proteomics seems feasible and useful in CML patients, both for studying patterns of protein expression and for identifying single proteins differentially expressed before and after treatment. Plasma proteomics may be useful to map disease activity and biological processes. Hence, plasma proteomics can be used to understand drug mechanisms and treatment responses in CML.

Abstract Introduction: The in-study and out-study sections of the European Treatment and Outcome Study (EUTOS) registry comprise data on imatinib-treated adult patients with chronic myeloid leukemia (CML) who were prospectively enrolled in clinical studies or registries between 2002 and 2006. All patients diagnosed with chronic-phase Philadelphia chromosome-positive CML were eligible for analysis. The new EUTOS long-term survival (ELTS) score was developed in 2,205 in-study patients (Blood 2014; 124(21):153). Its purpose is the discrimination of three risk groups with clinically significantly different probabilities of dying from CML. The score was validated in 1,120 out-study patients. Aims: Up to now, many investigators still apply the Sokal score for the prognostic discrimination of CML-patients treated with tyrosine kinase inhibitors (TKIs). The Sokal score allocated more than 20% of chronic-phase patients to the high-risk group while it was 12% with the new ELTS score. Long-term outcome with tyrosine kinase inhibitors (TKIs) suggests that the allocation of more than 20% chronic-phase CML patients into a high-risk group is too pessimistic. The focus of this analysis was the comparison of risk group allocations and prognosis between the two scores. Methods: Survival time was calculated from the date of start of treatment to death or to the latest follow-up date. Survival was censored at the time of allogeneic stem cell transplantation in first chronic phase. Cumulative incidence probabilities (CIPs) of dying of CML were compared with the Gray test and overall survival probabilities with the log-rank test. As "death due to CML", only death after confirmed disease progression was regarded. Progression was defined in accordance with the recommendations of the ELN (Baccarani et al, Blood 2013). Level of significance was 0.05. Results: Both registries combined, the 3,325 patients had a median observation time of 6.1 years. Six-year overall survival probability was 91% (95% confidence interval (CI): 89-92%). Death was due to CML in 142 of 309 deceased patients (46%).The 6-year CIP of dying of CML was 4% (CI: 4-5%). From low to high risk groups, the Sokal score resulted in 6-year CIPs of 3% (n=1358 (41%), CI: 2-4%), 4% (n=1209 (36%), CI: 3-5%), and 8% (n=758 (23%), CI: 6-11%) and the ELTS score in 6-year CIPs of 2% (n=2030 (61%), CI: 2-3%), 6% (n=898 (27%), CI: 4-7%), and 13% (n=397 (12%), CI: 10-17%). Of the 758 patients allocated to high risk by the Sokal score, the ELTS score classified 165 (22%) as low risk and 265 (35%) as intermediate risk. Compared to the 328 high-risk patients (43%) according to both scores (6-year CIP of dying: 13%, CI: 9-17%), the CIPs of dying were significantly lower for the 165 low-risk patients (p=0.0062, 6-year CIP: 5%, CI: 2-9%) and for the 265 intermediate-risk patients (p=0.0050, 6-year CIP: 5%, CI: 3-9%). These 430 Sokal high but ELTS non-high-risk patients (6-year OS: 89%. CI: 86-92%) showed significantly higher OS probabilities than the 328 Sokal and ELTS high-risk patients (p=0.030, 6-year OS: 81%. CI: 76-85%). Of the 2030 patients identified as low risk by the ELTS score, the Sokal score allocated 603 (30%) to the intermediate- and 165 (8%) to the high-risk group. Without significant CIP differences to the latter group, at 6 years, the CIP of dying was 2% (CI: 1-3%) in the 1262 low-risk and also 2% in the 603 intermediate-risk patients (CI: 1-3%). The OS probabilities of the 768 non-low-risk patients according to the Sokal score (6-year OS: 93%. CI: 91-95%) were not significantly different from the 1262 classified as low-risk by both scores (6-year OS: 95%. CI: 93-96%). Conclusions: To be able to perform comparisons between the various prognostic groups suggested by the Sokal and the EUTOS survival score with a reasonable power, data of in- and out-study samples were combined. The Sokal score allocated an absolute difference of 12% (n=430) more patients to the high-risk groups than the EUTOS survival score. As these patients had significantly and clinically relevantly lower CIPs and higher OS probabilities, the allocation of the Sokal score was not appropriate. Contrarily, the long-term outcome of 768 patients assessed as low-risk by the ELTS and non-low-risk by the Sokal score was not different from the outcome of 1262 assesses as low-risk patients by both scores. For prognosis of long-term survival outcome, the use of the EUTOS survival score is recommended. Disclosures Pfirrmann: BMS: Consultancy, Honoraria; Novartis Pharma: Consultancy, Honoraria. Hasford:Novartis: Research Funding. Saussele:Novartis Pharma: Honoraria, Other: Travel grant, Research Funding; BMS: Honoraria, Other: Travel grant, Research Funding; ARIAD: Honoraria; Pfizer: Honoraria, Other: Travel grant. Turkina:Bristol Myers Squibb: Consultancy; Pfizer: Consultancy; Novartis Pharma: Consultancy. Prejzner:Novartis Pharma: Honoraria; BMS: Honoraria. Steegmann:Novartis Pharma: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Simonsson:Novartis Pharma: Research Funding. Zaritskey:University of Heidelberg: Research Funding; Novartis: Consultancy. Zackova:Novartis Pharma: Consultancy; Bristol Myers Squibb: Consultancy. Janssen:Novartis: Research Funding; Pfizer: Consultancy; Bristol Myers Squibb: Consultancy; ARIAD: Consultancy. Cervantes:Novartis: Consultancy, Speakers Bureau; Sanofi-Aventis: Consultancy; CTI-Baxter: Consultancy, Speakers Bureau. Hehlmann:Novartis Pharma: Research Funding; BMS: Consultancy. Baccarani:Novartis: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Ariad: Consultancy, Speakers Bureau.

