Therapeutic effects of tyrosine kinase inhibitors and subtypes of BCR-ABL1 transcripts in Japanese chronic myeloid leukemia patients with three-way chromosomal translocations

•18 CML patients with a 3-way were studied, the first to do so in a JPN population.•Newly identified translocation breakpoints were seen in 7 of the 18 patients.•3 of the 18 patients had the same breakpoints of t(9;22;11)(q34;q11.2;q23).•The cumulative MR4.0 and 4.5 rates seemed to be lower in the CML with three-way.•The mRNA subtype frequency was reversed compared to the ratio in standard CML.