DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed solid tumors
• Measurable or evaluable disease

PATIENT CHARACTERISTICS:

Inclusion criteria:

• ECOG performance status 0-1
• Absolute neutrophil count ≥ 1.5 x 10^9/L
• Platelet count ≥ 100 x 10^9/L
• Hemoglobin ≥ 9 g/dL (no red blood cell transfusions allowed)
• Serum bilirubin ≤ 1.5 times upper limit of normal (ULN)
• PTT ≤ 1.5 times normal
• Serum creatinine ≤ 1.5 times ULN
• ALT or AST ≤ 2 times ULN (≤ 5 times ULN if liver metastases are present)
• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 30 days after completion of study therapy
• Able to read, understand, and provide written informed consent

Exclusion criteria:

• Evidence of a significant medical disorder or laboratory finding that, in the opinion of the investigator, compromises the patient's safety during study participation, including any of the following:

  • Uncontrolled infection or infection requiring a concomitant parenteral antibiotic
  • Uncontrolled diabetes
  • Congestive heart failure
  • Myocardial infarction within the past 6 months
  • Chronic renal disease
  • Coagulopathy (excluding prophylactic anticoagulation)
• Known HIV positivity
• Hepatitis B sAg-positive or known to be hepatitis C-positive with abnormal liver function tests

PRIOR CONCURRENT THERAPY:

• No more than 3 prior myelosuppressive chemotherapy regimens

  • Patients who have received more than 3 prior myelosuppressive regimens may be eligible, if considered to have adequate marrow, based on prior exposure to 1 of the following regimens:

    • Minimally myelosuppressive regimens
    • Limited courses of myelosuppressive regimens
• More than 4 weeks since prior and no other concurrent licensed or investigational anticancer treatment (6 weeks for nitrosoureas or mitomycin C)
• More than 24 hours since any prior radiotherapy and no likelihood of toxicity from this therapy
• More than 4 weeks since major surgery
• No prior radiotherapy to > 20% of bone marrow
• No prior high-dose chemotherapy (including either myeloablative or non-myeloablative transplantations)
• Prior and concurrent androgen deprivation therapy allowed
• Concurrent systemic steroids allowed, provided the patient has been on a stable dose for at least 2 weeks prior to first dose of PR-104
• No concurrent irradiation therapy (palliative or therapeutic), unless given in the absence of tumor progression