Cost-efficacy of imatinib versus allogeneic bone marrow transplantation with a matched unrelated donor in the treatment of chronic myelogenous leukemia: a decision-analytic approach

Healthcare Resource Utilization and Cost Associated with Allogeneic Hematopoietic Stem Cell Transplantation: A Scoping Review

This scoping review summarizes the evidence regarding healthcare resource utilization (HRU) and costs associated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study was conducted in accordance with the Joanne Briggs Institute methodology for scoping reviews. The PubMed, Embase, and Health Business Elite Electronic databases were searched, in addition to grey literature. The databases were searched from inception up to November 2022. Studies that reported HRU and/or costs associated with adult (≥18 years) allo-HSCT were eligible for inclusion. Two reviewers independently screened 20% of the sample at each of the 2 stages of screening (abstract and full text). Details of the HRU and costs extracted from the study data were summarized, based on the elements and timeframes reported. HRU measures and costs were combined across studies reporting results defined in a comparable manner. Monetary values were standardized to 2022 US Dollars (USD). We identified 43 studies that reported HRU, costs, or both for allo-HSCT. Of these studies, 93.0% reported on costs, 81.4% reported on HRU, and 74.4% reported on both. HRU measures and cost calculations, including the timeframe for which they were reported, were heterogeneous across the studies. Length of hospital stay was the most frequently reported HRU measure (76.7% of studies) and ranged from a median initial hospitalization of 10 days (reduced-intensity conditioning [RIC]) to 73 days (myeloablative conditioning). The total cost of an allo-HSCT ranged from $63,096 (RIC) to $782,190 (double umbilical cord blood transplantation) at 100 days and from $69,218 (RIC) to $637,193 at 1 year (not stratified). There is heterogeneity in the reporting of HRU and costs associated with allo-HSCT in the literature, making it difficult for clinicians, policymakers, and governments to draw definitive conclusions regarding the resources required for the delivery of these services. Nevertheless, to ensure that access to healthcare meets the necessary high cost and resource demands of allo-HSCT, it is imperative for clinicians, policymakers, and government officials to be aware of both the short- and long-term health resource requirements for this patient population. Further research is needed to understand the key determinants of HRU and costs associated with allo-HSCT to better inform the design and delivery of health care for HSCT recipients and ensure the quality, safety, and efficiency of care.

A Systematic Literature Review of the Economic Evaluations of Treatments for Patients with Chronic Myeloid Leukemia

BACKGROUND AND OBJECTIVES

The management of chronic myeloid leukemia is associated with an extensive economic burden, and as novel interventions are being tested in this disease, understanding the comparative effectiveness is of interest. Findings and conclusions of this important issue continue to evolve with improvements in clinical research and economic understanding. This systematic literature review aims to conduct a comprehensive assessment of economic evaluations in chronic phase chronic myeloid leukemia.

METHODS

Embase^®, MEDLINE^®, and the National Health Service Economic Evaluation Database were searched on 4 July, 2022 to identify economic evaluations of chronic myeloid leukemia. Health technology assessment websites and key conference proceedings were also searched. Economic evaluations comparing treatment options in adult patients with chronic phase chronic myeloid leukemia were included. The quality of the studies were assessed using Drummond's checklists.

RESULTS

The search retrieved 47 studies and 16 health technology assessments that fulfilled the eligibility criteria. Most were cost-utility analyses (23 studies and 11 health technology assessments) and were from the USA (n = 15) and China (n = 7). Twenty-seven studies and six health technology assessments included only patients with chronic phase chronic myeloid leukemia. Most models had a Markov structure, a 1 year to lifetime time horizon, and a 1-month cycle length. Commonly assessed treatments were various tyrosine kinase inhibitors (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) and other interventions such as interferon-α, hydroxyurea, and allogeneic stem cell transplant.

CONCLUSIONS

In patients with newly diagnosed chronic myeloid leukemia, imatinib regimens were cost effective, mostly owing to the availability of generics. Nilotinib and dasatinib were generally cost effective as second-line agents for patients who were resistant or intolerant to imatinib. Though progress has been made to better characterize the cost effectiveness of first-line and second-line chronic myeloid leukemia therapies, the paucity of published cost-effectiveness studies of third-line treatments increases the uncertainty associated with economic evaluations of later lines of therapy.

