Dose optimization of tyrosine kinase inhibitor therapy in chronic myeloid leukemia

Exploration of treatment-free remission in CML, based on molecular monitoring

BACKGROUND

Typical chronic myelogenous leukemia (CML) is a myeloproliferative neoplasm caused by t(9; 22)(q34; q11) translocation. This chromosomal translocation forms the BCR::ABL1 fusion gene. The tyrosine kinase encoded by the BCR::ABL1 is considered to be the main pathogenic diver. BCR::ABL1 is not only a therapeutic target, but also a monitoring target. Monitoring of BCR::ABL1 reveals the progression of the disease and guides the next treatment. Now for CML, the target of treatment has been focused on treatment-free remission (TFR).

METHODS

We conducted a literature review of current developments of treatment-free remission and molecular monitoring methods.

RESULTS

More effective and sensitive CML monitoring methods such as digital droplet PCR (ddPCR) and next generation sequencing (NGS) have further studied the measurable residual disease (MRD) and clonal heterogeneity, which provides strong support for the exploration of TFR. We discussed some of the factors that may be related to TFR outcomes at the molecular level, along with some monitoring strategies.

CONCLUSION

Currently, predictive indicators for treatment-free remission outcomes and recurrence are lacking in clinical practice. In future, treatment-free remission research should focus on combining the clinical indicators with molecular monitoring and biological markers to personalize patient conditions and guide clinicians to develop individualized treatment plans, so that more patients with CML can achieve safer and stabler treatment-free remission.

Imatinib-induced severe hematological toxicity: Prolonged myelosuppression resulting from extraordinary sensitivity in an old age

The advent of tyrosine kinase inhibitors (TKIs) has profoundly changed the therapeutic landscape of chronic myeloid leukemia (CML) in the chronic phase (CML-CP). Imatinib is the first-generation, and the first and as yet the most widely used TKI, and the recommended dose is 400 mg/day for treating CML-CP. Most patients tolerate this treatment well, and prolonged hematological toxicities have rarely been reported. In this manuscript, we report a newly diagnosed CML-CP patient who developed prolonged myelosuppression (lasting for more than three months) following only one week of imatinib at 400 mg/day as the solitary treatment. Imatinib was discontinued, and pancytopenia persisted, with a continuous decrease in hemoglobulin levels. After restoration of autologous hematopoiesis, reintroduction of imatinib at 100 mg/day resulted in recurrent myelosuppression, and subsequent treatment with imatinib at 50 mg/day achieved good hematological homeostasis. We hypothesized that extraordinary sensitivity resulted in severe and prolonged myelosuppression.

Chronic myeloid leukemia: the cutting-edge evidence and things we should know

The prognosis of patients with chronic myeloid leukemia has dramatically improved along with the progress of therapy. However, some concerns remain unresolved, and new treatment strategies have been implemented recently. In this Progress in Hematology corner, the following four issues are presented and discussed: (1) Guidelines for the treatment of chronic myeloid leukemia from the NCCN and ELN: Differences and similarities; (2) Asciminib as a third-line option in chronic myeloid leukemia; (3) Dose optimization of tyrosine kinase inhibitor therapy in chronic myeloid leukemia; and (4) Genetic landscape of chronic myeloid leukemia. All these review articles will provide critical information for hematologists and let us know things we should learn in order to treat patients with this disease adequately.