Treatment of consecutive patients with chronic myeloid leukaemia in the cooperating centres from the Czech Republic and the whole of Slovakia after 2000 - a report from the population-based CAMELIA Registry

Clear Improvement in Real-World Chronic Myeloid Leukemia Survival: A Comparison With Randomized Controlled Trials

Tyrosine kinase inhibitors (TKIs) have been improving the prognosis of patients with chronic myeloid leukemia (CML), but there are still large differences in survival among European countries. This raises questions on the added value of results from population-based studies, which use real-world data, compared to results of randomized controlled trials (RCTs) involving patients with CML. There are also questions about the extent of the findings on RCTs effectiveness for patients in the general population. We compare survival data extracted from our previous systematic review and meta-analysis of CML RCTs with the latest updated population-based survival data of EUROCARE-6, the widest collaborative study on cancer survival in Europe. The EUROCARE-6 CML survival estimated in patients (15–64 years) diagnosed in 2000–2006 vs. 2007–2013 revealed that the prognostic improvement highlighted by RCTs was confirmed in real-world settings, too. The study shows, evaluating for the first time all European regions, that the optimal outcome figures obtained in controlled settings for CML are also achievable (and indeed achieved) in real-world settings with prompt introduction of TKIs in daily clinical practice. However, some differences still persist, particularly in Eastern European countries, where overall survival values are lower than elsewhere, probably due to a delayed introduction of TKIs. Our results suggest an insufficient adoption of adequate protocols in daily clinical practice in those countries where CML survival values remain lower in real life than the values obtained in RCTs. New high-resolution population-based studies may help to identify failures in the clinical pathways followed there.

Dasatinib treatment long-term results among imatinib-resistant/intolerant patients with chronic phase chronic myeloid leukemia are favorable in daily clinical practice

To evaluate long-term real-life results of dasatinib therapy among chronic phase chronic myeloid leukemia patients resistant or intolerant to imatinib, we retrospectively analyzed data of 118 patients treated in centers participating in the database INFINITY. With median follow-up of 37 months, estimated 5-year cumulative incidences of complete cytogenetic and major molecular responses were 78% and 68%, respectively. The estimated 5-year probability of overall survival (OS) and event-free survival (EFS) were 86% and 83%, respectively. Both OS and EFS were significantly improved among patients with BCR-ABL1 transcript level ≤10% at 3 months. Dasatinib toxicity was tolerable however persistent in almost half our patients, even after years of therapy. Pleural effusion occurred in 29% of patients and was responsible for 30% of dasatinib discontinuations. Our results confirmed very good efficacy and acceptable toxicity of dasatinib in second line setting and support the evidence and importance of high-quality real-life CML patient management.

Prognosis of patients with chronic myeloid leukemia presenting in advanced phase is defined mainly by blast count, but also by age, chromosomal aberrations and hemoglobin

Chronic myeloid leukemia (CML) is usually diagnosed in chronic phase, yet there is a small percentage of patients that is diagnosed in accelerated phase or blast crisis. Due to this rarity, little is known about the prognosis of these patients. Our aim was to identify prognostic factors for this cohort. We identified 283 patients in the EUTOS population-based and out-study registries that were diagnosed in advanced phase. Nearly all patients were treated with tyrosine kinase inhibitors. Median survival in this heterogeneous cohort was 8.2 years. When comparing patients with more than 30% blasts to those with 20-29% blasts, the hazard ratio (HR) was 1.32 (95%-confidence interval (CI): [0.7-2.6]). Patients with 20-29% blasts had a significantly higher risk than patients with less than 20% blasts (HR: 2.24, 95%-CI: [1.2-4.0], P = .008). We found that the blast count was the most important prognostic factor; however, age, hemoglobin, basophils and other chromosomal aberrations should be considered as well. The ELTS score was able to define two groups (high risk vs non-high risk) with an HR of 3.01 (95%-CI: [1.81-5.00], P < .001). Regarding the contrasting definitions of blast crisis, our data clearly supported the 20% cut-off over the 30% cut-off in this cohort. Based on our results, we conclude that a one-phase rather than a two-phase categorization of de novo advanced phase CML patients is appropriate.

