The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

Phase I/II clinical trial of temsirolimus and lenalidomide in patients with relapsed and refractory lymphomas

The PI3K/Akt/mTOR (PAM) axis is constitutively activated in multiple lymphoma subtypes and is a promising therapeutic target. The mTOR inhibitor temsirolimus (TEM) and the immunomodulatory agent lenalidomide (LEN) have overlapping effects within the PAM axis with synergistic potential. This multicenter phase I/II study evaluated combination therapy with TEM/LEN in patients with relapsed and refractory lymphomas. Primary endpoints of the phase II study were rates of complete (CR) and overall response (ORR). There were 18 patients in the phase I dose-finding study, and TEM 25 mg weekly and LEN 20 mg on day 1 through day 21 every 28 days was established as the recommended phase II dose. An additional 93 patients were enrolled in the phase II component with three cohorts: diffuse large B-cell lymphoma (DLBCL, n=39), follicular lymphoma (FL, n=15), and an exploratory cohort of other lymphoma histologies with classical Hodgkin lymphoma (cHL) comprising the majority (n=39 total, n=20 with cHL). Patients were heavily pretreated with a median of four (range, 1-14) prior therapies and one-third with relapse following autologous stem cell transplantation (ASCT); patients with cHL had a median of six prior therapies. The FL cohort was closed prematurely due to slow accrual. ORR were 26% (13% CR) and 64% (18% CR) for the DLBCL and exploratory cohorts, respectively. ORR for cHL patients in the exploratory cohort, most of whom had relapsed after both brentuximab vedotin and ASCT, was 80% (35% CR). Eight cHL patients (40%) proceeded to allogeneic transplantation after TEM/LEN therapy. Grade ≥3 hematologic adverse events (AE) were common. Three grade 5 AE occurred. Combination therapy with TEM/LEN was feasible and demonstrated encouraging activity in heavily-pretreated lymphomas, particularly in relapsed/refractory cHL (clinicaltrials gov. Identifier: NCT01076543).

Characteristics and Outcome of Extranodal NK/T-cell Lymphoma in North America: A Retrospective Multi-Institutional Experience

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTL) is rare and clinical data from non-Asian countries are lacking. It is unclear whether outcomes and disease natural history is similar to reported Asian series. We assessed characteristics and outcomes of patients with ENKTL from major North American centers.

PATIENTS AND METHODS

We retrospectively identified patients with newly-diagnosed CD56 + ENKTL and studied disease characteristics and clinical outcomes.

RESULTS

One hundred and twenty-one patients with ENKTL diagnosed between June 1990 and November 2012 were identified. Eighty-three patients (69%) had stage I/II disease and were treated with combined modality therapy (CMT) (n = 53), chemotherapy alone (CT) (n = 14) or radiotherapy alone (RT) (n = 16).  Thirty-eight patients (31%) had stage III/IV disease and were treated with CMT (n = 12), CT (n = 23), or RT (n = 3).  The median follow-up for the entire cohort was 51 months. Patients with stage I/II disease, compared to those with stage III/IV disease, had superior 2-year progression free survival (PFS) 43% vs 19% (P = .03) and overall survival (OS) 59% vs. 29% (P= .004). Outcomes were similar for stage I/II patients who received CMT vs. RT alone with 2-year PFS (53% vs. 47%; P= .91) and OS (67% vs. 67%; P= .58). No significant differences in outcomes were noted based on race/ethnicity.

CONCLUSIONS

This series represents a large experience of ENKTL treated at several major North American academic centers.  Our data are consistent with Asian studies: (1) majority of patients present with early-stage disease; (2) overall poor outcome regardless of race/ethnicity; (3) CMT likely yields favorable outcomes for suitable candidates with early-stage disease.

