Arsenic trioxide in patients with refractory multiple myeloma: a prospective, phase II, single-arm study

Multiple myeloma [MM] characterized by proliferation of plasma cells in bone marrow and production of monoclonal immunoglobulin's. Recently, arsenic trioxide [ATO], has been considered for treatment refractory MM. We assessed the safety and efficacy of ATO for patients with refractory MM. A phase 2, study of arsenic trioxide was conducted in 12 MM patients, whose refractory to two standard therapy. Patients received arsenic trioxide, 0.25 mg/kg/d for 5 d/week during the first 2 consecutive weeks of each 4-week cycle with 2 week rest. Patients who completed one 4-week cycle were evaluated for response to treatment. Twelve patients with refractory multiple myeloma received ATO. Disease assessment was based the amount of serum proteins electrophoresis. Of the10 patients; stable disease was observed in four patients[33%], progression disease in five patients [41.6%], complete response in one patient [3.8%] and the remaining two patients could not be assessed for a response [because of increased liver enzymes after the first week]. Some adverse events: increase liver enzymes and serum creatinine, neutropenia, pruritus, nausea, vomiting, lower extremities edema, noninfectious diarrhea was observed. These results indicate that ATO is active and well tolerated as a single-agent salvage therapy, even in patients with late-stage, refractory MM