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Checkpoint blockade can reverse T-cell exhaustion and promote antitumor responses. Although blocking the PD-1 pathway has been successful in Hodgkin lymphoma, response rates have been modest in B-cell non-Hodgkin lymphoma (NHL). Coblockade of checkpoint receptors may therefore be necessary to optimize antitumor T-cell responses. Here, characterization of coinhibitory receptor expression in intratumoral T cells from different NHL types identified TIGIT and PD-1 as frequently expressed coinhibitory receptors. Tumors from NHL patients were enriched in CD8+ and CD4+ T effector memory cells that displayed high coexpression of TIGIT and PD-1, and coexpression of these checkpoint receptors identified T cells with reduced production of IFNγ, TNFα, and IL2. The suppressed cytokine production could be improved upon in vitro culture in the absence of ligands. Whereas PD-L1 was expressed by macrophages, the TIGIT ligands CD155 and CD112 were expressed by lymphoma cells in 39% and 50% of DLBCL cases and in some mantle cell lymphoma cases, as well as by endothelium and follicular dendritic cells in all NHLs investigated. Collectively, our results show that TIGIT and PD-1 mark dysfunctional T cells and suggest that TIGIT and PD-1 coblockade should be further explored to elicit potent antitumor responses in patients with NHL. more...

Supplementary figures S1-S8.

Supplementary Table S1-S2.

Purpose: T cells infiltrating follicular lymphoma (FL) tumors are considered dysfunctional, yet the optimal target for immune checkpoint blockade is unknown. Characterizing coinhibitory receptor expression patterns and signaling responses in FL T-cell subsets might reveal new therapeutic targets.Experimental Design: Surface expression of 9 coinhibitory receptors governing T-cell function was characterized in T-cell subsets from FL lymph node tumors and from healthy donor tonsils and peripheral blood samples, using high-dimensional flow cytometry. The results were integrated with T-cell receptor (TCR)-induced signaling and cytokine production. Expression of T-cell immunoglobulin and ITIM domain (TIGIT) ligands was detected by immunohistochemistry.Results: TIGIT was a frequently expressed coinhibitory receptor in FL, expressed by the majority of CD8 T effector memory cells, which commonly coexpressed exhaustion markers such as PD-1 and CD244. CD8 FL T cells demonstrated highly reduced TCR-induced phosphorylation (p) of ERK and reduced production of IFNγ, while TCR proximal signaling (p-CD3ζ, p-SLP76) was not affected. The TIGIT ligands CD112 and CD155 were expressed by follicular dendritic cells in the tumor microenvironment. Dysfunctional TCR signaling correlated with TIGIT expression in FL CD8 T cells and could be fully restored upon in vitro culture. The costimulatory receptor CD226 was downregulated in TIGIT+ compared with TIGIT− CD8 FL T cells, further skewing the balance toward immunosuppression.Conclusions: TIGIT blockade is a relevant strategy for improved immunotherapy in FL. A deeper understanding of the interplay between coinhibitory receptors and key T-cell signaling events can further assist in engineering immunotherapeutic regimens to improve clinical outcomes of cancer patients. Clin Cancer Res; 24(4); 870–81. ©2017 AACR. more...

Table S2. Expression of TIGIT ligands in B cells and T cells.

Supplementary Figure 1. IL-21 produc􀆟on is reduced in CD4 FL T cells; Supplementary Figure 2. TCR-induced signaling effectors have different kine􀆟c; Supplementary Figure 3. Iden􀆟fica􀆟on of T-cell subsets; Supplementary Figure 4. Distribu􀆟on of T-cell subsets in FL LN; Supplementary Figure 5. Expression pa􀆩erns of co-inhibitory receptors in CD8 and CD4 T-cell subsets; Supplementary Figure 6. Contribu􀆟on of Tregs among CD4+TIGIT+ T cells; Supplementary Figure 7. TIGIT is a highly expressed co-inhibitory receptor in FL; Supplementary Figure 8. TIGIT expression is stable over 􀆟me; Supplementary Figure 9. Recovery of TCR-induced signaling in TIGIT+ CD8+ FL T cells is robust. more...

Supplementary Figure 1. IL-21 produc􀆟on is reduced in CD4 FL T cells; Supplementary Figure 2. TCR-induced signaling effectors have different kine􀆟c; Supplementary Figure 3. Iden􀆟fica􀆟on of T-cell subsets; Supplementary Figure 4. Distribu􀆟on of T-cell subsets in FL LN; Supplementary Figure 5. Expression pa􀆩erns of co-inhibitory receptors in CD8 and CD4 T-cell subsets; Supplementary Figure 6. Contribu􀆟on of Tregs among CD4+TIGIT+ T cells; Supplementary Figure 7. TIGIT is a highly expressed co-inhibitory receptor in FL; Supplementary Figure 8. TIGIT expression is stable over 􀆟me; Supplementary Figure 9. Recovery of TCR-induced signaling in TIGIT+ CD8+ FL T cells is robust. more...

SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase (dNTPase) that restricts viral replication in infected cells and limits the sensitivity to cytarabine by hydrolysing its active metabolite, as recently shown in acute myeloid leukemia. Cytarabine is an essential component in the Nordic mantle cell lymphoma protocols (MCL2 and MCL3) for induction and high-dose chemotherapy treatment before autologous stem cell transplantation for younger patients with mantle cell lymphoma (MCL). We here investigated the expression of SAMHD1 in a population-based cohort of MCL (N = 150). SAMHD1 was highly variably expressed in MCL (range, 0.4% to 100% of positive tumor cells). Cases with blastoid/pleomorphic morphology had higher SAMHD1 expression (P = 0.028) and SAMHD1 was also correlated to tumor cell proliferation (P = 0.016). SAMHD1 expression showed moderate correlation to the expression of the transcriptional regulator SOX11 (P = 0.036) but genetic silencing of SOX11 and SAMHD1 by siRNA in MCL cell lines did not suggest mutual regulation. We hypothesized that expression of SAMHD1 could predict short time to progression in patients treated with Cytarabine as part of high-dose chemotherapy. Despite the correlation with known biological adverse prognostic factors, neither low or high SAMHD1 expression correlated to PFS or OS in patients treated according to the Nordic MCL2 or MCL3 protocols (N = 158). more...

Background: The aim of this study was to investigate dosimetry data and clinical variables to predict hematological toxicity in non-Hodgkin lymphoma (NHL) patients treated with [177Lutetium]Lu-liloto-mab satetraxetan. Material and methods: A total of 17 patients treated with [177Lu]Lu-lilotomab satetraxetan in a first-in-human phase 1/2a study were included. Absorbed dose to the red marrow was explored using SPECT/CT-imaging of the lumbar vertebrae L2–L4 over multiple time points. Percentage reduction of thrombocytes and neutrophils at nadir compared to baseline (PBN) and time to nadir (TTN) were chosen as indicators of myelosuppression and included as dependent variables. Two models were applied in the analysis, a multivariate linear model and a sigmoidal description of toxicity as a function of absorbed dose. A total of 10 independent patient variables were investigated in the multivariate analysis. Results: Absorbed dose to the red marrow ranged from 1 to 4 Gy. Absorbed dose to the red marrow was found to be the only significant variable for PBN for both thrombocytes and neutrophils. The sigmoid function gave similar results in terms of accuracy when compared to the linear model. Conclusion: Myelosuppression in the form of thrombocytopenia and neutropenia in patients treated with [177Lu]Lu-lilotomab satetraxetan can be predicted from the SPECT/CT-derived absorbed dose estimate to the red marrow. The present work was financially supported by the South-Eastern Norway Regional Health Authority. more...

Background Response to modern treatment strategies, which combine cytotoxic compounds with immune stimulatory agents and targeted treatment is highly variable among MCL patients. Thus, providing prognostic and predictive markers for risk adapted therapy is warranted and molecular information that can help in patient stratification is a necessity. In relapsed MCL, biopsies are rarely available and molecular information from tumor tissue is often lacking. Today, the main tool to access risk is the MCL international prognostic index (MIPI), which does not include detailed biological information of relevance for different treatment options. To enable continuous monitoring of patients, non-invasive companion diagnostic tools are needed which can further reduce cost and patient distress and enable efficient measurements of biological markers. Methods We have assessed if serum-based protein profiling can identify immune related proteins that stratify relapsed MCL patients based on risk. Overall, 371 scFv targeting 158 proteins were assessed using an antibody microarray platform. We profiled patients (n = 44) who had been treated within the MCL6-Philemon trial combining targeted and immune-modulatory treatment. Results The downstream processing led to the identification of the relapsed immune signature (RIS) consisting of 11 proteins with potential to stratify patients with long and short overall survival (OS). Moreover, in this population, MIPI alone failed to separate high, intermediate and low risk patients, but a combined index based on MIPI together with RIS, MIPIris, showed improved performance and significantly stratified all three risk groups based on OS. Conclusions Our results show that addition of biological parameters to previous prognostic indices improves patient stratification among patients treated with BTK inhibitor triplet combination, particularly, in the identification of an extreme high risk group. more...