Management of Chronic Myeloid Leukemia in Advanced Phase

Management of chronic myeloid leukemia (CML) in advanced phases remains a challenge also in the era of tyrosine kinase inhibitors (TKIs) treatment. Cytogenetic clonal evolution and development of resistant mutations represent crucial events that limit the benefit of subsequent therapies in these patients. CML is diagnosed in accelerated (AP) or blast phase (BP) in <5% of patients, and the availability of effective treatments for chronic phase (CP) has dramatically reduced progressions on therapy. Due to smaller number of patients, few randomized studies are available in this setting and evidences are limited. Nevertheless, three main scenarios may be drawn: (a) patients diagnosed in AP are at higher risk of failure as compared to CP patients, but if they achieve optimal responses with frontline TKI treatment their outcome may be similarly favorable; (b) patients diagnosed in BP may be treated with TKI alone or with TKI together with conventional chemotherapy regimens, and subsequent transplant decisions should rely on kinetics of response and individual transplant risk; (c) patients in CP progressing under TKI treatment represent the most challenging population and they should be treated with alternative TKI according to the mutational profile, optional chemotherapy in BP patients, and transplant should be considered in suitable cases after return to second CP. Due to lack of validated and reliable markers to predict blast crisis and the still unsatisfactory results of treatments in this setting, prevention of progression by careful selection of frontline treatment in CP and early treatment intensification in non-optimal responders remains the main goal. Personalized evaluation of response kinetics could help in identifying patients at risk for progression.

Tyrosine kinase inhibitors in chronic myeloid leukaemia: which, when, for whom?

The therapeutic armamentarium for chronic myeloid leukaemia (CML) comprises mainly tyrosine kinase inhibitors (TKIs), with several agents available for frontline treatment, or for the treatment of disease resistance or intolerance to the first-choice or second-choice drug. The availability of different drugs is a major achievement, but means that choices must be made - which can be difficult and questionable at times. The most important end point considered in decision-making regarding treatment for any cancer is overall survival, but additional factors (such as age, prognostic category, safety, or the possibility of achieving treatment-free remission) should be considered when selecting an agent for frontline treatment. Regardless of the TKI selected for first-line treatment, guidelines that define the importance of reaching specific response indicators and procedures for vigilant follow-up monitoring are established to ensure timely implementation of second-line TKIs. Herein, we discuss the benefits and risks of the different TKIs available for the treatment of patients with CML, and how to decide when to employ these agents at different treatment settings.

Advanced phase chronic myeloid leukaemia (CML) in the tyrosine kinase inhibitor era - a report from the Swedish CML register

OBJECTIVES

The primary goal in management of chronic phase (CP) chronic myeloid leukaemia (CML) is to prevent disease progression to accelerated phase (AP) or blast crisis (BC). We have evaluated progression rates in a decentralised healthcare setting and characterised patients progressing to AP/BC on TKI treatment.

METHODS

Using data from the Swedish CML register, we identified CP-CML patients diagnosed 2007-2011 who progressed to AP/BC within 2 yrs from diagnosis (n = 18) as well as patients diagnosed in advanced phase during 2007-2012 (n = 36) from a total of 544 newly diagnosed CML cases. We evaluated baseline characteristics, progression rates, outcome and adherence to guidelines for monitoring and treatment.

RESULTS

The cumulative progression rate at 2 yrs was 4.3%. All 18 progression cases had been treated with imatinib, and six progressed within 6 months. High-risk EUTOS score was associated to a higher risk of progression. Insufficient cytogenetic and/or molecular monitoring was found in 33%. Median survival after transformation during TKI treatment was 1.4 yrs. In those presenting with BC and AP, median survival was 1.6 yrs and not reached, respectively.

CONCLUSION

In this population-based setting, progression rates appear comparable to that reported from clinical trials, with similar dismal patient outcome. Improved adherence to CML guidelines may minimise the risk of disease progression.

