Delayed stem cell transplantation for the management of relapsed or refractory multiple myeloma

The optimal timing of stem cell transplantation for multiple myeloma is con troversial, Late stem cell collection is undesirable because of the inabili ty to mobilize stem cells. We report on 64 recipients of stem cells collect ed within 1 year after diagnosis, none of whom had transplantation in plate au phase of their disease. Patients seen within 12 months after diagnosis r eceived four cycles of standard vincristine, doxorubicin, and dexamethasone (VAD) chemotherapy and then had stem cells mobilized. Patients were then p laced on maintenance vincristine, BCNU, melphalan, cyclophosphamide, and pr ednisone or melphalan and prednisone chemotherapy for 12 cycles. At the sig n of first progression, transplantation occurred. Fourteen patients were re fractory to VAD chemotherapy, 20 relapsed on maintenance chemotherapy, and 30 relapsed off chemotherapy. The time to platelet engraftment was not affe cted by the duration of stem cell cryopreservation or extent of chemotherap y exposure after mobilization, The complete response rate was 34%. The actu arial median survival from initial diagnosis, from transplant day 0, and po st-transplant progression-free survival was 51, 20 and 11.4 months, respect ively. The patient status at transplantation and percentage of plasma cells circulating in the blood at apheresis influenced post-transplant survival; circulating plasma cells, status at transplantation and plasma cell labeli ng index influenced progression-free survival, Response duration was shorte r in patients relapsing on chemotherapy.