B-cell lymphoma-2 (BCL2) downregulation is a useful feature -supporting a neoplastic phenotype in mature T-cell lymphomas

Normal T-cells express high levels of BCL2 protein, data regarding BCL2 expression status and its diagnostic utility in T-cell lymphoma is scarce. We evaluated BCL2 expression in a series of mature T-cell lymphoproliferations including indolent and more recently recognized entities (follicular helper T-cell (TFH) lymphomas). Sixty-six neoplastic biopsies (60 patients) representing mature nodal, extranodal and leukemia T-cell neoplasms were collected from three institutes (2 US and 1 Japan) and were compared with reactive T-cells in 8 benign tissues/blood and 9 T-cell rich B-cell proliferations. BCL2 immunostaining was performed and scored based on intensity weighted H-score (0-300). Next generation sequencing (5 cases), BCL2 gene sequencing, and real time-PCR (3 cases) were conducted. Association of H-score with overall survival (using proportional hazards modeling) was assessed in non-leukemic T-cell lymphoproliferations (TCL). Most TCLs showed significantly downregulated median BCL2 H-score (125, range 18-300) with the exception of T-cell prolymphocytic leukemia (T-PLL) and hepatosplenic T-cell lymphoma (HSTL) both of which showed uniform strong retention of BCL2 as did the 8 reactive tissues (median H-score 280; p=0.000). Notably all TFH lymphoma CD4 neoplastic T-cells, subcutaneous panniculitis-like T-cell lymphoma (SPTCL) CD8 adipocyte-rimming T-cells and T-cell large lymphocyte leukemia (T-LGLL) with pathogenic STAT5B and TP53 mutation showed BCL2 downregulation. No BCL2 mutations were observed by NGS or sequencing with decreased BCL2 mRNA transcripts by real-time PCR. BCL2 downregulation is pervasive among many T-cell lymphoproliferations and unrelated to any mutations. There is utility for BCL2 immunostaining in some challenging situations as discussed in manuscript.

SWOG 1918: A phase II/III randomized study of R-miniCHOP with or without oral azacitidine (CC-486) in participants age 75 years or older with newly diagnosed aggressive non-Hodgkin lymphomas - Aiming to improve therapy, outcomes, and validate a prospective frailty tool

Diffuse large B cell lymphoma (DLBCL) is an aggressive but potentially curable malignancy; however, cure is highly dependent on the ability to deliver intensive, anthracycline-based chemoimmunotherapy. Nearly one third of cases of DLBCL occur in patients over age 75 years, and advanced age is an important adverse feature in prognostic models. Despite this incidence in older patients, there is no clear accepted standard of care due to under-representation of this group in large randomized clinical trials. Furthermore, insufficient assessments of baseline frailty and prediction of toxicity hamper clinical decision-making. Here, we present an ongoing randomized study of R-miniCHOP chemoimmunotherapy with or without oral azacitidine (CC-486, Onureg) for patients age 75 and older with newly diagnosed DLBCL and associated aggressive lymphomas. The incorporation of an oral hypomethylating agent is based on increased tumor methylation as a biologic feature of older patients with DLBCL and a desire to minimize the injection burden for this population. This is the first randomized study in this population conducted in North America by the National Clinical Trials Network (NCTN) and will enroll up to 422 patients including 40 patients in a safety run-in phase. This study incorporates an objective assessment of baseline frailty (the FIL Tool) and a serial comprehensive geriatric assessment (CGA). Key correlative tests will include circulating tumor DNA (ctDNA) assays at pre-specified timepoints to explore if ctDNA quantity and methylation patterns correlate with response. S1918 has the potential to impact future trial design and to change the standard of care for patients 75 years and older with aggressive lymphoma given its randomized design, prospective incorporation of geriatric assessments, and exploration of ctDNA correlatives. Trial registration: The trial is registered with ClinicalTrial.gov Identifier NCT04799275.

Phase 1 study of oral azacitidine (CC-486) plus R-CHOP in previously untreated intermediate- to high-risk DLBCL