Pattern of chronic myeloid leukemia in the imatinib era in a Sub-Saharan African setting

Chronic myeloid leukemia (CML) is an orphan disease in Africa because of the inaccessibility to specific treatment and the high cost of diagnosis and monitoring patients. The aim of this study was to report CML treatment response in a developing country in the tyrosine kinase inhibitor era. We conducted a longitudinal study of our cohort of CML patients. Socio-demographic, diagnosis, therapeutic, and treatment response parameters were studied. Sokal score, disease phase at diagnosis, delay from diagnosis to treatment, and treatment response were analyzed for their impact on survival. Fifty-five patients with a diagnosis of CML and who received treatment with imatinib for a minimum of 3 months were included in this study. Median follow-up was 170 patient-years. The sex ratio (M/F) was 1.62 and median age at diagnosis was 42 years. At diagnosis, 85.5 % of the patients were in chronic phase (CP), 12.7 % in accelerated phase (AP), and 1.8 % in blast crisis (BC). Sokal risk score distribution was as follows: low risk 29.8 %, intermediate risk 38.3 %, and high risk 31.9 %. Median time from first symptoms to first medical visit was 6.2 months and median time from first medical visit to cytogenetic and or molecular confirmation was 12.4 months. Mean delay time from first medical visit to imatinib initiation was 12.5 months (95 % CI 6.3-18.7). The complete hematologic response (CHR) at 3 months, the major cytogenetic response (MCR) at 12 months, and the major molecular response (MMR) at 24 months were respectively 82.4, 75, and 25 %. The 2-year overall survival rate was 81 %. Advanced phase at the diagnosis, discontinuation of imatinib therapy over 15 % of the time, lack of CHR at 3 months, lack of MCR at 12 months, and progression of the disease during imatinib therapy were associated with a risk of death (p ≤ 0.05). Our data confirm the improved prognosis of CML treated with imatinib in the setting of a developing country. However, response rates are lower than in developed countries, and additional efforts should be made to facilitate early diagnosis and improve access to TKI, treatment compliance, and regular molecular monitoring of patients.

Fluorescent In Situ Hybridization Monitoring and Effect of Detected Early Responses in the Outcome of Patients With Chronic Phase Chronic Myeloid Leukemia: A Report From a Latin American Country

INTRODUCTION

The cytogenetic hallmark of chronic myeloid leukemia (CML) is the Philadelphia chromosome. Monitoring the response in patients receiving therapy is a standard of care. The present study was conducted to assess the monitoring adherence and reliableness of fluorescent in situ hybridization (FISH) as a monitoring tool and the effect of a complete cytogenetic response (CCyR) assessed by FISH on the prognosis of patients in a chronic phase (CP)-CML cohort.

MATERIALS AND METHODS

We retrospectively analyzed the data from 63 newly diagnosed CP-CML patients treated with imatinib mesylate at a dose of 400 mg/day as frontline therapy. The clinical data and cytogenetic test results at diagnosis and during monitoring were collected. The cytogenetic monitoring adherence assessment rates were measured. A correlation between chromosome banding analysis (CBA) and FISH was performed. The CCyR assessed by FISH was defined as < 1% BCR-ABL1(+) nuclei. The Kaplan-Meier method was used for overall survival analysis and time-to-event estimates.

RESULTS

The cytogenetic monitoring assessment adherence was 50.8% at 3 months, 93.5% at 6 months, 96.7% at 12 months, and 88.6% at 18 months. The Pearson correlation coefficient showed a significantly positive association (r = 0.84; P < .001) between CBA and FISH. The median follow-up duration after imatinib mesylate initiation was 60 months. A CCyR was achieved in 90.4% of patients within the first 18 months of therapy. At 3 months, 31 patients underwent a FISH evaluation, and 13 (41.9%) had achieved a CCyR. The patients who did not achieve a CCyR at 3 months had a significantly inferior probability of 5-year failure-free survival (38% vs. 94%; P = .001) and progression-free survival (80% vs. 100%; P = .043) compared with those with a CCyR.

CONCLUSION

We found improved monitoring adherence compared with the previous reports of Latin American populations. In countries with a high incidence of failure for CBA and a lack of real-time polymerase chain reaction standardization, FISH is a sensitive monitoring tool. In our cohort, patients not achieving an early CCyR, as tested by FISH, were a poor prognosis subgroup with worse rates of failure-free survival and progression-free survival.

