BACKGROUND: Imatinib (STI571 or Glivec, Novartis) is a new type of tyrosine 
kinase inhibitor that selectively inhibits various tyrosine kinases including 
ABL, BCR-ABL, KIT and PDGF receptors.
IMATINIB IN CML: Earlier studies have shown that Imatinib is highly effective in 
the treatment of chronic myeloid leukemia (CML), which is characterized by 
translocation of chromosome material from chromosome 9 to chromosome 22 with 
formation of the so-called Philadelphia chromosome. During this process, an 
abnormal fusion protein, tyrosine kinase BCR-ABL, is formed. In a phase I study 
it was shown that a daily dose of 300 mg Imatinib resulted in a complete 
hematological response in almost 98% of the patients.
IMATINIB IN GIST: Gastrointestinal stromal tumors (GIST) are also suitable 
indications for treatment with Imatinib, the prerequisite being overexpression 
by the tumor of c-KIT (CD117). This tumor entity responds extremely poorly to 
polychemotherapy. Initial case reports and various study approaches appear to 
indicate that treatment of GIST with Imatinib is a highly promising therapeutic 
option in this entity. Follow-up studies with FDG-PET have shown an appreciable 
decrease in uptake by tumor tissue, in some cases within only a few days, which 
may well indicate an inhibition of intratumoral metabolism and growth. Most 
patients with metastatic GIST achieve durable responses with imatinib, and the 
disappearance of cancer-related symptoms is often rapid.
CONCLUSION: Imatinib is the first effective systemic therapy for advanced GIST.