Tandem autologous vs autologous plus reduced intensity allogeneic transplantation in the upfront management of multiple myeloma: meta-analysis of trials with biological assignment.

We utilized meta-analysis to compare tandem autologous (TA) hematopoietic SCT (auto-HSCT) or single auto-HSCT followed by reduced intensity conditioning (RIC), allogeneic (AR) hematopoietic SCT in the upfront management of patients with multiple myeloma (MM). A comprehensive search strategy of published and unpublished reports utilized the following entry criteria: newly diagnosed patients, first autologous transplantation in both arms, use of an RIC regimen and assignment to TA or AR based exclusively on the availability of an HLA matched donor. Six trials were identified yielding 1192 subjects in TA and 630 in AR. Patients in AR had higher likelihoods of TRM (relative risk (RR)=3.3, 95% confidence interval (CI)=2.2-4.8) and CR (RR=1.4, 95% CI=1.1-1.8). OS was not different in the first 36 months (hazard ratio (HR)=1.15, 95% CI=0.91-1.45) or after (HR=0.74, 95% CI=0.53-1.04) 36 months from assignment. Similar findings were seen for PFS. When compared with TA in the upfront management of MM, AR is associated with higher TRM and CR without improvement in PFS or OS.