Current approach to the treatment of chronic myeloid leukaemia

Of all the cancers, chronic myeloid leukaemia (CML) has witnessed the most rapid evolution of the therapeutic milieu in recent decades. The introduction of tyrosine kinase inhibitors (TKIs) as a therapeutic option has profoundly changed patient experience and outcome. The availability of multiple new highly effective therapies has increasingly underscored the importance of a good understanding of the underlying pathophysiological basis in CML, as well as patient-specific factors in choosing the right treatment for every individual. The treatment of CML has migrated in many jurisdictions from the office of a highly specialized malignant hematologist to the general hematologist or even a general practitioner. The goal of this review is to offer an overview of the modern approach to the treatment of CML, with an emphasis on chronic phase (CP) CML, including both TKI-based therapies such as imatinib, dasatinib, nilotinib, bosutinib and ponatinib, and non-TKI medications, such as omacetaxine. We discuss evidence behind each drug, most common and material adverse reactions and outline how this information can be used in selecting the right drug for the right patient. We also discuss evidence as it relates to other therapies, including stem cell transplant (SCT), and patients in accelerated (AP) and blastic phase (BP).

Model-based cost-effectiveness analyses for the treatment of chronic myeloid leukaemia: a review and summary of challenges

Assessing the economic value of treatments for chronic myeloid leukaemia (CML) is important but poses a number of challenges. This paper reviews economic models of CML treatment to learn lessons from this experience and support ongoing efforts to model CML. A search of databases and submissions to key health technology assessment agencies identified 12 studies that reported 22 models. Common practice included the use of cohort Markov models-most models used health states organised around the key stages in CML: chronic phase, accelerated phase and blast phase-and the use of utility estimates in the literature that correspond with the National Institute for Health and Care Excellence reference case. Two key areas of uncertainty were the extrapolation of survival outcomes beyond the period observed by the trial; and the effectiveness of second-line therapies. Further work is required to overcome these uncertainties in existing models, such as longer-term trial data collection, including trials of second-line therapies; validation of health-related quality-of-life instruments; and the testing of alternative modelling approaches. In the meantime, it is important that the impact of uncertainties is tested through the use of sensitivity and scenario analysis.

Systematic assessment of decision-analytic models for chronic myeloid leukemia

BACKGROUND

Several tyrosine kinase inhibitors (TKIs) are approved for the treatment of chronic myeloid leukemia (CML). Decision-analytic modeling can help to extrapolate data from short-term clinical trials and also consider quality of life when evaluating different treatment strategies.

OBJECTIVE

Our goal was to describe and analyze the structural and methodological approaches of published decision-analytic models for various treatment strategies in CML and to derive recommendations for the development of future CML models.

DATA SOURCES

We performed a systematic literature search in electronic databases (MEDLINE/PreMEDLINE, EconLit, EMBASE, NHS EED, and Tuft's CEA Registry) to identify published studies evaluating CML treatment strategies using mathematical models. The search was updated in August 2013.

STUDY SELECTION

The models were required to compare different treatment strategies in relation to relevant clinical and patient-relevant health outcomes [e.g., life-years gained, quality-adjusted life-years] over a defined time horizon and population.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used standardized forms for data extraction, description of study design, methodological framework, and data sources for each model.

RESULTS

We identified 18 different decision-analytic modeling studies. Of these, 17 included economic evaluations. Modeling approaches included decision trees, Markov cohort models, state-transition models with individual (Monte Carlo) simulations, and mathematical equations. Analytic time horizons ranged from 2 years to a lifetime. Treatment strategies compared included bone marrow or stem cell transplantation, conventional chemotherapy, interferon-α, and TKIs. Only one model evaluated a second-generation TKI. Most models did not report a model validation. All models conducted deterministic sensitivity analyses and four reported a probabilistic sensitivity analysis.

LIMITATIONS

Articles that were not published in English or German were not included in this review. Our literature search was restricted to published full-text articles in certain databases. Therefore, publications that met our inclusion criteria but were published in different databases, different languages, or as abstracts only may have been missed.

CONCLUSIONS

While several well-designed models of CML treatment strategies exist, there remains a need for the assessment of the long-term efficacy and cost effectiveness of novel treatment options such as second-generation TKIs. Additionally, these models should be validated using independent data.

