ALBERT

Description: Key Points Imatinib does not prevent accumulation of genomic instability in CML-CP. Imatinib-refractory leukemia stem cells may be a source of genomic instability in CML-CP.

Description: Background The efficacy and safety of subsequent TKIs in pts who have experienced failure of dasatinib is not fully known. Ponatinib, a pan-BCR-ABL inhibitor, was evaluated in a phase 2, international, open-label clinical trial (PACE). This post-hoc analysis explored the efficacy and safety of ponatinib following failure of dasatinib in CP-CML pts in the PACE trial. Methods The PACE trial enrolled 449 pts, including 270 with CP-CML. Pts had to be resistant or intolerant to dasatinib or nilotinib, or they had to have the T315I mutation at baseline. The primary endpoint in CP-CML was major cytogenetic response (MCyR) at any time within 12 months after treatment initiation. The trial is ongoing. Data as of 1 April 2013 are reported, with a minimum follow-up of 18 months for pts remaining on study. The efficacy and safety of ponatinib (45 mg QD) in 107 CP-CML pts following failure of dasatinib as the most recent prior therapy, irrespective of other TKI therapy, is presented (Group D). Eighteen pts who experienced failure of dasatinib but received ≥1 anticancer therapy, other than hydroxyurea or anagrelide, prior to ponatinib treatment were excluded from the analyses. Data are also presented for 2 subsets of Group D: 52 pts whose only TKI therapy was imatinib followed by dasatinib (Group I-D), and 46 pts whose only TKI therapy was imatinib, then nilotinib, and then dasatinib (Group I-N-D). An analysis of cross-intolerance was also conducted in 69 pts with prior dasatinib treatment at any time who discontinued dasatinib due to intolerance. Results Baseline characteristics are shown in the table. Group I-D tended to be younger, with less time since diagnosis versus Group I-N-D. At the time of analysis, 60%, 65%, and 54% of pts in Groups D, I-D, and I-N-D remained on study. The most common reasons for discontinuation were adverse events (AEs; 16%, 15%, 17%) and progressive disease (9%, 6%, 11%) in Groups D, I-D, and I-N-D. Efficacy end points are shown in the table. In Group D, MCyR was seen in pts with the following dasatinib-resistant mutations at baseline: V299L, 3/4 (75%); T315I, 17/23 (74%); F317L, 3/10 (30%). The most common treatment-related AEs were thrombocytopenia (44%, 37%, 57%), rash (39%, 39%, 39%), and dry skin (39%, 29%, 52%) in Groups D, I-D, and I-N-D. Serious cardiovascular, cerebrovascular, and peripheral vascular AEs occurred in 6%, 3%, and 3% of pts in Group D (treatment-related: 3%, 1%, 0%). Seventy-three of 217 pts receiving prior dasatinib at any time discontinued dasatinib due to intolerance. Of these 73 pts, 27 experienced the same AE(s) with ponatinib that led to dasatinib intolerance; 12 pts had grade 3/4 thrombocytopenia, 6 pts had other grade 3/4 AEs (3 with neutropenia, 1 each with pleural effusion, dyspnea, pulmonary hypertension), 8 pts had grade 1/2 AEs. Six of these 27 pts discontinued ponatinib due to the same AE that led to dasatinib intolerance. Thrombocytopenia was the primary AE involved in cross-intolerance (4 pts); congestive cardiac failure (grade 5) and pleural effusion each occurred once. Conclusions Ponatinib has substantial activity in pts with CP-CML following failure of dasatinib, with a safety profile reflective of this heavily pretreated population. Cross-intolerance between dasatinib and ponatinib was infrequent. Disclosures: Hochhaus: Ariad, Novartis, BMS, MSD, Pfizer: Research Funding; Novartis, BMS, Pfizer: Honoraria. Cortes:Ariad, Pfizer, Teva: Consultancy; Ariad, BMS, Novartis, Pfizer, Teva: Research Funding. Kim:BMS, Novartis,IL-Yang: Consultancy; BMS, Novartis, Pfizer,ARIAD,IL-Yang: Research Funding; BMS, Novartis,Pfizer,IL-Yang: Honoraria; BMS, Novartis,Pfizer: Speakers Bureau; BMS, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Pinilla-Ibarz:Novartis, Ariad: Research Funding; Novartis, Ariad, BMS and Pfizer: Speakers Bureau. le Coutre:Novartis: Research Funding; Novatis, BMS, Pfizer: Honoraria. Paquette:ARIAD, BMS, Novartis: Consultancy, Honoraria, Speakers Bureau. Chuah:Novartis, Bristol-Myers Squibb: Honoraria. Nicolini:Novartis, Ariad and Teva: Consultancy; Novartis & Bristol Myers Squibb: Research Funding; Novartis, BMS, Teva, Pfizer, Ariad: Honoraria; Novartis, BMS, Teva: Speakers Bureau; Novartis, Ariad, Teva, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Apperley:Novartis: Research Funding; Ariad, Bristol Myers Squibb, Novartis, Pfizer, Teva: Honoraria. Talpaz:Ariad, BMS, Sanofi, INCYTE: Research Funding; Ariad, Novartis: Speakers Bureau; Ariad, Sanofi, Novartis: Membership on an entity’s Board of Directors or advisory committees. DeAngelo:Araid, Novartis, BMS: Consultancy. Abruzzese:BMS, Novartis: Consultancy. Rea:BMS, Novartis, Pfizer, Ariad, Teva: Honoraria. Baccarani:Ariad, Novartis, BMS: Consultancy; Ariad, Novartis, BMS, Pfizer, Teva: Honoraria, Speakers Bureau. Müller:Novartis, BMS, Ariad: Consultancy, Honoraria; Novartis, BMS: Research Funding. Gambacorti-Passerini:Pfizer: Research Funding; Pfizer, BMS: Honoraria. Lustgarten:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Rivera:ARIAD: Employment. Clackson:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Turner:ARIAD: Employment. Haluska:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Deininger:BMS, ARIAD, NOVARTIS: Consultancy; BMS, NOVARTIS, CELGENE, GILEAD: Research Funding; ARIAD, NOVARTIS: Advisory Boards, Advisory Boards Other. Hughes:Novartis, BMS, ARIAD: Honoraria, Research Funding. Goldman:Ariad: Honoraria. Shah:Ariad, Bristol-Myers Squibb: Consultancy, Research Funding. Kantarjian:RIAD, Novartis, BMS, Pfizer: Research Funding.

