DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed melanoma

  • Metastatic or unresectable disease

• The following melanoma types are allowed:

  • Cutaneous
  • Mucosal
  • Ocular
  • Unknown primary
• Evidence of residual, recurrent, or metastatic disease by radiographic examination

• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan

  • Tumor lesions located within a previously irradiated volume that are the only site of measurable disease must have clear evidence of progression
• No known brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy

• At least 3 months

Hematopoietic

• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal

Renal

• Creatinine normal OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance
• No history of allergic reaction attributed to compounds of similar chemical or biological composition to suberoylanilide hydroxamic acid
• No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Prior adjuvant interferon for stage II or stage III disease allowed
• Prior vaccine therapy as adjuvant therapy or for metastatic disease allowed
• No more than 1 prior cytokine and/or chemotherapy regimen for metastatic disease
• No concurrent prophylactic hematopoietic colony-stimulating factors except erythropoietin

Chemotherapy

• See Biologic therapy
• More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy

• No concurrent steroids except topical or inhaled steroids

Radiotherapy

• See Disease Characteristics
• More than 4 weeks since prior radiotherapy and recovered

Surgery

• Not specified

Other

• At least 2 weeks since prior valproic acid
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational agents
• No other concurrent anticancer agents or therapies