Patients With Refractory, Metastatic Cancer Harboring KIT Mutation or Amplification to Investigate the Clinical Efficacy and Safety of Imatinib Therapy

Inclusion Criteria: 1. age ≥ 20 2. advanced, refractory cancer patients who failed standard of care (SOC) 3. KIT aberration: defined as mutation in exons 9, 11, 13, 17 or 18, or nanostring CNV by quantitative PCR (greater than 3 copies) or subject with specific sensitivity (Z-score\<-1) to imatinib by Avatar scan whose disease has progressed following standard therapy or that has not responded to standard therapy or for which there is no standard therapy 4. ECOG performance status of 0\~2 5. measurable or evaluable lesion per RECIST 1.1 criteria 6. adequate marrow, hepatic, renal and cardiac functions * Serum aspartate transaminase (AST) and serum alanine transaminase (ALT) ≤ 2.5 x upper limit of normal (ULN), or AST and ALT ≤ 5 x ULN if liver function abnormalities are due to underlying malignancy * Total serum bilirubin ≤ 1.5 x ULN * Absolute neutrophil count(ANC) ≥ 1,500/uL * Platelets ≥ 100,0000/uL * Hemoglobin ≥ 9.0 g/dL 7. provision of a signed written informed consent Exclusion Criteria: 1. severe co-morbid illness and/or active infections 2. pregnant or lactating women 3. history of major surgery or radiotherapy within 4 weeks 4. active CNS metastases not controllable with radiotherapy or corticosteroids (however, CNS metastases (except for leptomeningeal seeding) are allowed if controlled by gamma knife surgery or surgery or radiotherapy or steroid) 5. known history of hypersensitivity to study drugs