FOXP1 suppresses immune response signatures and MHC class II expression in activated B-cell-like diffuse large B-cell lymphomas.

The FOXP1 (forkhead box P1) transcription factor is a marker of poor prognosis in diffuse large B-cell lymphoma (DLBCL). Here microarray analysis of FOXP1-silenced DLBCL cell lines identified differential regulation of immune response signatures and major histocompatibility complex class II (MHC II) genes as some of the most significant differences between germinal center B-cell (GCB)-like DLBCL with full-length FOXP1 protein expression versus activated B-cell (ABC)-like DLBCL expressing predominantly short FOXP1 isoforms. In an independent primary DLBCL microarray data set, multiple MHC II genes, including human leukocyte antigen DR alpha chain (HLA-DRA), were inversely correlated with FOXP1 transcript expression (P<0.05). FOXP1 knockdown in ABC-DLBCL cells led to increased cell-surface expression of HLA-DRA and CD74. In R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone)-treated DLBCL patients (n=150), reduced HLA-DRA (<90% frequency) expression correlated with inferior overall survival (P=0.0003) and progression-free survival (P=0.0012) and with non-GCB subtype stratified by the Hans, Choi or Visco-Young algorithms (all P<0.01). In non-GCB DLBCL cases with <90% HLA-DRA, there was an inverse correlation with the frequency (P=0.0456) and intensity (P=0.0349) of FOXP1 expression. We propose that FOXP1 represents a novel regulator of genes targeted by the class II MHC transactivator CIITA (MHC II and CD74) and therapeutically targeting the FOXP1 pathway may improve antigen presentation and immune surveillance in high-risk DLBCL patients

Double-hit lymphoma: So what?

The revised WHO classification moved all aggressive B-cell lymphomas with a MYC translocation and a concurrent translocation of BCL2 and/or BCL6 into a single diagnostic category. These are the double- and triple-hit lymphomas. These represent a group with typically a poor outcome to conventional therapy, and as a result, intensification of immunochemotherapy has been explored. The optimal approach is far from clear, and recent insight into the biology suggest that they may represent just a subgroup of molecular high-grade B-cell lymphomas that maybe identified by gene expression profiling. There are a number of novel therapeutic approaches under investigation.</p

Treatment of sporadic Burkitt lymphoma in adults, a retrospective comparison of four treatment regimens

Burkitt lymphoma is an aggressive B cell malignancy accounting for 1–2% of all adult lymphomas. Treatment with dose-intensive, multi-agent chemotherapy is effective but associated with considerable toxicity. In this observational study, we compared real-world efficacy, toxicity, and costs of four frequently employed treatment strategies for Burkitt lymphoma: the Lymphome Malins B (LMB), the Berlin-Frankfurt-Münster (BFM), the HOVON, and the CODOX-M/IVAC regimens. We collected data from 147 adult patients treated in eight referral centers. Following central pathology assessment, 105 of these cases were accepted as Burkitt lymphoma, resulting in the following treatment groups: LMB 36 patients, BFM 19 patients, HOVON 29 patients, and CODOX-M/IVAC 21 patients (median age 39 years, range 14–74; mean duration of follow-up 47 months). There was no significant difference between age, sex ratio, disease stage, or percentage HIV-positive patients between the treatment groups. Five-year progression-free survival (69%, p = 0.966) and 5-year overall survival (69%, p = 0.981) were comparable for all treatment groups. Treatment-related toxicity was also comparable with only hepatotoxicity seen more frequently in the CODOX/M-IVAC group (p = 0.004). Costs were determined by the number of rituximab gifts and the number of inpatients days. Overall, CODOX-M/IVAC had the most beneficial profile with regards to costs, treatment duration, and percentage of patients completing planned treatment. We conclude that the four treatment protocols for Burkitt lymphoma yield nearly identical results with regards to efficacy and safety but differ in treatment duration and costs. These differences may help guide future choice of treatment

