The predictive value of the initial clinical and laboratory parameters for the response to the second line therapy with nilotinib was studied in 189 patients with chronic phase of chronic myeloid leukemia (CML), who were resistant to imatinib therapy. Overall, a complete cytogenetic response (CCR) was achieved in 59.8% of patients, a major molecular response (MMR) in 43.4% of patients, and a deep molecular response (MR4) in 25.7% of patients. Estimated 5-year progression free survival (PFS) was 82.1%, 5-year overall survival (OS) — 83.2%.
Independent parameters associated with the achievement of CCR, MMR, and MR4 on the second line nilotinib therapy were identified: the duration of the disease less than 72 months prior to the appointment of the second line nilotinib therapy, the maximum tumor clone reduction during prior imatinib therapy to the level of CCR and deeper, the tumor clone reduction at the time of nilotinib appointment to the level of CCR. The latter parameter also determined better event free survival and PFS in the study group.