Abstract 3761
Early assessment of molecular and cytogenetic response at 3 months of imatinib treatment has been shown to predict survival and might trigger treatment intensification in slow ...responders who are supposed to harbor a BCR-ABL positive clone with inferior susceptibility to tyrosine kinase inhibition (Hanfstein et al., Leukemia 2012). BCR-ABL transcript levels at 3 months depend on levels at diagnosis and the subsequent decline under treatment. Which of both parameters determines the clinical course and allows for prediction of survival is unclear. The BCR-ABL/ABL ratio is supposed to be skewed for high values, e.g. >10%, due to the fact that ABL transcripts are also amplified from the fusion gene and in fact BCR-ABL/(ABL + BCR-ABL) is determined. Therefore, Beta-glucuronidase (GUS) was used as reference gene to determine high transcript levels at diagnosis. In addition, the linearity of the BCR-ABL/GUS scale allowed for an optimization of prognostic cut-off levels. We compared the significance of 1) BCR-ABL/GUS at diagnosis, 2) BCR-ABL/GUS at 3 months, 3) the individual reduction of transcripts given by (BCR-ABL/GUS at 3 months)/(BCR-ABL/GUS at diagnosis), and 4) the established 10% BCR-ABL/ABL landmark expressed on the international scale (BCR-ABLIS).
A total of 337 patients (pts) were investigated. According to the protocol of the German CML study IV pts could have been pre-treated with imatinib up to 6 weeks before randomization. 56 pts with imatinib onset before initial blood sampling within the study were excluded from the analysis. A total of 281 evaluable patients (median age 51 years, range 17–85, 42% female) were treated with an imatinib-based therapy consisting of imatinib 400 mg/d (n=76), imatinib 800 mg/d (n=110) and combinations of standard dose imatinib with interferon alpha (n=84) and low-dose cytarabine (n=11). Median follow-up was 4.8 years (range 1–10). Transcript levels of BCR-ABL, ABL, and GUS were determined by quantitative RT-PCR from samples taken before imatinib onset (“at diagnosis”) and 3 month samples. Only patients expressing typical BCR-ABL transcripts (b2a2 and/or b3a2) were considered. Disease progression was defined by the incidence of accelerated phase, blastic phase or death from any reason. A landmark analysis was performed for progression free survival (PFS) and overall survival (OS) after dichotomizing patients by a cut-off optimized by the cumulative martingale residuals method.
The median BCR-ABL/GUS ratio was 15.5% at diagnosis (0.07–271) and 0.62% at 3 months (0–34.7) reflecting a decline by 1.4 log. Disease progression was observed in 17 patients (6.0%), 14 of them died (5.0%). With regard to the above described parameters the following findings were observed: 1) at diagnosis no cut-off level could be identified for BCR-ABL/GUS ratios to separate two prognostic groups according to long-term PFS or OS. 2) At 3 months an optimized 2.8% BCR-ABL/GUS cut-off separated a high-risk group of 61 pts (22% of pts, 8-year PFS 78%, 8-year OS 81%) from a good-risk group of 220 pts (78% of pts, 8-year PFS 94%, 8-year OS 94%, p<0.001, respectively). 3) At 3 months an individual reduction of BCR-ABL transcripts to at least 40% (0.4 log) of the initial level separated best and divided a high-risk group of 33 pts (12% of pts, 8-year PFS 74%, 8-year OS 80%) from a good-risk group of 248 pts (88% of pts, 8-year PFS 93%, 8-year OS 93%, p<0.001, respectively). 4) When the established 10% BCR-ABLIS at 3 months was investigated, 63 pts were high-risk (22% of pts, 8-year PFS 82%, 8-year OS 85%) and 218 good-risk (78% of pts, 8-year PFS 91%, 8-year OS 93%, p=0.002 for PFS, p=0.011 for OS).
Initial BCR-ABL transcript levels at diagnosis did not show prognostic significance. To predict survival at 3 months of treatment the absolute transcript level normalized by ABL or GUS can be used.
Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Hochhaus:Novartis, BMS, MSD, Ariad, Pfizer: Consultancy Other, Honoraria, Research Funding. Müller:Novartis, BMS: Consultancy, Honoraria, Research Funding.
