Resistance of Philadelphia-chromosome positive leukemia towards the kinase inhibitor imatinib (STI571, Glivec): a targeted oncoprotein strikes back

Leukemia. 2003 May;17(5):829-38. doi: 10.1038/sj.leu.2402889.


Cancer research within the last decades elucidated signaling pathways and identified genes and proteins that lead or contribute to malignant transformation of a cell. Discovery of the Bcr-Abl oncoprotein as the molecular abnormality causing chronic myeloid leukemia (CML) paved the way for the development of a targeted anticancer therapy. The substantial activity of imatinib mesylate (STI571, Glivec) in CML and Philadelphia (Ph)-chromosome positive acute lymphoblastic leukemia (Ph+ ALL) changed the therapeutic approach to Ph+ leukemia and rang the bell for a new era of anticancer treatment. However, when the phenomenon of relapse occurred despite continued imatinib treatment, we had to learn the lesson that imatinib can select for a resistant disease clone. If such a clone still depends on Bcr-Abl, it either carries a BCR-ABL point mutation that prevents binding of the drug or expresses the fusion protein at high levels. Alternatively, leukemia cells that harbor secondary genetic alterations resulting in Bcr-Abl-independent proliferation are selected for their growth advantage in the presence of imatinib. Point mutations in the BCR-ABL kinase domain prevent binding of imatinib but still allow binding of ATP, thus retaining Bcr-Abl kinase activity. Mutated BCR-ABL is frequently detected in cases of imatinib-resistant Ph+ leukemia and therefore represents the main challenge for the investigation of alternative strategies to either overcome resistance or to prevent the emergence of a resistant leukemic clone.

Publication types

  • Review

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Benzamides
  • Drug Resistance, Neoplasm*
  • Fusion Proteins, bcr-abl / antagonists & inhibitors*
  • Fusion Proteins, bcr-abl / genetics
  • Humans
  • Imatinib Mesylate
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Piperazines / therapeutic use*
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Pyrimidines / therapeutic use*


  • Antineoplastic Agents
  • Benzamides
  • Piperazines
  • Pyrimidines
  • Imatinib Mesylate
  • Protein-Tyrosine Kinases
  • Fusion Proteins, bcr-abl