Impact of Treatment Strategies on Clinical Outcomes In Chronic Phase Chronic Myeloid Leukemia (CP-CML) Patients In Canada

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2569-2569
Author(s):  
Nancy Cribb ◽  
Tazmin Merali ◽  
Bonnie MK Donato

Abstract Abstract 2569 Background: New treatment options in chronic myeloid leukemia (CML) have become available in the past years. However, there is a scarcity of published data documenting how patients are treated as well as the impact of the treatment of CP-CML in Canada. Objective: To describe current treatment patterns and clinical outcomes of CP-CML patients receiving treatment in Canada. Methods: Treatment data on CP-CML patients was extracted from a cancer patient treatment summary database, ONCO-CAPPS. The database is comprised of treatment summaries of over 12,000 Canadian cancer patients from across the country. For the study, CP-CML patients aged 18 years or older, who received 400mg of imatinib as 1st-line treatment, and who completed at least 4 continuous weeks of this treatment between October 1, 2008 and December 31, 2009, were eligible for study inclusion. Results: A total of 301 patients met the selection criteria. At the time of review, 62% of patients had a confirmed diagnosis of CP-CML for 2 years or more. Of the CP-CML patients in the study who were prescribed 400mg of imatinib as their initial CP-CML treatment, 51% (155/301) received a 2nd line treatment option, either a dose modification or a change of therapy. Of those requiring 2nd line treatment, 32% (50/155) of patients received an increase in their imatinib dose, resulting in an average daily dose of 664 mg, and representing a 66% increase in the dose of imatinib. Average response times for patients who received an increase in imatinib dose for Complete Hematological Response (CHR) was 183 days, for Complete Cytogenetic Response (CCyR) was 671 days, and for Major Molecular Response (MMR) was 971 days. These response times exceed both Canadian Consensus Guidelines as well as the 2009 ELN (European Leukemia Network) recommendations. Furthermore, 45% (69/155) of patients receiving a 2nd line CML treatment experienced intolerance to imatinib 400 mg resulting in dose decrease or treatment interruption. Switching to second generation tyrosine kinase inhibitor agents (dasatinib or nilotinib) due to inadequate response, loss of response or intolerance to imatinib occurred in 20% of the population. Conclusions: Analysis of Canadian patients over time revealed that 51% of CP-CML patients initiated on 400mg imatinib received 2nd line treatment. The most frequent modification was due to intolerance. Of note, 32% received a dose escalation, which was more common than switching to a second generation tyrosine kinase inhibitor. Furthermore, response times observed amongst patients in this study whose imatinib dose was escalated exceeded timelines for treatment response determination as noted in both internationally and locally recognized treatment guidelines. Published research demonstrates that delays in achieving response are associated with increased risk of progression among patients with CML. Disclosures: Cribb: Drug Intelligence Inc.: Research Funding. Merali:Bristol-Myers Squibb Canada: Research Funding. Donato:Drug Intelligence Inc.: Research Funding.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3099-3099 ◽  
Author(s):  
Ingmar Glauche ◽  
Hendrik Liebscher ◽  
Christoph Baldow ◽  
Matthias Kuhn ◽  
Philipp Schulze ◽  
...  

