Treatment with Revlimid (lenalidomide), Velcade (bortezomib), and dexamethasone (RVD), in addition to a stem cell transplant, improved progression-free survival among multiple myeloma patients compared to RVD alone.
But a recent Phase 3 trial (NCT01191060) demonstrated that this benefit did not translate to better overall survival at four years.
The study, “Lenalidomide, Bortezomib, and Dexamethasone with Transplantation for Myeloma,” was published in the New England Journal of Medicine.
Some studies have suggested that combination treatment with RVD may be equally as effective as high-dose chemotherapy and stem cell transplants for patients with multiple myeloma. To investigate this, researchers at the University Institute Cancer Toulouse Oncopole designed a clinical trial to examine the issue.
The study recruited 700 patients with multiple myeloma, of which half received eight cycles of RVD only. The other half of the group was pretreated with three RVD cycles before receiving high-dose Alkeran (melphalan) and a stem cell transplant. In addition, both groups received maintenance treatment with Revlimid for a year.
Half of the patients who received RVD combination treatment and a stem cell transplant had not progressed at 50 months, while the median progression-free survival for the RVD alone group was only 36 months.
More patients had a complete response in the transplant group (59%) and 79% in this group did not have minimal residual disease. In those treated only with RVD, 48% had a complete response and 65% had no minimal residual disease.
Nevertheless, at four years, 81% in the transplant group, and 82% in the RVD group were still alive, suggesting that the delay in progression did not translate to a better overall survival.
A loss of neutrophil immune cells and stomach disease of Grade 3 and 4 severity were more common in the transplant group, as were infections. More severe issues, including treatment-related deaths and cancers caused by the treatment, were equally common. Also, the number of patients in the two groups who stopped the treatment early because of side effects were similar.
Researchers argued that the similar rates of overall survival in the two groups may be related to the use of RVD. Since RVD therapy has been shown in earlier studies to be effective in treating relapses, the team believes this might have improved survival statistics. But they also concur that the use of transplants as salvage therapy in relapsed patients may have influenced survival.