First-line treatment of newly diagnosed elderly patients with chronic myeloid leukemia: current and emerging strategies

Bcr-Abl Tyrosine Kinase Inhibitors in the Treatment of Pediatric CML

The therapeutic approach to Chronic Myeloid Leukemia (CML) has changed since the advent of the tyrosine kinase inhibitor (TKI) imatinib, which was then followed by the second generation TKIs dasatinib, nilotinib, and, finally, by ponatinib, a third-generation drug. At present, these therapeutic options represent the first-line treatment for adults. Based on clinical experience, imatinb, dasatinib, and nilotinib have been approved for children even though the studies that were concerned with efficacy and safety toward pediatric patients are still awaiting more specific and high-quality data. In this scenario, it is of utmost importance to prospectively validate data extrapolated from adult studies to set a standard therapeutic management for pediatric CML by employing appropriate formulations on the basis of pediatric clinical trials, which allow a careful monitoring of TKI-induced adverse effects especially in growing children exposed to long-term therapy.

Dasatinib-Induced Hypopigmentation in Pediatric Patient with Chronic Myeloid Leukemia: A Case Report and Review of the Literature

Dasatinib is an oral second-generation multitarget tyrosine-kinase inhibitor (TKI) that is efficacious in treating imatinib-resistant chronic myeloid leukemia (CML) or intolerant cases. Noncutaneous adverse effects with dasatinib are well known in the literature, most commonly cytopenias and fluid retention, while pigmentary abnormalities have rarely been reported. We report the case of a 12-year-old male known case of CML, who presented to dermatology clinic approximately 2 years after initiating dasatinib treatment, with new-onset hypopigmentation of his upper limb, upper chest, and both knees of six months' duration.

Dasatinib for the treatment of chronic myeloid leukemia: patient selection and special considerations

Dasatinib is one of the second-generation tyrosine kinase inhibitors used in imatinib resistance and/or intolerance, as well as in the frontline setting in patients with chronic myeloid leukemia-chronic phase, and also in patients with advanced disease. It is also utilized in Philadelphia chromosome-positive acute lymphocytic leukemia. While choosing the appropriate tyrosine kinase inhibitor (ie, dasatinib) for each individual patient, comorbidities and BCR-ABL1 kinase domain mutations should always be taken into consideration, among other things. This review mainly focuses on patient selection prior to dasatinib administration in the treatment of chronic myeloid leukemia.

'Real-life' study of imatinib therapy in chronic phase-chronic myeloid leukemia: A novel retrospective observational longitudinal analysis

OBJECTIVES

Imatinib is a cornerstone of treatment of chronic myeloid leukemia. It remains unclear whether transient treatment discontinuation or dose changes affect outcome and this approach has not yet been approved for use outside clinical trials.

METHODS

We conducted a retrospective single-institution observational study to evaluate factors affecting response in 'real-life' clinical practice in 138 chronic myeloid leukemia patients in chronic phase treated with imatinib. We used a novel longitudinal data analytical model, with a generalized estimating equation model, to study BCR-ABL variation according to continuous standard dose, change in dose or discontinuation; BCR-ABL transcript levels were recorded. Treatment history was subdivided into time periods for which treatment was given at constant dosage (total 483 time periods). Molecular and cytogenetic complete response was observed after 154 (32%) and 358 (74%) time periods, respectively.

RESULTS

After adjusting for length of time period, no association between dose and cytogenetic complete response rate was observed. There was a significantly lower molecular complete response rate after time periods at a high imatinib dosage.

DISCUSSION

This statistical approach can identify individual patient variation in longitudinal data collected over time and suggests that changes in dose or discontinuation of therapy could be considered in patients with appropriate biological characteristics.

Rotation of nilotinib and imatinib for first-line treatment of chronic phase chronic myeloid leukemia

The introduction of second-generation tyrosine-kinase inhibitors (TKIs) has generated a lively debate on the choice of first-line TKI in chronic phase, chronic myeloid leukemia (CML). Despite the TKIs have different efficacy and toxicity profiles, the planned use of two TKIs has never been investigated. We report on a phase 2 study that was designed to evaluate efficacy and safety of a treatment alternating nilotinib and imatinib, in newly diagnosed BCR-ABL1 positive, chronic phase, CML patients. One hundred twenty-three patients were enrolled. Median age was 56 years. The probabilities of achieving a complete cytogenetic response, a major molecular response, and a deep molecular response (MR 4.0) by 2 years were 93%, 87%, and 61%, respectively. The 5-year overall survival and progression-free survival were 89%. Response rates and survival are in the range of those reported with nilotinib alone. Moreover, we observed a relatively low rate of cardiovascular adverse events (5%). These data show that the different efficacy and toxicity profiles of TKIs could be favorably exploited by alternating their use. Am. J. Hematol. 91:617-622, 2016. © 2016 Wiley Periodicals, Inc.

