Temozolomide Plus PEG-Interferon Alfa-2B in Treating Patients With Advanced Solid Tumors

DISEASE CHARACTERISTICS:

* Histologically confirmed advanced solid tumor that is refractory to standard therapy OR
* Histologically confirmed chemotherapy-naive advanced cancer for which no curative therapy or higher priority palliative chemotherapy exists
* Brain metastasis allowed
* No bone marrow involvement of tumor

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* ECOG 0-2

Life expectancy:

* Not specified

Hematopoietic:

* Absolute neutrophil count greater than 1,500/mm\^3 AND/OR
* Platelet count greater than 100,000/mm\^3

Hepatic:

* ALT or AST less than 3 times upper limit of normal (ULN) (5 times ULN if liver metastases present)
* No autoimmune hepatitis

Renal:

* Creatinine less than 2.5 times ULN

Cardiovascular:

* No severe coronary artery disease
* No congestive heart failure

Pulmonary:

* No severe chronic obstructive pulmonary disease

Gastrointestinal:

* No frequent vomiting
* No medical condition that would interfere with oral medication intake (e.g., partial bowel obstruction, partial intestinal bypass, or external biliary diversion)

Other:

* No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
* No known or suspected hypersensitivity to imidazotetrazin, interferon alfa, or any excipient or vehicle included in the formulation or delivery system of study drug
* No history of autoimmune disease
* No preexisting severe psychiatric condition or history of severe psychiatric disorder (including suicidal ideation or attempt)
* No life-threatening condition or severe preexisting condition
* No uncontrolled thyroid abnormalities
* No nonmalignant systemic disease
* No active uncontrolled infection
* HIV negative
* No AIDS-related illness
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* At least 3 weeks since prior biologic agents (e.g., bi-specific antibodies, interleukin-2, or interferon) and recovered (excluding alopecia)
* No prior allogeneic, syngeneic, or autologous bone marrow or stem cell transplantation
* No other concurrent biologic therapy
* No concurrent colony stimulating factors or epoetin alfa for the prevention of myelotoxicity

Chemotherapy:

* See Disease Characteristics
* At least 4 weeks since prior chemotherapy (more than 6 weeks for nitrosoureas, melphalan, or mitomycin) and recovered (excluding alopecia)
* No prior high-dose chemotherapy and stem cell transplantation
* No more than 3 prior chemotherapy regimens
* No other concurrent chemotherapy

Endocrine therapy:

* Not specified

Radiotherapy:

* At least 6 weeks since prior wide-field radiotherapy to at least 25% of bone marrow (e.g., pelvic radiotherapy)
* More than 6 weeks since prior strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium
* Recovered from prior radiotherapy (excluding alopecia)
* No concurrent radiotherapy

Surgery:

* At least 4 weeks since prior major surgery
* At least 1 week since prior minor surgery

Other:

* At least 4 weeks since prior investigational therapy