Patients receiving an allogeneic hematopoietic cell transplantation (allo-HCT) after the use of PD-1 inhibitors seem to be at a higher risk of developing acute graft-versus-host disease (aGHVD) ...through etiopathogenetic mechanisms not fully elucidated. Herein, we investigated the effect of nivolumab administered prior to allo-HCT on the following early T-cell reconstitution and its modulation by the GVHD prophylaxis (tacrolimus/sirolimus vs. posttransplant cyclophosphamide PTCY). In all nivolumab-exposed patients we detected circulating nivolumab in plasma for up to 56 days after allo-HCT. This residual nivolumab was able to bind and block PD-1 on T-cells at day 21 after allo-HCT, inducing a T cell activation that was differentially modulated depending on the GVHD prophylactic regimen. Among patients receiving tacrolimus/sirolimus, nivolumab-exposed patients had a higher incidence of severe aGVHD and a more effector T-cell profile compared with anti-PD-1-naïve patients. Conversely, patients receiving PTCY-based prophylaxis showed a similar risk of aGVHD and T-cell profile irrespective of the previous nivolumab exposure. In conclusion, nivolumab persists in plasma after transplantation, binds to allogeneic T cells and generates an increased T-cell activation. This T-cell activation status can be mitigated with the use of PTCY, thus reducing the risk of aGVHD.
The presence of minimal residual disease detected by polymerase chain reaction techniques prior to allogeneic hematopoietic stem cell transplantation has proven to be an independent prognostic factor ...for poor outcome in children with acute lymphoblastic leukemia.
The aim of this study was to ascertain whether the presence of minimal residual disease detected by multiparametric flow cytometry prior to allogeneic hematopoietic stem cell transplantation is related to outcome in children acute lymphoblastic leukemia. Minimal residual disease was quantified by multiparametric flow cytometry at a median of 10 days prior to hematopoietic stem cell transplantation in 31 children (age range, 10 months to 16 years) with acute lymphoblastic leukemia. Thirteen patients were transplanted in first remission. Stem cell donors were HLA-identical siblings in 8 cases and matched unrelated donors in 23. Twenty-six children received a total body irradiation-containing conditioning regimen. According to the level of minimal residual disease, patients were divided into two groups: minimal residual disease-positive (>or=0.01%) (n=10) and minimal residual disease-negative (<0.01%) (n=21).
Estimated event-free survival rates at 2 years for the minimal residual disease-negative and -positive subgroups were 74% and 20%, respectively (P=0.004) and overall survival rates were 80% and 20%, respectively (P=0.005). Bivariate analysis identified pre-transplant minimal residual disease as the only significant factor for relapse and also for death (P<0.01).
The presence of minimal residual disease measured by multiparametric flow cytometry identified a group of patients with a 9.5-fold higher risk of relapse and a 3.2-fold higher risk of death than those without minimal residual disease. This study supports the strong relationship between pre-transplantation minimal residual disease measured by multiparametric flow cytometry and outcome following allogeneic hematopoietic stem cell transplantation and concur with the results of previous studies using polymerase chain reaction techniques.
Approximately 30%-40% of patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) infused with CD19-targeted chimeric antigen receptor (CAR) T cells achieve durable responses. Consensus ...guidelines suggest avoiding bendamustine before apheresis, but specific data in this setting are lacking. We report distinct outcomes after CAR T-cell therapy according to previous bendamustine exposure.
The study included CAR T-cell recipients from seven European sites. Safety, efficacy, and CAR T-cell expansion kinetics were analyzed according to preapheresis bendamustine exposure. Additional studies on the impact of the washout period and bendamustine dose were performed. Inverse probability treatment weighting (IPTW) and propensity score matching (PSM) analyses were carried out for all efficacy comparisons between bendamustine-exposed and bendamustine-naïve patients.
The study included 439 patients with R/R LBCL infused with CD19-targeted commercial CAR T cells, of whom 80 had received bendamustine before apheresis. Exposed patients had significantly lower CD3
cells and platelets at apheresis. These patients had a lower overall response rate (ORR, 53%
72%;
< .01), a shorter progression-free survival (PFS, 3.1
6.2 months;
= .04), and overall survival (OS, 10.3
23.5 months;
= .01) in comparison with the bendamustine-naïve group. Following adjustment methods for baseline variables, these differences were mitigated. Focusing on the impact of bendamustine washout before apheresis, those with recent (<9 months) exposure (N = 42) displayed a lower ORR (40%
72%;
< .01), shorter PFS (1.3
6.2 months;
< .01), and OS (4.6
23.5 months;
< .01) in comparison with bendamustine-naïve patients. These differences remained significant after IPTW and PSM analysis. Conversely, the cumulative dose of bendamustine before apheresis did not affect CAR-T efficacy outcomes.
Recent bendamustine exposure before apheresis was associated with negative treatment outcomes after CD19-targeted CAR T-cell therapy and should be therefore avoided in CAR T-cell candidates.
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