title: Comparative efficacy of tandem autologous versus autologous followed by allogeneic hematopoietic cell transplantation in patients with newly diagnosed multiple myeloma: a systematic review and meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Despite advances in understanding of clinical, genetic, and molecular aspects of multiple myeloma (MM) and availability of more effective therapies, MM remains incurable. The autologous-allogeneic (auto-allo) hematopoietic cell transplantation (HCT) strategy is based on combining cytoreduction from high-dose (chemo- or chemoradio)-therapy with adoptive immunotherapy. However, conflicting results have been reported when an auto-allo HCT approach is compared to tandem autologous (auto-auto) HCT. A previously published meta-analysis has been reported; however, it suffers from serious methodological flaws.
  
  
  METHODS
  A systematic search identified 152 publications, of which five studies (enrolling 1538 patients) met inclusion criteria. All studies eligible for inclusion utilized biologic randomization.
  
  
  RESULTS
  Assessing response rates by achievement of at least a very good partial response did not differ among the treatment arms [risk ratio (RR) (95% CI) = 0.97 (0.87-1.09), p = 0.66]; but complete remission was higher in the auto-allo HCT arm [RR = 1.65 (1.25-2.19), p = 0.0005]. Event-free survival did not differ between auto-allo HCT group versus auto-auto HCT group using per-protocol analysis [hazard ratio (HR) = 0.78 (0.58-1.05)), p = 0.11] or using intention-to-treat analysis [HR = 0.83 (0.60-1.15), p = 0.26]. Overall survival (OS) did not differ among these treatment arms whether analyzed on per-protocol [HR = 0.88 (0.33-2.35), p = 0.79], or by intention-to-treat [HR = 0.80 (0.48-1.32), p = 0.39] analysis. Non-relapse mortality (NRM) was significantly worse with auto-allo HCT [RR (95%CI) = 3.55 (2.17-5.80), p < 0.00001].
  
  
  CONCLUSIONS
  Despite higher complete remission rates, there is no improvement in OS with auto-allo HCT; but this approach results in higher NRM in patients with newly diagnosed MM. At present, totality of evidence suggests that an auto-allo HCT approach for patients with newly diagnosed myeloma should not be offered outside the setting of a clinical trial.
authors.affiliation: Blood and Marrow Transplantation Program, H. Lee Moffitt Cancer Center/University of South Florida College of Medicine, Tampa, FL, USA.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Kharfan-Dabaja
authors.forename: Mehdi
authors.initials: M
authors.lastname: Hamadani
authors.forename: Tea
authors.initials: T
authors.lastname: Reljic
authors.forename: Taiga
authors.initials: T
authors.lastname: Nishihori
authors.forename: William
authors.initials: W
authors.lastname: Bensinger
authors.forename: Benjamin
authors.initials: B
authors.lastname: Djulbegovic
authors.forename: Ambuj
authors.initials: A
authors.lastname: Kumar
mesh_terms: D006801:Humans; D018380:Hematopoietic Stem Cell Transplantation; D009101:Multiple Myeloma / Q000175:diagnosis / Q000628:therapy; D016032:Randomized Controlled Trials as Topic; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D016896:Treatment Outcome