National and regional population-based registries are, provided diagnostic accuracy and full coverage of the target population, indispensible tools for epidemiological research. Chronic myeloid leukaemia (CML) registries with more comprehensive reporting may also provide complementary data on treatment outcome to those obtained from clinical trials. Reports from several European CML registries consistently show a crude annual incidence of 0.7-1.0/100,000, a median age at diagnosis of 57-60 years and a male/female ratio of 1.2-1.7. The incidence of CML has been stable over time. Worldwide, variations in the reported incidence of CML may be due to methodological issues, but a true difference between different geographical areas and/or ethnical subgroups cannot be excluded. The prevalence of CML is not well known but has been estimated to be 10-12/100,000 inhabitants with a steady increase due to the dramatic improvement in survival of these patients. In recent population-based studies, CML patients have an overall survival that is comparable to that shown in large clinical trials, though relative survival in patients >70 years is still decreased. The importance of socio-economic factors and health-care setting for outcome and the possible increased risk of secondary cancer in CML are areas of ongoing research.

In patients with chronic myeloid leukemia (CML), first-line imatinib treatment leads to 8-year overall survival (OS) probabilities above 80%. Many patients die of reasons unrelated to CML. This work tackled the reassessment of prognosis under particular consideration of the probabilities of dying of CML. Analyses were based on 2290 patients with chronic phase CML treated with imatinib in six clinical trials. ‘Death due to CML’ was defined by death after disease progression. At 8 years, OS was 89%. Of 208 deceased patients, 44% died of CML. Higher age, more peripheral blasts, bigger spleen and low platelet counts were significantly associated with increased probabilities of dying of CML and determined a new long-term survival score with three prognostic groups. Compared with the low-risk group, the patients of the intermediate- and the high-risk group had significantly higher probabilities of dying of CML. The score was successfully validated in an independent sample of 1120 patients. In both samples, the new score differentiated probabilities of dying of CML better than the Sokal, Euro and the European Treatment and Outcome Study (EUTOS) score. The new score identified 61% low-risk patients with excellent long-term outcome and 12% high-risk patients. The new score supports the prospective assessment of long-term antileukemic efficacy and risk-adapted treatment.

