Allogeneic transplantation in multiple myeloma – How, when or at all?

Abstract

Allogeneic transplantation (allo) of patients with multiple myeloma is a controversial treatment due to high transplant related mortality (TRM) with myeloablative conditioning before the transplant. However, using reduced intensity conditioning (RIC) and previous autologous transplantation (auto) has dramatically reduced TRM. This, in combination with a lower relapse/progression rate, has in two out of six prospective studies resulted in prolongation of both progression free survival (PFS) and overall survival (OS) as compared to auto. No prospective study has proven auto – single or tandem – to be better than the auto/RICallo modality. The rapid development of relatively effective drugs in multiple myeloma has made most centers reluctant to use upfront RICallo. Considering the initial TRM of 12–16% with this treatment, it is now mainly used after progression-relapse following auto. New studies including more effective GVHD prevention and combination of allo with new drugs in the conditioning and as maintenance therapy are ongoing or in planning. Until clear advantageous results have been shown it seems reasonable to use the auto/RICallo procedure mainly in relapsed patients or upfront in patients with poor prognostic parameters such as del17p, del8p or gain 1q. The prospects for long-term survival or perhaps cure for a fraction of patients seem highest following some kind of allo.