Chronic myeloid leukemia incidence, survival and accessibility of tyrosine kinase inhibitors: a report from population-based Lithuanian haematological disease registry 2000-2013

BACKGROUND

Currently available chronic myeloid leukaemia (CML) survival reports have originated from more affluent countries. Herein we report the entire country data on incidence and survival of CML, as well as penetrance of tyrosine kinase inhibitors (TKIs) in Lithuania.

METHODS

We analyzed all patients (N = 601) from the national haematological disease monitoring system who were diagnosed with CML between 2000 and 2013. Crude (CR) and age-standardized (weighted) (ASW(R)) incidence and mortality rates, as well as 1-, 5-, and 10-year relative survival rates (RSR) were calculated. Information on TKI penetration is also reported.

RESULTS

Throughout the entire 2000-2013 period the median age at diagnosis of CML patients was 62 years. The respective incidence and mortality CRs were 1.28 and 0.78, both characterized by decreasing trends over the observation period. A 5-year RSR increased from 0.33 [95 % CI, 0.27-0.40] in 2000-2004 to 0.55 [95 % CI, 0.47-0.63] in 2005-2009. However, the respective 5-year RSRs for patients aged 65-74 and ≥75 were only 0.33 [95 % CI, 0.24-0.42] and 0.18 [95 % CI 0.07-0.23] during the entire study period. TKI penetrance for CML patients grew from 1.5 % in 2000-2004 to 30.6 % in 2005-2009 and 69.1 % in 2010-2013. TKI penetrance was low in the older age groups (60 % for the 65-74 and 19 % for the ≥75 patient group, in 2010-2013).

CONCLUSION

Relative CML survival in Lithuania steadily improved and paralleled the increase in TKI treatment availability. Patients above 64 years rarely received TKIs and their relative survival remained low throughout the observation period. The latency of TKI availability may have influenced the survival trends.

Chronic myeloid leukemia in the Netherlands: a population-based study on incidence, treatment, and survival in 3585 patients from 1989 to 2012

OBJECTIVE

To assess the impact and results of treatment of CML in the general population, we conducted a population-based, nationwide study on 3585 CML patients diagnosed between 1989 and 2012 in the Netherlands.

METHODS

Patient demographics were obtained from the Netherlands Cancer Registry. Information on age, gender, year of diagnosis, first treatment, and date of death were recorded. Overall survival (OS) was adjusted for death rates in the normal population.

RESULTS

Incidence in males decreased slightly from 1.2 per 100.000 person years (PY) in 1989-2000 to 0.9 in 2001-2012. For females, incidence remained stable with 0.7 per 100.000 PY in both periods. Incidence was age dependent and highest in males in the last decades of life. Treatment before 2000 mainly consisted of chemotherapy, while after 2007 TKI use was 88%. Five-year relative survival was only 36% before the introduction of TKIs but significantly increased to 79% after the introduction of TKI.

CONCLUSIONS

This study gives insight into CML incidence, treatment, and survival in routine care in the Netherlands. Although OS improved since the introduction of TKIs, there is still room for further improvement.

Long-term outcome of chronic myeloid leukemia patients treated frontline with imatinib

For almost 10 years imatinib has been the therapeutic standard of chronic myeloid leukemia. The introduction of other tyrosine kinase inhibitors (TKIs) raised a debate on treatment optimization. The debate is still heated: some studies have protocol restrictions or limited follow-up; in other studies, some relevant data are missing. The aim of this report is to provide a comprehensive, long-term, intention-to-treat, analysis of 559 newly diagnosed, chronic-phase, patients treated frontline with imatinib. With a minimum follow-up of 66 months, 65% of patients were still on imatinib, 19% were on alternative treatment, 12% died and 4% were lost to follow-up. The prognostic value of BCR-ABL1 ratio at 3 months (⩽10% in 81% of patients) was confirmed. The prognostic value of complete cytogenetic response and major molecular response at 1 year was confirmed. The 6-year overall survival was 89%, but as 50% of deaths occurred in remission, the 6-year cumulative incidence of leukemia-related death was 5%. The long-term outcome of first-line imatinib was excellent, also because of second-line treatment with other TKIs, but all responses and outcomes were inferior in high-risk patients, suggesting that to optimize treatment results, a specific risk-adapted treatment is needed for such patients.

