Phase III study of intermittent 5-drug regimen (VBCMP) versus intermittent 3-drug regimen (VMP) versus intermittent melphalan and prednisone (MP) in myelomatosis.

A prospective randomized trial in 96 patients with previously untreated myelomatosis was performed comparing 3 regimens of chemotherapy: (i) Intermittent vincristine, BCNU, cyclophosphamide, melphalan, and prednisone (VBCMP) to (ii) intermittent vincristine, melphalan and prednisone (VMP) to (iii) intermittent melphalan and prednisone (MP). Induction response rates and survival were similar in all 3 regimens. An improvement in relapse-free survival was observed by adding vincristine to MP, but this did not achieve statistical difference (p = 0.10). Patients given VBCMP fared slightly worse than those given VMP. The haematologic toxicity was similar in all 3 regimens, but the tolerability of VBCMP was lower. Although showing no statistical differences between the 3 treatment regimens, the results support the view that a combination of MP 'standard' induction therapy in MM with frequently administered vincristine has a trend towards postponing treatment failure due to development of resistance to melphalan.