OBJECTIVES:
* Determine the safety and side effects of arsenic trioxide administered in combination with thalidomide, dexamethasone, and ascorbic acid in patients with relapsed or refractory multiple myeloma.
* Determine, preliminarily, the anticancer effects of this regimen in these patients.
* Determine the duration of anticancer effects in patients treated with this regimen.
* Determine the effect of this regimen on bone and immune function in these patients.
OUTLINE: Patients receive arsenic trioxide IV continuously and oral ascorbic acid once daily on days 1-5 in week 1 and twice weekly in weeks 2-12 and oral thalidomide once daily in weeks 1-14. Treatment with arsenic trioxide, ascorbic acid, and thalidomide repeats every 14 weeks for up to 4 courses in the absence of disease progression or unacceptable toxicity. Patients also receive oral dexamethasone once daily on days 1-4. Treatment with dexamethasone repeats every 28 days.
PROJECTED ACCRUAL: A total of 30 patients will be accrued for this study.