Utility values for specific chronic myeloid leukemia chronic phase health states from the general public in the United Kingdom

This study elicited time trade-off (TTO) and standard gamble (SG) preference values associated with four health states corresponding to response levels in chronic phase chronic myeloid leukemia (CML) from members of the general public in the UK (n = 235). Health states studied were treatment-free remission (TFR), complete molecular response (CMR, i.e. undetectable disease on treatment), molecular response and reappearance of detectable disease (i.e. relapse from TFR to molecular response requiring treatment). TFR was the most preferred health state (mean utility of 0.97 [TTO] and 0.87 [SG]) followed by CMR (mean utility of 0.96 [TTO] and 0.85 [SG]) followed by molecular response (mean utility of 0.94 [TTO] and 0.80 [SG]) followed by reappearance of detectable disease (mean utility of 0.90 [TTO] and 0.72 [SG]). SG values were significantly lower than TTO values (p < 0.001). The study demonstrated that different treatment responses may impact on the health-related quality of life of patients with chronic phase CML.

Economic evaluation of hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation is a highly expensive clinical intervention with considerable therapeutic benefit but serious adverse effects on health status in some circumstances. Consequently, it is an important target for economic evaluation in which the monetary costs and clinical consequences of optional treatment strategies are compared. The need for such formal assessment is further demanded by the expanded use of hematopoietic stem cell transplantation globally, including its utilization in developing countries. With respect to costs, those incurred by patients and families are often substantial, while those incurred by hospitals may be inadequately reimbursed. Determination of consequences should not be limited to measurements of clinical effectiveness but rather include adjustments for quality of life. Rigorous economic evaluation can provide hard evidence in deliberations of value for money, especially in the context of limited resources for health care.

Economics of hematopoietic cell transplantation

Given the rapidly rising healthcare costs, it is important to understand the economic costs of hematopoietic cell transplantation (HCT), a procedure that is being used more frequently in the treatment of various hematologic disorders. Studies have reported a wide range of costs for HCT, from $36 000 to $88 000 (USD) for a single autologous transplantation for the initial hospitalization, to $200 000 (USD) or more for a myeloablative allogeneic procedure involving an unrelated donor. Common posttransplantation complications, such as infections and GVHD, have been shown to be significant cost drivers. Comparisons across studies are limited by differences in patient populations, cost ascertainment methods, and length of follow-up. This article summarizes the current state of knowledge about costs and cost-effectiveness of HCT, highlighting the challenges in conducting these studies and identifying important areas for future research. We discuss the need for more value-based assessments of HCT using high-quality approaches to measuring costs and outcomes so that potential future efforts to contain costs are well informed and appropriate.

Outcomes from unrelated donor hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) offers a curative treatment option for management of a variety of hematologic malignancies. While sibling donors have been the gold standard for adult patients in need of an HCT, not all patients have a suitable family donor. The availability of unrelated volunteer donor registries and alternative stem cell sources has expanded the wide application of this procedure.

METHODS

PubMed and MEDLINE were searched for human trials and the English language from 2001 to 2011. Factors influencing transplantation outcomes involving unrelated donors over the last decade are discussed, and feasible alternative stem cell sources when a matched unrelated donor is not available are reviewed.

RESULTS

HCT using a matched unrelated donor offers outcomes comparable to sibling HCT due to current molecular-based HLA typing and improvements in conditioning regimens and/or supportive care. The primary factor that contributes to improved outcome is the degree of donor-to-recipient HLA matching. The selection of younger unrelated donors has also been associated with improved outcomes in HCT. Evidence supports the universal application of matched unrelated donors even in high-risk leukemia and/or older patients. In adult patients without a matched related donor, other promising options as stem cell source includes mismatched unrelated donors, umbilical cord blood units, and haploidentical donors.

CONCLUSIONS

With current methodologies for molecular HLA typing and supportive care tools, outcomes of transplants with matched unrelated donors are comparable to those achieved with sibling donors. Alternative stem cell donors when a matched unrelated donor is not available are feasible expanding the stem cell donor pool.

