Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed multiple myeloma

- Advanced disease

- Must be refractory to ≥ 2 different methods of standard treatment

- Measurable disease, defined as serum paraprotein ≥ 1g/L or urine light chain ≥ 200
mg/24 hours

- No brain involvement or leptomeningeal disease

- No spinal cord compression unless the following criteria are met:

- Patient has undergone prior surgery or radiotherapy

- Neurological findings are ≤ grade 1

- Patient is off steroids for spinal cord edema or is on a stable regimen of ≤ 10
mg/day of prednisone or equivalent

PATIENT CHARACTERISTICS:

- ECOG performance status (PS) 0-2 (ECOG PS 3 allowed if related to skeletal lesions)

- Life expectancy ≥ 12 weeks

- Absolute granulocyte count ≥ 1,000/mm^3*

- Platelet count ≥ 50,000/mm^3*

- Hemoglobin ≥ 8.0 g/dL* (no transfusion within the past 7 days)

- AST and ALT ≤ 2.5 times upper limit of normal (ULN)

- Bilirubin ≤ 2 times ULN

- Creatinine clearance ≥ 30 mL/min

- LVEF ≥ 40%

- QTc < 450 msec

- No evidence of dysrhythmias on EKG

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No congestive heart failure

- No angina pectoris

- No cardiac arrhythmia

- No uncontrolled hypertension, defined as systolic blood pressure (BP) > 180 mm Hg
and/or diastolic BP > 105 mm Hg

- No myocardial infarction within the past year

- No active infection

- No HIV, hepatitis B, or hepatitis C infection

- No history of psychosis

- No history of subcortical brain damage

- No hypersensitivity to fluphenazine hydrochloride or other phenothiazines

- No history of seizures or extrapyramidal symptoms

- No other serious illness or medical condition

- No other malignancy within the past 5 years except adequately treated nonmelanoma
skin cancer or carcinoma in situ of the cervix NOTE: *Patients with values outside of
this range due to infiltration by myeloma may be allowed at the discretion of the
investigator

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- Recovered from prior therapy

- At least 21 days since prior chemotherapy, immunotherapy, or radiotherapy

- At least 21 days since prior and no concurrent systemic steroids

- Patients who have been taking chronically administered steroids for ≥ 1 month at
a dose ≤ 10 mg/day of prednisone or equivalent are eligible

- At least 28 days since prior investigational agents

- At least 6 weeks since prior selective serotonin reuptake inhibitors (SSRIs) (a
wash-out period equivalent to 5 times the terminal elimination half-life is required
for tricyclic antidepressants or norepinephrine reuptake inhibitors)

- No concurrent SSRIs, tricyclic antidepressants, or norepinephrine reuptake inhibitors

- No concurrent dialysis therapy

- No concurrent hematopoietic growth factors except epoetin alfa

- Treatment with hematopoietic growth factors may be started during study if
patient develops or has progressive cytopenia

- No concurrent anticholinergics or other antipsychotics

- No concurrent antiseizure drugs except Neurontin for treatment of neuropathy