Purpose 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Tumor dosimetry and response evaluation can be challenging after radioimmunotherapy (RIT). Changes in FDG PET/CT parameters after RIT and correlations with tumor-absorbed doses has not been examined previously in patients with lymphoma. Treatment-induced changes were measured at FDG PET/CT and ceCT to evaluate response at the lesion level after treatment, and correlations with tumor-absorbed doses were investigated. Methods Forty-five tumors in 16 patients, with different pre-treatment and pre-dosing regimens, were included. Dosimetry was performed based on multiple SPECT/CT images. FDG PET/CT was performed at baseline and at 3 and 6 months. SUVmax, MTV, TLG, and changes in these parameters were calculated for each tumor. Lesion response was evaluated at 3 and 6 months (PET3months and PET6months) based on Deauville criteria. Anatomical changes based on ceCT at baseline and at 6 and 12 months were investigated by the sum of perpendiculars (SPD). Results Tumor-absorbed doses ranged from 35 to 859 cGy. Intra- and interpatient variations were observed. Mean decreases in PET parameters from baseline to 3 months were ΔSUVmax-3months 61%, ΔMTV3months 80%, and ΔTLG3months 77%. There was no overall correlation between tumor-absorbed dose and change in FDG PET or ceCT parameters at the lesion level or significant difference in tumor-absorbed doses between metabolic responders and non-responders after treatment. Conclusion Our analysis does not show any correlation between tumor-absorbed doses and changes in FDG PET or ceCT parameters for the included lesions. The combination regimen, including cold antibodies, may be one of the factors precluding such a correlation. Increased intra-patient response with increased tumor-absorbed doses was observed for most patients, implying individual variations in radiation sensitivity or biology. Trial registration ClinicalTrials.gov Identifier (NCT01796171). Registered December 2012 more...

Survival for patients diagnosed with mantle cell lymphoma (MCL) has improved drastically in recent years. However, patients carrying mutations in tumour protein p53 (TP53) do not benefit from modern chemotherapy-based treatments and have poor prognosis. Thus, there is a clinical need to identify missense mutations through routine analysis to enable patient stratification. Sequencing is not widely implemented in clinical practice for MCL, and immunohistochemistry (IHC) is a feasible alternative to identify high-risk patients. The aim of the present study was to investigate the accuracy of p53 as a tool to identify patients withTP53missense mutations and the prognostic impact of overexpression and mutations in a Swedish population-based cohort. In total, 317 cases were investigated using IHC and 255 cases were sequenced, enabling analysis of p53 andTP53status among 137 cases divided over the two-cohort investigated. The accuracy of predicting missense mutations from protein expression was 82%, with sensitivity at 82% and specificity at 100% in paired samples. We further show the impact of p53 expression andTP53mutations on survival (hazard ratio of 3 center dot 1 in univariate analysis for both), and the association to risk factors, such as high MCL International Prognostic Index, blastoid morphology and proliferation, in a population-based setting. more...

Eskelund et al examined clonal hematopoiesis (CH) in a cohort of patients with mantle cell lymphoma (MCL) treated with first-line chemotherapy and autologous stem cell transplantation. In young, good-risk MCL patients, CH after first-line therapy arises almost entirely from preexisting clones, stabilizes after a period of expansion posttransplantation, and does not negatively impact survival. more...

B-cell depletion induced by anti-cluster of differentiation 20 (CD20) monoclonal antibody (mAb) therapy of patients with lymphoma is expected to impair humoral responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination, but effects on CD8 T-cell responses are unknown. Here, we investigated humoral and CD8 T-cell responses following two vaccinations in patients with lymphoma undergoing anti-CD20-mAb therapy as single agent or in combination with chemotherapy or other anti-neoplastic agents during the last 9 months prior to inclusion, and in healthy age-matched blood donors. Antibody measurements showed that seven of 110 patients had antibodies to the receptor-binding domain of the SARS-CoV-2 Spike protein 3–6 weeks after the second dose of vaccination. Peripheral blood CD8 T-cell responses against prevalent human leucocyte antigen (HLA) class I SARS-CoV-2 epitopes were determined by peptide-HLA multimer analysis. Strong CD8 T-cell responses were observed in samples from 20/29 patients (69%) and 12/16 (75%) controls, with similar median response magnitudes in the groups and some of the strongest responses observed in patients. We conclude that despite the absence of humoral immune responses in fully SARS-CoV-2-vaccinated, anti-CD20-treated patients with lymphoma, their CD8 T-cell responses reach similar frequencies and magnitudes as for controls. Patients with lymphoma on B-cell depleting therapies are thus likely to benefit from current coronavirus disease 2019 (COVID-19) vaccines, and development of vaccines aimed at eliciting T-cell responses to non-Spike epitopes might provide improved protection. more...

Mantle cell lymphoma (MCL) is a rare, often aggressive type of B-cell lymphoma with poor survival and no cure. Cancer and cancer treatment has a negative impact on health-related quality of life (HRQOL) both during active disease and in the long term, and improvement of HRQOL is a crucial objective of cancer therapy in older patients and no curative intent. Baseline HRQOL has in other lymphoma populations been shown to be predictive of outcome. Here, we explored HRQOL, and its association with survival, by the EORTC QLQ-C30 questionnaire, before, during and after chemotherapy in a patient cohort with mantle cell lymphoma, treated within the NLG-MCL4 trial, designed to evaluate the addition of lenalidomide (LEN) to rituximab-bendamustine (R-B) as first-line treatment. Fifty-one patients were enrolled, median age was 71 years (range 62-84), 37 were men (73%). Pre-treatment HRQOL was similar to scores from the reference population with healthy individuals. During treatment, HRQOL deteriorated, but reverted to the same level as the reference population after treatment. There was a correlation between physical function (p=0.001) and role function (p=0.006) at baseline and WHO performance status, but not with other clinical or genetic prognostic factors. None of the baseline factors were predictive for treatment related to HRQOL in this cohort. Pre-treatment physical (p=0.011) and role function (p=0.032) were independent factors associated with overall survival, and physical function (p=0.002) was also associated with progression free survival. These findings may possibly be used to design support during treatment and improve rehabilitation. Further investigations are needed for assessment of long-term HRQOL. This article is protected by copyright. All rights reserved. more...

Unlike chimeric antigen receptors, T-cell receptors (TCRs) can recognize intracellular targets presented on human leukocyte antigen (HLA) molecules. Here we demonstrate that T cells expressing TCRs specific for peptides from the intracellular lymphoid-specific enzyme terminal deoxynucleotidyl transferase (TdT), presented in the context of HLA-A*02:01, specifically eliminate primary acute lymphoblastic leukemia (ALL) cells of T- and B-cell origin in vitro and in three mouse models of disseminated B-ALL. By contrast, the treatment spares normal peripheral T- and B-cell repertoires and normal myeloid cells in vitro, and in vivo in humanized mice. TdT is an attractive cancer target as it is highly and homogeneously expressed in 80-94% of B- and T-ALLs, but only transiently expressed during normal lymphoid differentiation, limiting on-target toxicity of TdT-specific T cells. TCR-modified T cells targeting TdT may be a promising immunotherapy for B-ALL and T-ALL that preserves normal lymphocytes.Engineered T cells kill leukemic cells with little off-target toxicity. more...