How I treat childhood CML

Chronic myeloid leukemia (CML) is composed of 3% of pediatric leukemias, making evidence-based recommendations difficult. Imatinib has revolutionized the treatment for adult CML by eliminating allogeneic stem cell transplantation for almost all patients in chronic phase. Shown effective in pediatric CML, imatinib and successive tyrosine kinase inhibitors (TKI) have provided more therapeutic options. Because stem cell transplantation has been better tolerated in children and adolescents, the decision to treat by either TKI or transplantation is controversial. We present a recent case of a 12-month-old boy diagnosed with BCR-ABL(+) CML to highlight the controversies in treatment recommendations. We review the pediatric stem cell transplantation outcomes as well as the pediatric experience with imatinib and other TKIs. Finally, we compare the side effects as well as costs associated with allogeneic stem cell transplantation versus TKI therapy. We recommend that frontline therapy for pediatric CML in chronic phase is TKI therapy without transplantation. Patients in accelerated or blast crisis or who fail to reach landmarks on TKIs either because of intolerance or resistance should pursue stem cell transplantation. Although we recommend adopting adult clinical experience to guide therapeutic decision making, the issues of infant CML, drug formulation, pharmacokinetics, and adolescent compliance merit clinical investigation.

Utility values for chronic myelogenous leukemia chronic phase health states from the general public in the United Kingdom

This study estimated time trade-off preference values associated with the four chronic myelogenous leukemia (CML) chronic phase-related health states (i.e. untreated, hematologic response, cytogenetic response and molecular response) among members of the general public in the UK (n = 241). All four health states were associated with decreases in preference values from full health. The molecular response to treatment was the most preferred health state (mean utility of 0.94). The second-most preferred health state was cytogenetic response followed by hematologic response (mean utilities were 0.89 and 0.80, respectively). The least preferred health state was untreated chronic phase CML (mean utility of 0.72). The utility values for each state were significantly different from one another (p < 0.001). This study demonstrated and quantified the impact that more robust treatment responses have on the health-related quality of life of patients with chronic phase CML.

Application of cost-effectiveness analysis to demonstrate the potential value of companion diagnostics in chronic myeloid leukemia

AIM

A cost-effectiveness analysis was performed to assess the potential value of companion diagnostics in supporting treatment decisions for dasatinib and nilotinib in chronic myeloid leukemia.

MATERIALS & METHODS

A decision model was developed, and model inputs were taken from the literature and publicly available sources. The perspective of the healthcare sector in the Netherlands was used. Sensitivity and scenario analyses were performed to assess uncertainty in the results.

RESULTS

Companion diagnostics could improve health and reduce costs, despite the estimates being uncertain owing to limited evidence for comparative effectiveness between dasatinib and nilotinib. The results were sensitive to the cost of treatment, utility of progression and progression-free survival.

CONCLUSION

This case demonstrates the use of cost-effectiveness analysis at an early stage of health technology assessment to generate economic evidence for the use of companion diagnostics in treatment decisions and to support decision-making for their development.

Prevalence, determinants, and outcomes of nonadherence to imatinib therapy in patients with chronic myeloid leukemia: the ADAGIO study

Imatinib mesylate (imatinib) has been shown to be highly efficacious in the treatment of chronic myeloid leukemia (CML). Continuous and adequate dosing is essential for optimal outcomes and with imatinib treatment possibly being lifelong, patient adherence is critical. The ADAGIO (Adherence Assessment with Glivec: Indicators and Outcomes) study aimed to assess prospectively over a 90-day period the prevalence of imatinib nonadherence in patients with CML; to develop a multivariate canonical correlation model of how various determinants may be associated with various measures of nonadherence; and to examine whether treatment response is associated with adherence levels. A total of 202 patients were recruited from 34 centers in Belgium, of whom 169 were evaluable. One-third of patients were considered to be nonadherent. Only 14.2% of patients were perfectly adherent with 100% of prescribed imatinib taken. On average, patients with suboptimal response had significantly higher mean percentages of imatinib not taken (23.2%, standard deviation [SD] = 23.8) than did those with optimal response (7.3%, SD = 19.3, P = .005; percentages calculated as proportions x 100). Nonadherence is more prevalent than patients, physicians, and family members believe it is, and therefore should be assessed routinely. It is associated with poorer response to imatinib. Several determinants may serve as alert signals, many of which are clinically modifiable.

