Outcome In Follicular Lymphoma Research Articles

Molecular Biomarkers in Prediction of High-Grade Transformation and Outcome in Patients with Follicular Lymphoma: A Comprehensive Systemic Review.

Follicular lymphoma (FL) is the most prevalent indolent B-cell lymphoma entity, often characterized by the t(14;18) BCL2-IGH translocation. The malignancy represents a clinically and biologically highly heterogeneous disease. Most patients have favorable prognoses; however, despite therapeutic advancements, the disease remains incurable, with recurrent relapses or early disease progression. Moreover, transformation to an aggressive histology, most often diffuse large-B-cell lymphoma, remains a critical event in the disease course, which is associated with poor outcomes. Understanding the individual patient's risk of transformation remains challenging, which has motivated much research on novel biomarkers within the past four decades. This review systematically assessed the research on molecular biomarkers in FL transformation and outcome. Following the PRISMA guidelines for systemic reviews, the PubMed database was searched for English articles published from January 1984 through September 2024, yielding 6769 results. The identified publications were carefully screened and reviewed, of which 283 original papers met the inclusion criteria. The included studies focused on investigating molecular biomarkers as predictors of transformation or as prognostic markers of time-related endpoints (survival, progression, etc.). The effects of each biomarker were categorized based on their impact on prognosis or risk of transformation as none, favorable, or inferior. The biomarkers included genetic abnormalities, gene expression, microRNAs, markers of B cells/FL tumor cells, markers of the tumor microenvironment, and soluble biomarkers. This comprehensive review provides an overview of the research conducted in the past four decades, underscoring the persistent challenge in risk anticipation of FL patients.

Current standard treatments and future outlook for follicular lymphoma

Follicular lymphoma (FL) is the most common subtype of indolent lymphoma. Survival outcomes for FL have improved since the introduction of anti-CD20 monoclonal antibodies, such as rituximab, and median overall survival has reached 15-20 years. However, FL is an incurable disease that subsequently progresses or relapses, and progression-free and overall survival tend to shorten with repeated relapses. For patients with limited-stage disease, radiation therapy is generally the treatment of choice and results in a median survival of approximately nearly 20 years. For advanced-stage patients with low tumor burden, watchful waiting continues to be the appropriate strategy at present. It remains unclear whether rituximab monotherapy might change this watchful waiting approach and result in a benefit from early intervention in patients with low tumor burden. For advanced-stage patients with high tumor burden, chemoimmunotherapy including rituximab or obinutuzumab followed by maintenance therapy is the standard treatment. For relapsed or refractory patients, treatment options such as chemoimmunotherapy, lenalidomide-rituximab, tazemetostat, chimeric antigen receptor T-cell therapies, and CD3/CD20 bispecific antibodies are available or in development. This review presents current standard treatments, recent advances, and future perspectives on the management of FL.

Gene targeted and immune therapies for nodal and gastrointestinal follicular lymphomas.

Follicular lymphoma (FL) is the most common indolent B-cell lymphoma (BCL) globally. Recently, its incidence has increased in Europe, the United States, and Asia, with the number of gastrointestinal FL cases expected to increase. Genetic abnormalities related to t(14;18) translocation, BCL2 overexpression, NF-κB pathway-related factors, histone acetylases, and histone methyltransferases cause FL and enhance its proliferation. Meanwhile, microRNAs are commonly used in diagnosing FL and predicting patient prognosis. Many clinical trials on novel therapeutics targeting these genetic abnormalities and immunomodulatory mechanisms have been conducted, resulting in a marked improvement in therapeutic outcomes for FL. Although developing these innovative therapeutic agents targeting specific genetic mutations and immune pathways has provided hope for curative options, FL treatment has become more complex, requiring combinatorial therapeutic regimens. However, optimal treatment combinations have not yet been achieved, highlighting the importance of a complete under-standing regarding the pathogenesis of gastrointestinal FL. Accordingly, this article reviews key research on the molecular pathogenesis of nodal FL and novel therapies targeting the causative genetic mutations. Moreover, the results of clinical trials are summarized, with a particular focus on treating nodal and gastrointestinal FLs.

EE530 Global Clinical, Economic, Health-Related Quality of Life Burden, and Treatment Outcomes in Follicular Lymphoma: A Systematic Review

EE530 Global Clinical, Economic, Health-Related Quality of Life Burden, and Treatment Outcomes in Follicular Lymphoma: A Systematic Review

High Ki67 Index Is Associated with Shorter Progression Free Survival in Follicular Lymphoma Patients Treated with Frontline Immunochemotherapy

