Preliminary experience of allogeneic stem cell transplantation for lymphoproliferative disorders using BEAM-CAMPATH conditioning: an effective regimen with low procedure-related toxicity

Autologous transplantation has an established role in the treatment of lymp hoproliferative disorders, but allogeneic transplantation remains controver sial. In an attempt to reduce the high procedure-related mortality reported with allografting in lymphoma, we have used BEAM (BCNU, etoposide, cytarab ine and melphalan), a standard conditioning regimen for autologous transpla ntation. As BEAM may be insufficiently immunosuppressive to permit durable engraftment in the allogeneic setting, patients received additional pretran splant immunosuppression with the anti-CD52 antibody CAMPATH-1G from day -5 to day -1. Twelve patients (median age 46 years) underwent allogeneic transplantation for lymphoma (n = 11) or chronic lymphocytic leukaemia (n = 1) from HLA-ide ntical (n = 9) or mismatched (n = 3) sibling donors. Cyclosporin A and meth otrexate were used as graft-versus-host disease (GVHD) prophylaxis. One pat ient died of progressive lymphoma at day +12, the remaining 11 patients eng rafted rapidly, with eight demonstrating full donor chimerism, One patient had an episode of rejection and received a further stern cell infusion with sustained recovery Only one patient developed GVHD (grade I). The low inci dence of acute GVHD may be in part related to persisting levels of in vivo CAMPATH-1G at the time of transplantation. Of 11 evaluable patients, nine a chieved complete remission (CR), and a further patient achieved CR after do nor lymphocyte infusion at 5 months. Our preliminary experience is that this regimen was well tolerated with a l ow risk of GVHD and appears no more toxic than a BEAM autograft. Further fo llow-up is required to see whether the low incidence of GVHD impacts upon r elapse risk.