Azacitidine and Recombinant Interferon Alfa-2b in Treating Patients With Stage III or Stage IV Melanoma or Stage IV Kidney Cancer That Cannot Be Removed By Surgery

Inclusion Criteria: * Histologically confirmed diagnosis of 1 of the following: * Melanoma * Unresectable stage III disease * Stage IV disease * Renal cell carcinoma * Unresectable and/or stage IV disease * Measurable disease * No untreated brain metastases or leptomeningeal disease * Patients with previously treated brain metastases are eligible provided they have no evidence of progression for ≥ 4 weeks following treatment and do not require steroids * Performance status - ECOG 0-2 * Performance status - Karnofsky 60-100% * More than 3 months * WBC ≥ 3,000/mm\^3 * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 9.0 g/dL (may be transfused to this level) * PT or PTT \< 1.5 times upper limit of normal (ULN) * Bilirubin ≤ 2.0 mg/mL * AST and ALT ≤ 3 times ULN (5 times ULN for patients with liver metastases) * Albumin ≥ 3.0 g/dL * Creatinine ≤ 1.7 mg/dL * Creatinine clearance ≥ 50 mL/min * No symptomatic congestive heart failure * No unstable angina pectoris * No ventricular cardiac arrhythmia * No myocardial infarction within the past 3 months * No dyspnea at rest * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No active gastrointestinal bleeding or ulcer disease * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No other uncontrolled illness * No history of allergic reaction attributed to compounds of similar chemical or biologic composition to study agents * At least 2 weeks since prior immunotherapy * Prior adjuvant interferon alfa for metastatic disease or in the adjuvant setting allowed * At least 3 weeks since prior cytotoxic agents (6 weeks for nitrosoureas or mitomycin) * See Disease Characteristics * At least 2 weeks since prior hormonal therapy * At least 1 week since prior and no concurrent steroids * At least 3 weeks since prior radiotherapy * At least 2 weeks since prior minor surgery * At least 3 weeks since prior major surgery * Recovered from all prior therapy * No concurrent combination antiretroviral therapy for HIV-positive patients * No other concurrent investigational agents * No other concurrent anticancer therapy