Revisiting six established practices in the treatment of chronic myeloid leukaemia

Chronic Myeloid Leukemia: A Review

Importance

Chronic myeloid leukemia (CML) has an annual incidence of 2 cases per 100 000 people and is newly diagnosed in approximately 9300 individuals per year in the US. Approximately 150 000 people in the US and 5 million worldwide have CML.

Observations

Chronic myeloid leukemia is a myeloproliferative neoplasm characterized by the presence of the Philadelphia chromosome, which is defined by the BCR::ABL1 oncogene that develops after fusion of the ABL1 proto-oncogene to the constitutively active BCR gene. Approximately 90% of people with CML present with an indolent chronic phase of CML, defined as blasts of less than 10% in the blood or bone marrow, absence of extramedullary evidence of leukemia, basophils of less than 20%, and platelet counts of 100 to 1000 × 109/L. The most advanced stage is CML blastic phase (CML-BP), characterized by the World Health Organization as 20% or more blasts/immature cells and by the MD Anderson Cancer Center and European LeukemiaNet as 30% or more. Approximately 1% to 2% of patients with CML present with CML-BP. Since 2000, first-generation tyrosine kinase inhibitors (TKIs) targeting BCR::ABL1, such as imatinib, and second-generation TKIs, such as bosutinib, dasatinib, and nilotinib, have improved CML-related mortality from 10% to 20% per year to 1% to 2% per year, such that patients with CML have survival rates similar to those of a general age-matched population. Six BCR::ABL1 TKIs have been approved by the US Food and Drug Administration, including 5 that are first-line treatment (imatinib, dasatinib, bosutinib, nilotinib, and asciminib) and 5 approved for treatment after disease progression despite initial therapy (dasatinib, bosutinib, nilotinib, ponatinib, asciminib). Effects on improved survival are similar with all TKIs, although more patients are able to promptly achieve and maintain BCR::ABL1 clearance with second- and third-generation TKIs. Medication adherence is important to maintain treatment responsiveness. All TKIs are associated with hematologic toxicity, such as myelosuppression, with additional agent-specific adverse effects, such as pleural effusion (dasatinib), arterio-occlusive events such as myocardial infarction, stroke, and peripheral artery disease (nilotinib, ponatinib), gastrointestinal disturbance (bosutinib), or increased amylase and lipase with pancreatitis (ponatinib, asciminib, nilotinib). These adverse effects should be considered when selecting a TKI. Allogeneic hematopoietic stem cell transplant is a reasonably safe therapy, with cure rates ranging from 20% to 60% based on the stage of CML at the time of transplant. Stem cell transplant is reserved for patients with CML who do not respond to second-generation TKIs, those with intolerance to multiple TKIs, or those with accelerated-phase CML or CML-BP.

Conclusions and Relevance

Chronic myeloid leukemia is a myeloproliferative neoplasm that can typically be effectively treated with TKIs, improving survival similar to that of a general age-matched population. Many patients require continuous TKI therapy. Therefore, TKI therapy should be selected with consideration of adverse effects, and patients should be helped to maximize adherence to TKI treatment.

Global landscape and trends in lifetime risks of haematologic malignancies in 185 countries: population-based estimates from GLOBOCAN 2022

Background

Haematologic malignancies accounted for 6.6% of total cancer cases and 7.2% of total cancer-related deaths worldwide in 2022. We implemented a novel approach to estimate the lifetime risk of developing and dying from various types of haematologic malignancies at the global, regional and country-specific perspectives in 2022.

Methods

We retrieved incidence and mortality rates for Hodgkin lymphoma (HL), Non-Hodgkin lymphoma (NHL), multiple myeloma (MM) and leukaemia from GLOBOCAN 2022 of 185 countries, along with the national population statistics and all-cause mortality data sourced from the United Nations. For trend analysis, we obtained consecutive cancer registry data spanning from 2003 to 2017 from the Cancer Incidence in Five Continents (CI5) Plus database. After quality control, datasets from 30 countries were included. We used the "adjusted for multiple primaries (AMP)" method to calculate the lifetime risk of incidence (LRI) and mortality (LRM) by cancer type, selected age interval, sex, country and geographic region.

