Initial molecular response at 3 months may predict both response and event-free survival at 24 months in imatinib-resistant or -intolerant patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase treated with nilotinib

J Clin Oncol. 2012 Dec 10;30(35):4323-9. doi: 10.1200/JCO.2011.40.5217. Epub 2012 Oct 29.

Abstract

Purpose: The association between initial molecular response and longer-term outcomes with nilotinib was examined.

Patients and methods: Patients with imatinib-resistant or -intolerant chronic myeloid leukemia in chronic phase from the phase II nilotinib registration study with available postbaseline BCR-ABL1 transcript assessments were included (N = 237).

Results: BCR-ABL1 transcript levels (International Scale [IS]) at 3 months correlated with complete cytogenetic response (CCyR) by 24 months. Patients with BCR-ABL1 (IS) of > 1% to ≤ 10% at 3 months with nilotinib had higher cumulative incidence of CCyR by 24 months than patients with BCR-ABL1 (IS) of > 10% (53% v 16%). BCR-ABL1 (IS) at 3 months predicted major molecular response (MMR) by 24 months. Cumulative incidence of MMR by 24 months for patients with BCR-ABL1 (IS) of > 0.1% to ≤ 1%, > 1% to ≤ 10%, and > 10% was 65%, 27%, and 9%, respectively. These differences were observed for patients with or without baseline BCR-ABL1 mutations and for those with imatinib resistance or intolerance. Estimated event-free survival (EFS) rates at 24 months decreased with higher transcript levels at 3 months; patients with BCR-ABL1 (IS) of ≤ 1% had an estimated 24-month EFS rate of 82%, compared with 70% for patients with BCR-ABL1 (IS) of > 1% to ≤ 10% and 48% for patients with BCR-ABL1 (IS) of > 10%.

Conclusion: Patients with BCR-ABL1 (IS) of > 10% at 3 months had a lower cumulative incidence of CCyR and MMR and lower rates of EFS versus patients with BCR-ABL1 (IS) of ≤ 10%. Prospective studies may determine whether close monitoring or alternative therapies are warranted for patients with minimal initial molecular response.

Trial registration: ClinicalTrials.gov NCT00471497.

Publication types

  • Clinical Trial, Phase II
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antineoplastic Agents / therapeutic use*
  • Benzamides / therapeutic use*
  • Disease-Free Survival
  • Drug Resistance, Neoplasm
  • Fusion Proteins, bcr-abl / biosynthesis
  • Fusion Proteins, bcr-abl / genetics*
  • Humans
  • Imatinib Mesylate
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / metabolism
  • Mutation
  • Piperazines / therapeutic use*
  • Pyrimidines / therapeutic use*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Remission Induction
  • Survival Rate
  • Treatment Outcome
  • Young Adult

Substances

  • 4-methyl-N-(3-(4-methylimidazol-1-yl)-5-(trifluoromethyl)phenyl)-3-((4-pyridin-3-ylpyrimidin-2-yl)amino)benzamide
  • Antineoplastic Agents
  • Benzamides
  • Piperazines
  • Pyrimidines
  • RNA, Messenger
  • Imatinib Mesylate
  • Fusion Proteins, bcr-abl

Associated data

  • ClinicalTrials.gov/NCT00471497