Imatinib, Capecitabine, and Cisplatin in Treating Patients With Unresectable or Metastatic Stomach Cancer

DISEASE CHARACTERISTICS:

* Histologically confirmed gastric cancer

  * Unresectable and/or metastatic disease
* Incurable with any conventional multimodality approach by interdisciplinary assessment of the local tumor board
* Immunohistochemical documentation of c-kit (CD117) and PDGF-R overexpression by tumor if obtainable (preferably on a tumor sample taken within 6 weeks of study entry)
* At least one evaluable site of disease according to RECIST criteria
* No known brain metastasis or CNS disorder that might alter study compliance or may worsen during or following therapy

PATIENT CHARACTERISTICS:

* ECOG performance status 0-2
* WBC ≥ 3,000/μL
* ANC ≥ 2,000/μL
* Platelet count ≥ 100,000/μL
* Hemoglobin ≥ 9.0 g/dL
* Total bilirubin \< 2 times upper limit of normal (ULN)
* SGOT and SGPT \< 2.5 times ULN (5 times ULN if hepatic metastases present)
* Glomerular filtration rate ≥ 60 mL/min
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective barrier contraception during and for up to 3 months after completion of study treatment
* No known or documented hypersensitivity against fluoropyrimidines, tyrosine kinase inhibitors, cisplatin, other platinums, or their respective derivatives
* No gastrointestinal disorder that might affect the gastrointestinal absorption of capecitabine or imatinib mesylate or ability to swallow for the oral administration of capecitabine or imatinib mesylate
* At least 5 years since prior primary malignancy except if the other primary malignancy is not currently clinically significant nor requiring active intervention, or if other primary malignancy is a basal cell skin cancer or carcinoma in situ of the cervix
* No other concurrent malignant disease
* No NYHA class III-IV cardiac disease (i.e., congestive heart failure or myocardial infarction within the past 6 months)
* No severe and/or uncontrolled medical disease (i.e., uncontrolled diabetes, chronic renal disease, or active uncontrolled infection)
* No known neuropathy, impaired hearing, history of seizures, and/or psychiatric disorder that might alter study compliance or may worsen during or following therapy
* No documented dihydropyrimidine dehydrogenase deficiency
* No known chronic liver disease (i.e., chronic active hepatitis or cirrhosis)
* No known diagnosis of HIV infection or other serious uncontrolled infections
* No significant history of non-compliance to medical regimens or inability to grant reliable informed consent

PRIOR CONCURRENT THERAPY:

* No chemotherapy or investigational agents within the past 4 weeks (6 weeks for nitrosoureas or mitomycin C) unless the disease is rapidly progressing
* No prior radiotherapy to ≥ 25% of the bone marrow
* No major surgery within the past 2 weeks
* No concurrent warfarin or acetaminophen

  * Therapeutic anticoagulation using heparin or low-molecular weight heparin allowed
* No concurrent sorivudine or related substances
* No other concurrent anticancer agents, including chemotherapy and biologic agents
* No other concurrent investigational drugs