Background: Follicular lymphoma (FL) remains an incurable disease for most patients (pts), characterized by a relapsing and remitting pattern. For pts with relapsed/refractory (r/r) FL, treatment outcomes typically worsen with each subsequent line of therapy, highlighting an unmet need. Tisagenlecleucel (tisa-cel) has demonstrated clinical benefits and manageable safety in pediatric and young adult pts with r/r B-cell acute lymphoblastic leukemia and adult pts with r/r diffuse large B-cell lymphoma. In a prior phase (Ph) 2a study of 14 pts with r/r FL, 71% achieved durable complete remission with tisa-cel (Chong et al. ICML 2019). Here we present a planned interim analysis of ELARA, a Ph 2, international trial of tisa-cel in adults with r/r FL. Methods: Adults with histologically confirmed FL (grades [Gr] 1-3A) being r/r within 6 mo after second-/later-line therapy (including an anti-CD20 monoclonal antibody with an alkylating agent) or relapsed after autologous hematopoietic stem cell transplant (autoHSCT), and with ECOG performance score of 0-1 were eligible. Pts with histologic transformation, prior allogeneic HSCT, or active CNS involvement were excluded. All pts received lymphodepleting chemotherapy followed by tisa-cel infusion of 0.6-6×108 CAR-T cells (bridging therapy prior to infusion was permitted). Disease was reassessed prior to infusion for all pts who received bridging therapy to establish a new baseline. After infusion, disease assessments were performed every 3 mo. The primary endpoint was complete response rate (CRR) based on best response by central review (Lugano 2014 criteria). Pts evaluable for efficacy had measurable disease at infusion and ≥6 mo follow-up from infusion or discontinued early. Secondary endpoints included overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Results: As of May 26, 2020, 122 pts were screened, 98 were enrolled, 97 received tisa-cel (median follow-up, 6.5 mo), and 52 were evaluable for efficacy (median follow-up, 9.9 mo). At study entry, median age among treated pts was 57 y (range, 29-73), 66% of pts were male, 84% had stage III-IV disease, and 60% had a FLIPI score ≥3. The median number of prior lines of therapy was 4 (range, 2-13), including prior autoHSCT in 36%; 77% were refractory to the last prior treatment (75% ≥2 prior regimens), and 60% had disease progression within 2 y of initial anti-CD20-containing treatment. Overall, 43% of pts received bridging therapy; 18% were treated as outpatient. Of the first 52 pts evaluable for efficacy, CRR was 65.4% (34/52; 99.5% CI, 45.1-82.4) in the intent-to-treat (ITT) population and 71.1% (33/46; 99.5% CI, 56.5-84.0) in the per-protocol (PP) population; ORR was 82.7% (43/52; 95% CI, 69.7-91.8) in the ITT population and 84.8% (39/46; 95% CI, 71.1-93.7) in the PP population. In pts with best response of CR, probability of response lasting ≥6 mo was 89.7% (84.4% for all responding pts [CR+PR]). CRR and ORR were consistent across key prognostic subgroups and per investigator assessment. Median DOR, PFS, OS, and time to next antilymphoma treatment were not reached. Of 97 pts evaluable for safety, 69% experienced Gr ≥3 adverse events, most commonly neutropenia (Gr 3, 13%; Gr 4, 15%); 48% of pts had cytokine release syndrome related to tisa-cel (CRS; Gr 1, 29%; Gr 2, 20%; Gr ≥3, 0%; per Lee scale). To treat CRS, 15% of pts required tocilizumab and 3% required steroids. Any grade serious neurologic events (NEs; per CTCAE v4.03) occurred in 10% of pts; 2% had Gr ≥3 and all recovered (1 pt developed Gr 4 immune-effector cell neurotoxicity syndrome related to tisa-cel concomitant with possible HHV6 encephalitis; 1 pt developed Gr 3 delirium unrelated to tisa-cel after progression of disease and start of salvage therapy). Median time to CRS and serious NEs onset were 4 and 8.5 d, respectively, with respective median time to resolution of 4 and 2 d. Three pts died from progressive disease; no deaths were treatment-related. Conclusions: Preliminary data from ELARA suggest that tisa-cel is effective in extensively treated r/r FL, resulting in high CRRs and ORRs, including in high-risk pts. The overall safety profile is favorable, with no severe CRS and very low NE reported, requiring limited anticytokine therapy. Updated safety and efficacy results on 97 pts (including dose and cellular kinetics data) will be presented at the meeting. Disclosures Fowler: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding. Dickinson:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Merck Sharp & Dohme: Consultancy; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau. Dreyling:Astra Zeneca: Consultancy; Abbvie: Research Funding; Roche: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Beigene: Consultancy; Gilead: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy. Martinez-Lopez:Janssen: Consultancy, Honoraria; Novartis: Consultancy; Janssen-cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Research Funding; Incyte: Consultancy, Research Funding. Kolstad:Merck: Research Funding; Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding. Popplewell:Pfizer: Research Funding; Novartis: Research Funding; Roche: Research Funding. Chavez:Genentech: Speakers Bureau; Epizyme: Speakers Bureau; Gilead: Consultancy; Verastem: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; BeiGene: Speakers Bureau; Novartis: Consultancy; Kite, a Gilead Company: Consultancy, Speakers Bureau; Pfizer: Consultancy; AstraZeneca: Speakers Bureau; Morphosys: Consultancy, Speakers Bureau; Merck: Research Funding; Bayer: Consultancy; Celgene: Consultancy. Bachy:Beigene: Membership on an entity's Board of Directors or advisory committees; Roche, Celgene, Amgen, Janssen, Gilead, Novartis, Sanofi: Honoraria; Amgen: Research Funding; Roche, Gilead: Consultancy. Kato:AbbVie, AstraZeneca, Celgene, Chugai, Eisai, Janssen, and Novartis: Consultancy; hugai, Takeda, Kyowa-Kirin, Abbvie, Novartis, Eisai, Janssen, Celgene, Ono: Research Funding; Chugai, Takeda, MSD, Kyowa-Kirin, Janssen, Celgene, Ono, Mundi, Dainippon-Sumitomo, Novartis: Honoraria. Harigae:Novartis, Chugai, BMS: Honoraria. Kersten:BMS: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Celgene: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Amgen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Janssen/Cilag: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Miltenyi Biotech: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Takeda: Research Funding; Roche: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Kite/Gilead: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); MSD: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Novartis: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Andreadis:Novartis: Research Funding; Gilead/Kite: Consultancy; Merck: Research Funding; Incyte: Consultancy; Karyopharm: Honoraria; Jazz Pharmaceuticals: Honoraria; BMS/Celgene/Juno: Honoraria, Research Funding; Genentech: Consultancy, Current equity holder in publicly-traded company. Riedell:Bayer: Honoraria; Karyopharm Therapeutics: Honoraria; Morphosys: Research Funding; Celgene/Bristol-Myers Squibb Company: Honoraria, Research Funding; Verastem Oncology: Honoraria; Kite Pharmaceuticals/Gilead: Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Nastoupil:Karus Therapeutics: Research Funding; Gamida Cell: Honoraria; Gilead/KITE: Honoraria; Novartis: Honoraria, Research Funding; Merck: Research Funding; Celgene: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Bayer: Honoraria; Janssen: Honoraria, Research Funding; LAM Therapeutics: Research Funding; TG Therapeutics: Honoraria, Research Funding; Genentech, Inc.: Honoraria, Research Funding. von Tresckow:Takeda: Honoraria, Other: Travel support, Research Funding; Amgen: Honoraria; Pfizer: Honoraria; Kite/Gilead: Honoraria; Roche: Honoraria; MSD Sharp & Dohme: Honoraria, Research Funding; Takeda: Honoraria, Other: Travel support, Research Funding; Novartis: Other: Travel support, Research Funding. Ferreri:Morphosys: Research Funding; Hutchinson: Research Funding; BMS: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding. Teshima:Sharp & Dohme Corp: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer Japan Inc.: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; TEIJIN PHARMA LIMITED: Honoraria; The Center of Innovation Program from Japan Science and Technology Agency: Other; Fuji Pharma Co., Ltd.: Honoraria; NIPPON SHINYAKU CO., LTD.: Honoraria; Janssen Pharmaceutical K.K.: Other; Japan Society for the Promotion of Science KAKENHI (17H04206): Other; Novartis Pharma K.K.: Consultancy, Other: Manuscript preparation, Research Funding; Takeda Pharmaceutical Company Limited: Consultancy, Honoraria; Chugai Pharmaceutical Co., Ltd.: Research Funding; Astellas Pharma Inc.: Research Funding; Merck: Consultancy, Honoraria; Sanofi K.K.: Research Funding. Patten:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria. McGuirk:Novartis: Research Funding; Fresenius Biotech: Research Funding; Astellas: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Allo Vir: Consultancy, Honoraria, Research Funding; Kite Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pluristem Ltd: Research Funding; Gamida Cell: Research Funding; Bellicum Pharmaceutical: Research Funding. Petzer:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite-Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Viardot:Amgen: Honoraria, Other: advisory board; Novartis: Honoraria, Other: advisory board; Kite/Gilead: Honoraria, Other: advisory board; Roche: Honoraria, Other: advisory board. Zinzani:ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Malladi:Novartis: Consultancy, Honoraria. Bubuteishvili Pacaud:Novartis: Current Employment. Forcina:Novartis: Current Employment. Zia:Novartis: Current Employment. Schuster:Novartis, Genentech, Inc./ F. Hoffmann-La Roche: Research Funding; AlloGene, AstraZeneca, BeiGene, Genentech, Inc./ F. Hoffmann-La Roche, Juno/Celgene, Loxo Oncology, Nordic Nanovector, Novartis, Tessa Therapeutics: Consultancy, Honoraria. Thieblemont:Cellectis: Speakers Bureau; Roche, Amgen, Kyte Gilead, Celgene, Abbvie, Novartis, Cellectis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Roche, Hospita: Research Funding. more...