Abstract 355
The prognostic relevance of variant t(9;22) and additional cytogenetic aberrations (ACA) at diagnosis of chronic myeloid leukemia (CML) is conflicting.
We used baseline and outcome data ...of 1028 patients (607 male, 421 female, median age 53, range 16–88) with chronic phase CML randomized to the German CML-Study IV (imatinib IM 800 mg n=264 vs IM 400 mg n=253 vs IM 400 mg + IFN n=281 vs IM 400 mg after IFN failure n=108 vs IM 400 mg + AraC n=122) to investigate the impact of variant t(9;22) and of clonal ACA at diagnosis on time to complete cytogenetic remission (CCyR) and major molecular response (MMR), accepted markers of prognosis. Cytogenetic analysis was performed after 24- and/or 48 h culture on G-banded metaphases. If appropriate, fluorescent-in-situ-hybridization on metaphases was used in addition. Since lack of the Y chromosome is regarded as a negligible age-related, not leukemia-associated event, those patients were excluded from evaluation.
In total, 123/1028 patients (12%) showed additional cytogenetic findings at diagnosis: 52/1028 patients (5.1%) had variants of the t(9;22), 33/1028 patients (3.2%) lacked the Y chromosome, 38/1028 patients (3.7%) had other additional numerical or structural aberrations. 105/1028 patients (10.2%) had only one type of additional cytogenetic finding, while 18/1028 patients (1.8%) showed ≥ 2 types of additional cytogenetic findings. 905/1028 patients (88%) had no variant t(9;22) or ACA. Median age, sex and treatment were similarly distributed (Table 1).
In 45/52 patients (86.5%) with variant t(9;22), one further chromosome was involved (three way translocation), whereas in 7/52 patients (13.5%) ≥ 2 chromosomes were involved (complex variant). No involvement of the chromosomes 10, 18, 20, 21, X, or Y has been found.
For patients without variant t(9;22) and ACA, with variant t(9;22), with variant t(9;22) and ACA other than –Y, and with ACA other than -Y and variant t(9;22), median time (years) to CCyR was 0.98, 0.84, 1.08 and 1.34, median time (years) to MMR was 1.4, 1.55, 1.8 and 2.17, and probability (%, confidence interval) for 2 years overall survival was 0.97 (0.96-0.98), 0.96 (0.89-0.99), 0.95 (0.90-0.99) and 0.94 (0.85-0.99), respectively.
There was no difference regarding time to CCyR, time to major molecular response (MMR) and 2 years overall survival between patients with variant t(9;22) or ACA compared to those without variant t(9;22) or ACA.
We conclude that additional chromosomal abnormalities at diagnosis have no negative prognostic impact. This finding is hypothesis generating. For confirmation of this hypothesis longer observation of the course of patients with variant t(9;22) and ACA is needed.
VariableNo variant t(9;22) or ACAVariant t(9;22)Variant t(9;22) and ACA other than -YACA other than –Y and variant t(9;22)n905529038Median age52565453Sex (% female)41%42%40%37%IM after IFN failure964117IM + Ara C1048135IM 400 mg22411209IM + IFN25312208IM 800 mg22817269
Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership, Research Funding. German CML-Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; Roche: Research Funding; BMBF: Research Funding; Essex: Research Funding.