Resistance to standard immunochemotherapy remains an unmet challenge in diffuse large B-cell lymphoma (DLBCL), and aberrant DNA methylation may contribute to chemoresistance. Promising early-phase results were reported with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) plus subcutaneous azacitidine, a hypomethylating agent. In this phase 1 study, we evaluated CC-486 (oral azacitidine) plus 6 cycles of R-CHOP in patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. CC-486 doses of 100, 150, 200, or 300 mg given 7 days before cycle 1 and on days 8-21 of cycles 1-5 were evaluated; additional patients were enrolled in the expansion phase to examine preliminary efficacy. The primary objectives were to determine the safety and the maximum tolerated dose (MTD) of CC-486 in combination with R-CHOP. The most common grade 3/4 toxicities were hematologic, including neutropenia (62.7%) and febrile neutropenia (25.4%); grade 3/4 nonhematologic toxicities were uncommon (<7%). The MTD was not established; 2 patients had dose-limiting toxicities (1 with grade 4 febrile neutropenia; 1 with grade 4 prolonged neutropenia). The recommended phase 2 dose was established as 300 mg. The overall response rate was 94.9%, with 52 patients (88.1%) achieving complete responses. With a median follow-up of 28.9 months, estimated 1- and 2-year progression-free survival rates were 84.1% and 78.6%, respectively. Overall, epigenetic priming with CC-486 before R-CHOP can be delivered with acceptable safety to patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. ClinicalTrials.gov: NCT02343536.

Single-route CNS prophylaxis for aggressive non-Hodgkin lymphomas: real-world outcomes from 21 US academic institutions

Prophylaxis is commonly used to prevent central nervous sy stem (CNS) relapse in diffuse large B-cell lymphoma (DLBCL), with no clear standard of care. We retrospectively evaluated 1162 adult patients across 21 US academic centers with DLBCL or similar histologies who received single-route CNS prophylaxis as part of frontline therapy between 2013 and 2019. Prophylaxis was administered intrathecally(IT) in 894 (77%) and using systemic high-dose methotrexate (HD-MTX) in 236 (20%); 32 patients (3%) switched route due to toxicity and were assessed separately. By CNS-International Prognostic Index (IPI), 18% were considered low-risk, 51% moderate, and 30% high. Double-hit lymphoma (DHL) was confirmed in 243 of 866 evaluable patients (21%). Sixty-four patients (5.7%) had CNS relapse after median 7.1 months from diagnosis, including 15 of 64 (23%) within the first 6 months. There was no significant difference in CNS relapse between IT and HD-MTX recipients (5.4% vs 6.8%, P = .4), including after propensity score matching to account for differences between respective recipient groups. Weighting by CNS-IPI, expected vs observed CNS relapse rates were nearly identical (5.8% vs 5.7%). Testicular involvement was associated with high risk of CNS relapse (11.3%) despite most having lower CNS-IPI scores. DHL did not significantly predict for CNS relapse after single-route prophylaxis, including with adjustment for treatment regimen and other factors. This large study of CNS prophylaxis recipients with DLBCL found no significant difference in CNS relapse rates between routes of administration. Relapse rates among high-risk subgroups remain elevated, and reconsideration of prophylaxis strategies in DLBCL is of critical need.

DA-R-EPOCH vs R-CHOP in DLBCL: How do we choose?

The emerging molecular and prognostic characterization of diffuse large B-cell lymphoma (DLBCL) has challenged the rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) treatment paradigm in recent years, with the identification of several DLBCL subtypes associated with significantly inferior survival after standard R-CHOP therapy. Efforts to improve upon the R-CHOP backbone have included dose intensification as well as the addition of new agents; the infusional dose-adjusted rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH) regimen has been identified as a potential replacement for R-CHOP in high-risk DLBCL. In this review, we provide a historical perspective on the R-CHOP and DA-R-EPOCH regimens and summarize the clinical trial literature regarding the efficacy of each regimen in various risk groups of DLBCL. Further, we propose clinical management scenarios in which DA-R-EPOCH may be preferred, including some for patient populations in which the use of R-CHOP vs DA-R-EPOCH is controversial.

Outcomes and Utilization Trends of Front-Line Autologous Hematopoietic Cell Transplantation for Mantle Cell Lymphoma

