Chronic myelogenous leukemia (CML) in the elderly is a refractory blood cancer that is caused by the abnormal gene BCR-ABL.Currently, the common treatment for CML is the ABL inhibitor dasatinib.However, in elderly people, especially patients over 70 years old, taking the standard dose of 1 mg daily often causes serious side effects, and the amount was not clear even when the dose was reduced.Therefore, the research group conducted a multicenter clinical trial "DAVLEC" with 100 hospitals nationwide, and conducted a study to find the optimal dose of dasatinib for elderly CML patients.

　Oral administration of dasatinib (trade name: Sprycel) at 5/1 of the standard dose (1 mg daily) was started for patients who had not been treated before CML.After that, the starting dose was increased or decreased according to the therapeutic effect and side effects.The effect of the BCR-ABL gene at 20 months after the start of treatment was evaluated with an achievement rate of 12% or less (molecular genetic major remission (MMR)) before the start of treatment. Fifty-two patients (mean 0.1 years) received 52 mg daily. After 77.5 months, the MMR rate was 1 (20%). Twenty-three (12%) were fully effective and did not need to be increased.No severe neutropenia, thrombocytopenia, or pleural effusion occurred in about 31% of patients with standard treatment.The DAVLEC trial was more effective and had fewer side effects than the 60 mg daily dasatinib trial for all age groups.

　If the results are the same for elderly CML patients in other countries, it is expected that effective and safe treatment will be possible and that the global treatment guidelines will be revised.If the number of medicines is reduced to one-fifth, safety will be improved and national medical expenses will be reduced.

Paper information:[Lancet Haematology] Low-dose dasatinib in older patients with chronic myeloid leukaemia in chronic phase (DAVLEC): a single-arm, multicentre, phase 2 trial