Single, sequential, and multiple alkylating agent therapy for multiple myeloma: a CALGB Study.

Four intravenous (IV) alkylating agent regimens were tested in 615 previously untreated patients with multiple myeloma. Patients were randomized to receive melphalan, cyclophosphamide, and carmustine in combination (MCBP), sequentially (Seq-MCBP), or in combination with doxorubicin (MCBPA). The fourth group received IV melphalan (MP) as the only alkylating agent. All groups received a tapering dose of prednisone. Toxicity was similar for all regimens although the nadir of cytopenia was reached more quickly for the regime including melphalan only. Response as measured by reduction in myeloma protein or other parameters were similar for the four treatments. Survival was significantly poorer for the group receiving the alkylating agents in sequence. The survival of high tumor cell load patients who were azotemic was better in the groups treated with IV MP or with the combination of IV MCBP. In view of the simplicity and probable cost savings attached to single-agent treatment, a melphalan/prednisone regimen should be considered as initial therapy for all patients with myeloma.