Abstract 783▪FN2▪This icon denotes a clinically relevant abstract
The advent of second generation tyrosine kinase inhibitors (TKI) in the front line treatment setting of chronic myeloid leukemia ...(CML) has tightened the evaluation of imatinib response. Early assessment of response markers might identify slow responders harboring a BCR-ABL positive clone with an inferior susceptibility to tyrosine kinase inhibition. This group of patients could benefit from an early dose escalation or a change of treatment to a second generation TKI thus avoiding the risk of disease progression. Therefore we sought to evaluate the impact of molecular and cytogenetic response levels after 3 months of imatinib treatment on the further course of disease. Patients and methods: A total of 1,340 patients (median age 52 years, range 16–88, 40% female) were included into the randomized German CML study IV and treated with an imatinib based therapy consisting of imatinib 400 mg/d (n=381), imatinib 800 mg/d (n=399) and combinations of standard dose imatinib with interferon alpha (n=402) and low-dose cytarabine (n=158). Median follow-up was 4.7 years (range 0–9). Molecular response after 3 months was assessed in 743 patients, cytogenetic response in 498 patients. The BCR-ABL expression was determined by quantitative RT-PCR and standardized according to the international scale (BCR-ABL IS). Only patients expressing typical BCR-ABL transcripts (b2a2, b3a2, b2a2 and b3a2) were considered. Cytogenetic response was determined by conventional metaphase analysis. Disease progression was defined by the incidence of accelerated phase, blastic phase or death from any reason. A landmark analysis was performed for progression free survival (PFS) and overall survival (OS). Results: Disease progression was observed in 149 patients (11.1%), 127 patients died (9.5%). After 3 months of treatment the median BCR-ABL IS was 2.6% (0-100), the median proportion of Philadelphia chromosome positive metaphases (Ph+) was 8% (0-100). The BCR-ABL landmarks of 1% and 10% after 3 months of imatinib both proved to discriminate significantly for PFS and OS: BCR-ABL IS <1% (n=233) vs. ≥1% (n=486), p=0.041 for PFS, p=0.048 for OS; BCR-ABL IS <10% (n=524) vs. ≥10% (n=195), p=0.004 for PFS and p=0.001 for OS. A stratification in 3 risk groups according to the achievement of a BCR-ABL IS of <1%, 1–10% and >10% after 3 months resulted in a significant difference between the poor risk group (>10%, n=195) and the intermediate risk group (1-10%, n=291): p=0.038 for PFS and p=0.012 for OS. The difference between the intermediate risk group and the good risk group (<1%, n=233) was not significant. The five year survival probability was 97%, 94% and 87% for the good, intermediate and poor risk group, respectively. Cytogenetic response landmarks after 3 months of imatinib were also predictive for PFS and OS: Ph+ ≤35% (n=362) vs. Ph+ >35% (n=123), p=0.022 for PFS, p=0.043 for OS; Ph+ ≤65% (n=401) vs. Ph+ >65% (n=84), p=0.004 for PFS and p=0.011 for OS. A 3 group stratification did not reach statistical significance. Conclusions: The achievement of molecular and cytogenetic response landmarks after 3 months of imatinib treatment is predictive for long term progression free and overall survival. At 3 months a BCR-ABL IS of 10% or more is associated with a 5-year overall survival of 87% suggesting an early change of treatment, whereas a BCR-ABL IS of 1% or less indicates a favorable 5-year overall survival of 97%.
Schnittger:Münchner Leukämie Labor: Equity Ownership. Haferlach:Münchner Leukämie Labor: Equity Ownership. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.
Abstract 782
Current evidence indicates that acquired genetic instability in chronic myeloid leukemia (CML) as a consequence of the t(9;22)(q34;q11) and the resulting BCR-ABL fusion causes the ...continuous acquisition of additional chromosomal aberrations (ACA) and mutations and thereby progression to accelerated phase and blast crisis (BC). Around 10 –12% of patients in chronic phase (CP) CML have ACA already at diagnosis. During the course of the disease this number rises to 80% in BC. Acquisition of ACA during treatment is considered as a poor prognostic indicator, whereas the impact of ACA at diagnosis is controversial.
Patients and methods: Clinical and cytogenetic data of 1151 out of 1311 patients with Philadelphia and BCR-ABL positive CP CML randomized until 2009 to the German CML-Study IV were investigated in a prospective study. There were 459 females (40%) and 692 males (60%). Median age was 53 years (range, 16–88). All patients were treated with imatinib alone or in combination with interferon alpha or araC. The impact of ACA at diagnosis on time to complete cytogenetic and major molecular remission (CCR, MMR) and progression-free and overall survival (PFS, OS) was investigated. Written informed consent was obtained from all patients prior to entering the study.
