Prior to the availability of long-term BCR-ABL inhibitor data, short-term surrogate end points predictive of longer-term outcomes have been identified using data from clinical trials of patients with CML-CP treated with interferon-α-based therapy and approved BCR-ABL inhibitors.
Among 208 CML patients, b3a2 BCR-ABL transcripts were most commonly detected (66.82%) followed by b2a2 (28.84%), b3a2 + b2a2 (3.36%), b3a2 + e19a2 (0.48%) and b2a2 + e19a2 (0.48%). b3a2 transcripts were more frequently detected than b2a2 transcripts, in the whole group of 208 as well as in 183 CML-CP patients (P<0.0001).
Kinase domain (KD) mutations in the BCR-ABL gene are associated with resistance to imatinib in chronic myeloid leukemia (CML) but their incidence and prognostic significance in chronic phase (CP) patients without resistance are unclear.