Rapid initial decline in BCR-ABL1 is associated with superior responses to second-line nilotinib in patients with chronic-phase chronic myeloid leukemia

BMC Cancer. 2013 Apr 2;13:173. doi: 10.1186/1471-2407-13-173.

Abstract

Background: We evaluated BCR-ABL1 kinetics in patients treated with nilotinib and analyzed whether a dynamic model of changes in BCR-ABL1 levels over time could be used to predict long-term responses.

Methods: Patients from the nilotinib registration trial (CAMN107A2101; registered at http://www.clinicaltrials.gov as NCT00109707) who had imatinib-resistant or -intolerant Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase (CP) or accelerated phase with BCR-ABL1 > 10% (on the international scale [IS]) at baseline and, in the first 6 months, had at least three BCR-ABL1 transcript measurements and an average daily dose of at least 720 mg were included in this analysis (N = 123).

Results: More than half of patients (65/123; 53%) had a slow monophasic response and the remainder (58/123; 47%) had a biphasic response, in which patients had a rapid initial decrease in BCR-ABL1 transcripts followed by a more gradual response. The biphasic response type strongly correlated with improved event-free survival (EFS). Data in the first 6 months of follow-up were sufficient to predict EFS at 24 months.

Conclusions: Unlike newly diagnosed patients with Ph+ CML-CP-in whom the majority had a biphasic response-approximately half of patients with imatinib-resistant or -intolerant CML had a slower, monophasic response. Second-line patients who did have a biphasic response had an EFS outlook similar to that of newly diagnosed patients treated with imatinib. Our model was comparable to using BCR-ABL1 (IS) ≤ 10% at 6 months as a threshold for predicting EFS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chronic Disease
  • Drug Resistance, Neoplasm / genetics*
  • Follow-Up Studies
  • Fusion Proteins, bcr-abl / genetics*
  • Humans
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / mortality
  • Models, Theoretical
  • Prognosis
  • Protein Kinase Inhibitors / therapeutic use*
  • Pyrimidines / therapeutic use*
  • Survival Rate

Substances

  • 4-methyl-N-(3-(4-methylimidazol-1-yl)-5-(trifluoromethyl)phenyl)-3-((4-pyridin-3-ylpyrimidin-2-yl)amino)benzamide
  • Protein Kinase Inhibitors
  • Pyrimidines
  • Fusion Proteins, bcr-abl

Associated data

  • ClinicalTrials.gov/NCT00109707