Immune Profiling of Double and Triple Hit High Grade B Cell Lymphoma Patients Treated with DA-EPOCH Reveals Activation of T Cells and Reduced T Cell Exhaustion

Introduction Treatment of patients with high grade B cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBL-DH/TH) with intensified immune-chemotherapy DA-EPOCH-R results in a 48-month event-free survival of 71.0% [Dunleavy, Lancet Haematol 2018]. In the HOVON-152, we investigate the added value of immune checkpoint PD-1 inhibition for patients who achieve complete metabolic remission (CMR) after DA-EPOCH-R induction. Nonetheless, whether DA-EPOCH-R has an effect on the immune system, and - reversely - whether the composition of immune system influences DA-EPOCH-R therapy are not known. To gain more insight on these important issues, we performed longitudinal high-throughput immune profiling of patients during the DA-EPOCH-R induction phase of the HOVON-152. Methods In the HOVON-152 single arm, phase II trial (NCT03620578) HGBL-DH/TH patients received 1 cycle of R-CHOP followed by 5 cycles of DA-EPOCH-R induction treatment. Peripheral blood was sampled after one cycle of R-CHOP (enrollment), before start of the 3rd DA-EPOCH-R cycle (midterm) and after the last DA-EPOCH-R cycle (end-of-induction, EOI). Patients achieving CMR at EOI (Deauville score 1-3 after induction) were identified as responders and proceeded with nivolumab consolidation (480 mg iv every 4 weeks) for 1 year. For the profiling we selected 55 patients (32 responders and 23 non-responders, enriched for non-responders) who completed the whole study. T and NK cells were enumerated through quantitative, dual platform flow cytometry of unseparated full blood. The frequencies of NK and T cell subsets were determined in cryopreserved PBMC through multiparameter flow cytometry. The high-throughput flow cytometry data were analyzed by computational methods UMAP and FlowSOM. Non-parametric methods were used for statistical testing. Results DA-EPOCH-R had no apparent effects on the total number of NK cells. The frequency of cytotoxic CD56dim NK cells was, however, gradually decreased during DA-EPOCH-R (p More interestingly, DA-EPOCH-R appeared to have significant impact on T cells: while total T cell frequencies and numbers showed only a temporary decrease at midterm, a progressive decrease in the CD4/CD8 ratio (p=0.016) and a progressive increase in the expression of T cell activation markers CD127 (p Further analyses regarding the possible impact of immune system on DA-EPOCH-R outcome revealed that a (relative) abundance of non-cytotoxic CD56bright NK cells (p=0.006) and higher CD3 T cells (p=0.04) at enrollment was associated with achievement of CMR. Conclusion In conclusion, treatment of HGBL-DH/TH patients with DA-EPOCH-R results not only in the expected rituximab-mediated alterations in the NK cell compartment, but also influences the T cell compartment with a shift towards a lower CD4/CD8 ratio, more T cell activation and a reduction of PD-1 expression on CD8 T cells. Higher T cell frequencies at baseline and decreased frequencies of PD-1+ CD8 T cells at EOI were furthermore associated with achievement of CMR. Overall, these data contribute to a wider understanding of NK and T cell dynamics during DA-EPOCH-R and points to an considerable involvement of T cells in therapy outcome. Disclosures Nijland:Takeda: Research Funding; Roche: Research Funding; Genmab: Consultancy. Klerk:Roche: Other: speaker fee (ASH). Mutseaers:Glaxo Smith Kline: Consultancy; Astra Zeneca: Research Funding; BMS: Consultancy. Mutis:Janssen: Research Funding; Genmab: Research Funding; Takeda: Research Funding. Chamuleau:Genmab: Research Funding; Novartis: Honoraria; Abbvie: Honoraria; Roche: Honoraria; Gilead: Research Funding; BMS/Celgene: Honoraria, Research Funding. OffLabel Disclosure: Nivolumab as immune checkpoint inhibitor (inhibiting PD-1) in consolidation phase for the treatment of DH/TH-HGBL patients Author notes *Asterisk with author names denotes non-ASH members