Interleukin-12 and Trastuzumab in Treating Patients With Cancer That Has High Levels of HER2/Neu

Inclusion Criteria:

* Patients must have a histologically proven Her2 overexpressing malignancy as determined by any standardized assay currently in clinical use
* Patients must have measurable or evaluable disease
* The patient must have failed standard curative and/or palliative therapies for their disease
* Life expectancy of at least 6 months
* No concurrent malignancy other than non-melanoma skin carcinoma
* Adequate hematopoietic, cardiac, renal, and hepatic function
* Calculated creatinine clearance will be used to assess renal function
* Karnofsky Performance Status index \>= 70%
* Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control) prior to study entry and for the duration of study participation; a woman of childbearing potential is defined as a female who is biologically capable of becoming pregnant
* Normal cardiac ejection fraction by echocardiogram or MUGA (i.e., greater than OSU lower limit of normal)
* Written signed informed consent; the patient must be aware that his/her disease is neoplastic in nature and willingly consent after being informed of the procedure to be followed, the experimental nature of the therapy, alternatives, potential benefits, side-effects, risks, and discomforts

Exclusion Criteria:

* History of significant peripheral neuropathy or significant central nervous system disease
* Brain or central nervous system metastasis at entry
* Active or unstable cardiovascular disease or cardiac disease requiring drug or device intervention; history of coronary artery disease or congestive heart failure
* Pregnant or nursing women
* Surgery, radiotherapy, chemotherapy, or hormonal therapy during the three weeks prior to the initiation of therapy
* Exposure to any investigational drug within three weeks prior to the start of dosing
* Concurrent use of systemic corticosteroids
* Known seropositive for hepatitis B surface antigen
* Known seropositive for HIV antibody
* Serious concurrent infection requiring intravenous antibiotic therapy
* Clinically significant autoimmune disease (e.g., rheumatoid arthritis)
* Clinically significant gastrointestinal bleeding or uncontrolled peptic ulcer disease
* History of inflammatory bowel disease
* Any other major illness which, in the investigator's judgment, will substantially increase the risk associated with the patient's participation in this study
* Prior therapy with Herceptin