Description: Quantitative determination of residual BCR-ABL transcript levels has been accepted as integral part of the management of CML patients. However, heterogeneity of molecular approaches results in a lack of comparability between different studies. Thus, there is an unmet need for harmonization of both procedures and expression of results. In a series of consensus meetings within the European LeukemiaNet a list of prerequisites to achieve an optimal sensitivity and standardization has been elaborated: use of at least 10ml peripheral blood processed within 36 hrs; bedside RNA stabilization for multicenter trials; standardized PCR protocols optimized for each platform; use of a single plasmid containing target and housekeeping genes to avoid dilution errors; use of total ABL and/or beta glucuronidase (GUS) as internal controls. To substantiate these theses an international multicenter trial within 36 labs in 14 countries was initiated. The aim of the study was to assess the variability of results obtained from different labs using the PAXgene Blood RNA System® (PreAnalytiX, Hombrechtikon, Switzerland) for RNA extraction, individual protocols for cDNA synthesis, 3 different PCR platforms (TaqMan®, TM, n=24, LightCycler®, LC, n=14, Rotorgene® n=1), and optimized quantitative RT-PCR conditions. In order to standardize results, b3a2 BCR-ABL and GUS sequences were cloned into a pCR 2.1-TOPO vector® (Invitrogen, Carlsbad, CA), which was distributed to all participants in serial dilutions as external control for quantification of BCR-ABL, total ABL, and GUS mRNA transcripts. Ten samples containing dilutions (10, 2, 1, 0.1%) of b3a2 or b2a2 BCR-ABL positive cells in normal leukocytes and negative controls were prepared, blinded, and shipped to the participants. Transcript numbers were determined in triplicates, ratios BCR-ABL/ABL and BCR-ABL/GUS were calculated and expressed in %. Median ratios BCR-ABL/ABL for b3a2 samples were 8.9, 1.7, 0.85, and 0.11%; for b2a2 samples 9.1, 1.6, 0.82, and 0.10%. Median ratios BCR-ABL/GUS for b3a2 samples were 3.4, 0.77, 0.37, and 0.042%; for b2a2 samples 2.8, 0.48, 0.29, and 0.031%. Four of 36 participants (11%) detected low BCR-ABL copy numbers in negative control samples. The coefficients of variation (CV) for all participants, TM, and LC users were 0.62, 0.57, and 0.59 for ratios BCR-ABL/ABL; 1.03, 0.85, and 1.22 for ratios BCR-ABL/GUS, respectively. Standard errors to the regression line were significantly lower evaluating ratios BCR-ABL/GUS (median 0.075, range 0.0046–0.90) compared to ratios BCR-ABL/ABL (median 0.18, range 0.022–2.2, p

