Laura Gallur

PURPOSE 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. METHODS 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. RESULTS 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% v 72%; P < .01), a shorter progression-free survival (PFS, 3.1 v 6.2 months; P = .04), and overall survival (OS, 10.3 v 23.5 months; P = .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% v 72%; P < .01), shorter PFS (1.3 v 6.2 months; P < .01), and OS (4.6 v 23.5 months; P < .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. CONCLUSION 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.

This prospective multi-institutional phase II study was designed to assess the efficacy and safety of dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin) plus rituximab (DA-EPOCH-R) in untreated patients with poor prognosis large B-cell lymphomas. Eighty-one patients diagnosed with diffuse large B-cell lymphoma (DLBCL, n = 68), primary mediastinal DLBCL (n = 6) and follicular lymphoma Grade 3b (n = 7), with an age-adjusted International Prognostic Index >1, were eligible for analysis. Median age was 60 years (range: 21-77). Sixty-five patients (80·2%) achieved complete response. After a median follow-up time of 64 months, 10-year event-free survival and overall survival (OS) were 47·8% and 63·6%, respectively. None of the studied clinical and biological characteristics were associated with poorer outcome. Interestingly, patients with BCL6 rearrangement achieved a 10-year OS of 100%, while patients with BCL2 rearrangement exhibited a poorer outcome compared to activated B-cell tumours and germinal centre B-cell without BCL2 rearranged tumours. Results achieved with DA-EPOCH-R showed a good long-term outcome and a tolerable toxicity profile in high-risk large B cell lymphoma patients. Outcome was not affected by tumour cell proliferation or by cell of origin, highlighting the requirement of new biological markers for patient subclassification of high-risk DLBCL patients.

BACKGROUND: 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. DESIGN AND METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.