Purpose The aim of this study was to explore the β-emitting lutetium-177 labelled anti-CD37 antibody NNV003 (177Lu-NNV003, Humalutin®) for the treatment of non-Hodgkin’s lymphoma in in vitro studies and in animal models. Methods Cytotoxicity of 177Lu-NNV003 was measured in REC-1 (mantle cell lymphoma) and DOHH-2 (diffuse large B cell lymphoma) cell lines. Biodistribution was studied in mice bearing subcutaneous DOHH-2 or MEC-2 (chronic lymphocytic leukaemia) xenografts. The therapeutic effect of a single injection of 177Lu-NNV003 was measured in mice intravenously or subcutaneously injected with REC-1 cells. Haematological and histopathological assessments were used to evaluate the toxic effect of 177Lu-NNV003. The immunotherapeutic effect of NNV003 was assessed by measuring binding to Fcγ receptors, activation of ADCC and ADCP. NNV003’s immunogenicity potential was assessed using in silico immunogenicity prediction tools. Results 177Lu-NNV003 showed an activity dependent antiproliferative effect in all cell lines. Maximum tumour uptake in vivo was 45% of injected activity/g in MEC-2 tumours and 15% injected activity/g in DOHH-2 tumours. In mice injected intravenously with REC-1 cells, 177Lu-NNV003 (50–100 MBq/kg) improved survival compared to control groups (p more...

Purpose: 177Lu-lilotomab satetraxetan, a novel CD37 directed radioimmunotherapy (RIT), has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Absorbed dose for all tumor tissue in the body is a crucial parameter in RIT which has traditionally been challenging to calculate. The aim of this study was to investigate the correlations between baseline FDG PET/CT and posttreatment SPECT/CT parameters, absorbed dose-response relationships and clinical responses.Materials and methods: A total of 15 patients with different pre-treatment and pre-dosing regimens were included. 177Lu-lilotomab satetraxetan was administered at dosage levels of 10, 15 or 20 MBq/kg. Total radioimmunoconjugate tumor volume (tRTV), total radioimmunoconjugate lesion uptake (tRLU) and total tumor absorbed dose (tTAD) were calculated from posttreatment SPECT/CT. The measured uptake values and absorbed doses were normalized for dosage when appropriate. For some of the analyses, the cohort was divided into low (arm 1) and high (arm 4+5) non-radioactive lilotomab pre-dosing groups. tMTV and tTLG were calculated from FDG PET/CT performed at baseline, 3 and 6 months after RIT, and the percent change for these parameters calculated (∆tMTV3months, ∆tTLG3months and ∆tMTV6months, ∆tTLG6months). Clinical responses were evaluated at 6 months.Results: tTMV and tRTV were significantly correlated (p higher at PET3months for patients receiving tTAD≥200cGy compared to patients receiving lower tumor absorbed doses (p=.03 for both). Also, significant decreases in ∆tMTV3months, ∆tTLG3months and ∆tMTV6months, ∆tTLG6months were observed with increasing tTAD in the high lilotomab patient group. Similarly, responders (patients with complete remission and partial remission) had higher mean tTAD compared to non-responders (stable disease and progressive disease). This was statistically significant in the high lilotomab group. Across the entire population, all non-responders had tTAD < 200cGy, and all patients with tTAD ≥ 200cGy were responders.Conclusion: This work indicates that 177Lu-lilotomab satetraxetan targets FDG avid lesions, and that increasing baseline (tMTV) does not have a decreasing effect on the total tumor absorbed dose (tTAD). The patient group receiving a higher amount of lilotomab pre-dosing demonstrated an absorbed dose–response relationship. Similar results were not observed in the low lilotomab group, which were expected since an overall very good response rate could mask such a relationship for this group. Regardless of pre-dosing, a mean absorbed dose to the total tumor tissue (tTAD) limit of 200cGy may prove valuable to separate clinical non-responders from responders. more...

Tisagenlecleucel is an autologous anti-CD19 chimeric antigen receptor-T cell therapy with clinically meaningful outcomes demonstrated in patients with relapsed/refractory (r/r) B-cell lymphoma. In a previous pilot study of tisagenlecleucel in r/r follicular lymphoma (FL), 71% of patients achieved a complete response (CR). Here we report the primary, prespecified interim analysis of the ELARA phase 2 multinational trial of tisagenlecleucel in adults with r/r FL after two or more treatment lines or who relapsed after autologous stem cell transplant (no. NCT03568461). The primary endpoint was CR rate (CRR). Secondary endpoints included overall response rate (ORR), duration of response, progression-free survival, overall survival, pharmacokinetics and safety. As of 29 March 2021, 97/98 enrolled patients received tisagenlecleucel (median follow-up, 16.59 months; interquartile range, 13.8–20.21). The primary endpoint was met. In the efficacy set (n = 94), CRR was 69.1% (95% confidence interval, 58.8–78.3) and ORR 86.2% (95% confidence interval, 77.5–92.4). Within 8 weeks of infusion, rates of cytokine release syndrome were 48.5% (grade ≥3, 0%), neurological events 37.1% (grade ≥3, 3%) and immune effector cell-associated neurotoxicity syndrome (ICANS) 4.1% (grade ≥3, 1%) in the safety set (n = 97), with no treatment-related deaths. Tisagenlecleucel is safe and effective in extensively pretreated r/r FL, including in high-risk patients., The study was sponsored and designed by Novartis Pharmaceuticals Corporation and was approved by the IRB at each participating institution. more...

We characterised patients with mantle cell lymphoma (MCL) with poor prognosis based on differences in immune infiltration. Different expressions of the tumour cell markers Cyclin D1 and sex-determining region Y-box transcription factor 11 (SOX11), and the immune markers cluster of differentiation 3 (CD3), CD4, CD8, CD25, forkhead box protein P3 (FoxP3), T-box transcription factor TBX21 (T-bet), programmed cell death protein 1 (PD-1), programmed-death ligand 1 (PD-L1) and CD163 were investigated for all-cause mortality in 282 patients with MCL and time-to-progression (TTP) in 106 clinical trial patients. With increasing age, a significantly lower infiltration of CD3(+) T lymphocytes was seen. T-cell infiltration was independent of cellular tumour antigen p53 (p53) expression, Ki-67, morphology and frequency of tumour cells. The all-cause mortality was higher in patients with PD-L1-expression above cut-off [hazard ratio (HR) 1 center dot 97, 95% confidence interval (CI) 1 center dot 18-3 center dot 25, adjusted for sex and MCL International Prognostic Index (MIPI)] and a higher frequency of CD163(+) cells (continuously, HR 1 center dot 51, 95% CI 1 center dot 03-2 center dot 23, adjusting for age, sex, morphology, Ki-67 and p53). In patients treated within the Nordic Lymphoma Group MCL2/3 trials, TTP was shorter in patients with a higher frequency of FoxP3(+) cells (HR 3 center dot 22, 95% CI 1 center dot 40-7 center dot 43) and CD163(+) cells (HR 6 center dot 09, 95% CI 1 center dot 84-20 center dot 21), independent of sex and MIPI. When combined a higher frequency of CD163(+) macrophages and PD-L1(+) cells or high CD163(+) macrophages and FoxP3(+) regulatory T cells indicated worse outcome independent of established risk factors. The T-cell infiltrate was in turn independent of molecular characteristics of the malignant cells and decreased with age. more...

Checkpoint blockade can reverse T-cell exhaustion and promote antitumor responses. Although blocking the PD-1 pathway has been successful in Hodgkin lymphoma, response rates have been modest in B-cell non-Hodgkin lymphoma (NHL). Coblockade of checkpoint receptors may therefore be necessary to optimize antitumor T-cell responses. Here, characterization of coinhibitory receptor expression in intratumoral T cells from different NHL types identified TIGIT and PD-1 as frequently expressed coinhibitory receptors. Tumors from NHL patients were enriched in CD8+ and CD4+ T effector memory cells that displayed high coexpression of TIGIT and PD-1, and coexpression of these checkpoint receptors identified T cells with reduced production of IFNγ, TNFα, and IL2. The suppressed cytokine production could be improved upon in vitro culture in the absence of ligands. Whereas PD-L1 was expressed by macrophages, the TIGIT ligands CD155 and CD112 were expressed by lymphoma cells in 39% and 50% of DLBCL cases and in some mantle cell lymphoma cases, as well as by endothelium and follicular dendritic cells in all NHLs investigated. Collectively, our results show that TIGIT and PD-1 mark dysfunctional T cells and suggest that TIGIT and PD-1 coblockade should be further explored to elicit potent antitumor responses in patients with NHL. more...

For patients with indolent non-Hodgkin lymphoma who fail initial anti-CD20–based immunochemotherapy or develop relapsed or refractory disease, there remains a significant unmet clinical need for new therapeutic approaches to improve outcomes and quality of life. 177Lu-lilotomab satetraxetan is a next-generation single-dose CD37-directed radioimmunotherapy (RIT) which was investigated in a phase 1/2a study in 74 patients with relapsed/refractory indolent non-Hodgkin B-cell lymphoma, including 57 patients with follicular lymphoma (FL). To improve targeting of 177Lu-lilotomab satetraxetan to tumor tissue and decrease hematologic toxicity, its administration was preceded by the anti-CD20 monoclonal antibody rituximab and the “cold” anti-CD37 antibody lilotomab. The most common adverse events (AEs) were reversible grade 3/4 neutropenia (31.6%) and thrombocytopenia (26.3%) with neutrophil and platelet count nadirs 5 to 7 weeks after RIT. The most frequent nonhematologic AE was grade 1/2 nausea (15.8%). With a single administration, the overall response rate was 61% (65% in patients with FL), including 30% complete responses. For FL with ≥2 prior therapies (n = 37), the overall response rate was 70%, including 32% complete responses. For patients with rituximab-refractory FL ≥2 prior therapies (n = 21), the overall response rate was 67%, and the complete response rate was 24%. The overall median duration of response was 13.6 months (32.0 months for patients with a complete response). 177Lu-lilotomab satetraxetan may provide a valuable alternative treatment approach in relapsed/refractory non-Hodgkin lymphoma, particularly in patients with comorbidities unsuitable for more intensive approaches. This trial was registered at www.clinicaltrials.gov as #NCT01796171. more...