Description: Introduction The outcome of elderly patients with chronic myeloid leukemia (CML) treated with imatinib has been studied in several trials. However, there are no reports on the effects of different imatinib dosages in older vs. younger CML patients. Methods To evaluate the efficacy of imatinib in the elderly, we analyzed data from the German CML-Study IV, a randomized 5-arm trial designed to optimize imatinib therapy alone or in combination. There was no upper age limit for inclusion. Patients with BCR-ABL positive CML in chronic phase randomized to imatinib 400 mg/d (IM400) or imatinib 800 mg/d (IM800) were compared, stratified according to median age at diagnosis in western populations ≥ 65 years vs. 〈 65 years, regarding effectively administered imatinib dose, time to hematologic, cytogenetic and molecular remissions, adverse events (AEs), rates of progression to accelerated phase (AP) and blast crisis (BC), survival, and causes of death. The full 800 mg dose was given after a 6 weeks run-in period with imatinib 400 mg/d to avoid excessive cytopenias. The dose could then be reduced according to tolerability for maximum patients' compliance. Results From July 2002 through March 2012, 1,551 patients were randomized, 828 of these to IM400 or IM800. Median age of these patients was 52 years (IM400: 53 years; IM800: 51 years). 784 patients were evaluable for follow-up (IM400: 382; IM800: 402). 193 patients were ≥ 65 years, 591 〈 65 years. 110 patients (29%) on IM400 and 83 (21%) on IM800 were ≥ 65 years. Median observation time on IM400 was 63.0 months in the elderly and 67.6 months in the younger group, on IM800 50.9 months in the elderly and 50.1 months in the younger group. The median dose per day was lower for elderly patients on IM800 (421 mg/d for patients ≥ 65 years vs. 556 mg/d for patients 〈 65 years), with the highest median dose in the first year (466mg/d for patients ≥ 65 years vs. 630mg/d for patients 〈 65 years). The median dose for patients on IM400 was 400 mg/d for both age groups. There was no difference between age groups in achieving a complete hematologic remission or a complete cytogenetic remission, neither if IM400 and IM800 were combined, nor in an analysis according to treatment groups. Elderly patients on IM400 achieved major molecular remission (MMR) and deep molecular remission (MR4) significantly later than younger patients (18.1 vs. 15.9 months, p=0.013; 54.4 vs. 33.3 months, p=0.012, respectively) whereas no difference was detected for patients on IM800 (11.9 vs. 10.5 months; 24.2 vs. 26.1 months, respectively). Imatinib was well tolerated in elderly patients with only few WHO grade 3-4 AEs being more frequent in the elderly than in younger patients (dermatologic AEs on IM400: 5.4 vs. 0.4%; infections on IM800: 8.3 vs. 2.5%). There were no significant differences between age groups in probabilities of progression to AP or BC neither if IM400 and IM800 were combined, nor in an analysis according to treatment groups. Five-year age-adjusted relative survival for elderly patients was comparable to that of younger patients. Conclusion We could demonstrate that elderly patients achieved molecular remissions significantly later when treated with standard dose imatinib but not when treated with higher imatinib dosages. As the safety profile of IM800 in senior patients was favorable too we conclude, that the optimal dose for elderly patients could be higher than 400 mg/d. Disclosures: Müller: Ariad: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Hochhaus:Pfizer: Consultancy; ARIAD: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Travel Other. Hehlmann:BMS: Consultancy, Research Funding; Novartis: Research Funding. Saussele:BMS: Honoraria, Research Funding, Travel, Travel Other; Pfizer: Honoraria; Novartis: Honoraria, Research Funding, Travel Other.

Description: The BCR–ABL T315I mutation represents a major mechanism of resistance to tyrosine kinase inhibitors (TKIs). The objectives of this retrospective observational study were to estimate overall and progression-free survival for chronic myeloid leukemia in chronic-phase (CP), accelerated-phase (AP), or blastic-phase (BP) and Philadelphia chromosome—positive (Ph)+ acute lymphoblastic leukemia (ALL) patients with T315I mutation. Medical records of 222 patients from 9 countries were reviewed; data were analyzed using log-rank tests and Cox proportional hazard models. Median age at T315I mutation detection was 54 years; 57% cases were men. Median time between TKI treatment initiation and T315I mutation detection was 29.2, 15.4, 5.8, and 9.1 months, respectively, for CP, AP, BP, and Ph+ ALL patients. After T315I mutation detection, second-generation TKIs were used in 56% of cases, hydroxyurea in 39%, imatinib in 35%, cytarabine in 26%, MK-0457 in 11%, stem cell transplantation in 17%, and interferon-α in 6% of cases. Median overall survival from T315I mutation detection was 22.4, 28.4, 4.0, and 4.9 months, and median progression-free survival was 11.5, 22.2, 1.8, and 2.5 months, respectively, for CP, AP, BP, and Ph+ ALL patients. These results confirm that survival of patients harboring a T315I mutation is dependent on disease phase at the time of mutation detection.

