Distinct predictive factors influence on achievement of early molecular response by frontline imatinib in chronic phase chronic myeloid leukemia.

To explore the factors for achieving early molecular responses (EMR; BCR-ABL1 ≤10% at 3 months, ≤1% at 6 months) by imatinib (IM), baseline characteristics including individual BCR-ABL1 transcript level, dose intensity, and IM trough level on day 29 were analyzed in 286 chronic phase chronic myeloid leukemia patients. Distinct predictive factors for achieving EMR at 3 months and 6 months were noted. Blast count at diagnosis and IM trough level on day 29 were significantly associated with an achievement of 3-month EMR. Early decline of BCR-ABL1 transcript, low Sokal risk, and mean daily dose (≥350mg/day) by 6 months were associated with an achievement of 6-month EMR. Understanding the predictive factors for EMR may provide additional information to guide clinical decisions on the changing therapies at each landmark.