Melphalan, Arsenic Trioxide, and Ascorbic Acid in Treating Patients With Relapsed or Refractory Multiple Myeloma

DISEASE CHARACTERISTICS:

* Diagnosis of multiple myeloma meeting at least 1 of the following criteria:
* Relapsed disease after a response to standard first-line chemotherapy (e.g., vincristine, doxorubicin, and dexamethasone \[VAD\] OR melphalan and prednisone) or first-line high-dose chemotherapy
* Refractory disease (failed to achieve at least stable disease) to most recent chemotherapy with or without systemic corticosteroids
* Measurable disease, defined as a monoclonal immunoglobulin spike on serum electrophoresis of ≥ 1 g/dL AND/OR urine monoclonal immunoglobulin spike of ≥ 200 mg/24 hours
* No non-secretory myeloma
* No plasma cell leukemia

PATIENT CHARACTERISTICS:

Age

* 18 and over

Performance status

* Karnofsky 60-100%

Life expectancy

* More than 3 months

Hematopoietic

* Platelet count ≥ 50,000/mm\^3 (30,000/mm\^3 if bone marrow is extensively infiltrated)
* Hemoglobin ≥ 8.0 g/dL
* Absolute neutrophil count ≥ 1,000/mm\^3
* Pancytopenia secondary to multiple myeloma or hypersplenism allowed

Hepatic

* AST and ALT ≤ 3 times upper limit of normal (ULN)
* Bilirubin ≤ 2 times ULN (unless clearly related to disease)
* No known active hepatitis B or C infection

Renal

* Calcium \< 14 mg/dL

Cardiovascular

* No evidence of acute ischemia or new conduction system abnormality by electrocardiogram
* No myocardial infarction within the past 6 months
* No New York Heart Association class III or IV heart failure
* No poorly controlled hypertension
* No prolonged corrected QT interval (\> 460 ms) with potassium \> 4 mmol/L and magnesium ≥ 1.8 mmol/L

Other

* No active infection
* No POEMS syndrome (plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes)
* No diabetes mellitus
* No other serious medical or psychiatric illness that would preclude study participation
* No known allergic reaction attributable to compounds of similar chemical or biological composition to study drugs
* No history of grand mal seizures
* HIV negative
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

* More than 4 weeks since prior immunotherapy or antibody therapy

Chemotherapy

* See Disease Characteristics
* More than 3 weeks since prior chemotherapy (6 weeks for nitrosoureas)

Endocrine therapy

* See Disease Characteristics
* No other concurrent corticosteroids

Radiotherapy

* More than 4 weeks since prior radiotherapy

Surgery

* More than 4 weeks since prior major surgery

Other

* No other concurrent investigational agents