Description: BCR-ABL measurement by real-time quantitative PCR (RQ-PCR) has become an essential component for assessing treatment response for CML. A major molecular response (MMR) has prognostic significance and can be used to guide therapeutic decisions. However, the various methods are not standardized and the value representing MMR varies, which may lead to misinterpretation of molecular response. To align data, an international reporting scale (IS) was proposed where MMR is 0.10%. Conversion to the IS is achieved by applying laboratory (lab) specific conversion factors (CF). We aimed to calculate CF for diverse RQ-PCR methods by reference of patient BCR-ABL values to those generated in a reference lab with an established CF; validate the CF by subsequent patient sample exchange; examine the concordance of BCR-ABL values after IS conversion; determine if manufactured reference material is suitable for CF calculation. 34 labs from 13 countries (Australia/New Zealand 11, North/South America 9, Asia 8, Europe 6) sent 615 patient samples to the Adelaide reference lab to determine their specific CF. The RQ-PCR methods varied by the control gene (ABL 17, BCR 12, GUSβ 4, G6PDH 2, β2M 1, GAPDH 1; 3 labs used 2 controls therefore 37 methods), instrument, probe technology and standards. The CF for each method was calculated from the bias of patient BCR-ABL values between the originating lab and the reference lab, providing the bias was consistent across the dynamic range (Bland and Altman, Lancet,1986;1:307). CF were determined for 33 methods, 1 failed due to inconsistencies in the bias and 3 labs sent insufficient samples. CF were validated by sending subsequent sets of patient samples to the reference lab. The validation process is complete for 12 methods using 384 samples. The specific CF remained valid for each method. The mean bias between the reference and originating lab values was negligible after conversion. The limits of agreement indicated that 95% of values were within ±4.6-fold of the reference value. In contrast, prior to conversion 95% of values were within ±13-fold. Importantly after conversion the concordance in the range representing MMR was 87% (154/178 samples). In the future, conversion to the IS will be achieved using certified reference material, however this is currently not available. In order to mimic the patient bias CF calculation we prepared prototype reference material using BCR-ABL positive cells diluted to 4 levels using volunteer cells. The material was distributed to 29 labs and analysis completed for 24 methods. For 12 of the 24 the CF calculated using the reference material was consistent with the patient bias CF. This indicates that CF calculation is achievable using manufactured reference material but optimization is required before widespread distribution. In summary, alignment of BCR-ABL data generated from diverse methods is achievable using an international standardisation approach, and differences between laboratories are small enough to allow consistent interpretation of results and clinical decision-making.

Description: High rates of complete cytogenetic response (CCR), the availability of sensitive methods to detect residual disease, and direct therapeutic consequences are leading motives to integrate regular molecular monitoring into the standards for the management of patients (pts) with chronic myeloid leukemia (CML). We sought to determine long-term dynamics of BCR-ABL mRNA expression levels in 132 CML pts (75 m, 57 f, median age 51, range 20–71 yrs) recruited into the IRIS study in 17 German centers. Pts were randomized to receive imatinib (n=69) or interferon α+Ara-C (IFN, n=63). Due to intolerance or lack of response 41 pts crossed over from IFN to imatinib. Response to therapy was sequentially monitored by conventional cytogenetics from bone marrow metaphases (n=806). BCR-ABL transcripts were determined in 1414 peripheral blood samples by quantitative real time RT-PCR (RQ-PCR) using the LightCycler technology. In case of low level (

Description: Molecular response to imatinib (IM) in chronic myeloid leukemia (CML) is associated with a biphasic but heterogeneous decline of BCR-ABL transcript levels. We analyzed this interindividual heterogeneity and provide a predictive mathematical model to prognosticate the long-term response and the individual risk of molecular relapse on treatment cessation. The parameters of the model were determined using 7-year follow-up data from a randomized clinical trial and validated by an independent dataset. Our model predicts that a subset of patients (14%) achieve complete leukemia eradication within less than 15 years and could therefore benefit from discontinuation of treatment. Furthermore, the model prognosticates that 31% of the patients will remain in deep molecular remission (MR5.0) after treatment cessation after a fixed period of 2 years in MR5.0, whereas 69% are expected to relapse. As a major result, we propose a predictor that allows to assess the patient-specific risk of molecular relapse on treatment discontinuation and to identify patients for whom cessation of therapy would be an appropriate option. Application of the suggested rule for deciding about the time point of treatment cessation is predicted to result in a significant reduction in rate of molecular relapse.