Findings

In 2022, the global lifetime risk of incidence (LRI) and mortality (LRM) for all haematologic malignancies was 1.67% and 0.98%, respectively. LRI was highest for NHL, whereas the LRM was highest for leukaemia. On a general level, males exhibited higher LRI and LRM compared to females. Both LRI and LRM increased with higher Human Development Index (HDI) levels. The LRI and LRM for haematologic malignancies were notably high in regions such as Australia/New Zealand, Northen America, as well as Northen, Western and Southern Europe, whereas they were comparatively low in Middle, Western and Eastern Africa. We observed about 5-fold regional disparity in the LRI/LRM ratio for HL, ranging from 1.50 in Middle Africa to 7.67 in Western Europe. Individuals aged 60 and above still faced 71.26% and 78.57% remaining risks for developing and dying from all haematologic malignancies. Among the 185 countries studied, NHL was the haematologic malignancy with the highest LRI in 68.65% of the countries. However, leukaemia had the highest LRM in 58.92% of these countries. MM exhibited the highest LRI and LRM particularly in islands surrounding the Caribbean Sea. Out of 30 countries with eligible consecutive cancer surveillance data, 24 exhibited significant upward trends in LRI of all haematologic malignancies, with AAPCs ranging from 0.5% in USA to 4.3% in Latvia. 25 countries showed significant upward trends in LRM, with AAPCs ranging from 1.0% in USA to 5.5% in Republic of Korea.

Interpretation

The global lifetime risks of haematologic malignancies exhibit considerable variations across different world regions, necessitating country-specific and targeted decision-making strategies. In contrast to traditional indicators, the compositive lifetime risks provide intuitive measures with profound public health implications, offering fresh insights into the development of regional disease prevention and control strategies.

Funding

CAMS Innovation Funds for Medical Sciences (No. 2021-I2M-1-061, No. 2021-I2M-1-011).

Chronic myeloid leukemia: 2025 update on diagnosis, therapy, and monitoring

DISEASE OVERVIEW

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm with an annual incidence of two cases/100 000. It accounts for approximately 15% of newly diagnosed cases of leukemia in adults.

DIAGNOSIS

CML is characterized by a balanced genetic translocation, t(9;22) (q34;q11.2), involving a fusion of the Abelson murine leukemia (ABL1) gene from chromosome 9q34 with the breakpoint cluster region (BCR) gene on chromosome 22q11.2. This rearrangement is known as the Philadelphia chromosome. The molecular consequence of this translocation is the generation of a BCR::ABL1 fusion oncogene, which in turn translates into a BCR::ABL1 oncoprotein.

FRONTLINE THERAPY

Four tyrosine kinase inhibitors (TKIs), imatinib, dasatinib, bosutinib, and nilotinib, are approved by the United States Food and Drug Administration (FDA) for first-line treatment of newly diagnosed CML in the chronic phase (CML-CP). Clinical trials with second and third-generation TKIs in frontline CML-CP therapy reported significantly deeper and faster responses but had no impact on survival prolongation, likely because of their potent efficacy and the availability of effective TKIs salvage therapies for patients who have a cytogenetic relapse with frontline TKI therapy. All four TKIs are equivalent if the aim of therapy is to improve survival. In younger patients with high-risk disease and in whom the aim of therapy is to induce a treatment-free remission status, second-generation TKIs may be favored.

