Ps1536 Empirical Antibiotic Therapy for Neutropenic Fever After Allogeneic Stem Cell Transplantation Influences Graft‐versus‐host Disease‐related Mortality

Abstract

Background: About 30% of Hodgkin Lymphoma (HL) patients are refractory to induction therapy or relapse. Standard salvage treatment is often followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) if at least a partial remission is achieved. However 30-50% of relapsed-refractory (R/R) patients fail to achieve PR. Recently the PD-1 targeting antibody Nivolumab has shown promising activity in HL patients relapsed after ASCT but the expected CR rate is only about 20%. Administration of nivolumab as early post-ASCT consolidation might improve results However, several reports have highlighted the relevance of patient immune-competence. In this view, T-cell count is severely depleted after ASCT. Aims: Here we report the preliminary results of a prospective trial investigating the feasibility, and the efficacy of post-ASCT Nivolumab with the support of unselected autologous lymphocyte reinfusions (ALI). Methods: HL patients under the age of 60 with active, relapsed/refractory disease who have already failed at least two chemotherapy lines and Brentuximab were eligible for the trial. All enrolled patient underwent lymphocyte aphaeresis, with a minimum target of 5x10 7 CD3+/kg. All patients then received ASCT with FEAM conditioning. After ASCT, the first ALI wasdelivered 7 days after engraftment. ALI dosing was incremental, one logarithm at each step, starting from 1x10 4 /kg in the first infusion to a maximum of 1x10 7 /kg in the fourth and last infusion. Each ALI was followed after 48 hours by the administration of Nivolumab 240 mg flat dose. The second ALI dose was administered at 14 days after the first one. The third and the fourth were given every 21 days. Lymphocyte subpopulations were extensively studied on peripheral blood samples before and after each ALI and each Nivolumab administration, by 12-colours flow cytometry. Clinical response was evaluated 21 days after completion of the fourth ALI + Nivolumab.