Nilotinib: a second-generation tyrosine kinase inhibitor for the treatment of chronic myelogenous leukemia

BACKGROUND

Nilotinib, a second-generation tyrosine kinase inhibitor (TKI) formerly known as AMN107, was approved by the US Food and Drug Administration (FDA) on October 29, 2007, for the treatment of adult patients with chronic-phase (CP) and accelerated-phase (AP) Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) resistant to or intolerant of prior treatment that included imatinib.

OBJECTIVE

The purpose of this review was to evaluate the pharmacology, pharmacokinetic properties, and pharmacodynamic properties of nilotinib; results of clinical trials in patients with CML, Ph+ acute lymphoblastic leukemia (ALL), and gastrointestinal stromal tumors (GISTs); and potential drug interactions.

METHODS

Literature was identified and reviewed using searches of MEDLINE (1966-April 1, 2008), the American Society of Hematology and American Society of Clinical Oncology abstracts databases (2002-2008 annual meetings/symposia), the European Hematology Association abstracts database (2006-2007 annual meetings), and the American Association for Cancer Research symposia (2000-2007). Search terms included, but were not limited to, nilotinib, AMN107, chronic myelogenous leukemia, acute lymphoblastic leukemia, bcr-abl, imatinib resistance, adverse events, pharmacology, and clinical trials.

RESULTS

Nilotinib is an orally bioavailable derivative of imatinib with improved specificity toward the breakpoint cluster region-Abelson murine leukemia (bcr-abl) viral protooncogene. In preclinical studies, nilotinib was found to have activity against 32 of 33 imatinib-resistant bcr-abl mutations, but not against the T3151 mutation. On pharmacokinetic analysis, T(max) was 3 hours. The calculated t((1/2)) following multiple daily dosing was approximately 17 hours. The main metabolic pathways identified were oxidation and hydroxylation. The parent compound is the circulating component found in serum; the metabolites were not found to contribute to pharmacologic activity. Nilotinib is a competitive inhibitor of cytochrome P450 (CYP) 3A4, CYP2C8, CYP2C9, and CYP2D6. In 2 Phase II, open-label, single-arm clinical studies, nilotinib was found to be beneficial in patients with CML that was imatinib resistant or intolerant. Overall, 58% of patients with CML-CP achieved a major cytogenetic response; 42%, a complete cytogenetic response; and 77%, a complete hematologic response (CHR). At 18 months, the estimated overall survival rate was 91%. Of patients whose disease had progressed to AP, nilotinib was associated with major cytogenetic response in 32%; complete cytogenetic response in 19%; and CHR in 30%. At 12 months, an estimated 56% of patients lacked progression of disease, and the estimated overall survival rate was 82%. Concurrent use of CYP3A4 inhibitors should be avoided. The most common toxicities attributable to nilotinib include rash, pruritus, nausea, fatigue, headache, constipation, diarrhea, and vomiting. Grade 3/4 toxicities (> or = 10%) have included thrombocytopenia, neutropenia, elevated lipase, hyperglycemia, and hypophosphatemia. Nilotinib has been associated with a prolonged QT interval, and sudden death has been reported. The FDA-approved regimen of nilotinib is 400 mg PO BID on an empty stomach.

CONCLUSIONS

Nilotinib is an oral second-generation bcr-abl TKI indicated for the treatment of imatinib resistant or -intolerant Ph+ CML-CP and -AP in adults. Positive clinical activity and tolerability have been reported in clinical trials. Clinical data on off-label indications and in patients with Ph+ ALL and GIST continue to emerge.

Updated estimates of survival and cost effectiveness for imatinib versus interferon-alpha plus low-dose cytarabine for newly diagnosed chronic-phase chronic myeloid leukaemia

BACKGROUND

For trials in which participants are followed beyond the main study period to assess long-term outcomes, economic evaluations conducted using short-term data should be systematically updated to reflect new information.

