Expression of e14a2 or both e14a2 and e13a2 predicts optimal ELN responses and longer event-free survival (EFS) and transformation-free survival (TFS), according to a study of 481 patients with chronic myeloid leukemia (CML) treated with different tyrosine kinase inhibitors and expressing various BCR-ABL transcripts. Researchers found:

• 200 patients expressed e13a2, 196 expressed e14a2, and 85 expressed both transcripts.

• The proportion of patients with e13a2, e14a2 and both achieving complete cytogenic response at 3 and 6 months was 59%, 67% and 63%, and 73%, 81% and 82%, respectively.

• Major molecular response rates were 27%, 49% and 50% at 3 months, 42%, 67% and 70% at 6 months, and 55%, 83% and 76% at 12 months, respectively.

• In multivariate analysis, e14a2 and both predicted for optimal responses at 3, 6 and 12 months.

• Type of transcript also predicted improved probability of EFS and TFS.

Citation: Jain P, Kantarjian H, Patel KP, et al. Impact of BCR-ABL transcript type on response and survival in patients with chronic phase chronic myeloid leukemia treated with tyrosine kinase inhibitors. [Published online ahead of print January 4, 2016]. Blood. doi: 10.1182/blood-2015-10-674242.