Although autologous hematopoietic cell transplantation (auto-HCT) has become a common practice for eligible patients in the front-line setting with mantle cell lymphoma (MCL), there are limited data regarding trends in auto-HCT utilization and associated outcomes. This study used the Center for International Blood and Marrow Transplant Research (CIBMTR) database to evaluate survival outcomes and auto-HCT utilization in adults age ≥18 years who underwent auto-HCT within 12 months of diagnosis of MCL between January 2000 and December 2018. The 19-year period from 2000 to 2018 was divided into 4 separate intervals-2000 to 2004, 2005 to 2009, 2010 to 2014, and 2015 to 2018-and encompassed 5082 patients. To evaluate transplantation utilization patterns, we combined MCL incidence derived from the SEER 21 database with CIBMTR- reported auto-HCT activity within 12 months of diagnosis of MCL. Primary outcomes included overall survival (OS) along with the auto-HCT utilization rate. The cumulative incidence of nonrelapse mortality at 1 year decreased from 7% in the earliest cohort (2000 to 2004) to 2% in the latest cohort (2015 to 2018). Mirroring this trend, OS outcomes improved continually with time, with a 3-year OS of 72% in the earliest cohort improving to 86% in the latest cohort. In addition, we noted an increase in auto-HCT utilization from 2001 to 2018, particularly in patients age ≤65 years. This large retrospective analysis highlights trends in auto-HCT utilization and outcomes in patients with MCL and emphasizes the need to optimize pretransplantation and post-transplantation treatment strategies to enhance survival outcomes.

Media coverage of evidence outputs during the COVID-19 pandemic: findings from one national agency

Background

The COVID-19 Evidence Synthesis Team within the Health Information and Quality Authority (HIQA) in Ireland produced a range of evidence-based reports on a broad range of public health topics related to COVID-19. These evidence outputs (EO) arose directly from questions posed by policy makers and clinicians supporting Ireland's National Public Health Emergency Team (NPHET). Findings from these EOs informed the national response to the COVID-19 pandemic in Ireland and influenced international public health guidance. How research findings are presented through domestic news can influence behaviour and risk perceptions.

Methods

We investigated traditional media coverage of nine COVID-19 EOs and associated press releases, published (April to July 2020) by HIQA. NVivo was used for conceptual content analysis of manifest content. ‘Core messages' from each evidence output were proposed and 488 sources from national and regional broadcast, print, and online media were coded at the phrase level. The presence of political and public health actors in coverage were also coded.

Results

Coverage largely did not distort or misrepresent the results of the EOs, however, there was variability in terms of what content was reported on and to what extent different stakeholders were involved in the contextualization of the findings of the EOs. Coverage appeared to focus more on ‘human-interest' stories as opposed to more technical reports (e.g. focusing on viral load, antibodies, testing, etc.). Selective reporting and the variability in the use of quotes from governmental and public health stakeholders changed and contextualized results in different manners than perhaps originally intended in the press release.

Conclusions

Our findings provide a case-study of European media coverage of evidence reports produced by a national agency. Results highlighted several strengths and weaknesses of current communication efforts.

Evaluating rapid review provision to inform policy during the COVID-19 pandemic

Background

Evidence based decision making is central to population health, particularly during a pandemic. Few studies examine the production and use of evidence in decision-making during crisis management. This study describes and evaluates the provision of rapid evidence products by a single agency to support national decision making.

Methods

Semi-structured interviews were conducted with a convenience sample of evidence providers (who gathered and disseminated the required evidence) and service users (policy makers). Interviews were transcribed verbatim and analysed using thematic analysis. Quantitative data of work activity were summarised descriptively.

Results

Three themes were generated from the data: the work, the use and the future, with a fourth theme cross-cutting across these: the team. The work followed clear protocols and was centrally managed. The scope and changing nature of the evidence were highlighted as issues. The service providers reported a strong sense of team work and ‘being in this together', however, the majority of the participants felt that the workload was huge and exhausting and not sustainable long-term. Overall the service users thought the rapid evidence synthesis was indispensable to the decision-making process and had trust and confidence in the work, largely based on existing working relationships with the team. While they recognised that the evidence synthesis support would be an essential component of the continued pandemic response, they did query the sustainability of the process and reflected on the amount of work the team performed.

Conclusions

This evaluation, drawing on qualitative data, has highlighted that, across the services users and evidence providers, the support provided by HIQA was generally perceived as positive. From the service users' perspective, having access to the team was indispensable to the decision making process. However, the sustainability of the work load was identified as a major challenge.

COVID-19 - Interventions and lifestyle factors that prevent infection or minimise progression to severe disease

Background

This evidence summary synthesised the evidence relating to pharmacological and non-pharmacological interventions in the community to prevent COVID-19/progression to severe disease. An additional aim was to identify potentially modifiable lifestyle factors associated with reduced risk of infection/progression to severe disease.