METHODS

We used 60-month survival data from the IRIS (International Randomized study of Interferon vs STI571) trial to update previously published cost-effectiveness estimates, based on 19 months of follow-up, of imatinib versus interferon (IFN)-alpha plus low-dose cytarabine in patients with chronic-phase chronic myeloid leukaemia. For patients treated with imatinib, we used the 60-month data to calibrate the survival curves generated from the original cost-effectiveness model. We used historical data to model survival for patients randomized to IFNalpha. We updated costs for medical resources using 2006 Medicare reimbursement rates and applied average wholesale prices (AWPs) and wholesale acquisition costs (WACs) to study medications.

RESULTS

Five-year survival for patients randomized to imatinib was better than predicted in the original model (89.4% vs 83.2%). We estimated remaining life expectancy with first-line imatinib to be 19.1 life-years (3.8 life-years over the original model) and 15.2 QALYs (3.1 QALYs over the original estimate). Estimates for IFNalpha remained at 9.1 life-years and 6.3 QALYs. When we applied AWPs to study medications, incremental cost-effectiveness ratios (ICERs) were $US 51,800-57,500 per QALY. When we applied WACs, ICERs were $US 42,000-46,200 per QALY.

CONCLUSION

Although the analysis revealed that the original survival estimates were conservative, the updated cost-effectiveness ratios were consistent with, or slightly higher than, the original estimates, depending on the method for assigning costs to study medications.

Cost utility of allogeneic stem cell transplantation with matched unrelated donor versus treatment with imatinib for adult patients with newly diagnosed chronic myeloid leukaemia

OBJECTIVE

To estimate, from the perspective of the German statutory health insurance, the cost utility of allogeneic stem cell transplantation with matched unrelated donor (MUD-SCT) in newly diagnosed, chronic-phase chronic myeloid leukaemia (CML) patients aged 40 years or younger, relative to the treatment with imatinib.

METHODS

The incremental cost-effectiveness ratio (ICER) of the additional cost of imatinib versus MUD-SCT per quality-adjusted life year (QALY) gained was chosen as a target assessment. ICER was quantified using a Markov cohort modelling approach. The evaluation encompassed 5 years of treatment with either approach, and only direct medical costs (in euro, year 2005) were considered.

RESULTS

There were incremental costs of euro77,410 for imatinib therapy per QALY gained versus MUD-SCT. No strategy was clearly dominant; on average, during 5 years, cost savings of euro63,433 were obtained and 0.82 QALY lost by SCT compared to treatment with imatinib. QALYs gained in CML patients with either treatment resulted in considerable cost to the third-party payer in Germany. The results were particularly sensitive to the price of imatinib.

CONCLUSIONS

The analysis finds that imatinib is more costly but more effective (as measured in QALYs) over a 5-year time horizon. The resulting ICER of euro77,410 per QALY is higher than commonly cited thresholds. The cost utility of MUD-SCT to treat CML in patients with a European Group for Blood and Marrow Transplantation score < or = to 2 compares with that of the imatinib strategy.

New strategies in controlling drug resistance in chronic myeloid leukemia

PURPOSE

Imatinib has been quite effective in maintaining patients with CML in the chronic phase (CP); however, some patients develop imatinib resistance. This review addresses the mechanisms underlying imatinib resistance and the strategies currently being used to overcome that resistance.

SUMMARY

Chronic myeloid leukemia (CML) is a stem cell cancer caused by BCR-ABL. Imatinib, a BCR-ABL inhibitor, has significantly decreased CML mortality by stopping disease progression in CP. This success has been tempered by the appearance of imatinib-resistant clones. These clones allow CML to progress to advanced stages of disease where the prognosis is poor. Mechanisms of imatinib resistance include plasma protein binding, drug efflux, mutation of BCR-ABL, gene amplification of BCR-ABL, and activation of BCR-ABL independent proliferative pathways. The first four of these mechanisms could potentially be addressed by increasing the imatinib dose and recent clinical trials have shown this to be the case. Pharmacokinetic analysis demonstrated that patients with low imatinib plasma concentrations fared more poorly then patients with high plasma concentrations. Doubling the standard dose of 400 mg per day increased patient responses while decreasing the time to response. Toxicity was also increased resulting in approximately 50% of patients decreasing the dose. The strategy of waiting to see who failed imatinib at 400 mg per day and then increasing the dose of that subpopulation was unsuccessful. The interpretation of these data is that it is beneficial to treat CML as aggressively as possible as early as possible. Dasatinib is the second BCR-ABL inhibitor to become available. It binds with a 350-fold greater affinity to BCR-ABL and shows efficacy against a number of imatinib-resistant mutations. Dasatinib also inhibits SRC kinase, which may play a role in both maintaining BCR-ABL activity and in BCR-ABL independent signaling pathways. Clinical trials with dasatinib have had favorable results and are comparable with high-dose imatinib. Imatinib also compares favorably with stem cell transplant (SCT). Economic analysis shows imatinib and dasatinib therapies, while quite expensive, are on par with dialysis in terms of cost of quality adjusted life years.