Abstract Predicting minimal residual disease (MRD) levels in tyrosine kinase inhibitor (TKI)-treated chronic myeloid leukemia (CML) patients is of major clinical relevance. The reason is that residual leukemic (stem) cells are the source for both, potential relapses of the leukemicclone but also for its clonal evolution and, therefore, for the occurrence of resistance. The state-of-the art method for monitoring MRD in TKI-treated CML is the quantification of BCR-ABL levels in the peripheral blood (PB) by PCR. However, the question is whether BCR-ABL levels in the PB can be used as a reliable estimate for residual leukemic cells at the level of hematopoietic stem cells in the bone marrow (BM). Moreover, once the BCR-ABL levels have been reduced to undetectable levels, information on treatment kinetics is censored by the PCR detection limit. Clearly, BCR-ABL negativity in the PB suggests very low levels of residual disease also in the BM, but whether the MRD level remains at a constant level or decreases further cannot be read from the BCR-ABL negativity itself. Thus, also the prediction of a suitable time point for treatment cessation based on residual disease levels cannot be obtained from PCR monitoring in the PB and currently remains a heuristic decision. To overcome the current lack of a suitable biomarker for residual disease levels in the BM, we propose the application of a computational approach to quantitatively describe and predict long-term BCR-ABL levels. The underlying mathematical model has previously been validated by the comparison to more than 500 long-term BCR-ABL kinetics in the PB from different clinical trials under continuous TKI-treatment [1,2,3]. Here, we present results that show how this computational approach can be used to estimate MRD levels in the BM based on the measurements in the PB. Our results demonstrate that the mathematical model can quantitatively reproduce the cumulative incidence of the loss of deep and major molecular response in a population of patients, as published by Mahon et al. [4] and Rousselot et al. [5]. Furthermore, to demonstrate how the model can be used to predict the BCR-ABL levels and to estimate the molecular relapse probability of individual patients, we compare simulation results with more than 70 individual BCR-ABL-kinetics. For this analysis we use patient data from different clinical studies (e.g. EURO-SKI: NCT01596114, STIM(s): NCT00478985, NCT01343173) where TKI-treatment had been stopped after prolonged deep molecular response periods. Specifically, we propose to combine statistical (non-linear regression) and mechanistic (agent-based) modelling techniques, which allows us to quantify the reliability of model predictions by confidence regions based on the quality (i.e. number and variance) of the clinical measurements and on the particular kinetic response characteristics of individual patients. The proposed approach has the potential to support clinical decision making because it provides quantitative, patient-specific predictions of the treatment response together with a confidence measure, which allows to judge the amount of information that is provided by the theoretical prediction. References [1] Roeder et al. (2006) Dynamic modeling of imatinib-treated chronic myeloid leukemia: functional insights and clinical implications, Nat Med 12(10):1181-4 [2] Horn et al. (2013) Model-based decision rules reduce the risk of molecular relapse after cessation of tyrosine kinase inhibitor therapy in chronic myeloid leukemia, Blood 121(2):378-84. [3] Glauche et al. (2014) Model-Based Characterization of the Molecular Response Dynamics of Tyrosine Kinase Inhibitor (TKI)-Treated CML Patients a Comparison of Imatinib and Dasatinib First-Line Therapy, Blood 124:4562 [4] Mahon et al. (2010) Discontinuation of imatinib in patients with chronic myeloid leukaemia who have maintained complete molecular remission for at least 2 years: the prospective, multicentre Stop Imatinib (STIM) trial. Lancet Oncol 11(11):1029-35 [5] Rousselot 
et al. (2014) Loss of major molecular response as a trigger for restarting TKI therapy in patients with CP- CML who have stopped Imatinib after durable undetectable disease, JCO 32(5):424-431 Disclosures Glauche: Bristol Meyer Squib: Research Funding. von Bubnoff:Amgen: Honoraria; Novartis: Honoraria, Research Funding; BMS: Honoraria. Saussele:ARIAD: Honoraria; Novartis: Honoraria, Other: Travel grants, Research Funding; Pfizer: Honoraria, Other: Travel grants; BMS: Honoraria, Other: Travel grants, Research Funding. Mustjoki:Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Ariad: Research Funding; Novartis: Honoraria, Research Funding. Guilhot:CELEGENE: Consultancy. Mahon:NOVARTIS PHARMA: Honoraria, Research Funding; BMS: Honoraria; PFIZER: Honoraria; ARIAD: Honoraria. Roeder:Bristol-Myers Squibb: Honoraria, Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4045-4045
Author(s):  
H Jean Khoury ◽  
Leonard T Heffner ◽  
Martha Arellano ◽  
Anand P Jillella ◽  
Vamsi K Kota ◽  
...  

Imatinib (IM) can be safely discontinued in patients with chronic myeloid leukemia (CML) with sustained complete molecular remission. Previous publications from France and Australia have shown that overall 40% maintain MMR or MR5 for up to 5 years after IM is stopped. We report single US center experience with tyrosine kinase inhibitor (TKI) discontinuation. Between 06/2010 and 7/2015, 22 patients with CML in chronic (CP, n=19), accelerated (AP, n=2) and lymphoid blast phase (LBP, n=1) discontinued IM (n=17), dasatinib (DAS, n=3) or bosutinib (BOS, n=2), and were monitored by qPCR for BCR-ABL1 monthly for the first 3 months, quarterly for the following 2 years and then bi-annually. TKI was restarted in case of confirmed loss of MMR on a repeat qPCR. Reason for TKI discontinuation was predominantly driven by patients' request and TKI intolerance. Median age was 66 (range, 21-84). The 3 who discontinued DAS had IM-resistant (loss of CCyR; n=1), IM-intolerant CP (n=1), or received DAS as first-line agent (n=1). BOS was discontinued for IM-intolerant CP (n=1), or while in CR2 in a patient with LBP that transformed from IM resistant CP and relapsed following chemotherapy (HCVAD). Median duration of TKI therapy pre-discontinuation for the entire cohort was 89 months (range, 26-106). Three patients are not evaluable due to short follow-up (TKI stopped between 5/2015 and 7/2015). With a median follow-up of 40 months (range, 8-60), 7 (41%, 6 CP and 1 AP), all previously on IM lost MMR a median of 3 months (range, 3-24) after TKI was stopped and restarted IM. Loss of CHR occurred 13 months after loss of MMR in 1 patient who elected not to restart IM at the time MMR was lost, due to complications from cardiac transplant rejection. All 7 achieved MMR following restart of IM. Median duration of TKI therapy pre-discontinuation for these 7 patients was 60 months (range, 48-98). 12 patients (59%, 10 CP, 1 AP, 1 LBP) remain off TKI and have not lost MMR, 8 with continuously undetectable BCR-ABL1; and 4 had 1-2 transient detectable BCR-ABL1 at MR4 levels. Median duration of TKI therapy pre-discontinuation for these 12 patients was 87 months (range, 26-106). Loss of MMR-free survival is depicted in the Figure. We conclude that, similar to previous reports, TKI can be safely discontinued in patients with CML without reappearance of BCR-ABL1 in 50-60%. Figure 1. Figure 1. Disclosures Jillella: Seattle Genetics, Inc.: Research Funding. Kota:Leukemia Lymphoma Society: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees.


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