At diagnosis 1003/1151 patients (87%) had the standard t(9;22)(q34;q11) only and 69 patients (6.0%) had a variant t(v;22). In 60 of 69 patients with t(v;22), only one further chromosome was involved in the translocation, in 7 patients two, and in 2 patients three further chromosomes were involved. Seventy-nine patients (6.9%) had ACA. Of these, 38 patients (3.3%) lacked the Y chromosome (-Y) and 41 patients (3.6%) had ACA except -Y. Sixteen of the 41 patients had major-route ACA (+8, i(17)(q10), +der(22)t(9;22)(q34;q11), ider(22)(q10)t(9;22)(q34;q11)) and 25 minor-route ACA e.g. t(3;12), t(4;6), t(2;16), t(1;21). In patients with major-route ACA, trisomy 8 was the most frequent additional alteration (n=9). +der(22)t(9;22)(q34;q11) was observed in six patients, isochromosome (17)(q10) in five patients and ider(22)(q10)t(9;22)(q34;11) in three patients.
After a median observation time of 5.3 years for patients with t(9;22), t(v;22), -Y, minor- and major-route ACA median times to CCR were 1.01, 0.95, 0.98, 1.49 and 1.51 years, to MMR 1.40, 1.58, 1.65, 2.49 and > 7 years, 5-year PFS 90%, 81%, 88%, 96% and 50% and 5-year OS 92%, 87%, 91%, 96% and 53%, respectively. In patients with major-route ACA times to CCR and MMR were longer. PFS and OS were shorter (p<0.001) than with standard t(9;22)(q34;q11). Loss of Y chromosome had no influence on time to CCR or MMR, PFS and OS.
We conclude that the prognostic impact of additional cytogenetic findings at diagnosis of CML is heterogeneous and consideration of their types may be important. Major-route ACA identify a small group of patients with significantly poorer prognosis as compared to all other patients requiring early and more intensive intervention such as stem cell transplantation.
Hochhaus:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kneba:Hoffmann La Roche: Honoraria.
Abstract 1681
The prognostic impact of different levels of molecular remission (BCR-ABL transcript expression according to International Scale, IS) at various time points on survival under imatinib ...treatment is still unclear. Whereas recently published data from the IRIS trial described relevant milestones at 6, 12, and 18 months for event-free and progression-free survival (PFS; Hughes et al., Blood 2010), little is known about an association of molecular response with overall survival (OS). The aim of this evaluation of the German CML Study IV was to elucidate the risk of disease progression and death as a function of the depth of molecular response in order to provide guidance in the interpretation of BCR-ABL levels in the clinical setting. Methods: 1,340 patients (median age 52 years, range 16–88, 60% male) were recruited into the randomized German CML Study IV and treated with an imatinib-based therapy as follows: imatinib 400 mg/d, n=381; imatinib 800 mg/d, n=399; imatinib 400 mg/d + interferon alpha, n=402; imatinib 400 mg/d + low-dose cytarabine, n=158. A total of 1,262 patients with typical b2a2 and b3a2 BCR-ABL transcripts were evaluable. Molecular responses were assessed in 811, 764, 671, and 619 patients at 6, 12, 18, and 24 months, respectively. Disease progression was defined as accelerated phase or blastic phase, or death from any reason. Landmark analyses and log-rank tests for OS and PFS were performed according to the achievement of different BCR-ABL response levels at different time points. Results: Patients were grouped according to the degree of molecular response (<0.1%, 0.1%-1%, 1%-10%, >10% BCR-ABL IS) at each of the 4 time points and evaluated for 5-year OS and PFS. Estimated 5-year OS for the different molecular response categories was: 97% vs 96% vs 90% vs 88% (6 months, p=0.009); 96% vs 95% vs 89% vs 69% (12 months, p<0.001); 98% vs 97% vs 92% vs 66% (18 months, p<0.001); 97% vs 96% vs 96% vs 68% (24 months, p<0.001). Applying the 4 response categories revealed estimated 5-year PFS of 97% vs 96% vs 91% vs 86% (p=0.004) at 6 months, 97% vs 92% vs 89% vs 72% (p<0.001) at 12 months, 99% vs 95% vs 90% vs 77% (p<0.001) at 18 months, and 97% vs 97% vs 93% vs 65% (p<0.001) at 24 months (s. Table). Conclusions: Faster and deeper response to imatinib-based treatment revealed to be associated with improved overall and progression-free survival. Inferior OS and PFS can be deducted from the synopsis of BCR-ABL expression and treatment duration, e.g. >1% BCR-ABL IS at 6 months or 12 months might be, and >10% BCR-ABL IS should be a trigger for a treatment change. Thereby this analysis might provide decision guidance for alteration or continuation of primary imatinib treatment. Display omitted
Schnittger:Münchner Leukämie Labor: Equity Ownership. German CML Study Group:EU: Research Funding; BMBF: Research Funding; Novartis: Research Funding; Deutsche Krebshilfe: Research Funding; Roche: Research Funding; Essex: Research Funding.