CONCLUSION

A better understanding of imatinib resistance mechanisms has resulted in the development of useful strategies both to predict responders and nonresponders and to minimize imatinib resistance and prolong the life of the patient.

Imatinib: a review of its use in chronic myeloid leukaemia

Imatinib (Gleevec, Glivec) is a synthetic tyrosine kinase inhibitor used in the treatment of chronic myeloid leukaemia (CML). It is specifically designed to inhibit the breakpoint cluster region (BCR)-Abelson (ABL) fusion protein that results from the chromosomal abnormality known as the Philadelphia chromosome. CML is characterised by this abnormality, which leads to abnormalities of the peripheral blood and bone marrow including an increase in the number of granular leukocytes. Imatinib is approved in numerous countries worldwide for the treatment of newly diagnosed Philadelphia chromosome-positive (Ph+) chronic-phase CML, Ph+ accelerated-phase or blast-crisis CML, and in patients with Ph+ chronic-phase CML who have failed to respond to interferon-alpha therapy. It is also indicated in paediatric patients with newly diagnosed Ph+ chronic-phase CML, in accelerated-phase or blast-crisis CML, or in chronic-phase CML after failure of interferon-alpha therapy or when the disease has recurred after haematopoietic stem cell transplantation (HSCT). Approved indications, however, may vary by country. Imatinib is effective and generally well tolerated in patients with Ph+ CML. In patients with newly diagnosed chronic-phase CML, imatinib was more effective than interferon-alpha plus cytarabine in preventing progression of the disease and in achieving haematological and cytogenetic responses. Overall survival rates remain high after 5 years of follow-up, and historical comparisons with other treatments demonstrate improved overall survival with imatinib in the long term. Patients with accelerated-phase or blast-crisis CML, or those who have not responded to prior interferon-alpha therapy also benefit from imatinib treatment. Some patients become resistant or intolerant to imatinib therapy; management strategies to overcome these problems include dosage adjustment, other treatments, or combination therapy with imatinib and other agents. Allogeneic HSCT is currently the only potentially curative treatment, but it is associated with high rates of morbidity and mortality and is not suitable for all patients. The introduction of imatinib has had a marked impact on outcomes in patients with CML. It remains a valuable treatment for all stages of the disease, especially initial treatment of newly diagnosed Ph+ chronic-phase CML, and is endorsed by European and US treatment guidelines as a first-line option.

Economic evaluations of leukemia: A review of the literature

Objectives:Leukemia, together with lymphoma and multiple myeloma, are hematological malignancies, malignancies of the blood-forming organs. There are four major types of leukemia: acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and chronic lymphocytic leukemia (CLL). There is a growing amount of literature of the health economic aspects of leukemia. However, no comprehensive review is yet performed on the health economic evidence for the disease. Hence, our aim was to review and analyze the existing literature on economic evaluations of the different types of leukemia.

Methods:A systematic literature search used electronic databases to identify published cost analyses and economic evaluations of leukemia treatments. After reviewing all identified studies, sixty studies were considered relevant for the purpose of the review.

Results:The identified studies were published after 1990, with a few exceptions. Many of the identified economic evaluations in leukemia, particularly for ALL and AML, may be defined as cost-minimization analyses, where only the costs of different treatment strategies are compared. In CML, a new treatment, imatinib, was introduced in 2001 and several cost-effectiveness analyses have since then been conducted comparing imatinib with previous first line treatments.

Conclusions:This review indicates that there is a shortage of cost-effectiveness information in leukemia. The introduction of new therapies will stress the need for new economic evaluations in this group of diseases. More information about the total costs, that is, including indirect costs, and quality of life effects would be valuable in future evaluations in leukemia.