Methods

A systematic search of published peer-reviewed articles and non-peer-reviewed pre-prints was undertaken from 1 January 2020 to 19 April 2021; no language restrictions were applied. All potentially eligible papers were exported to Covidence. Titles/abstracts and full texts were single screened for relevance. Data extraction and quality appraisal of included studies was completed by a single reviewer and checked by a second.

Results

In total, 50 studies, three randomised controlled trials (RCTs), one non-RCT and 46 cohort studies were included. The four included controlled trials tested variations of the pharmacological intervention, ivermectin. While these controlled trials reported a protective effect for ivermectin use, these trials were of poor quality and had serious risk of bias. Across 46 cohort studies, the modifiable lifestyle risk factors identified were obesity, smoking, vitamin D status, physical activity, alcohol consumption and processed meat consumption. These studies reported mixed results in terms of the association between modifiable lifestyle risk factors and poor COVID-19 outcomes.

Conclusions

At the time of writing there is no high quality evidence of benefit to support pharmacological interventions to prevent COVID-19. Although there were mixed results for the risk factors identified, maintenance of healthy weight, smoking cessation, engaging in physical activity and moderation of alcohol and processed meat consumption are likely to be beneficial to health and should continue to be encouraged.

Characteristics and Outcome of Extranodal NK/T-Cell Lymphoma in North America: A Retrospective Multi-Institutional Experience

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTL) is rare and clinicaldata from non-Asian countries are lacking. It is unclear whether outcomes and diseasenatural history is similar to reported Asian series. We assessed characteristics and outcomes of patients with ENKTL from major North American centers.

PATIENTS AND METHODS

We retrospectively identified patients with newly-diagnosedCD56 + ENKTL and studied disease characteristics and clinical outcomes.

RESULTS

121 patients with ENKTL diagnosed between June 1990 and November 2012 were identified. Eighty-three patients (69%) had stage I/II disease and were treatedwith combined modality therapy (CMT) (n=53), chemotherapy alone (CT) (n=14) orradiotherapy alone (RT) (n=16). Thirty-eight patients (31%) had stage III/IV diseaseand were treated with CMT (n=12), CT (n=23), or RT (n=3). The median follow-up forthe entire cohort was 51 months. Patients with stage I/II disease, compared to thosewith stage III/IV disease, had superior 2-year progression free survival (PFS) 43% vs19% (p=0.03) and overall survival (OS) 59% vs 29% (p=0.004). Outcomes were similarfor stage I/II patients who received CMT vs RT alone with 2-year PFS (53% vs 47%;p=0.91) and OS (67% vs 67%; p=0.58). No significant differences in outcomes werenoted based on race/ethnicity.

CONCLUSIONS

This series represents a large experience of ENKTL treated at several major North American academic centers.

OUR DATA ARE CONSISTENT WITH ASIAN STUDIES

1) majority of patients present with early-stage disease; 2) overall poor outcome regardless of race/ethnicity; 3) CMT likely yields favorable outcomes for suitable candidates with early-stage disease.

Effect of time to relapse on overall survival in patients with mantle cell lymphoma following autologous haematopoietic cell transplantation

In young and fit patients with mantle cell lymphoma (MCL), intensive induction therapy followed by a consolidative autologous haematopoietic cell transplant (autoHCT) is the standard of care in the front-line setting. Recently, time-to-event analysis has emerged as an important risk assessment tool in lymphoma, though its impact in MCL is not well defined. We utilized the Center for International Blood and Marrow Transplant Research database to evaluate the effect of post-autoHCT time to relapse on overall survival (OS) over time in 461 patients who underwent autoHCT within 12 months of MCL diagnosis. On multivariate analysis, the impact of relapse on OS was greatest at the six-month [hazard ratio (HR) = 7·68], 12-month (HR = 6·68), and 18-month (HR = 5·81) landmark timepoints. Using a dynamic landmark model we demonstrate that adjusted OS at five years following each landmark timepoint improved with time for relapsing and non-relapsing patients. Furthermore, early relapse (<18 months) following autoHCT defines a high-risk group with inferior post-relapse OS. This retrospective analysis highlights the impact of time to relapse on OS in MCL patients undergoing up-front autoHCT and emphasizes the need to consider novel therapeutic approaches for patients suffering early relapse.