Patients with mantle cell lymphoma (MCL) generally have a dismal prognosis. Intensified induction treatment with rituximab and high dose cytarabine (R_HDAC), and consolidation with high-dose therapy with autologous stem cell support has resulted in 10-year overall survival (OS) higher than 60%. However, the clinical course varies. Diagnostic tools capable of stratifying patients include the MCL International Prognostic Index (MIPI), gene expression-based proliferation signature, Ki-67 proliferation index or tumour cell morphology. Here, we tested the performance of a newly developed Nanostring-based RNA expression-based proliferation assay (MCL35) on formalin-fixed paraffin-embedded tumour tissue from younger patients recruited in or treated according to Nordic MCL protocols compared to the prognosticators listed above. Seventy-four patients were included and the assay performed well in all cases except four, which had inadequate RNA quality. The patients were evenly distributed in the MCL35 low-, intermediate- and high-risk categories. MCL35 low- and intermediate- risk groups had overlapping progression-free survival (PFS), while patients in the high-risk category had significantly inferior PFS. Combining MCL35 with MIPI or the MIPI-C (MIPI with the addition of binary Ki67 score +/-30%) showed a better discrimination than either assessment alone. In conclusion, the MCL35 assay alone or combined with MIPI or MIPI-C scores can identify patients who still have a dismal outcome despite intensified treatment. more...

Introduction: Regulatory T cells (Tregs), a highly immunosuppressive subset of CD4 + T cells, represent a key challenge in the tumor microenvironment by limiting potent antitumor immune responses. While high densities of tumor-infiltrating Tregs are associated with poor prognosis in patients with various types of solid cancers, their prognostic impact in B-cell non-Hodgkin lymphoma (NHL) remains unclear. Emerging studies suggest substantial heterogeneity in the phenotype and suppressive capacities of Tregs, emphasizing the importance of understanding Treg diversity and the need for additional markers to identify highly suppressive Tregs. Our in-depth characterization of Tregs in NHL tumors could open new paths for rational drug design, facilitating selective therapeutic manipulation of Tregs to reduce immunosuppression and improve anti-tumor immunity. Methods: Single-cell suspensions from NHL patients (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and healthy donors (tonsils and peripheral blood)) were analyzed by fluorescent flow- and mass cytometry to characterize Tregs, focusing on their expression of co-stimulatory and co-inhibitory checkpoint receptors. The immunosuppressive capacity of Tregs was measured by in vitro co-culture of FACS-sorted subsets of Tregs together with autologous CellTrace Violet-labelled T effector cells as responder cells, using samples from FL and tonsils. Live CD4 + T cells were obtained by FACS sorting from DLBCL (n = 3), FL (n = 3) and healthy donor tonsils (n = 3) and subjected to single-cell RNA sequencing (scRNA-seq), Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) and scTCR-seq by the 10X Genomics platform. The computational framework of CIBERSORTx was used to generate unique signature matrices for the three Treg subsets identified by scRNA-seq, to facilitate validation in separate scRNA-seq cohorts (King, Sci Immunol 2021; Roider, Nat Cell Biol 2020), and to impute frequencies of the Treg subsets in cohorts with bulk RNA-seq data (Chapuy, Nat Med 2018; Schmitz, NEJM 2018; Pastore, Lancet Oncol 2015). Results: Immunophenotyping by mass cytometry revealed a subset of activated Tregs identified by co-expression of TIGIT, CTLA-4, PD-1, ICOS and OX40, and higher expression of FOXP3, CD25 and CD45RO, that was present in DLBCL and tonsils, but lacking in peripheral blood. This was validated by fluorescent flow cytometry, demonstrating significantly higher frequencies of activated Tregs in NHL tumors compared to PBMCs and tonsils from healthy donors. The phenotypic heterogeneity of intratumoral Tregs reflected different suppressive capacities as activated Tregs more potently suppressed the proliferation of autologous effector CD4 + and CD8 + T cells than naïve Tregs. For global transcriptomic profiling of CD4 + T cells from FL, DLBCL and tonsillar samples, we integrating scRNA-seq and CITE-seq data from 17,774 cells, revealing 13 distinct cellular states including three states of Tregs: naïve, activated and non-conventional LAG3 +FOXP3 - Tregs. Activated Tregs had higher expression of checkpoint receptors (TNFRSF4, TNFRSF18, ICOS), phosphatases (DUSP2, DUSP4), NF-κB pathway (NFKBIA, TNFAIP3, NFKBIZ, REL), chemokine receptors (CXCR4) and transcription factors (JUNB, IRF1, STAT3) as compared to naïve Tregs. We next used a computational approach to develop unique signature matrices for each Treg subset. This approach demonstrated strong concordance between CIBERSORTx estimated cell abundances of the three Treg subsets and the ground truth, and was validated in two external scRNA-seq cohorts. The development of unique signature matrices for Treg subsets facilitated imputation of their frequencies in bulk RNA-seq datasets. These analyses revealed that higher frequency of activated Tregs was enriched in the germinal B cell subtype of DLBCL and was associated with adverse outcome in FL. Conclusion: This study demonstrates that Tregs infiltrating NHL tumors are transcriptionally and functionally diverse and include highly immunosuppressive activated Tregs co-expressing several checkpoint receptors, which distinguish them from peripheral blood Tregs. Activated intratumoral Tregs could hamper clinical responses to checkpoint blockade, and identifying and targeting their vulnerabilities has the potential to improve anti-tumor immune responses. Disclosures Holte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Alizadeh: Cibermed: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; CAPP Medical: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Forty Seven: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Foresight Diagnostics: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Roche: Consultancy, Honoraria; Janssen Oncology: Honoraria; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Bristol Myers Squibb: Research Funding. more...