Treatment interruptions and non-adherence with imatinib and associated healthcare costs: a retrospective analysis among managed care patients with chronic myelogenous leukaemia

OBJECTIVES

Identify treatment interruptions and non-adherence with imatinib; examine the clinical and patient characteristics related to treatment interruptions and non-adherence; and estimate the association between treatment interruptions and non-adherence with imatinib and healthcare costs for US managed care patients with chronic myeloid leukaemia (CML).

METHODS

This retrospective analysis utilised electronic healthcare claims data from a US managed care provider. Adult patients with CML (as determined by International Classification of Diseases, ninth revision, Clinical Modification [ICD-9-CM] diagnosis code) were identified who began treatment with imatinib from 1 June 2001 through 31 March 2004. Treatment interruptions (i.e. failure to refill imatinib within 30 days from the run-out date of the prior prescription) were identified during the 12-month follow-up period. Medication possession ratio (MPR), calculated as total days' supply of imatinib divided by 365, was also examined. Healthcare costs (i.e. paid amounts for all prescription medications and medical services received, including health plan and patient liability) were examined in three ways: (i) total healthcare costs; (ii) total healthcare costs exclusive of imatinib costs; and (iii) total medical costs. All costs were converted to US dollars (2004 values) using the medical component of the Consumer Price Index. MPR was modelled using ordinary least squares regression. Presence of treatment interruptions was modelled using logistic regression. The association between MPR and healthcare costs was estimated using a generalised linear model specified with a gamma error distribution and a log link. All models included adjustment for age, gender, number of concomitant medications, starting dose of imatinib and cancer complexity.

RESULTS

A total of 267 patients were identified. Average age was approximately 50 years, and 43% were women. Mean MPR was 77.7%, with 31% of patients having a treatment interruption. However, all of these patients resumed imatinib within the study period. In this population, MPR decreased as the number of concomitant medications increased (p = 0.002), and was lower among women (p = 0.003), patients with high cancer complexity (p = 0.003) and patients with a higher starting dose of imatinib (p = 0.04). Women were approximately twice as likely as men to have a treatment interruption (p = 0.009), as were patients with a high cancer complexity (p = 0.03). After adjusting for the aforementioned covariates, MPR was found to be inversely associated with healthcare costs excluding imatinib (p < 0.001) and medical costs (p < 0.001). A 10% point difference in MPR was associated with a 14% difference in healthcare costs excluding imatinib and a 15% difference in medical costs. For example, patients with an MPR of 75% incur an additional 4072 US dollars in medical costs annually compared with patients with an MPR of 85%.

CONCLUSIONS

Treatment interruptions and non-adherence with imatinib, both of which could lead to undesired clinical and economic outcomes, appear to be prevalent. Physicians and pharmacists should educate patients and closely monitor adherence to therapy, as improving adherence and limiting treatment interruptions may not only optimise clinical outcomes but also reduce the economic burden of CML.

Clinical outcomes and direct hospital costs of reduced-intensity allogeneic transplantation in chronic myeloid leukemia

A reduced-intensity conditioning allogeneic stem cell transplantation was given to 19 patients (aged 15-59 years) in the first chronic phase and one patient in the accelerated phase with chronic myeloid leukemia (CML) after a regimen consisting of fludarabine (Flu), busulfan (Bu) and ATG Fresenius. The median follow-up was 27 months. Until day +100, no transplant-related mortality was recorded. The incidence of acute and chronic graft-versus-host disease (GvHD) was 55 and 75%, respectively. Two patients (10%) died from GvHD. Fourteen (70%) patients achieved molecular remission. Additional post-transplant intervention (donor lymphocyte infusion, imatinib) was necessary, however, in 10 patients (50% of the patients; non-achievement of stable molecular remission or later relapses). The total direct cost of the transplantation treatment for all of the patients came to 1,572,880 euro. If the patients had been treated with imatinib and followed-up with the same time period as they were following a transplantation, the direct cost of the imatinib treatment would have been 2,005,117 euro. The transplantation treatment appears to be less expensive after approximately 2 years of follow-up. Flu+Bu+ATG is a low-toxicity regimen for patients with CML. However, a close follow-up is necessary and about 50% of the patients require further therapeutic intervention.