American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and European Society for Blood and Marrow Transplantation Clinical Practice Recommendations for Transplantation and Cellular Therapies in Mantle Cell Lymphoma

Autologous (auto-) and allogeneic (allo-) hematopoietic cell transplantation (HCT) are accepted treatment modalities in contemporary treatment algorithms for mantle cell lymphoma (MCL). Chimeric antigen receptor (CAR) T cell therapy recently received approval for MCL; however, its exact place and sequence in relation to HCT remain unclear. The American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and the European Society for Blood and Marrow Transplantation jointly convened an expert panel to formulate consensus recommendations for role, timing, and sequencing of auto-HCT, allo-HCT, and CAR T cell therapy for patients with newly diagnosed and relapsed/refractory (R/R) MCL. The RAND-modified Delphi method was used to generate consensus statements. Seventeen consensus statements were generated, with a few key statements as follows: in the first line setting, auto-HCT consolidation represents standard of care in eligible patients, whereas there is no clear role of allo-HCT or CAR T cell therapy outside of clinical trials. In the R/R setting, the preferential option is CAR T cell therapy, especially in patients with MCL failing or intolerant to at least one Bruton's tyrosine kinase inhibitor, while allo-HCT is recommended if CAR T cell therapy fails or is infeasible. Several recommendations were based on expert opinion, where the panel developed consensus statements for important real-world clinical scenarios to guide clinical practice. In the absence of contemporary evidence-based data, the panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MCL.

ASTCT, CIBMTR, and EBMT clinical practice recommendations for transplant and cellular therapies in mantle cell lymphoma

Autologous (auto-) or allogeneic (allo-) hematopoietic cell transplantation (HCT) are accepted treatment modalities for mantle cell lymphoma (MCL). Recently, chimeric antigen receptor (CAR) T-cell therapy received approval for MCL; however, its exact place and sequence in relation to HCT is unclear. The ASTCT, CIBMTR, and the EBMT, jointly convened an expert panel to formulate consensus recommendations for role, timing, and sequencing of auto-, allo-HCT, and CAR T-cell therapy for patients with newly diagnosed and relapsed/refractory (R/R) MCL. The RAND-modified Delphi method was used to generate consensus statements. Seventeen consensus statements were generated; in the first-line setting auto-HCT consolidation represents standard-of-care in eligible patients, whereas there is no clear role of allo-HCT or CAR T-cell therapy, outside of a clinical trial. In the R/R setting, the preferential option is CAR T-cell therapy especially in MCL failing or intolerant to at least one Bruton's tyrosine kinase inhibitor, while allo-HCT is recommended if CAR T-cell therapy has failed or is not feasible. In the absence of contemporary evidence-based data, the panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MCL.

A phase I/II trial of brentuximab vedotin plus rituximab as frontline therapy for patients with immunosuppression-associated CD30+ and/or EBV + lymphomas

Treatment strategies for post-transplant lymphoproliferative disorders (PTLD) consist of response-adapted risk-stratified methods using immunosuppression reduction, immunotherapy, and chemotherapy. We investigated the efficacy of Brentuximab vedotin given concurrently with Rituximab (BV + R) once weekly for four weeks, followed by optional consolidation, and up to one year of maintenance. Among 20 assessable patients, BV + R therapy resulted in an overall response rate of 75% (95% CI 51 to 91, p = 0.044) with 60% achieving a complete response. Median time to best response was 28 days. Two-year progression-free survival and overall survival rates were 75 and 90%, respectively. Most common severe grade 3/4 treatment-related toxicities included neutropenia (40%), hypertension (30%), infection (25%), and peripheral neuropathy (15%). BV + R is a novel and effective therapeutic strategy that achieved rapid and durable remissions in previously untreated PTLD patients; however, this treatment platform requires further modification due to the high rates of treatment-related toxicity.Key pointsBrentuximab vedotin + Rituximab showed ORR and CR rates of 75 and 60% in patients with immunosuppression-associated lymphoid malignanciesHigh rates of treatment delay were attributed to treatment-related toxicity; further dosing optimization of this regimen is required.

