Arsenic Trioxide and Dexamethasone in Treating Patients With Recurrent or Refractory Stage II or Stage III Multiple Myeloma

RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Combining more than one drug may kill more cancer cells.

PURPOSE: Phase II trial to study the effectiveness of combining arsenic trioxide and dexamethasone in treating patients who have recurrent or refractory stage II or stage III multiple myeloma.

OBJECTIVES:

* Determine the response rate of patients with recurrent or refractory stage II or III multiple myeloma treated with arsenic trioxide and dexamethasone.
* Determine the rates of overall and relapse-free survival in patients treated with this regimen.
* Determine the safety profile of this treatment regimen in these patients.

OUTLINE: Patients receive arsenic trioxide IV daily for 5 days during the first week only and then 2 days a week thereafter. Patients also receive IV or oral dexamethasone on days 1-4 every 4 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. Disease assessments are conducted every 4 weeks. Patients achieving complete response (CR) receive 2 additional courses of therapy after initial determination of CR.

Final assessments are conducted 4 weeks after the last study treatment and then annually thereafter.

PROJECTED ACCRUAL: A total of 55 patients will be accrued for this study.

Eligibility Criteria:
DISEASE CHARACTERISTICS:

* Diagnosis of stage II or III multiple myeloma
* Refractory myeloma defined as progressive disease (more than 25% increase in M protein or in radiographic findings of nonsecretory myeloma) despite up to 3 courses of prior cytotoxic chemotherapy

  * No more than 3 prior cytotoxic regimens
  * No more than 1 prior high-dose cytotoxic regimen with stem cell transplantation
* History of disease progression after prior steroid antimyeloma therapy
* No smoldering myeloma
* Measurable disease based on presence of serum and urine M protein and/or measurable plasmacytoma

PATIENT CHARACTERISTICS:

Age:

* Over 18

Performance status:

* Karnofsky 70-100%

Life expectancy:

* At least 3 months

Hematopoietic:

* Absolute granulocyte count greater than 1,200/mm\^3\*
* Platelet count greater than 75,000/mm\^3\*
* Hemoglobin greater than 10 g/dL\* NOTE: \*Unless due to multiple myeloma

Hepatic:

* Bilirubin no greater than 2 times upper limit of normal (ULN)
* SGOT and SGPT no greater than 2 times ULN

Renal:

* Creatinine no greater than 1.5 times ULN

Cardiovascular:

* Absolute QT interval less than 460 msec in the presence of normal potassium and magnesium levels
* No significant underlying cardiac dysfunction
* No conduction defects
* No unstable angina
* No congestive heart failure
* No New York Heart Association class II-IV cardiac disease
* No myocardial infarction within the past 6 months

Other:

* No preexisting grade 2 or greater neurotoxicity/neuropathy
* No other malignancy within the past 5 years except curatively treated carcinoma in situ of the cervix or nonmelanoma skin cancer
* No uncontrolled diabetes mellitus
* No active serious infection uncontrolled by antibiotics
* No history of grand mal seizures (other than infantile febrile seizures)
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* See Disease Characteristics
* See Chemotherapy
* At least 28 days since prior biologic therapy

Chemotherapy:

* See Disease Characteristics
* At least 28 days since prior cytotoxic chemotherapy, including high-dose cytotoxic regimen with stem cell transplantation
* No other concurrent cytotoxic chemotherapy

Endocrine therapy:

* See Disease Characteristics

Radiotherapy:

* At least 28 days since prior radiotherapy except for focal radiation for symptom control

Surgery:

* Not specified