SALVAGE THERAPY

For CML post-failure on frontline therapy, second-line options include second and third-generation TKIs. Although potent and selective, these TKIs exhibit unique pharmacological profiles and response patterns relative to different patient and disease characteristics, such as patients' comorbidities and financial status, disease stage, and BCR::ABL1 mutational status. Patients who develop the T315I "gatekeeper" mutation display resistance to all currently available TKIs except ponatinib, asciminib, and olverembatinib. Allogeneic stem cell transplantation remains an important therapeutic option for patients with CML-CP and failure (due to resistance) of at least two TKIs and for all patients in advanced-phase disease. Older patients who have a cytogenetic relapse post-failure on all TKIs can maintain long-term survival if they continue a daily most effective/least toxic TKI, with or without the addition of non-TKI anti-CML agents (hydroxyurea, omacetaxine, azacitidine, decitabine, cytarabine, and others).

Ponatinib-review of historical development, current status, and future research

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

Chronic myeloid leukaemia: Biology and therapy

Chronic myeloid leukaemia (CML) is caused by BCR::ABL1. Tyrosine kinase-inhibitors (TKIs) are the initial therapy. Several organizations have reported milestones to evaluate response to initial TKI-therapy and suggest when a change of TKI should be considered. Achieving treatment-free remission (TFR) is increasingly recognized as the optimal therapy goal. Which TKI is the best initial therapy for which persons and what depth and duration of molecular remission is needed to achieve TFR are controversial. In this review we discuss these issues and suggest future research directions.

Maximizing the Value of Chronic Myeloid Leukemia Management Using Tyrosine Kinase Inhibitors in the USA: Potential Determinants and Consequences of Healthcare Resource Utilization and Costs, with Proposed Optimization Approaches

BACKGROUND AND OBJECTIVES

The introduction and widespread use of effective and well-tolerated tyrosine kinase inhibitors for chronic myeloid leukemia have been associated with marked increments in life expectancy and disease prevalence. These changes have been accompanied by elevations in costs of tyrosine kinase inhibitors, which typically must be taken ad vitam after diagnosis and tend to be more expensive than medical therapies for many other hematologic malignancies. The aims of this review included evaluating the potential associations and consequences of healthcare resource utilization and costs of tyrosine kinase inhibitors and possible clinical management approaches to mitigate them.

METHODS

A PubMed search of English-language US study reports was conducted that covered the interval of 2001 (US approval of imatinib) through 17 April, 2023 augmented by manual reviews of published bibliographies from the referenced articles and searches of other databases: Google Scholar and Scopus.

RESULTS

On the basis of this analysis of chiefly real-world evidence (administrative claims database studies), healthcare resource utilization and costs can be considered indicators of ineffective chronic myeloid leukemia management, including potentially mutation-driven treatment resistance and costly tyrosine kinase inhibitor switches, non-adherence, and suboptimal tolerability, which may culminate in the progression of disease from the chronic to an accelerated or blast phase, with additional excess costs. Costs of tyrosine kinase inhibitors are also associated with reduced treatment adherence. At a willingness-to-pay threshold of $50,000-$200,000 per quality-adjusted life-year, tyrosine kinase inhibitors can be considered cost effective from a US payer perspective. Potential clinical approaches to mitigate costs include regular molecular monitoring with proactive assessments of BCR::ABL1 gene mutations to avoid costly treatment switches, as well as interventions to enhance treatment adherence and tyrosine kinase inhibitor tolerability.

CONCLUSIONS

Healthcare resource utilization and costs of chronic myeloid leukemia care may be considered barometers of ineffective management, including mutation-driven tyrosine kinase inhibitor resistance and switching as well as non-adherence and intolerance. Future prospective research is warranted to help determine whether costs can be reduced and other treatment outcomes optimized via more proactive and effective diagnostic interventions (i.e., regular molecular monitoring and proactive mutational testing) and treatment approaches. The strengths and limitations of this review include its emphasis on observational research, which, on one hand, offers a naturalistic "real-world" perspective on current chronic myeloid leukemia management, but, on the other hand, is associational in nature and cannot be used to determine causality and/or its direction.