Second allogeneic transplants for multiple myeloma: a report from the EBMT Chronic Malignancies Working Party

Abstract

The EBMT Chronic Malignancies Working Party performed a retrospective analysis of 215 patients who underwent a second allo-HCT for myeloma between 1994 and 2017, 159 for relapse and 56 for graft failure. In the relapse group, overall survival (OS) was 38% (30-46%) at 2 years and 25% (17-32%) at 5 years. Patients who had a HLA-identical sibling (HLAid-Sib) donor for their first and second transplants had superior OS (5 year OS: HLAid-Sib/HLAid-Sib: 35% (24-46%); Others 9% (0-17%), p < 0.001). There was a significantly higher incidence of acute grade II-IV GvHD in those patients who had also developed GvHD following their initial HLA-identical sibling allo-HCT (HLAid-Sib/HLAid-Sib: 50% (33-67%); Other 22% (8-36%), p = 0.03). More as opposed to fewer than 2 years between transplants was associated with superior 5-yr OS (31% (21-40%) vs. 10% (1-20%), P = 0.005). On multivariate analysis, consecutive HLA-identical sibling donor transplants conferred a significant OS advantage (0.4 (0.24-0.67), p < 0.001). In the graft failure group, OS was 41% at 2 years. In summary, a second allo-HCT using a HLA-identical sibling donor, if available, provides the best transplant outcomes for relapsed myeloma in this setting.

Fig. 1. Overall and Progression-Free Survival following a second allogeneic transplant for relapsed myeloma and factors affecting these outcomes.

a Overall survival of patients who underwent a second allo-HCT for relapsed myeloma. b Overall survival of patients who had two consecutive HLA-identical sibling donor transplants (HLA-HLA) versus other donor types. c Overall survival of patients who underwent a second allo-HCT for relapsed myeloma based on time between first and second allo-HCT (2-year cut-off). d Progression-free survival of patients who underwent a second allo-HCT for relapsed myeloma. e Progression-free survival of patients who had two consecutive HLA-identical sibling donor transplants (HLA-HLA) versus other donor types. f Progression-free survival of patients who underwent a second allo-HCT for relapsed myeloma based on time between first and second allo-HCT (2-year cut-off).

Fig. 2. Relapse incidence and NRM rates following a second allogeneic transplant for relapsed myeloma and factors affecting these outcomes.

a Cumulative incidence of relapse (solid line) and non-relapse mortality (dashed line) over 5 years in patients whose second allo-HCT was for relapsed myeloma. b Cumulative incidence of relapse (solid line) and non-relapse mortality (dashed line) over 5 years based on the type of stem cell donor (HLA-HLA) in patients whose second allo-HCT was for relapsed myeloma. c Cumulative incidence of relapse (solid line) and non-relapse mortality (dashed line) over 5 years based on Disease Stage (low or advanced) in patients whose second allo-HCT was for relapsed myeloma. d Cumulative incidence of relapse (solid line) and non-relapse mortality (dashed line) over 5 years based on age of transplant recipient in patients whose second allo-HCT was for relapsed myeloma.

Fig. 3. Overall and Progression-Free Survival in patients with myeloma following a second allogeneic transplant for graft failure and factors affecting these outcomes.

a Two-year overall survival and progression-free survival of MM patients who underwent a second allo-HCT for graft failure. b Cumulative incidence of relapse (solid line) and non-relapse mortality (dashed line) over 2 years in MM patients whose second allo-HCT was for graft failure. c Two-year cumulative incidence of relapse based on disease stage (low or advanced) in MM patients whose second allo-HCT was for graft failure. d Two-Year cumulative incidence of non-relapse mortality based on disease stage (low or advanced) in MM patients whose second allo-HCT was for graft failure.