Relative survival in patients with chronic-phase chronic myeloid leukaemia in the tyrosine-kinase inhibitor era: analysis of patient data from six prospective clinical trials

BACKGROUND

Tyrosine-kinase inhibitors improve overall survival in patients with chronic myeloid leukaemia in chronic phase (CML-CP). Survival compared with the general population by age, response, and type of tyrosine-kinase inhibitor is not known. With use of data from trials of tyrosine kinase inhibitors, we compared overall survival in patients with newly diagnosed CML-CP to that of general population.

METHODS

In this cohort analysis, we included data from patients with CML-CP enrolled in six consecutive or parallel prospective clinical trials of tyrosine-kinase inhibitors at a single institution from July 30, 2000, to Sept 17, 2012. We analysed data for response and survival with the Kaplan-Meier method. For estimated overall survival in the general population, we obtained data from national vital statistics reports and matched to patients with CML-CP by age, sex, ethnicity, and year at diagnosis. We assessed numbers and causes of death within 1 year of beginning treatment by age group and by response to therapy. We then did univariate analysis and multivariate analysis to investigate factors associated with survival probability.

FINDINGS

Our analysis included 483 patients, 271 received imatinib, 105 received nilotinib, and 107 received dasatinib. Most patients were younger than 65 years, and no patients were older than 85 years. Median follow-up was 99·4 months (IQR 44·9-121·6), by which time 53 (11%) patients had died. The most common causes of death were progression to advanced disease stage, including complications of stem-cell transplantation (17 [4%] patients), secondary malignancies (nine [2%] patients), and cardiovascular causes (nine [2%] patients). 5-year overall survival in patients with CML-CP decreased in older age categories. For the whole population of patients with CML-CP, 5-year survival was only slightly lower than that of the matched general population (relative survival 94·7% [95% 92·1-97·4]). Individuals of all ages with a report of complete cytogenetic response to treatment or deeper within 1 year had a 5-year survival similar to that of the general population.

INTERPRETATION

In the era of treatment with tyrosine-kinase inhibitors, patients diagnosed with CML-CP can expect a 5-year survival that is only slightly lower than that of the general population. With access to tyrosine-kinase inhibitors, most patients with chronic myeloid leukaemia could enjoy a near normal life expectancy.

FUNDING

MD Anderson Cancer Center, National Cancer Institute.

Impact of imatinib interruption and duration of prior hydroxyurea on the treatment outcome in patients with chronic myeloid leukemia: Single institution experience

BACKGROUND

Optimal response requires that patients should be maintained on the drug continuously.

OBJECTIVES

To evaluate the influence of imatinib interruption and prior hydroxyurea use on the outcome of patients with chronic myeloid leukemia.

MATERIALS AND METHODS

Between January 2010 and November 2013, patients with chronic phase who received imatinib at the Kasr Al-ainy Center of Clinical Oncology were included.

RESULTS

Sixty patients were included in this study, thirty three patients (55%) received imatinib upfront, while 27 (45%) received imatinib post hydroxyurea. Imatinib was not given regularly in 50% of patients. In terms of response, only major molecular response and complete molecular response were statistically significant in favor of patients who were receiving imatinib regularly compared to those who had interruption (p<0.001, p<0.001, respectively) , while there was no difference in patients stratified according to prior hydroxyurea. The median progression free survival was 30.3 months (95% CI 24.3-36.3). Among the group of patients who received imatinib regularly, progression free survival was longer (p=0.049), there was no difference between those who received prior hydroxyurea versus those who did not (p=0.67).

CONCLUSION

Duration of prior hydroxyurea had no impact on response or progression free survival, while patients regular on imatinib had statistically significant difference with respect to major molecular response, complete molecular response and progression free survival compared to those who had periods of drug interruption, thus we need more governmental support to supply the drug without interruption to improve the outcome of therapy.