Background: Follicular lymphoma is an indolent disease with a continuous relapsing pattern and typically requires multiple lines of therapy. Novel therapies such as tisagenlecleucel are being investigated to improve outcomes. Primary analysis of the single-arm, multicenter, Phase II ELARA trial in r/r FL demonstrated that tisagenlecleucel resulted in high overall (ORR) and complete response rates (CRR), and prolonged progression-free survival (PFS) at a median follow-up of 11 months (mo). Here, we report updated efficacy results from the overall population at a median follow-up of 17 mo, and a subgroup analysis of pts with high-risk disease from the ELARA trial (NCT03568461). Methods: Eligible adult pts had histologically confirmed r/r FL (grades 1-3A) after ≥2 lines of therapy or had relapsed after autologous stem cell transplant. Bridging therapy was allowed and was followed by disease evaluation before tisagenlecleucel infusion. Pts received tisagenlecleucel (0.6-6×10 8 CAR+ viable T cells) after lymphodepleting chemotherapy (fludarabine [25 mg/m 2] + cyclophosphamide [250 mg/m 2] QD for 3 d or bendamustine [90 mg/m 2] QD for 2 d). Endpoints included ORR, CRR, PFS, and duration of response (DOR). Descriptive efficacy subanalyses were performed for 9 high-risk subgroups, including prior hematopoietic stem cell transplant (HSCT), ≥5 prior lines of therapy, progression of disease within 24 mo from first immunochemotherapy (POD24), double-refractory disease, high Follicular Lymphoma International Prognostic Index (FLIPI) at study entry, high lactate dehydrogenase at baseline, high C-reactive protein (CRP) prior to infusion, radiological bulky disease (by GELF criteria), and high total metabolic tumor volume (TMTV; >510 cm 3) at baseline (median 155.32 cm 3; range 0.1-2470.4 cm 3). Descriptive subgroup analysis was supported by multivariate analysis to identify factors predictive of worse outcomes. Results: As of March 29, 2021, 97 pts received tisagenlecleucel and 94 were evaluable for primary efficacy analysis (median follow-up 17 mo). High and durable responses were seen in the overall ELARA population (ORR 86.2%, CRR 69.1%, 9-mo DOR 76.0%, and 12-mo PFS 67.0%). In CR pts at 9 mo, PFS was 85.5% and estimated probability of remaining in response was 86.5%. Safety reflected known tisagenlecleucel profile; 48% of pts had CRS (majority were grade 1/2) and 11.3% had neurological events (3% grade ≥3). In the subgroup analysis, pts were stratified into risk groups. Efficacy (ORR, CRR) and durability of response were well maintained in all high-risk subgroups, except for POD24 (n=35), high TMTV (n=20), and ≥5 prior lines of therapy (n=27). Compared with corresponding low-risk subgroups, there was a numerical reduction in CRR for high-risk subgroups (POD24 59.0% vs 87.9%; high TMTV 40.0% vs 76.4%; ≥5 prior lines of therapy 59.3% vs 73.1%) (Figure). A reduction in 12-mo PFS was also identified for pts in these subgroups: POD24 (60.8% vs 77.9%), high baseline TMTV (54.5% vs 68.5%), and ≥5 prior lines of therapy (59.6% vs 69.7%). Evaluating the disease characteristics of the high TMTV subgroup compared with low TMTV, high TMTV was associated with a higher incidence of bulky disease (58.3% vs 90.0%), high FLIPI (54.2% vs 85.0%), and high CRP (45.8% vs 70.0%). In the multivariate analysis of high-risk factors, only POD24 (hazard ratio [HR] 2.34; 95% CI, 1.02- 5.34) and high TMTV (HR 2.53; 95% CI, 1.14-5.65) were associated with shorter PFS. For pts with both POD24 and high TMTV (n=12), the CRR was 16.7% with a 12-mo PFS of 36.0%. These analyses of high-risk subgroups are exploratory in nature and should be validated in a larger study cohort. Conclusions : With 17-mo median follow-up, tisagenlecleucel produced high ORR and CRR and was associated with durable response and promising 12-mo PFS in pts with r/r FL and 2+ prior lines of therapy. Safety was consistent with known tisagenlecleucel profile. POD24 and high TMTV were independently associated with PFS. These results suggest that tisagenlecleucel can induce high rates of durable response, including most pts in the high-risk disease subgroups, who have poor prognosis with current non-CAR-T cell therapies. Figure 1 Figure 1. Disclosures Thieblemont: Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Dickinson: Amgen: Honoraria; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Research Funding; Celgene: Research Funding; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Martinez-Lopez: Incyte: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; BMS: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; Astellas: Research Funding, Speakers Bureau. Kolstad: Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding. Popplewell: Pfizer: Other: Travel; Novartis: Other: Travel; Hoffman La Roche: Other: Food. Chavez: AstraZeneca: Research Funding; Novartis: Consultancy; MorphoSys: Speakers Bureau; Karyopharm Therapeutics: Consultancy; Adaptive: Research Funding; Kite/Gilead: Consultancy; Abbvie: Consultancy; Merck: Research Funding; BeiGene: Speakers Bureau; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Speakers Bureau; Epizyme: Speakers Bureau. Bachy: Roche: Consultancy; Takeda: Consultancy; Kite, a Gilead Company: Honoraria; Novartis: Honoraria; Daiishi: Research Funding; Incyte: Consultancy. Kato: Kyowa Kirin: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Research Funding; Dainippon-Sumitomo: Honoraria; Daiichi Sankyo: Consultancy, Research Funding; Chugai: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; AstraZeneca: Consultancy; Abbvie: Consultancy, Research Funding; MSD: Honoraria; Mundi: Honoraria; Novartis: Consultancy, Research Funding; Ono: Honoraria, Research Funding. Harigae: Novartis Pharma: Honoraria, Research Funding; Chugai Pharma: Honoraria; Janssen Pharma: Honoraria; Ono pharma: Honoraria, Other: Subsidies or Donations; Astellas Pharma: Other: Subsidies or Donations; Kyowakirin: Other: Subsidies or Donations; Bristol Myers Squibb: Honoraria. Kersten: Kite/Gilead: Honoraria, Research Funding; Novartis: Honoraria; Miltenyi Biotech: Honoraria; BMS/Celgene: Honoraria, Research Funding; Roche: Honoraria; Takeda: Honoraria. Andreadis: GenMAB: Research Funding; Karyopharm: Honoraria; Incyte: Honoraria; BMS/Celgene: Research Funding; Epizyme: Honoraria; Crispr Therapeutics: Research Funding; Atara: Consultancy, Honoraria; Novartis: Research Funding; Kite: Honoraria; Merck: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; TG Therapeutics: Honoraria. Riedell: Kite/Gilead: Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; BeiGene: Consultancy; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees; Xencor: Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Calibr: Research Funding. Pérez-Simón: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Chen: Mesolbast: Honoraria; Morphosys: Honoraria. Nastoupil: MorphoSys: Honoraria; Bayer: Honoraria; Genentech: Honoraria, Research Funding; Takeda: Honoraria, Other: DSMC, Research Funding; IGM Biosciences: Research Funding; Denovo Pharma: Other: DSMC; Bristol Myers Squibb/Celgene: Honoraria, Research Funding; Caribou Biosciences: Research Funding; Novartis: Honoraria, Research Funding; Gilead/Kite: Honoraria, Research Funding; TG Therapeutics: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; ADC Therapeutics: Honoraria; Epizyme: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Von Tresckow: Pentixafarm: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Congress and travel support, Research Funding; MSD: Consultancy, Honoraria, Other: Congress and travel support, Research Funding; Kite-Gilead: Consultancy, Honoraria; BMS-Celgene: Consultancy, Honoraria, Other: Congress and travel support; AstraZeneca: Honoraria, Other: Congress and travel support; Amgen: Consultancy, Honoraria; AbbVie: Other: Congress and travel support; Pfizer: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other, Research Funding. Ferreri: Gilead, Novartis, Juno, PletixaPharm, Roche, Incyte: Membership on an entity's Board of Directors or advisory committees; BMS, Beigene, Pharmacyclics, Hutchison Medipharma, Amgen, Genmab, ADC Therapeutics, Gilead, Novartis, Pfizer: Research Funding. Teshima: Fuji pharma CO.,Ltd: Research Funding; Astellas Pharma Inc.: Research Funding; TEIJIN PHARMA Limited: Research Funding; CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; Pfizer Inc.: Honoraria; Merck Sharp & Dohme: Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin Co.,Ltd.: Honoraria, Research Funding; Takeda Pharmaceutical Company: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis International AG: Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Janssen Pharmaceutical K.K.: Other; Nippon Shinyaku Co., Ltd.: Research Funding; Bristol Myers Squibb: Honoraria; Sanofi S.A.: Research Funding; Gentium/Jazz Pharmaceuticals: Consultancy. Patten: ASTRA ZENECA: Honoraria; ABBVIE: Honoraria; NOVARTIS: Honoraria; GILEAD SCIENCES: Honoraria, Research Funding; ROCHE: Research Funding; JANSSEN: Honoraria. McGuirk: Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Novartis: Research Funding; Gamida Cell: Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding; EcoR1 Capital: Consultancy; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Astelllas Pharma: Research Funding; Bellicum Pharmaceuticals: Research Funding; Pluristem Therapeutics: Research Funding. Petzer: AppVie: Honoraria; Astra Zeneca: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Sandoz: Honoraria. Viardot: University Hospital of Ulm: Current Employment; F. Hoffmann-La Roche Ltd: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees. Zinzani: JANSSEN-CILAG: Other: Advisory board, Speakers Bureau; NOVARTIS: Consultancy, Other, Speakers Bureau; EUSAPHARMA: Consultancy, Other, Speakers Bureau; SANDOZ: Other: Advisory board; MSD: Consultancy, Other: Advisory board, Speakers Bureau; TAKEDA: Other: Advisory board, Speakers Bureau; BMS: Other: Advisory board, Speakers Bureau; TG Therapeutics: Other: Advisory board, Speakers Bureau; ROCHE: Other, Speakers Bureau; SERVIER: Other: Advisory board, Speakers Bureau; KYOWA KIRIN: Other, Speakers Bureau; Incyte: Other, Speakers Bureau; CELLTRION: Other: Advisory board, Speakers Bureau; ADC Therap.: Other; GILEAD: Other: Advisory board, Speakers Bureau; Beigene: Other, Speakers Bureau; VERASTEM: Consultancy, Other: Advisory board, Speakers Bureau. Malladi: Gilead Science: Consultancy; Gilead: Honoraria, Other: Travel support. Lobetti Bodoni: Spouse: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Spouse: Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Spouse: Celgene: Honoraria; Spouse: Harlcok Healthcare: Current holder of individual stocks in a privately-held company; Spouse: Takeda: Consultancy, Honoraria, Speakers Bureau; Spouse: Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Spouse: NHS: Ended employment in the past 24 months; Spouse: F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company; Gilead: Other: Travel sponsorship in June 2019; Novartis: Current Employment, Current equity holder in publicly-traded company. Masood: Novartis: Current Employment, Current holder of stock options in a privately-held company. Schuster: Genentech/Roche: Consultancy, Research Funding; Tessa Theraputics: Consultancy; Loxo Oncology: Consultancy; BeiGene: Consultancy; Juno Theraputics: Consultancy, Research Funding; Alimera Sciences: Consultancy; Merck: Research Funding; Incyte: Research Funding; Acerta Pharma/AstraZeneca: Consultancy; Abbvie: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; TG Theraputics: Research Funding; Pharmacyclics: Research Funding; Adaptive Biotechnologies: Research Funding; Nordic Nanovector: Consultancy; Celgene: Consultancy, Honoraria, Research Funding. Fowler: Bristol Myers Squibb, F. Hoffmann-La Roche Ltd, TG Therapeutics and Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; BostonGene, Corp: Current Employment, Current holder of stock options in a privately-held company. Dreyling: Bayer HealthCare Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau; Astra Zeneca: Consultancy, Speakers Bureau; BeiGene: Consultancy; Celgene: Consultancy, Research Funding, Speakers Bureau; Genmab: Consultancy; Amgen: Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Gilead/Kite: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; Abbvie: Research Funding. more...

