This phase II trial is studying how well giving sorafenib together with docetaxel and cisplatin works in treating patients with metastatic or locally advanced gastric or gastroesophageal junction cancer that cannot be removed by surgery. Sorafenib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the tumor. Drugs used in chemotherapy, such as docetaxel and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving sorafenib together with docetaxel and cisplatin may kill more tumor cells.

PRIMARY OBJECTIVES:

I. To evaluate the response rate (complete response and partial response) of the combination of BAY 43-9006 with docetaxel and cisplatin or oxaliplatin in patients with gastric and GEJ adenocarcinoma.

II. To evaluate the progression-free survival (PFS) and overall survival.

III. To evaluate the toxicities of BAY 43-9006 in patients with advanced and metastatic gastric or GEJ adenocarcinoma combined with docetaxel/cisplatin or docetaxel/oxaliplatin.

IV. To evaluate Raf status in the tumor and to correlate response and PFS to the presence or absence of an activating mutation in B-Raf.

V. To analyze the pharmacokinetic and pharmacogenetic properties of BAY 43-9006 including angiogenesis, monooxygenases, polymorphisms and multidrug-resistance (MDR). This study will be conducted via the E1Y03 mechanism.

OUTLINE: This is an open-label, multicenter study. Patients are stratified according to Siewert's tumor location (I vs II vs III) and extent of disease (locally advanced unresectable vs distant metastases).

Patients receive oral BAY 43-9006 twice daily on days 1-21. Patients also receive docetaxel intravenously (IV) over 1 hour and cisplatin IV over 1-2 hours on day 1. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed periodically for 3 years.

An addition of an arm containing oxaliplatin was proposed after meeting the accrual goal but did not move forward and the study was closed to accrual in July, 2007 with a final accrual of 44 patients.

Inclusion Criteria:

• Patients must have measurable, histologically confirmed, advanced unresectable or metastatic gastric or GEJ adenocarcinoma; imaging studies must be conducted within 4 weeks of study entry

• For patients with GEJ adenocarcinoma, the tumor location should be specified using the Siewert classification used in other NCI-sponsored Phase II studies in these disease sites

• Patients must have an ECOG performance status of 0-1

• Patients may have had adjuvant chemotherapy or chemoradiation therapy, with or without 5-Fluorouracil if the treatment was performed more than 6 months before any evidence of recurrent or metastatic disease

• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately

• Must have the following baseline laboratory values obtained within 2 weeks of registration:

  • Absolute Granulocyte Count >= 1,500/mm^3
  • Platelet Count >= 100,000/mm^3
  • White Blood Count >= 3,000/mm^3
  • Serum Creatinine <= 1.5 mg/dl
  • Total Bilirubin <= 2.0 mg/dl
  • Aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/alkaline phosphatase (Alk phos) <= 2.5 x upper limit of normal

• Patients must be able to take oral medication without crushing, dissolving or chewing tablets

Exclusion Criteria:

• Prior radiotherapy, chemotherapy or investigational therapies, particularly inhibitors of tyrosine Kinases, signal transduction or angiogenesis in the treatment for their recurrent and/or metastatic gastric or GEJ adenocarcinoma

• Receiving any other investigational agents

• Being pregnant or breast-feeding; all females of childbearing potential must have a blood or urine test within 2 weeks prior to registration to rule out pregnancy

• HIV-positive patients receiving combination antiretroviral therapy are excluded from the study because of possible pharmacokinetic interactions with BAY 43-9006

• Brain metastases

• History of allergic reactions attributed to compounds of similar chemical or biologic composition to BAY 43-9006

• Acute active infection with significant clinical intervention per physician's discretion

• Previous or concurrent malignancies are not allowed, except:

  • Non-melanoma skin cancer and in situ cervical cancer
  • Treated cancer from which the patient has been continuously disease-free for more than five years

• Other uncontrolled intercurrent illnesses including, but not limited to: uncontrolled hypertension, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia or psychiatric illness/addictive disorders that would limit compliance with study requirements

• Evidence of bleeding diathesis

• Concurrent cytochrome P450 enzyme-inducing anti-epileptic drugs:

  • Phenytoin
  • Carbamazepine
  • Phenobarbital
  • Rifampin
  • St. John's Wort