Graft-versus-lymphoma effect in refractory cutaneous T-cell lymphoma after reduced-intensity HLA-matched sibling allogeneic stem cell transplantation

Cutaneous T-cell lymphomas (CTCL) are rare diseases that, in their advanced stages or in transformation, have a poor prognosis. Autologous stem cell transplantation (Au-SCT) after high-dose therapy has yielded disappointing results. Allogeneic transplantation (allo-SCT) provides the potential advantage of an immune-mediated graft-versus-lymphoma (GVL) effect. Reduced-intensity allo-SCT potentially offers a GVL effect, but with diminished toxicity related to the induction regimen; however, published experience with this approach in CTCL is limited. We report a series of three patients (age 35-49) with advanced, refractory (n=2) or transformed (n=1) CTCL who underwent reduced-intensity allo-SCT in the context of active disease. All three survived the peri-transplant period and, despite later having disease relapse, all exhibited evidence of a GVL effect. Relapses of the disease were in the context of immune suppression for graft-versus-host disease (GVHD), and when immune suppression was reduced, responses were regained. A comparison is made of these results to those in a review of the published literature to date. We conclude that while a GVL can be achieved for CTCL with reduced-intensity allogeneic transplantation, the clinical benefits are short lived and novel approaches are required to obtain sustained remissions.