CARDIOVASCULAR (CV)-RELATED HOSPITALIZATION IN PATIENTS WITH CHRONIC-PHASE CHRONIC MYELOID LEUKEMIA (CP-CML) IN SIMPLICITY, A PROSPECTIVE OBSERVATIONAL STUDY

This population-based registry was designed to provide robust and updated information on the characteristics and the epidemiology of chronic myeloid leukemia (CML). All cases of newly diagnosed Philadelphia positive, BCR-ABL1+ CML that occurred in a sample of 92.5 million adults living in 20 European countries, were registered over a median period of 39 months. 94.3% of the 2904 CML patients were diagnosed in chronic phase (CP). Median age was 56 years. 55.5% of patients had comorbidities, mainly cardiovascular (41.9%). High-risk patients were 24.7% by Sokal, 10.8% by EURO, and 11.8% by EUTOS risk scores. The raw incidence increased with age from 0.39/100 000/year in people 20–29 years old to 1.52 in those >70 years old, and showed a maximum of 1.39 in Italy and a minimum of 0.69 in Poland (all countries together: 0.99). The proportion of Sokal and Euro score high-risk patients seen in many countries indicates that trial patients were not a positive selection. Thus from a clinical point of view the results of most trials can be generalized to most countries. The incidences observed among European countries did not differ substantially. The estimated number of new CML cases per year in Europe is about 6370.

Abstract Introduction Clinical studies clearly show that treatment with tyrosine-kinase inhibitors (TKI) greatly improve the prognosis of patients with CML. Detailed treatment recommendations have since been deduced from clinical trial results by the European LeukemiaNet (Blood 122:872-884). However, little is known about whether these achievements can also be transferred to routine health care. This work investigates if all CML patients are treated in agreement with current standards and wether they achieve outcomes at least as good as those in clinical trials. Methods The web-based registry aimed to collect all newly diagnosed adult patients with chronic phase Ph+ and/or BCR-ABL1+ CML in 20 countries or pre-specified regions covering ~ 92.5 million inhabitants. Overall 2904 patients were registered between 2008 and 2012. Cytogenetic and molecular responses were analyzed using cumulative incidences considering death and progression as competing risks. Survival was analyzed using Kaplan-Meier curves and log rank tests. Results 2342 patients were diagnosed in chronic phase and had follow-up data available. The median age was 55 years (range: 18 to 99 years) and 53% were male; 11% of the patients were at high risk of not achieving complete cytogenetic remission (CCyR) at 18 months according to the EUTOS score. According to the Euro score 10% of the patients were in the high risk group, 51% in the intermediate and 39% in the low risk group. 18% were included in clinical trials. Treatment data of 1701 patients were contributed from 15 countries (85% of 2042 patients registered in those countries). As a first-line therapy 80% of patients received imatinib 15% nilotinib, 3% dasatinib and 3% hydroxyurea (HU). Of the patients receiving nilotinib or dasatinib 56% had been enrolled into clinical trials. There were no significant differences between female and male patients regarding the first-line therapy. More than half of the patients who were treated with HU alone were aged 70 or older. Time to first CCyR is known for 62% of patients. Median time to first CCyR was 10 months; after 12 months 57% (95% CI 54%-60%) and after 18 months 76% (95% CI 74%-79%) had achieved CCyR. Time to first CCyR differed significantly regarding the EUTOS score. Median time to first CCyR was 9 months for the low and 13 months for the EUTOS high risk group (p < 0.0001). After 18 months 78% (95% CI 75%-80%) of patients in the low and 69% (95% CI 60%-76%) of patients in the high risk group had achieved CCyR. The patients' age did not have major influence on the time to first CCyR (p=0.8974, median time to first CCyR: 18 to 39 years: 9 months, 40-65 years: 9 months, older than 65 years: 11 months). Time to first major molecular remission (MMR) could be calculated for 54% of patients. Median time to first MMR was 15 months. Cumulative incidence of MMR after 12 months was 41% (95% CI 38%- 44%). The median observation time of living patients was 29 months. 187 patients died (8%). Probability of OS for all patients at 12, 24 and 30 months was 97% (95% CI 96% - 97%), 94% (95% CI 93% - 95%) and 92% (95% CI 90% - 93%), respectively. 108 patients progressed of whom 62 subsequently died, while 125 patients died without prior progression. Probability of PFS for all patients at 12, 24 and 30 months was 95% (95% CI 94% - 96%), 92% (95% CI 91% - 93%) and 90% (95% CI 88% - 91%), respectively. Of the 187 patients who died, 33% died after progression. 67% died without prior progression. The probability of progression and subsequent death was 1% (95% CI 1% - 2%) after 12 months and 2% (95% CI 2% - 3%) after 24 months. The probability of dying without prior progression was 2% (95% CI 2% - 96%) after 12 months and 4% (95% CI 3% - 5%) after 24 months. Discussion The EUTOS population based registry provides the first unselected sample of adult Ph+ and/or BCR/ABL1+ adult CML patients in Europe. It shows that in Europe the success reported from commercial and academic studies is transferred to the general population. The majority of patients were treated first-line with imatinib, which was the only TKI approved for first-line use by the EMA during most of the registration period. Probabilities of PFS and OS in the registry are comparable to those in clinical trials. The importance of calculating both overall survival and leukemia-related survival is highlighted, since many patients die from different causes related or unrelated to leukemia and to treatment, but without progression. Disclosures Hoffmann: Novartis Oncology Europe: Research Funding. Baccarani:PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ARIAD Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; NOVARTIS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hasford:Novartis: Research Funding. Lindoerfer:Novartis Oncology Europe: Research Funding. Burgstaller:Novartis: Honoraria; Mundipharma: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; AOP Orphan Pharmaceuticals: Honoraria, Research Funding. Mayer:Novartis: Consultancy, Other: funding of travel, accomodations or expenses, Research Funding; BMS: Consultancy, Other: funding of travel, accomodations or expenses, Research Funding. Koskenvesa:GSK: Consultancy; Pfizer: Consultancy; Ariad: Other: funding of travel, accomodations or expenses; BMS: Consultancy, Other: funding of travel, accomodations or expenses; Novartis: Consultancy, Research Funding. Castagnetti:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria. Griskevicius:Novartis: Consultancy, Research Funding; Baxalta: Research Funding. Sacha:Angelini: Consultancy; Adamed: Consultancy; Novartis: Consultancy; BMS: Consultancy. Hellmann:Novartis: Consultancy, Other: funding of travel, accomodations or expenses, Research Funding, Speakers Bureau; BMS: Consultancy, Other: funding of travel, accomodations or expenses, Speakers Bureau. Turkina:Pfizer: Consultancy; Bristol Myers Squibb: Consultancy; Novartis Pharma: Consultancy. Zaritskey:University of Heidelberg: Research Funding; Novartis: Consultancy. Sninska:Novartis: Consultancy. Simonsson:Novartis Pharma: Research Funding. Saussele:Novartis Pharma: Honoraria, Other: Travel grant, Research Funding; ARIAD: Honoraria; Pfizer: Honoraria, Other: Travel grant; BMS: Honoraria, Other: Travel grant, Research Funding. Hochhaus:ARIAD: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Hehlmann:BMS: Consultancy; Novartis Pharma: Research Funding.

