EBMT 2019 | Tandem autologous-reduced-intensity allogeneic SCT for R/R HL

On Tuesday 26 March 2019, Oral Session 4 (OS4) took place at the 45^th Annual Meeting of the European Society of Blood and Marrow Transplantation (EBMT), Frankfurt, DE. During that session, Abstract OS4-1 was presented by Leyre Bento from Son Espases University Hospital, Palma de Mallorca, SP.

This presentation provided results of a retrospective study from the Lymphoma Working Party (LWP) and EBMT, regarding the efficacy and safety of tandem autologous-reduced intensity allogeneic stem cell transplantation (auto-RIC allo-SCT) in high-risk relapsed or refractory (R/R) Hodgkin lymphoma (HL). The primary endpoint of the study was progression-free survival (PFS) after auto-RIC-allo-SCT. Secondary endpoints included overall survival (OS), cumulative incidence of non-relapse mortality (NRM), incidence of relapse (IR) and graft-versus-host disease (GvHD).

Study design & baseline characteristics

• N = 130 patients with R/R HL from the EBMT registry treated with auto-RIC
• Median age at auto-SCT (range): 30 (18−65) years
• Males: 58%
• Median time between diagnosis and auto-SCT (range): 16 (2−174) months
• Median number of prior lines before auto-SCT (range): 2 (2−4)
  • Patients with ≥ 3 prior lines: 33% (n = 43)
• Patient disease status at auto-SCT:
  • Complete response (CR): 32% (n = 41)
  • Partial response (PR): 27% (n = 35)
  • Active disease: 41% (n = 54)
• RIC-SCT characteristics:
  • Donor type:
    • Identical sibling: 40%
    • Unrelated: 39%
    • Haplo: 21%
  • Conditioning:
    • Fludarabine (Flu) ± cyclophosphamide (Cy) ± busulfan: 38%
    • Flu + melphalan: 8%
    • Flu ± busulfan + thymoglobulin: 32%
    • Other: 21%
  • GvHD prophylaxis:
    • Cyclosporine & methotrexate: 36%
    • Cyclosporine & micofenolate mofetil: 16%
    • Post-transplant Cy: 17%
    • Other: 31%

Key results

• Three-year cumulative IR: 34% (95% CI, 25−43%)
• Three-year NRM: 13% (95% CI, 8−20%)
• Three-year PFS: 53% (95% CI, 44−63%)
• Three-year OS: 72% (95% CI, 64−80%)
• After a median follow-up of 44 months (range, 6−130):
  • Patients who relapsed: 33%
  • Patients who died: 34%
    • Death due to SCT-related causes: 53%
    • Death due to disease: 35%
    • Other causes: 12%
• Cumulative incidence of Grade III−IV acute GvHD at Day 100 after RIC-SCT: 10% (5−16%)
• Three-year cumulative incidence of chronic GvHD after RIC-SCT: 26% (18−36%)
• Univariate analysis revealed the following factors affecting PFS and IR:

• Three-year PFS according to time from diagnosis to auto-SCT:
  • ≤ 12 months: 49%
  • > 12 months: 54%
• Three-year OS according to time from diagnosis to auto-SCT:
  • ≤ 12 months: 69%
  • > 12 months: 72%
• Three-year PFS according to number of prior lines:
  • < 3 lines: 57%
  • ≥ 3 lines: 45%
• Three-year OS according to number of prior lines:
  • < 3 lines: 77%
  • ≥ 3 lines: 62%

Conclusions

• The low NRM and cumulative RI along with the promising PFS and OS rates suggest that auto-RIC-SCT might be an effective approach in R/R NHL
• Approximately 50% of patients with a time from diagnosis to auto-SCT ≤ 12 months or ≥ 3 prior lines before auto-SCT (high-risk population) remained disease free at three years