Fimepinostat (CUDC-907) in patients with relapsed/refractory diffuse large B cell and high-grade B-cell lymphoma: report of a phase 2 trial and exploratory biomarker analyses

Fimepinostat (CUDC-907), a first-in-class oral small-molecule inhibitor of histone deacetylase and phosphatidylinositol 3-kinase, demonstrated efficacy in a phase 1 study of patients with relapsed/refractory (R/R) diffuse large and high-grade B-cell lymphomas (DLBCL/HGBL), particularly those with increased MYC protein expression and/or MYC gene rearrangement/copy number gain (MYC-altered disease). Therefore, a phase 2 study of fimepinostat was conducted in this patient population with 66 eligible patients treated. The primary end-point of overall response (OR) rate for patients with MYC-IHC ≥40% (n = 46) was 15%. Subsequently, exploratory pooled analyses were performed including patients treated on both the phase 1 and 2 studies based upon the presence of MYC-altered disease as well as a biomarker identified by Virtual Inference of Protein activity by Enriched Regulon analysis (VIPER). For these patients with MYC-altered disease (n = 63), the overall response (OR) rate was 22% with seven responding patients remaining on treatment for approximately two years or longer, and VIPER yielded a three-protein biomarker classification with positive and negative predictive values of ≥85%. Prolonged durations of response were achieved by patients with MYC-altered R/R DLBCL/HGBL treated with single-agent fimepinostat. Combination therapies and/or biomarker-based patient selection strategies may lead to higher response rates in future clinical trials.

Abstract 1821: Integrative genomic analysis of diffuse large B cell lymphoma (DLBCL) identifies recurrent oncogenic alterations associated with distinct immune-related clusters

Introduction: Genetic alterations in tumor cells shape the cancer immune landscape and influence response to checkpoint blockade therapy (CBT). Despite recent advances in defining DLBCL genomics, the impact of genetic alterations on the DLBCL immune environment is not well-characterized. Here, we aim to define unique immune landscapes in DLBCL and determine the impact of lymphoma-cell intrinsic alterations on shaping immune environments in this disease, which may have implications for CBT response

Methods: Gene set variation analysis (GSVA) was used to generate sample-wise enrichment scores for immune-related gene sets in ~500 DLBCLs. A cell-of-origin (COO) signature that classifies DLBCLs based on transcriptional similarity to activated B cells (ABC) or germinal center B cells (GCB) was included to control for COO-related genomic heterogeneity. Samples were hierarchically clustered. Paired exome sequencing was analyzed to identify mutations associated with each cluster. Cas9-mediated gene editing was used to modulate genes of interest in a murine lymphoma model (A20)

Results: GSVA revealed 4 DLBCL immune clusters - ABC hot, ABC cold, GCB hot and GCB cold. Concordant with previous work, PD-L1 gene amplifications were highly enriched in ABC hot DLBCLs, while double-hit signature DLBCLs fell within the GCB cold cluster. Mutations and oncogenic pathways associated with each cluster were identified. ABC cold DLBCLs harbored recurrent inactivating mutations in TMEM30A and PRDM1, while mutations in KLHL6 and SPEN were associated with ABC hot DLBCLs. The GBC cold cluster was enriched for mutations in TP53 and FOXO1, and inactivating SOCS1 mutations were prevalent in GCB hot DLBCLs.

MYC activation signatures characterized ABC and GCB cold clusters. A20 lymphomas with inducible c-Myc activation (A20MycER) contained fewer CD8+ T cells following tamoxifen versus control treatment, confirming our computational findings. Moreover, as SOCS1 mutations strongly associated with GCB hot DLBCLs and are prevalent in CBT-sensitive lymphomas, the extent to which Socs1-deficient lymphoma cells showed increased sensitivity to the critical T cell effector cytokine IFNγ was examined. Upon IFNγ exposure, A20Socs1-/- cells showed increased pStat1 levels, enhanced expression of PD-L1 and MHC-I, and strikingly diminished proliferation compared to A20WT cells, suggesting that enhanced JAK/STAT signaling via Socs1-/- increases IFNγ sensitivity, rendering lymphoma cells vulnerable to CBT