Abstract 781▪FN2▪This icon denotes a clinically relevant abstract
Data on second line therapy with second generation tyrosine kinase inhibitors (TKI) in CML treatment were generated mainly from phase ...II/III industry initiated trials (Review Hehlmann Exp Op. 2011). 24-month overall survival (OS) varies between 88% and 94% after intolerance and/or resistance to imatinib for chronic phase (CP) and between 67% and 72% for accelerated phase (AP) or blast crisis (BC). Intention to treat analyses including outcome of patients after discontinuation of first line therapies have not been available as yet. We thought to evaluate overall and progression-free survival (OS and PFS) of imatinib intolerant vs. resistant patients under second line TKI with long-term follow-up within an investigator initiated trial.
We analyzed data of the German CML study IV, a randomized 5-arm trial to optimize imatinib therapy on an intention to treat basis. According to protocol, follow-up of patients on and after second generation TKI after imatinib intolerance and/or resistance was continued for OS and PFS. Analysis of PFS was only relevant, if intolerance and resistance to imatinib therapy occurred while a patient was still in chronic phase (CP). Patients were censored at the time of allogeneic stem cell transplantation (allo-SCT).
From July 2002 to December 2010, 1,502 patients with Philadelphia chromosome and /or BCR-ABL positive CML in CP were randomized. 129 patients of the “imatinib after interferon arm” and 36 other patients had to be excluded (14 due to incorrect randomization or withdrawal of consent, 22 with missing baseline information). 1337 were randomized to primary imatinib treatment (imatinib 400 mg vs. imatinib 800 mg vs. imatinib in combination with either interferon alpha or araC). Of these, 234 (17%) discontinued imatinib therapy. 156 patients were treated with 2nd generation TKI, 61 were directly referred to allo-SCT, 17 patients received other regimens (including interferon alpha only or hydroxyurea).
120 of 156 patients started second generation TKI therapy (nilotinib, n=41, dasatinib, n=75, bosutinib, n=2, nilotinib and dasatinib, n=2) within 3 months after stopping imatinib, received treatment for at least one week and were evaluable for PFS and OS. 36 patients received second TKI later (median 10 months, range 3.5–61.4). Median age was 50 years (range 16–78), 42.5% were female. 48 patients were intolerant, 48 failed imatinib within CP and 24 after loss of CP (accelerated phase, n=10, blast crisis, n=14). Median time to second generation TKI was 17 months (range 1.4–97 months) and median follow-up after start of second-line TKI 31 months (range 0.2–71 months). Risk stratification according to the EUTOS Score was high in 20 patients (17%) and low in 94 patients (78%) and unknown in 6 patients (5%). OS for all 120 patients 3 years after start of second generation TKI was 73%, 96% for intolerant and 80% for resistant patients in CP and 19% for resistant patients in advanced disease (s. Fig. 1). According to EUTOS score, 3-year OS was 78% for low and 56% for high risk patients. Probability of PFS of the 96 patients in 1st CP after 3 years was 96% for intolerant and 76% for resistant patients. After 2nd generation TKI, 18 patients received an allo-SCT: all were in CP, 2 patients after imatinib intolerance, 16 patients after imatinib resistance. Display omitted
Survival on second generation TKI is high for imatinib intolerant patients in first CP but much lower for resistant patients in first CP or for patients with advanced disease phases. Alternative treatment strategies are warranted for these patient groups.
Krause:Micromet: Research Funding. Kneba:Hoffmann La Roche: Honoraria. Hochhaus:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.
