Reduced Intensity Conditioning Regimen for Allografting Following Cytoreductive Autografting in Relapsed/Resistant Hodgkin’s Lymphoma.

Background: We postulated that it is possibile to safely extend the benefit of allografting to relapsed or resistant Hodgkin’s Lymphoma (HL) by combining cytoreduction with high-dose therapy/autologous stem cell transplant (HDT/ASCT) and graft versus HL effect mediated through transplanted donor immune cells with nonmyeloablative allografting (RICT).

Methods: Twenty-two patients, 32 years of age (range, 16–39) with heavily pretreated disease were given HDT/ASCT. At a median of 92 days after HDT/ASCT the patients received fludarabine 30 mg/m²/day x 3 days and cyclophosphamide 300 mg/m²/day x 3 days and non-T depleted donor peripheral blood stem cells from HLA-identical siblings. Postgrafting immunosuppression consisted of methotrexate and cyclosporine. Cyclosporine was withdrawn early in patients with mixed chimerism or disease progression. Donor lymphocyte infusions were given to 12 patients with stable mixed chimerism and/or progressive disease.

Results: Seventeen patients (77%) achieved full chimerism and 5 patients mixed chimerism. Twelve patients (55%) achieved CR after tandem transplant. The first signs of responsiveness in CR patients began at day ≥60 and the maximal response was achieved on day ≥80. The remitters patients achieved full chimerism and developed acute/chronic GVHD before regression of the disease; moreover, 5 patients achieved CR after DLI. At last follow-up (July 31, 2004), 9 out of 12 CR patients are alive at a median of 1844 days (range, 1092 to 2045). Subsequently, 5 patients relapsed and are now alive on therapy and four patients maintain CR after a median follow-up of 1874 days (range, 1092–2045). Acute GVHD grade ≥ II occurred in 9 patients (40%); chronic GVHD developed in 5 patients (23%), four of them with extensive chronic GVHD requiring further immunosuppressive therapy. Two patients died of GVHD/infections, 1 patient died of extensive chronic GVHD and 7 patients of progressive disease.

Conclusions: This tandem auto-allotransplant protocol demonstrated to be highly effective also in advanced resistant Hodgkin’s Lymphoma patients. The exploitation of graft-versus-lymphoma effect is a promising finding