Transplant outcomes in double-hit and double-expressor lymphoma

Alex Herrera of City of Hope in Duarte, California, and colleagues, performed a retrospective analysis of allogeneic stem cell transplant outcomes in patients with double-hit (DHL) or double-expressor lymphomas (DEL). This was published in the November 28 online version of Biology of Blood and Marrow Transplantation.

DHL and DEL are aggressive, B-cell lymphomas. DHL is characterized by gene rearrangement of MYC and BLC2 or BCL6. BCL2 chromosome rearrangement is more common, with a rate of 58% to 85% of DHL cases. DEL is described as co-expression of MYC and BCL2. The rearrangement or co-expression causes a rapidly progressive clinical course that is refractory to chemotherapy and leads to poor survival. Earlier work by Herrera showed that outcomes for DEL and DHL after autologous stem cell transplant led to 4-year progression-free survival (PFS) rates of only 48% and 28%, respectively. This multicenter study sought to observe outcomes following allogeneic transplant in these high-risk patients.

Patient Population

• N = 78 patients
  • DEL = 31 patients
  • DHL = 10 patients
  • Non-DHL, non-DEL = 37 patients
• Median age
  • DEL = 54 years
  • DHL = 47 years
  • Non-DHL, non-DEL = 55 years
• Prior autologous transplant
  • DEL = 55%
  • DHL = 70%
  • Non-DHL, non-DEL = 57%
• Transplant prep regimen
  • Reduced intensity = 77%
  • Myeloablative = 23%

Key Findings

• 4-year PFS: DEL = 30% (95% CI, 18%–51%) vs non-DEL = 39% (95% CI, 26%–58%), P = 0.24
• 4-year OS: DEL = 31% (95% CI, 18%–52%) vs non-DEL = 49%, (95% CI, 35%–68%), P = 0.17
• 4-year PFS DHL = 40% (95% CI, 19%–85%) vs non-DHL = 34% (95% CI, 24%–48%), P = 0.62
• 4-year OS DHL = 50% (95% CI, 27%–93%) vs non-DHL = 38% (95% CI, 27%–53%), P = 0.46
• There was no difference in PFS, OS, clinical incidence of remission, or non-relapse mortality in DEL, DHL or non-rearrangement and expressor groups
• Complete response or partial response pre-transplant was associated with improved PFS and OS
• Age over 55 years and complete or partial response at transplant were associated with lower risk of relapse
• No difference in PFS with or without prior autologous transplant

This retrospective analysis showed durable responses for allogeneic transplant in DEL and DHL patients.  In this very high-risk group, allogeneic transplant should be considered a viable treatment option in the relapsed and refractory setting.