Despite recent advances in lymphoma treatment, mantle cell lymphoma (MCL) remains incurable, and we are still unable to identify patients who will not benefit from the current standard of care. Here, we explore the prognostic value of recurrent genetic aberrations in diagnostic bone marrow (BM) specimens from 183 younger patients with MCL from the Nordic MCL2 and MCL3 trials, which represent current standard-of-care regimens. In the univariate model, mutations of TP53 (11%) and NOTCH1 (4%), and deletions of TP53 (16%) and CDKN2A (20%), were significantly associated with inferior outcomes (together with MIPI, MIPI-c, blastoid morphology, and Ki67 > 30%); however, in multivariate analyses, only TP53 mutations (HR, 6.2; P 30%, blastoid morphology, MIPI high-risk, and inferior responses to both induction- and high-dose chemotherapy. In conclusion, we show that TP53 mutations identify a phenotypically distinct and highly aggressive form of MCL with poor or no response to regimens including cytarabine, rituximab, and autologous stem-cell transplant (ASCT). We suggest patients with MCL should be stratified according to TP53 status, and that patients with TP53 mutations should be considered for experimental frontline trials exploring novel agents. more...

177Lu-lilotomab satetraxetan is a novel antibody radionuclide conjugate (ARC) currently in a phase 1/2a first-in-human dosage escalation trial for patients with relapsed CD37+ indolent non Hodgkin lymphoma (NHL). The aim of this study was to investigate biodistribution and absorbed doses to organs at risk. Methods: A total of seven patients treated with 177Lu-lilotomab satetraxetan were included for dosimetry. Patients were grouped based on two different pre-dosing regimens (with and without pre-dosing with 40 mg lilotomab) and were treated with different levels of activity per body weight (10, 15 and 20 MBq/kg). All patients were pre-treated with rituximab. Serial planar and SPECT/CT-images were used to determine time activity curves and patient specific masses for organs with 177Lu-lilotomab satetraxetan uptake. Doses were calculated with OLINDA/EXM. Results: Organs with distinct uptake of 177Lu-lilotomab satetraxetan, in addition to red bone marrow and tumors, were liver, spleen and kidneys. Largest uptake was found in the spleen, where doses ranged from 1.54 to 3.60 mGy/MBq. The liver received 0.70 to 1.15 mGy/MBq. The kidneys received the lowest dose of the source organs investigated; 0.16 to 0.79 mGy/MBq. No statistical significant differences in soft tissue absorbed doses for the two pre-dosing regimens were found. Whole body (WB) dose ranged from 0.08 to 0.17 mGy/MBq. Conclusion: The biodistribution study for patients treated with 177Lu-lilotomab satetraxetan revealed highest physiological uptake in liver and spleen, besides red marrow. For all dosage levels investigated, doses were found modest when compared to commonly assumed tolerance limits. The LYMRIT37-01 study is sponsored by Nordic Nanovector ASA. Johan Blakkisrud is supported by grants from the South-Eastern Norway Regional Health Authority. Harald Holte and Arne Kolstad were both in part supported by grants from the Norwegian Cancer Society. more...

Background: Mantle cell lymphoma (MCL) is a rare, often aggressive type of B-cell lymphoma with poor survival and no cure. Cancer and cancer treatment has a negative impact on health-related quality of life (HRQOL) both during active disease and in the long term, and improvement of HRQOL may be one of the most important objectives of cancer therapy. In addition, baseline HRQOL has in other lymphoma populations been shown to be predictive of outcome. Hitherto, there are only few reports on HRQOL in MCL. The primary aim of this study was to explore HRQOL before, during and after chemotherapy in an elderly population with MCL. Secondary aims were to identify predictors for HRQOL, information that can be used for improvement in rehabilitation. Methods: The cohort consisted of patients included in the multicenter open-label phase Ib-II NLG-MCL4 trial (LENA-BERIT), designed to evaluate the addition of lenalidomide (LEN) to rituximab-bendamustine (R-B) as first-line treatment in elderly patients (>65 years) with MCL. The treatment with R-B stopped after six months, LEN continued for six more months. HRQOL was assessed by the EORTC QLQ-C30 questionnaire pre-treatment, and after 6, 12 and 24 months post study inclusion. For the functional scales and the global quality of life scale a higher score represents a better level of functioning. For the symtom scales and single items, a higher score corresponds to a higher level of symtoms. Patient scores were compared to scores from a reference population sample at baseline. Survival was analysed by Kaplan-Meier estimates, and cox regression multivariate analysis was used to assess survival with adjustments for prognostic factors, age, sex and more. Results: Fifty-one patients were enrolled, 1 patient was excluded based on screen failure. Median age was 71 years (range 62-84), 37 were men (73%). Stratified according to Mantle Cell Lymphoma International Prognostic Index (MIPI), 5 (10%) were low-risk, 18 (38%) intermediate and 26 (52%) high-risk. Follow-up time for living patients were 52 months, and for deceased patients 27 months. Median overall survival time were 52 months. The proportion of patients reporting HRQOL data was at baseline; 48 (96%), after 6 months; 33 (83%), after 12 months; 27 (89%), and after 24 months; 12 (75%). During the first six months of treatment, several functional scores deteriorated, and after 12 months it had stabilised at baseline level or better. The global health status (QoL) improved at 12 months after diagnosis, but then dropped to baseline levels after 2 years. Before treatment, patients exhibited levels of the symptom scores, comparable to the reference population. Six months after start of therapy, the scores for pain, dyspnoea and insomnia were improved, while appetite loss and diarrhoea were impaired. After 12 months, the symptom scales improved to a level superior compared both to baseline and the reference population. The population was divided into two groups, with the median as cut-off values. In the multivariate analysis, including MIPI, gender and the presence of TP53 mutation, impaired pre-treatment physical function, role function and elevated pain score were independent prognostic markers for overall survival. Role function and pain were also independent prognostic markers for progression free survival. Conclusion: In this population of elderly patients with MCL, pre-treatment HRQOL was similar to the reference population. During treatment, HRQOL deteriorated, but reverted to the same level as the reference population after treatment. Pre-treatment physical and role function and pain were independent factors associated with overall survival. These novel findings may be used to design support during treatment and improve rehabilitation. Figure Disclosures Jerkeman: Roche: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Gilead: Research Funding; Abbvie: Research Funding. more...