Treatment patterns, overall survival, healthcare resource use and costs in elderly Medicare beneficiaries with chronic myeloid leukemia using second-generation tyrosine kinase inhibitors as second-line therapy

Objective Though the median age at diagnosis is 64 years, few studies focus on elderly (≥65 years) patients with chronic myeloid leukemia (CML). This study examines healthcare outcomes among elderly Medicare beneficiaries with CML who started nilotinib or dasatinib after imatinib. Research design and methods Patients were identified in the Medicare Research Identifiable Files (2006-2012) and had continuous Medicare Parts A, B, and D coverage. Main outcome measures Treatment patterns, overall survival (OS), monthly healthcare resource utilization and medical costs were measured from the second-line tyrosine kinase inhibitor (TKI) initiation (index date) to end of Medicare coverage. Results Despite similar adherence, dasatinib patients (N = 379) were more likely to start on the recommended dose (74% vs. 53%; p < 0.001), and to have dose reductions (21% vs. 11%, adjusted hazard ratio [HR] = 1.94; p = 0.002) or dose increases (9% vs. 7%; adjusted HR = 1.81; p = 0.048) than nilotinib patients (N = 280). Fewer nilotinib patients discontinued (59% vs. 67%; adjusted HR = 0.80; p = 0.026) or switched to another TKI (21% vs. 29%; adjusted HR = 0.72; p = 0.044) than dasatinib patients. Nilotinib patients had longer median OS (>4.9 years vs. 4.0 years; p = 0.032) and 37% lower mortality risk than dasatinib patients (adjusted HR = 0.63; p = 0.008). Nilotinib patients had 23% fewer inpatient admissions, 30% fewer emergency room visits, 13% fewer outpatient visits (all p < 0.05), and lower monthly medical costs (by $513, p = 0.024) than dasatinib patients. Limitations Lack of clinical assessment (disease phase and response to first-line therapy) and retrospective nature of study (unobservable potential confounding factors, non-randomized treatment choice). Conclusions In the current study of elderly CML patients, initiation of second-line TKIs frequently occurs at doses lower than the recommended starting doses and, despite this, many patients require dose adjustments. Here, nilotinib patients required fewer dose adjustments than dasatinib patients. Further research focusing on elderly CML patients is warranted in order to help define future best clinical practices.

Pediatric chronic myeloid leukemia is a unique disease that requires a different approach

Chronic myelogenous leukemia (CML) in children is relatively rare. Because of a lack of robust clinical study evidence, management of CML in children is not standardized and often follows guidelines developed for adults. Children and young adults tend to have a more aggressive clinical presentation than older adults, and prognostic scores for adult CML do not apply to children. CML in children has been considered to have the same biology as in adults, but recent data indicate that some genetic differences exist in pediatric and adult CML. Because children with CML may receive tyrosine kinase inhibitor (TKI) therapy for many decades, and are exposed to TKIs during a period of active growth, morbidities in children with CML may be distinct from those in adults and require careful monitoring. Aggressive strategies, such as eradication of CML stem cells with limited duration and intensive regimens of chemotherapy and TKIs, may be more advantageous in children as a way to avoid lifelong exposure to TKIs and their associated adverse effects. Blood and marrow transplantation in pediatric CML is currently indicated only for recurrent progressive disease, and the acute and long-term toxicities of this option should be carefully evaluated against the complications associated with lifelong use of TKIs.

The role of hematopoietic stem cell transplantation in chronic myeloid leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently recommended as 2nd or 3rd line therapy for patients with chronic myeloid leukemia (CML) in first chronic phase or as salvage for patients with very advanced disease. As a consequence, numbers of HSCT in chronic phase have dropped significantly since the introduction of tyrosine kinase inhibitors (TKI), numbers of transplants in advanced disease to a lesser extent. These current recommendations consider primarily disease risk, defined as failure of TKI therapy; they might need to be adapted. We propose a more balanced appraisal of HSCT for individual patients which should include disease risk, transplant risk, and macroeconomic aspects. HSCT should be integrated into the treatment algorithms from diagnosis and be considered very early at first TKI failure for patients with high disease but low transplant risk. For patients with very advanced disease and high transplant risk in contrast, HSCT might only be recommended in a restricted research setting.