Response to tyrosine kinase inhibitors in chronic myeloid leukemia: experience from a west Asian developing country

Tyrosine Kinase inhibitors (TKIs) have dramatically changed the prospects for patients with chronic myeloid leukemia (CML); however, information on CML and response to TKIs from Asia are limited, particularly from West Asia, including Iraq. To address the latter issue we evaluated and monitored a cohort of 108 Iraqi patients diagnosed as chronic phase-CML, enrolled in a government-sponsored national program. The patients were all treated initially by imatinib mesylate. Ninety-two percent of patients had a complete hematological response, 38% had a major molecular response, while 79% had a major cytogenetic response after a median follow-up of 35.7 months. The 3-year Event-Free, Progression-Free, and Overall survival rates were 79.6, 87 and 98.1%, respectively. A total of 26 patients (24.1%) were shifted to an alternative TKI (Nilotinib). After one year of therapy in seventeen of the latter patients, 24% had major molecular response. In conclusion, our results compare favorably with those reported from the West and some Asian countries, and have demonstrated the importance of molecular as well as cytogenetic monitoring, and confirmed the relative success of the national CML program in our country.

Definition and treatment of resistance to tyrosine kinase inhibitors in chronic myeloid leukemia

Resistance to tyrosine kinase inhibitors (TKIs) has many facets. The causes of resistance include low patient compliance, low plasma or intracellular drug concentration, BCR-ABL1 mutations, and clonal chromosome abnormalities in Ph+ cells, but in at least 50% of patients the causes are currently unknown. Primary resistance occurs when a predefined response level is not achieved within a prespecified period of time. Not achieving a complete hematologic response (CHR) within 3 months, not achieving a partial cytogenetic response and/or a BCR-ABL1 transcripts level ≤10% (international standard) within 6 months, and not achieving a complete cytogenetic response (CCyR) and/or a BCR-ABL1 transcripts level <1% within 12 months, define primary resistance. Secondary resistance is defined by a loss of CHR, or CCyR, or major molecular response. Resistance to imatinib calls without exceptions for a second-generation TKI. In case of resistance to two TKIs, an allogeneic stem cell transplantation should be considered.

Imatinib in chronic myeloid leukemia: an overview

Imatinib was the first signal transduction inhibitor (STI), used in a clinical setting. It prevents a BCR-ABL protein from exerting its role in the oncogenic pathway in chronic myeloid leukemia (CML). Imatinib directly inhibits the constitutive tyrosine kinase activity. Imatinib binds to BCR-ABL kinase domain by preventing the transfer of a phosphate group to tyrosine on the protein substrate and the subsequent activation of phosphorylated protein. As the result, the transmission of proliferative signals to the nucleus is blocked and leukemic cell apoptosis is induced. The FDA has approved imatinib as first-line treatment for newly diagnosed CML in December 2002 following an International Randomized Study (IRIS), initiated in June 2000, comparing imatinib at a single daily dose 400 mg to IFN alpha plus cytarabine in newly diagnosed patients with CML in CP. Results from this study show the outstanding effectiveness of imatinib and its superiority with respect to the rates of complete hematological response (CHR), major and complete cytogenetic response (MCyR, CCyR). Patients randomized to imatinib arm at 8 – year data cut off continue to have a durable hematologic and cytogenetic responses, low progression rates to AP or BC, and remarkable survival outcomes. An overall survival (OS) rate is 85% for patients receiving imatinib (93% when only CML-related deaths and those prior to stem cell transplantation are considered). The results have been confirmed in the last years by several groups. According these cumulative results the rates of CCyR achieved after one year of therapy with imatinib at standard dose ranged from 49% to 77%, and the proportion of patients who achieved major molecular response (MMR) after one year ranged between 18% and 58%. Discontinuation of imatinib has been also tried in patients in MMR, a molecular relapse occurs in about one third of patients, generally within 6 months from imatinib cessation.

Turkish Chronic Myeloid Leukemia Study: Retrospective Sectional Analysis of CML Patients

Objective: here have been tremendous changes in treatment and follow-up of patients with chronic myeloid leukemia (CML) in the last decade. Especially, regular publication and updating of NCCN and ELN guidelines have provided enermous rationale and base for close monitorization of patients with CML. But, it is stil needed to have registry results retrospectively to evaluate daily CML practices.