Conclusion: Through computational analyses in a large genomic dataset, we have defined unique immune-related DLBCL clusters and associated recurrent genomic alterations. Through ongoing studies in murine models, we aim to elucidate mechanisms by which particular oncogenic alterations in lymphoma cells shape the DLBCL immune landscape and impact CBT response

Citation Format: Sravya Tumuluru, James K. Godfrey, Jovian Yu, Alan Cooper, Michael Leukam, Sonali M. Smith, Xiufen Chen, Justin P. Kline. Integrative genomic analysis of diffuse large B cell lymphoma (DLBCL) identifies recurrent oncogenic alterations associated with distinct immune-related clusters [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1821.

Effect of time to relapse on overall survival (OS) in mantle cell lymphoma (MCL) patients (pts) following frontline high-dose therapy and autologous hematopoietic cell transplantation (autoHCT)

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Background: In MCL, outcomes are heterogeneous and the clinical significance of the timing of relapse following autoHCT and its impact on OS is not well defined. Using the CIBMTR database, we evaluate the effect of post-autoHCT time to relapse on OS over time. Methods: Adult MCL pts treated with up to two lines of rituximab-based induction therapy followed by first autoHCT within 1-year of diagnosis were identified between 2000-2018. Primary outcomes included OS and post-relapse OS. A dynamic landmark analysis was performed at 6-month intervals following autoHCT to evaluate the impact of relapse on OS while adjusting for significant patient- and disease-related variables. Post-relapse OS was evaluated in pts who experienced relapse. Results: Of the 461 pts included in the analysis, the median age was 60 years (range 29-78), 57% had a KPS of ≥ 90, 83% had stage III-IV disease at diagnosis, and 76% had extranodal involvement. BEAM was the most common conditioning regimen (58%) and 23% of pts received post-autoHCT maintenance rituximab. With a median follow-up of 67 months, the 5-year progression-free survival was 45.8% with a 5-year OS of 69.6%. On multivariate analysis, age ≥60 years was associated with worse OS (HR= 1.55, 95% CI 1.08-2.24, p=0.0191) at all landmark timepoints. Additionally, the impact of relapse on OS varied with time (p=0.006) and was greatest at the 6-month (HR=7.68), 12-month (HR=6.68), and 18-month (HR=5.81) landmark timepoints. The risk of death for relapsing pts decreased with time and was mirrored by an improvement in adjusted OS for both relapsing and non-relapsing pts. In total, 9.3% of patients relapsed prior to the 18-month landmark timepoint. Relapse at the 6-month, 12-month, and 18-month landmark timepoints correlated with a poor median post-relapse OS of 9 months, 24 months, and 34 months, respectively (Table). Conversely, patients relapsing after the 18-month landmark timepoint experienced a median post-relapse OS ranging from 44-67 months. Conclusions: In MCL, early relapse (< 18-months) following autoHCT defines a high-risk group with inferior post-relapse OS. This population should be considered for clinical trials or novel therapeutic approaches including early utilization of chimeric antigen receptor T-cell therapy.[Table: see text]

Behavioural relevance of spontaneous, transient brain network interactions in fMRI

How spontaneously fluctuating functional magnetic resonance imaging (fMRI) signals in different brain regions relate to behaviour has been an open question for decades. Correlations in these signals, known as functional connectivity, can be averaged over several minutes of data to provide a stable representation of the functional network architecture for an individual. However, associations between these stable features and behavioural traits have been shown to be dominated by individual differences in anatomy. Here, using kernel learning tools, we propose methods to assess and compare the relation between time-varying functional connectivity, time-averaged functional connectivity, structural brain data, and non-imaging subject behavioural traits. We applied these methods to Human Connectome Project resting-state fMRI data to show that time-varying fMRI functional connectivity, detected at time-scales of a few seconds, has associations with some behavioural traits that are not dominated by anatomy. Despite time-averaged functional connectivity accounting for the largest proportion of variability in the fMRI signal between individuals, we found that some aspects of intelligence could only be explained by time-varying functional connectivity. The finding that time-varying fMRI functional connectivity has a unique relationship to population behavioural variability suggests that it might reflect transient neuronal communication fluctuating around a stable neural architecture.