Pentamidine in Treating Patients With Relapsed or Refractory Melanoma

OBJECTIVES:

Primary

- To determine the response rate in patients with relapsed or refractory melanoma that
expresses wild-type p53 and S100B treated with pentamidine.

Secondary

- To observe the effect of this drug on the expression of S100B and p21 in tumor biopsy
samples.

- To observe the effect of this drug on S100B detectable in serum.

- To observe the time to progression in these patients.

- To assess the toxicities associated with the administration of this drug in these
patients.

OUTLINE: Patients receive pentamidine IV over 2 hours 5 days a week for 2 weeks. Courses
repeat every 4 weeks in the absence of disease progression or unacceptable toxicity.

Patients undergo tumor tissue and blood sample collection periodically for correlative
laboratory studies. Samples are assessed for p53 status and S100B, p53, and p21 expression
by immunohistochemistry, polymerase chain reaction, western blotting, luminescence assay,
and ELISA.

After completion of study treatment, patients are followed for 30 days.

DISEASE CHARACTERISTICS:

- Histologically confirmed melanoma

- Relapsed or refractory disease

- Tumor expresses wild-type p53

- Measurable S100B by immunohistochemistry

- Measurable disease, defined as at least one lesion that can be accurately measured in
at least one dimension (longest diameter to be recorded) as ≥ 20 mm by conventional
techniques or as ≥ 10 mm by spiral CT scan

- Tumor amenable to biopsy

- Must have been evaluated for potentially curative resection

- No unstable or symptomatic brain metastases (e.g., seizures, headache related to
tumor, or presence of neurologic deficits attributable to tumor)

- Patients with stable brain metastases (by CT scan or MRI) are eligible provided
they were treated with local therapy > 4 weeks ago AND do not require
maintenance steroid treatment

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- Life expectancy > 12 weeks

- WBC ≥ 3,000/mcL

- ANC ≥ 1,500/mcL

- Platelet count ≥ 80,000/mcL

- Hemoglobin ≥ 8 g/dL

- Total bilirubin ≤ 1.5 times normal

- AST and ALT ≤ 2.5 times upper limit of normal

- Creatinine ≤ 1.5 times normal or creatinine clearance ≥ 60 mL/min

- Not pregnant or nursing

- Fertile patients must use effective contraception during and for ≥ 3 months after
completion of study treatment

- Able to take oral medications on a regular basis

- No history of allergic reactions attributed to pentamidine

- Mean QTc ≤ 470 msec (with Bazett's correction) on screening ECG

- No history of familial long QT syndrome

- Proteinuria ≤ 1 on two consecutive dipsticks taken ≥ 1 week apart

- No concurrent uncontrolled illness including, but not limited to, any of the
following:

- Hypertension

- Ongoing or active infection

- Symptomatic congestive heart failure

- Unstable angina pectoris

- Renal failure

- Cardiac arrhythmia

- Psychiatric illness/social situations that would limit compliance with study
requirements

PRIOR CONCURRENT THERAPY:

- Recovered from all prior therapy

- Any number of prior chemotherapy regimens allowed

- More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin C)

- More than 4 weeks since prior radiotherapy or major surgery

- More than 30 days since prior participation in an investigational trial

- No concurrent medication that may markedly affect renal function (e.g., vancomycin,
amphotericin, zoledronic acid)

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other concurrent investigational agents