Materials and Methods: In this article, we have evaluated 1133 patients’ results with CML in terms of demographical features, disease status, response, resistance and use of second-generation TKIs.

Results: The response rate has been found relatively high in comparison with previously published articles, and we detected that there was a lack of appropriate and adequate molecular response assessment.

Conclusion: We concluded that we need to improve registry systems and increase the availability of molecular response assessment to provide high-quality patient care.

Conflict of interest:None declared.

Similar outcome of patients with chronic myeloid leukemia treated with imatinib in or out of clinical trials

INTRODUCTION

Outcomes of CML-CP patients treated in clinical trials are frequently perceived to be not representative of those treated outside of clinical trials.

PATIENTS AND METHODS

We investigated the outcomes of patients receiving imatinib outside of a clinical trial (off protocol) or in a clinical trial (on protocol) for CML-CP.

RESULTS

We identified 65 patients treated with imatinib off protocol and 71 patients treated on protocol with standard-dose imatinib. The overall complete cytogenetic response (CCyR) rate was 83% for patients treated on and off protocol. CCyR rates 12 months after initiation of imatinib were not statistically different (61% vs. 66%, respectively; P = .15). Patients treated off protocol had similar rates of overall major molecular response (72% vs. 73%) compared with the patients treated on protocol. The 5-year event-free survival rates were 84% and 86% for off and on protocol patients, respectively. There was also no significant difference in 5-year transformation free survival (94% vs. 96%) and overall survival (96% vs. 90%).

CONCLUSION

These results suggest that patients with CML treated outside of a clinical trial might have the same excellent outcome as those treated in a clinical trial provided they are followed with the same rigor.

Current survival measures reliably reflect modern sequential treatment in CML: correlation with prognostic stratifications

Using the data of 723 chronic myeloid leukemia (CML) patients in the chronic phase, we analyzed the prognostic value of the Sokal, Euro, and EUTOS scores as well as the level of BCR-ABL1 and the achievement of complete cytogenetic response (CCgR) at 3 months of imatinib therapy in relation to the so-called current survival measures: the current cumulative incidence (CCI) reflecting the probability of being alive and in CCgR after starting imatinib therapy; the current leukemia-free survival (CLFS) reflecting the probability of being alive and in CCgR after achieving the first CCgR; and the overall survival. The greatest difference between the CCI curves at 5 years after initiating imatinib therapy was observed for the BCR-ABL1 transcripts at 3 months. The 5-year CCI was 94.3% in patients with BCR-ABL1 transcripts ≤ 10% and 57.1% in patients with BCR-ABL1 transcripts > 10% (P = 0.005). Therefore, the examination of BCR-ABL1 transcripts at 3 months may help in early identification of patients who are likely to perform poorly with imatinib. On the other hand, CLFS was not significantly affected by the considered stratifications. In conclusion, our results indicate that once the CCgR is achieved, the prognosis is good irrespective of the starting prognostic risks.

EUTOS score predicts long-term outcome but not optimal response to imatinib in patients with chronic myeloid leukaemia

To test the recently developed EUTOS score in predicting optimal response to imatinib and the long-term outcome, 265 patients with early chronic phase chronic myeloid leukaemia treated with standard dose imatinib were analysed. Achievement of optimal response endpoints were higher in low-risk patients, though the difference was not statistically significant: PCyR at 6th month 86% vs 67% (p=0.06), CCyR at 12th month 80% vs 63% (p=0.09), MMR at 18th month 61% vs 36% (p=0.11). However, EUTOS score was predictive for the long-term response. With a median follow-up of 61 months, 53% high-risk patients experienced imatinib failure, compared to 23% in the low-risk group (p=0.013). Among high-risk patients, 4/17 (23%) progressed to accelerated/blastic phase or died, compared to 11/248 (5%) low-risk patients, with 5-year progression-free survival rates of 84±10% and 96±1%, respectively (p=0.04). Our data confirm that EUTOS score envisions the long-term outcome of imatinib therapy.