Abstract 3773
The vast majority of chronic myeloid leukemia (CML) patients express a BCR-ABL fusion gene mRNA encoding a 210 kDa tyrosine kinase which is constitutively activated and hence the ...mainspring of leukemic transformation. Two typical mRNA variants exist that differ in the presence or absence of the 75 basepair BCR exon 14: the e13a2 (lacking exon 14, also known as “b2a2”) and the e14a2 BCR-ABL transcript (“b3a2”). The significance of the additional 25 amino acid residues of the e14a2 BCR-ABL oncoprotein was extensively studied in the pre-imatinib era. However, the influence of the BCR-ABL transcript variant on the individual disease phenotype and outcome remained controversial and is still undefined in the imatinib era. Patients and methods: A total of 1,104 patients (median age 52 years, range 16–85, 40% female) expressing typical BCR-ABL transcript types (e13a2, n=447; e14a2, n=491; e13a2 and e14a2, n=166) were included in the randomized German CML study IV and treated with an imatinib based therapy consisting of imatinib 400 mg, imatinib 800 mg and combinations of standard dose imatinib with interferon alpha and low-dose cytarabine. The type of BCR-ABL transcript was defined by multiplex PCR. BCR-ABL expression was determined by quantitative RT-PCR and standardized according to the international scale (IS). Cytogenetic response was determined by conventional metaphase analyses. Response landmarks were defined according to European LeukemiaNet criteria, MR4 was defined as BCR-ABL IS ≤ 0.01% Results: No differences regarding age, sex and Euro risk were observed. A significant difference was observed comparing white blood cells (90,400/μl vs. 69,100/μl, p<0.001) and platelets (293,000/μl vs. 424,000/μl, p<0.001) at diagnosis (median, e13a2 vs. e14a2, respectively) indicating a distinct phenotype. No significant difference was observed regarding spleen size, basophils, eosinophils, blasts or adverse events under imatinib. Molecular response as determined by a transcript independent quantitative PCR assay was superior in e14a2 patients as compared to e13a2 patients (median time to major molecular response, MMR 1.5 years vs. 1.2 years, p<0.001; median time to MR4 4.2 years vs. 2.5 years, p<0.001). No difference was observed with regard to the achievement of a complete cytogenetic remission (CCyR). The superior molecular response rate of e14a2 patients did not translate into differences in progression free survival (PFS) or overall survival (OS). Conclusion: Distinct initial blood counts suggest a different phenotype of e13a2 and e14a2 driven CML. MMR and MR4 are achieved earlier by e14a2 patients whereas no difference was observed with regard to PFS and OS.
Schnittger:Münchner Leukämie Labor: Equity Ownership. Haferlach:Münchner Leukämie Labor: Equity Ownership. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.
Abstract 3762
The EUTOS Score was developed and validated as a prognostic tool for the achievement of complete cytogenetic response (CCR) at 18 months for chronic phase (CP) CML patients under ...imatinib therapy. The score identifies high-risk patients not reaching CCR at 18 months with a positive predictive value of 34% and a specificity of 92% using only two variables, peripheral blood basophils and spleen size at diagnosis (Hasford et al. Blood 2011). We sought to evaluate the clinical impact of the EUTOS score to predict molecular response. Therefore, we analyzed the EUTOS score with patients from the German CML-Study IV, a randomized 5-arm trial (imatinib 400 mg vs. imatinib 800 mg vs. imatinib in combination with interferon alpha vs. imatinib in combination with araC vs. imatinib after interferon failure).
From July 2002 to December 2010, 1,502 patients with BCR-ABL positive CML in CP were randomized. 129 patients with imatinib after interferon alpha and 36 other patients had to be excluded (14 due to incorrect randomization or withdrawal of consent, 22 with missing baseline information). 1,337 patients were evaluable for overall and progression-free survival (OS and PFS), 1,252 for molecular responses. 749 of these patients were part of the score development sample. Therefore cytogenetic analyses are not described here.
By EURO score, 36% of patients (n=475) were low risk, 51% (n=681) intermediate risk, and 12% (n=167) high risk. The EUTOS score was low risk in 88% (n=1163) and high risk in 12% (n=160). The high-risk patients differed between the two scores: EUTOS high-risk patients were classified according to EURO score in 12% as low (n=19), in 45% as intermediate (n=68) and in 43% as high risk (n=73).
