A randomized study comparing VMCP and MMPP in the treatment of multiple myeloma

To compare VMCP, a multidrug combination chemotherapy comprising vincristine (VCR), melphalan (MPH), cyclophosphamide (CPM) and prednisolone (PSL), with MMPP comprising MPH, ranimustine (MCNU), procarbazine, and PSL as induction, to elucidate the value of alternating combination chemotherapy, and to search for an appropriate maintenance therapy in multiple myeloma.

At 16 institutions in the Nagoya City area, we carried out a randomized trial of VMCP versus MMPP as the initial treatment. Patients who were refractory or resistant to the initial therapy were crossed over into the other arm (crossover trial). For patients who achieved a partial response (PR) or a minor response (MR) and in whom the paraprotein level ceased to decrease, the maintenance therapy was randomized either to an MPH/PSL combination (MP) or to alternating combination therapy (AT) with VMCP and MMPP.

In the 94 evaluable patients of the 111 enrolled, the response rate (PR rate) was 27.7% (13/47) in the VMCP arm and 44.7% (21/47) in the MMPP arm (P = 0.0859). The crossover trial resulted in a PR rate of 15.8% (3/19) for the VMCP-->MMPP crossover and 14.3% (2/14) for the MMPP-->VMCP crossover. The median survival time was 23.4 months for those initially begun in the VMCP arm and 24.9 months for those in the MMPP arm, showing a tendency for better survival during a follow-up of 2-6 years with MMPP treatment, but without statistical significance. The survival time of patients with progressive disease was significantly shorter than that of patients with PR, MR or no change (NC). However, there was no significant difference in the survival rate among those who achieved PR, MR, or NC. As to the maintenance therapy, there was no significant difference in survival between MP therapy and AT. Patients who reached a plateau phase survived significantly longer than those who did not. Except for six cases of grade 3 or 4 neurotoxicity in the VMCP arm, there was no significant difference in the hematologic or gastrointestinal toxicity between the two arms.

We conclude that VMCP is less effective for myeloma than MMPP as the induction treatment, that alternating noncrossresistant chemotherapeutic combinations do not offer an advantage in multiple myeloma, and that patients who reach a plateau phase have a significantly longer survival time.