Intolerance to tyrosine kinase inhibitors in chronic myeloid leukemia: Definitions and clinical implications

Area of Science:

• Oncology
• Pharmacology

Background:

• Tyrosine kinase inhibitor (TKI) therapy has transformed chronic myeloid leukemia (CML) treatment.
• While imatinib is effective, second-generation TKIs offer alternatives for intolerant patients.
• A standardized definition for imatinib intolerance is currently lacking.

Purpose of the Study:

• To address the absence of a standard definition for imatinib intolerance in CML.
• To explore the utility of patient quality of life as a measure of intolerance.
• To guide the development of clinical algorithms for managing adverse events in CML patients.

Main Methods:

• Review of current practices using Common Toxicity Criteria for grading adverse events.
• Discussion of the limitations of acute toxicity criteria for long-term CML therapy.
• Exploration of quality of life assessment tools, including a developing CML-specific variant of the M. D. Anderson Symptom Inventory.

Main Results:

• Current methods for defining intolerance, such as Common Toxicity Criteria, may not fully capture the long-term impact of TKI therapy.
• Patient quality of life emerges as a potentially more relevant metric for assessing true intolerance in CML.
• Development of CML-specific quality of life tools is underway.

Conclusions:

• A consistent definition of intolerance is needed to manage severe or chronic adverse events during imatinib therapy.
• Incorporating patient quality of life into intolerance definitions is essential for long-term CML management.
• The definition of intolerance will continue to evolve with long-term data from newer TKIs to optimize patient outcomes and quality of life.