Patients with high, intermediate, and low risk EURO score achieved MMR in 22, 16, and 13 months and CMR4 (BCR-ABL <=0.01%) in 59, 41, and 34 months. P-values for low vs. intermediate risk groups were borderline only (0.03 for MMR and 0.04 for CMR4), whereas p-values for high vs. low/intermediate risk groups were for both molecular response levels <0.001. At 12 months the proportion of patients in MMR was 38%, 46%, 54% for high, intermediate, and low risk patients, respectively. Similar results were observed with the Sokal score.
Patients with high risk EUTOS score achieved deep molecular responses (MMR and CMR4) significantly later than patients with low risk EUTOS score (MMR: median 21.0 vs. 14.8 months, p<0.001, Fig. 1a; CMR4: median 60.6 vs. 37.2 months, p<0.001, Fig. 1b). Display omitted
The proportions of patients achieving MMR at 12 months were significantly lower in the EUTOS high-risk group than in the EUTOS low-risk group (30.8% vs. 50.6%, p<0.001).
OS after 5 years was 85% for high and 91% for low risk patients (p=n.s.), PFS was 85% and 90%, respectively.
The EUTOS score clearly separates CML patients also according to MMR and CMR4 (MR4). The new EUTOS score should be used in future trials with tyrosine kinase inhibitors in CML.
Neubauer:Novartis: Honoraria, Research Funding; Roche: Research Funding. Kneba:Hoffmann La Roche: Honoraria. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Hochhaus:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. German CML Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; BMBF: Research Funding; EU: Research Funding; Roche: Research Funding; Essex: Research Funding.
Abstract 360
The lack of a sufficient response to first line imatinib treatment has been observed in a substantial proportion of CML patients and has been associated with an inferior survival. ...Therefore, response criteria have been defined to identify patients with treatment failure. A change of drug therapy to 2nd generation tyrosine kinase inhibitors or allogeneic stem cell transplantation is recommended for this group of patients (European LeukemiaNet, ELN, Baccarani et al., JCO 2009). We sought to evaluate the predictive value of early molecular response landmarks for treatment failure and disease progression to identify patients at risk and to provide a guidance for the interpretation of BCR-ABL levels.
949 patients included into the randomized German CML Study IV and treated with an imatinib based therapy consisting of standard dose imatinib (400 mg/d), high dose imatinib (800 mg/d) and combinations of standard dose imatinib with low dose cytarabine or interferon alpha were evaluable for molecular and cytogenetic analysis. BCR-ABL (IS) was determined by quantitative RT-PCR. The type of BCR-ABL transcript (b2a2, n=424; b3a2, n=464; b2a2 and b3a2, n=148) was defined by multiplex PCR. Patients with atypical BCR-ABL transcripts were excluded from the analysis. Cytogenetic response (CyR) was determined by G-banding metaphase analyses. Treatment failure has been defined according to ELN criteria as a lack of major CyR after 12 months and a lack of complete CyR after 18 months of imatinib treatment, respectively. CyR data were available for 479 pts between 12 and 18 months with a subset of 289 pts evaluable for 3 month molecular response (CyR data after 18 months, n=532; 3 month molecular subset, n=289). Disease progression comprises the incidence of accelerated phase, blast phase and death. Median follow-up for disease progression was 35 months (range 2–85). Fisher's exact test has been performed to evaluate the prognostic significance of 3 month BCR-ABL landmarks for 12 month and 18 month treatment failure. A landmark analysis has been performed for disease progression (logrank test).
In 20 of 289 evaluable pts treatment failure has been observed after 12 months, and in 29 of 289 pts after 18 months. 24 of 570 evaluable pts showed a disease progression after a median of 18 months (range 5–71). A stratification into three groups at 3 months reveals a significant difference concerning treatment failure between pts with BCR-ABL levels between 1% and 10% and those with BCR-ABL levels >10%. With regard to disease progression there is a statistical trend. Comparing two groups the 10% BCR-ABL cut-off is highly significant for both, treatment failure and disease progression. Missing the 10% BCR-ABL landmark after 3 months of imatinib treatment defines a poor risk group with a 20.7% risk of treatment failure after 18 months and a 8.1% risk of disease progression (Table).
