RESUMEN
Given the favorable immunologic effects of IL-2 post transplant, we conducted a feasibility study examining rIL-2 1.0x106 IU/m2/day (SQ) beginning on D+14 post-transplant and continuing for 90 days in 12 patients with low-grade lymphoproliferative disorders. Prior to high-dose chemotherapy and autologous peripheral blood stem cell transplantation (HDCT), 11 patients underwent cytoreduction with fludarabine and cyclophosphamide (Flu/Cy); 11 were in complete remission (CR) and one was in partial remission at the time of HDCT. All 12 patients were in CR 90 days post-HDCT. At a median follow-up of 30 (range 3-44) months, seven patients (58%) remain in remission, four are alive with disease, and one has died of disease progression, resulting in an overall survival of 92%. Kaplan-Meier estimates of progression-free survival (PFS) for the group demonstrate a median of 31 (range 3-43) months. Five patients required rIL-2 cessation at 8-58 days after starting the therapy due to hematologic toxicity. These results are comparable to those achieved in other published bone marrow and peripheral blood stem cell transplantion (PBSCT) series without the addition of rIL-2. Furthermore, rIL-2 using this schedule following fludarabine-based cytoreduction was associated with excessive hematologic toxicity.