We randomised 46 newly diagnosed patients with chronic myeloid leukaemia (median age 56) to receive dasatinib 100 mg QD or imatinib 400 mg QD and report outcome as an intention‐to‐treat analysis with 36 months follow‐up. Early cytogenetic and molecular responses were superior in the dasatinib group, with a tendency that imatinib patients caught up with time. For instance, MR 3.0 was reached at 3 months in 36% vs. 8% ( P = 0.02), at 12 months in 81% vs. 46% ( P = 0.02) and at 18 months in 73% vs. 65% (n.s.) of the patients in the two groups. In contrast, MR 4.5 was consistently superior in the dasatinib group at all time points from 6 months onwards, reaching 61% vs. 21% ( P < 0.05) at 36 months. Sixty‐four vs. 71% of the patients in the dasatinib and imatinib arms, respectively, remained on assigned drug. Dasatinib dose was frequently reduced, but with maintained excellent effect. One imatinib patient progressed to blastic phase, but no CML ‐related deaths occurred. In conclusion, our data compare favourably with those of the dasatinib registration study, DASISION . The fast and deep molecular responses induced by dasatinib compared with imatinib may be exploited to increase the proportion of patients who can achieve a treatment‐free remission after treatment discontinuation.

Patients with chronic myeloid leukemia who fail to achieve timely treatment responses have a worse prognosis. Although many patients respond well to first-line treatment with imatinib, a significant proportion relapse or experience an inadequate response. Since effective alternative Bcr-Abl inhibitors are available (i.e., dasatinib or nilotinib), several regional groups have proposed milestones for imatinib failure or suboptimal response based on the achievement of specified levels of response within a defined treatment duration. A suboptimal response indicates that, although patients may continue to receive a benefit from continuing imatinib treatment at the assigned dose, long-term outcome may be better with an alternative strategy. The underlying mechanisms behind suboptimal responses are multifactorial and may differ from those causing relapse.