Early assessment of molecular response after 3 months of imatinib therapy allows the identification of a patient cohort with an increased risk of treatment failure and disease progression.
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Müller:Novartis Corporation: Honoraria, Research Funding. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Hochhaus:Novartis Corporation: Honoraria, Research Funding.
Abstract 3411
Dose of therapy and time to response may be different in the elderly as compared to younger patients with CML. This has been reported previously for interferon α (Berger et al., ...Leukemia 2003). For imatinib, contradictory results have been presented (Rosti et al. Haematologica 2007, Guliotta et al. Blood 2009).
An analysis comparing dose-response relationship in patients more or less than 65 years (y) of age is warranted.
We analysed the German CML-Study IV, a randomized 5-arm trial to optimize imatinib therapy by combination, dose escalation and transplantation. Patients older and younger than 65y randomized to imatinib 400 mg (IM400) or 800 mg (IM800) were compared with regard to time to hematologic, cytogenetic and molecular remissions, imatinib dose, adverse events (AEs) and overall survival (OS).
From July 2002 to April 2009, 1311 patients with Ph+ CML in chronic phase were randomized, 623 patients were evaluable, 311 patients for treatment with IM400 and 312 for IM800. 84 (27%) and 66 (21%), respectively, were older than 65 years. All patients were evaluable for hematologic, 578 (140 >65y and 438 <65y) for cytogenetic, and 600 (143 and 457, respectively) for molecular responses. Median age was 70y vs. 49y for IM400 and 69y vs. 46y for IM800. The median dose per day was lower for elderly patients with IM800 (517mg vs. 666mg) and the same with IM400 (400mg each). Patients' characteristics at baseline were evenly distributed in all groups regarding gender, follow-up, hemoglobin, platelet count and spleen size. Leukocyte counts were significantly lower in elderly patients (IM400: 50/nl vs. 78/nl, IM800: 36/nl vs. 94/nl). EURO score was different due to age in elderly patients (low risk: IM400: 11% vs. 43%, IM800: 14% vs. 42%; intermediate risk: IM400: 79% vs. 44% and IM800: 73% and 43%). There was no difference in cytogenetic and molecular analyses between treatment groups. With regard to efficacy, there was no difference for older patients in achieving a complete cytogenetic remission (CCR) and major molecular remission (MMR) if IM400 and IM800 were compared together. If treatment groups were analyzed separately, older patients treated with IM400 reached CCR and MMR statistically significant slower than younger patients (CCR: median 14.2 months vs. 12.1 months, p=0.019; MMR: median 18.7 months vs. 17.5 months, p=0.006). There was no difference with IM800 (CCR: median 7.7 months vs. 8.9 months, MMR: median 9.9 months vs. 10.0 months). 3y-OS for older patients >65y was 94.7% and for patients <65y was 96.1%. Some differences were observed in the safety analyses. 530 patients (IM400: 278, IM800: 252) were evaluated on common toxicity criteria (WHO). Some hematologic AEs were documented slightly more often in the elderly than in the younger patients: for IM400 anemia grade 1–2 (60 vs. 42%) and leukopenia grade 3–4 (5.6 vs. 1.4%) and for IM800 anemia grade 1–4 (64 vs.47% and 7.2 vs. 5.7%) and thrombocytopenia grade 3–4 (9.3 vs. 7.1%). Non hematologic AEs were more prominent in IM800 and were mainly gastrointestinal symptoms (IM400: 33 vs. 31%, IM800: 48 and 44%) and edema (IM400: 28 vs. 29%, IM800: 35 vs. 50%). There was no difference for grade 3/4 non-hematological AEs in older patients in both groups.
Imatinib 400 mg and 800 mg are well tolerated also in the elderly. The IM800 dosage was more tolerability-adapted for the elderly, but there was no difference in reaching a CCR and MMR in contrast to the IM400 where a significantly slower response was detected in the elderly. Whether this difference is clinically relevant has yet to be determined. Updated results will be presented.
Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership, Research Funding. German CML-Study Group:Deutsche Krebshilfe: Research Funding; Novartis: Research Funding; Roche: Research Funding; BMBF: Research Funding; Essex: Research Funding.
