Children with refractory or relapsed Burkitt lymphoma have a poor chance to survive. We describe characteristics, outcome, re-induction and transplantation-approaches and evaluate risk factors among children with progression of a Burkitt lymphoma/leukemia included in NHL-BFM studies between 1986 and 2016. Treatment recommendation was re-induction including rituximab from the early 2000s followed by blood stem cell transplantation. The 3-year survival of the 157 children was 18.5{plus minus}3%. Survival significantly improved from 11{plus minus}3% before to 27{plus minus}5% after 2000 (p<.001) allowing for risk factor analyses among the latter 75 patients, of whom 28 had disease progressive during initial therapy. Survival of 14 patients with relapse after initial therapy for low risk disease (R1/R2) was 50{plus minus}13% compared to 21{plus minus}5% for 61 patients progressing after R3/R4-therapy (p<.02). 25 of 28 patients with progression during first-line therapy, 31 of 32 with progression during re-induction, 15 of 16 not reaching a complete remission before transplantation, 9 of 10 treated with rituximab front-line and all 13 patients not receiving rituximab during re-induction died. 46 patients received stem cell transplantation (20 autologous, 26 allogeneic). Survival after a regimen combining Rituximab with continuous-infusion chemotherapy followed by allogeneic transplantation was 67{plus minus}12% compared to 18{plus minus}5% for all other regimen and transplantations (p=.003). Patients with relapsed Burkitt lymphoma/leukemia have a poor chance to survive after current effective front-line therapies. Progression during initial or re-induction chemotherapy and initial high-risk disease are risk-factors in relapse. Time-condensed continuous-infusion re-induction followed by stem cell transplantation forms the basis for testing new drugs.

Minimal disseminated and residual disease (MDD/MRD) analyzed by qualitative PCR for NPM-ALK fusion transcripts are validated prognostic factors in pediatric ALK-positive anaplastic large cell lymphoma (ALCL). Although potentially promising, MDD quantification by quantitative real-time PCR in international trials is technically challenging. Quantification of early MRD might further improve risk stratification. We aimed to assess droplet digital PCR for quantification of minimal disease in an inter-laboratory setting in a large cohort of 208 uniformly treated ALCL patients. Inter-laboratory quality control showed high concordance. Using a previously described cut-off of 30 copies NPM-ALK/10⁴ copies ABL1 (NCN) in bone marrow and peripheral blood, MDD quantification allowed identification of very high-risk patients (5-year PFS% 34 ± 5 for patients with ≥30 NCN compared to 74 ± 6 and 76 ± 5 for patients with negative or <30 NCN, respectively, p < 0.0001). While MRD positivity was confirmed as a prognostic marker for the detection of very high-risk patients in this large study, quantification of MRD fusion transcripts did not improve stratification. PFS% was 80 ± 5 and 73 ± 6 for MDD- and MRD-negative patients, respectively, versus 35 ± 10 and 16 ± 8 for MRD-positive patients with <30 and ≥30 NCN, p < 0.0001. Our results suggest that MDD quantification by dPCR enables improved patient stratification in international clinical studies and patient selection for early clinical trials already at diagnosis.

Background: Due to development of chronic lung allograft dysfunction (CLAD), prognosis for patients undergoing lung transplantation (LTx) is still worse compared to other solid organ transplant recipients. Treatment options for slowing down CLAD progression are scarce with extracorporeal photopheresis (ECP) as an established rescue therapy. The aim of the study was to identify characteristics of responders and non‐responders to ECP treatment, assess their survival, lung function development and by that define the subset of patients who should receive early ECP treatment.Methods: We performed a retrospective study of all LTx patients receiving ECP treatment at the University Hospital Zurich between January 2010 and March 2020. Patients were followed‐up for a maximum period of 5 years. Mortality and lung function development were assessed by CLAD stage and by CLAD subtype before initiation of ECP treatment.Results: Overall, 105 patients received at least one ECP following LTx. A total of 57 patients (61.3%) died within the study period with a median survival of 15 months. Mortality was 57% for patients who started ECP at CLAD1, 39% for CLAD2, 93% for CLAD3, and 90% for CLAD4 (p < 0.001). Survival and lung function development was best in young patients at early CLAD stages 1 and 2. Response to ECP treatment was worst in patients with CLAD‐RAS/mixed subtype (14.3%) and patients with ECP initiation in CLAD stages 3 (7.1%) and 4 (11.1%). Survival was significantly better in a subset of patients with recurrent acute allograft dysfunction and earlier start of ECP treatment (105 vs 15 months).Conclusion: In this retrospective analysis of a large group of CLAD patients treated with ECP after LTx, early initiation of ECP was associated with better long‐term survival. Besides a subset of patients suffering of recurrent allograft dysfunction, especially a subset of patients defined as responders showed an improved response rate and survival, suggesting that ECP should be initiated in early CLAD stages and young patients. ECP might therefore prevent long‐term disease progression even in patients with CLAD refractory to other treatment options and thus prevent or delay re‐transplantation.