Introduction: Regulatory T cells (Tregs), a highly immunosuppressive subset of CD4 T cells, are enriched in B-cell non-Hodgkin lymphoma (NHL) and constitute a barrier to potent antitumor immune responses. Despite extensive studies, the significance of tumor-infiltrating Tregs on disease outcome is unclear and while Tregs may express co-inhibitory and co-stimulatory receptors, the role of intratumoral Tregs in the context of immune checkpoint therapy remains elusive. Emerging evidence suggests heterogeneity among Tregs and their suppressive capacities in cancer, emphasizing the need for additional markers to identify highly suppressive Tregs. Therefore, an in-depth characterization of Treg heterogeneity in NHL could provide important insight into the disease pathogenesis and have implications for rational drug design. Methods: Expression of checkpoint receptors in Tregs was characterized by fluorescence flow cytometry and mass cytometry analysis of single-cell suspensions from diffuse large B-cell lymphoma (DLBCL; n = 16), follicular lymphoma (FL; n = 8), mantle cell lymphoma (MCL; n = 10), marginal zone lymphoma (MZL; n = 2), chronic lymphocytic lymphoma (CLL; n = 7), as well as tonsils (n = 8) and peripheral blood (n = 4) from healthy donors. Functional characterization of intratumoral Tregs was performed by a proliferation assay using FACS-sorted Tregs as suppressor cells and autologous CellTrace Violet-labelled T effector cells as responder cells. Single-cell RNA sequencing (scRNA-seq) was performed on FACS-sorted CD4 T cells from 3 DLBCL, 3 FL and 3 healthy donor tonsils using the 10X Genomics single cell 5' based library construction and VDJ libraries for TCR-sequencing. Additionally, for simultaneous profiling of phenotypic features with the mRNA expression in single cells, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITEseq) was applied. The Treg compartment was characterized by clustering into distinct transcriptional Treg states and differential expression of marker genes. Results: TIGIT and CTLA-4 were identified as common markers of intratumoral Tregs, in addition to FOXP3 and CD25. Unsupervised computational analysis revealed two distinct Treg subsets, based on contrasting expression of PD-1, OX40, CD226 and ICOS (Figure 1A). One subset displayed a checkpoint receptorlow phenotype that corresponded to peripheral blood Tregs. The second subset had a checkpoint receptorhigh phenotype with elevated levels of PD-1, OX40, ICOS, TIGIT, CTLA-4 and increased levels of activation markers CD28, CD69 and CD95/Fas. The frequency of checkpoint receptorhigh Tregs was significantly increased in NHL tumors, compared to PBMCs and tonsils from healthy donors. FL tumors had the highest frequency of Tregs with receptorhigh phenotype among the NHL entities (median frequency of 86%, range 71-92%) and DLBCL had the highest donor-to-donor variation (median frequency of 77%, range 35-98%) (Figure 1B). This phenotypic heterogeneity of the Treg compartment reflected different suppressive capacities of the two subsets. Checkpoint receptorhigh Tregs were more potent mediators of immunosuppression in terms of suppressing the proliferation of autologous effector CD4 and CD8 T cells (Figure 1C). Furthermore, transcriptomic analysis of CD4 T cells by scRNA-seq and CITEseq revealed distinct transcriptomic signatures of the checkpoint receptorhigh and -receptorlow subsets. In addition, a third subset of Tregs, characterized by increased expression of LAG3 and immunosuppression-associated genes (CTLA-4, IL10, CD38, KLRB1) but lack of FOXP3, was identified (Figure 1D-E). Analysis of scTCR-sequences to compare TCR repertoires and to identify developmental trajectories will further add to our knowledge of intratumoral Tregs. Conclusions: These results reveal heterogeneity within the Treg compartment in NHL based on expression of checkpoint receptors, transcriptional profiles and suppressive capacities. As intratumoral Treg phenotypes differ from peripheral blood Tregs, this presents new therapeutic opportunities. Specific targeting of intratumoral Tregs would lead to stronger antitumor effects while limiting immune-related adverse events. A deeper understanding of Treg heterogeneity within the tumor microenvironment could therefore open new paths for rational design of immune checkpoint therapy. Disclosures Kolstad: Merck: Research Funding; Nordic Nanovector: Membership on an entity's Board of Directors or advisory committees, Research Funding. Alizadeh:Janssen: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy; Chugai: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Roche: Consultancy; Pfizer: Research Funding. more...

7508 Background: Most pts with r/r FL experience multiple relapses and progressively worse clinical outcomes with each line of therapy, underlining a need for novel therapies. Tisa-cel has demonstrated durable responses and manageable safety in adult pts with r/r diffuse large B-cell lymphoma. Here we report the primary analysis of ELARA, an international, single-arm phase 2 trial of tisa-cel in adult pts with r/r FL. Methods: Eligible pts (≥18 y) had r/r FL (grades [Gr] 1-3A) after ≥2 lines of therapy or had failed autologous stem cell transplant. Bridging therapy was permitted followed by disease assessment prior to tisa-cel infusion. Pts received tisa-cel (0.6-6×108 CAR+ viable T cells) after lymphodepleting chemotherapy. The primary endpoint was complete response rate (CRR) by central review per Lugano 2014 criteria. Secondary endpoints included overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), safety, and cellular kinetics. Predefined primary analysis occurred when ≥90 treated pts had ≥6 mo of follow-up. Results: As of September 28, 2020, 98 pts were enrolled and 97 received tisa-cel (median follow-up, 10.6 mo). At study entry, median age among treated pts was 57 y (range, 29-73), 85% had stage III-IV disease, 60% had a FLIPI score ≥3, 65% had bulky disease, and 42% had LDH > upper limit of normal. The median number of prior therapies was 4 (range, 2-13); 78% of pts were refractory to their last treatment (76% to any ≥2 prior regimens) and 60% progressed within 2 y of initial anti-CD20–containing treatment. Of 94 pts evaluable for efficacy, the CRR was 66% (95% CI, 56-75) and the ORR was 86% (95% CI, 78-92). CRRs/ORRs were comparable among key high-risk subgroups. Estimated DOR (CR) and PFS rates at 6 mo were 94% (95% CI, 82-98) and 76% (95% CI, 65-84), respectively. Of 97 pts evaluable for safety, 65% experienced Gr ≥3 adverse events within 8 weeks post-infusion, most commonly neutropenia (28%) and anemia (13%). Any-grade cytokine release syndrome (per Lee scale) occurred in 49% of pts (Gr ≥3, 0%). Any-grade neurological events (per CTCAE v4.03) occurred in 9% of pts (Gr 3, 0%; Gr 4, 1 pt and recovered). Three pts died from progressive disease. Cellular kinetic parameters for tisa-cel were estimated using transgene levels (by qPCR) in peripheral blood. Cmax and AUC0-28d were similar between responders (CR or partial response) and non-responders (stable or progressive disease). Maximum transgene levels were reached by a median of 10 days in responders and 12.9 days in non-responders; transgene persistence was detected up to 370 days and 187 days, respectively. Conclusions: These data demonstrate the efficacy and acceptable safety of tisa-cel in pts with r/r FL, including high-risk pts after multiple lines of prior therapy, and suggest that tisa-cel may be a promising therapy for pts with r/r FL. Clinical trial information: NCT03568461. more...

Background Follicular lymphoma (FL) is an indolent non-Hodgkin lymphoma that has a risk of transformation to more aggressive lymphoma. Relatively little is known about the nonmalignant B-cell and T-cell subset composition within the tumor microenvironment and whether altered phenotypes are associated with patterns of lymphoma B-cell heterogeneity. Methods Two mass cytometry (CyTOF) panels were designed to immunophenotype B and T cells in FL tumors. Populations of malignant B cells, nonmalignant B cells, and T cells from each FL tumor were identified and their phenotypes compared to B and T cells from healthy human tonsillar tissue. Results Diversity in cellular phenotype between tumors was greater for the malignant B cells than for nonmalignant B or T cells. The malignant B-cell population bore little phenotypic similarity to any healthy B-cell subset, and unexpectedly clustered closer to naive B-cell populations than GC B-cell populations. Among the nonmalignant B cells within FL tumors, a significant lack of GC and plasmablast B cells was observed relative to tonsil controls. In contrast, nonmalignant T cells in FL tumors were present at levels similar to their cognate tonsillar T-cell subsets. Conclusion Mass cytometry revealed that diverse HLA-DR expression on FL cells within individual tumors contributed greatly to tumor heterogeneity. Both malignant and nonmalignant B cells in the tumor bore little phenotypic resemblance to healthy GC B cells despite the presence of T follicular helper cells in the tumor. These findings suggest that ongoing signaling interactions between malignant B cells and intra-tumor T cells shape the tumor microenvironment. © 2016 International Clinical Cytometry Society more...

Red marrow (RM) is often the primary organ at risk in radioimmunotherapy; irradiation of marrow may induce short- and long-term hematologic toxicity. 177Lu-lilotomab satetraxetan is a novel anti-CD37 antibody-radionuclide conjugate currently in phase 1/2a. Two predosing regimens have been investigated, one with 40 mg of unlabeled lilotomab antibody (arm 1) and one without (arm 2). The aim of this work was to compare RM-absorbed doses for the two arms and to correlate absorbed doses with hematologic toxicity. Methods Eight patients with relapsed CD37+ indolent B-cell non-Hodgkin lymphoma were included for RM dosimetry. Hybrid SPECT and CT images were used to estimate the activity concentration in the RM of L2-L4. Pharmacokinetic parameters were calculated after measurement of the 177Lu-lilotomab satetraxetan concentration in blood samples. Adverse events were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. Results The mean absorbed doses to RM were 0.9 mGy/MBq for arm 1 (lilotomab+) and 1.5 mGy/MBq for arm 2 (lilotomab-). There was a statistically significant difference between arms 1 and 2 (Student t test, P = 0.02). Total RM-absorbed doses ranged from 67 to 127 cGy in arm 1 and from 158 to 207 cGy in arm 2. For blood, the area under the curve was higher with lilotomab predosing than without (P = 0.001), whereas the volume of distribution and the clearance of 177Lu-lilotomab satetraxetan was significantly lower (P = 0.01 and P = 0.03, respectively). Patients with grade 3/4 thrombocytopenia had received significantly higher radiation doses to RM than patients with grade 1/2 thrombocytopenia (P = 0.02). A surrogate, non-imaging-based, method underestimated the RM dose and did not show any correlation with toxicity. Conclusion Predosing with lilotomab reduces the RM-absorbed dose for 177Lu-lilotomab satetraxetan patients. The decrease in RM dose could be explained by the lower volume of distribution. Hematologic toxicity was more severe for patients receiving higher absorbed radiation doses, indicating that adverse events possibly can be predicted by the calculation of absorbed dose to RM from SPECT/CT images. more...