European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013

Advances in chronic myeloid leukemia treatment, particularly regarding tyrosine kinase inhibitors, mandate regular updating of concepts and management. A European LeukemiaNet expert panel reviewed prior and new studies to update recommendations made in 2009. We recommend as initial treatment imatinib, nilotinib, or dasatinib. Response is assessed with standardized real quantitative polymerase chain reaction and/or cytogenetics at 3, 6, and 12 months. BCR-ABL1 transcript levels ≤10% at 3 months, <1% at 6 months, and ≤0.1% from 12 months onward define optimal response, whereas >10% at 6 months and >1% from 12 months onward define failure, mandating a change in treatment. Similarly, partial cytogenetic response (PCyR) at 3 months and complete cytogenetic response (CCyR) from 6 months onward define optimal response, whereas no CyR (Philadelphia chromosome-positive [Ph+] >95%) at 3 months, less than PCyR at 6 months, and less than CCyR from 12 months onward define failure. Between optimal and failure, there is an intermediate warning zone requiring more frequent monitoring. Similar definitions are provided for response to second-line therapy. Specific recommendations are made for patients in the accelerated and blastic phases, and for allogeneic stem cell transplantation. Optimal responders should continue therapy indefinitely, with careful surveillance, or they can be enrolled in controlled studies of treatment discontinuation once a deeper molecular response is achieved.

Tyrosine kinase inhibitor usage, treatment outcome, and prognostic scores in CML: report from the population-based Swedish CML registry

Clinical management guidelines on malignant disorders are generally based on data from clinical trials with selected patient cohorts. In Sweden, more than 95% of all patients diagnosed with chronic myeloid leukemia (CML) are reported to the national CML registry, providing unique possibilities to compile population-based information. This report is based on registry data from 2002 to 2010, when a total of 779 patients (425 men, 354 women; median age, 60 years) were diagnosed with CML (93% chronic, 5% accelerated, and 2% blastic phase) corresponding to an annual incidence of 0.9/100,000. In 2002, approximately half of the patients received a tyrosine kinase inhibitor as initial therapy, a proportion that increased to 94% for younger (<70 years) and 79% for older (>80 years) patients during 2007-2009. With a median follow-up of 61 months, the relative survival at 5 years was close to 1.0 for patients younger than 60 years and 0.9 for those aged 60 to 80 years, but only 0.6 for those older than 80 years. At 12 months, 3% had progressed to accelerated or blastic phase. Sokal, but not European Treatment and Outcome Study, high-risk scores were significantly linked to inferior overall and relative survival. Patients living in university vs nonuniversity catchment areas more often received tyrosine kinase inhibitors up front but showed comparable survival.

Evaluation of 5-year imatinib treatment of 458 patients with CP-CML in routine clinical practice and prognostic impact of different BCR-ABL cutoff levels

We evaluated responses to the treatment and long-term outcomes of chronic myeloid leukemia patients treated with imatinib as first-line treatment in routine clinical setting from two countries with centralized tyrosine kinase inhibitors (TKIs) treatment. We assessed prognostic significance of European LeukemiaNet (ELN) 2006- and 2009-defined responses and the prognostic value of molecular responses at defined time points on 5-year survivals. Among the cumulative rates of incidence of hematologic, cytogenetic, and molecular responses and all important survival parameters, we evaluated the prognostic significance of different BCR-ABL transcript-level ratios (≤1%; >1%–≤10%; >10%) at 3, 6, 12, and 18 months (n = 199). The ELN optimal response criteria and their predictive role were significantly beneficial for event-free survival at all given time points. We found significant improvement in survivals of patients with BCR-ABL lower than 10% in the 6th and 12th months. Significantly better outcome was found in patients who achieved major molecular response (MMR) in the 12th month. The cumulative incidences of complete cytogenetic response (CCyR) and MMR were significantly associated with the molecular response in the 3rd month. The ELN response criteria and their predictive role were helpful at given time points; however, the 2009 definition did not significantly alter the prognostic accuracy compared with that of the 2006 definition. The significant value was observed for cytogenetic responses at the 6th and 12th month. Moreover, progression-free and event-free survivals were improved with MMR at the 12th month.