Introduction The Follicular Lymphoma International Prognostic Index (FLIPI) is a commonly used prognostic tool in follicular lymphoma (FL). However, there is a need for better risk stratification to predict risk of progression after frontline chemoimmunotherapy. Ki67 proliferation index has prognostic value in many lymphomas and is widely available in clinical laboratories. However, the impact of Ki67 on outcomes in FL have not been conclusive. Studies have been limited by the method of quantifying Ki67 (entire specimen or intrafollicular [IF]), heterogeneous treatments, or small single institution studies. Moreover, the impact of Ki67 on predicting disease progression at 24 months (POD24) is unknown. We sought to study the predictive value of Ki67 on PFS in FL treated with Bendamustine Rituximab (BR) or RCHOP with or without Rituximab maintenance (RM) as first line therapy at 2 tertiary care centers. Methods This study was conducted with approval by the Wake Forest University Health Sciences IRB. We retrospectively analyzed 122 patients with FL (grade 1-3A) from 2010 to 2021 at Atrium Health (AH) Levine Cancer Institute (n=72) and AH Wake Forest Baptist Medical Center (n=50) who underwent first line therapy with BR or RCHOP and had tissue/slides available for analysis. Clinical data was collected through electronic medical record review. Archival slides and paraffin-embedded blocks were retrieved. Ki67 immunohistochemistry (IHC) (SP6, Cell Marque, Rocklin, CA), was performed if it was not available from the original work-up (8 cases). CD21 IHC (1F8, Dako, Denmark) was performed in select cases to confirm the presence of follicles in order to assess IF Ki67. Diagnosis, grade, and Ki67 stains were evaluated by 2 hematopathologists. The IF Ki67 index was determined by visual estimate to the nearest 10%. All cases with scores between 20-40% were re-reviewed to achieve a consensus score. Ki67 controls were exchanged between the two centers to ensure equivalent staining. Comparisons of patient characteristics were done by Kruskal-Wallis test for continuous variables (age) or Chi-square tests (categorical variables). Survival analysis was performed using Kaplan-Meier estimation and log-rank testing. Cox proportional hazards modeling was used for multivariable progression free survival (PFS) analysis. Results The clinical and pathologic characteristics are shown in Table 1. No differences in demographics [age, stage, cytologic grade, FLIPI, IF Ki67 status (<30 or ≥30) and treatment selection] were seen between the two centers. 100 cases were grade 1-2 (82.0%) and 22 were grade 3A (18.0%). Consistent with expected treatment patterns in FL, more patients were treated with BR (70.5%) compared to RCHOP (29.5%) and RCHOP was more frequently used in grade 3A compared to grade 1-2 FL patients. As expected, low FLIPI score (0-1) was associated with favorable PFS (P=0.02, Figure 1A), but not OS. However, treatment regimen (BR vs RCHOP), use of RM, and cytologic grade (grade 1-2 vs 3A) were not associated with PFS or OS. The IF Ki67 index was elevated (≥30%) in 46 cases (38%) and high IF Ki67 was associated with shorter PFS (P=0.002, Figure 1B), but was not associated with OS (P=0.11). When stratified by treatment regimen and IF Ki67, these results were maintained ( Figure 1C). There was no association between FLIPI and IF Ki67 (P=0.10). In a multivariable regression analysis, IF Ki67 ≥30 was associated with a significantly higher risk of progression (HR= 2.3, 95% CI 1.3 to 4, P=0.005) after accounting for the effect of FLIPI. In an exploratory analysis, a FLIPI/Ki67 (FKi) score was devised in which one point was given for either FLIPI ≥ 2 or IF Ki67 ≥ 30% giving a possible score of 0, 1 or 2. The FKi score was associated with PFS (P=0.0005, Figure 1D). Moreover, IF Ki67 ≥ 30 was associated with a higher risk of POD 24 (P=0.037). FLIPI ≥2 was also associated with POD24 (P=0.005). Conclusion Intrafollicular Ki67 ≥ 30% predicts for increased risk of progression independent of FLIPI in patients with FL treated with frontline immunochemotherapy. Addition of Ki67 to FLIPI is strongly associated with PFS in FL. Ki67 stains were done over an 11 year period in different laboratories, demonstrating the wide applicability and robustness of the Ki67 IHC technique. Larger studies incorporating IF Ki67 in risk stratification models are warranted in FL.

Personalized Monitoring of Circulating Tumor DNA By a Specific Signature of Trackable Mutations after Chimeric Antigen Receptor t-Cell Therapy in Non-Hodgkin B Cell Lymphoma

Introduction CART-cell therapy (CART) has produced a paradigm shift in the treatment of relapsing non-Hodgkin B-cell lymphoma (NHBcL). However, patients continue to relapse. Thus, developing strategies to optimize disease surveillance after this therapy is becoming increasingly important to attain disease-free survival and predict a potential relapse in advance. To facilitate its applicability, such strategies should also be minimally invasive. Hence, this study aims to explore the value of CloneSight, a circulating tumor DNA (ctDNA) monitoring approach based on a signature of personalized trackable mutations for the follow-up of NHBcL under CART. Methods A total of 30 NHBcL patients treated with CD19 CART-cell therapy were included in this work. Ten patients were diagnosed with Follicular Lymphoma (FL), and 20 with Diffuse Large B-Cell-Lymphoma (DLBCL). Genomic profiling was performed at relapse using FFPE biopsies and cfDNA liquid biopsies to detect somatic mutations by a custom capture enrichment panel (Twist, USA) covering 134 genes. Sequencing was conducted with the Illumina NextSeq platform. Then, the patient-specific somatic mutations were used as biomarkers for quantifying Minimal Residual Disease (MRD) on liquid biopsy follow-up samples with a sensitivity of 10 −4 (Jiménez-Ubieto A et al., Leukemia 2023). The amplicon-based, patient-specific MRD mini-panel also included primers to quantify the CART Phi construct relative to the albumin control gene. A total of 118 peripheral blood samples were collected. Plasma was isolated at day +7, +14, +30, +60, +90, and before progression (59 DLBCL and 59 FL samples). PET/CT examinations were performed on days +90, +180, +365 and every six months in FL, and the same for DLBCL but additionally on day +30. Results We found 185 trackable somatic mutations suitable for MRD monitoring (mean: 6.2 per patient). The most frequently mutated genes were CREBBP (80%), KMT2D (50%) and EP300 (30%) in FL, and KMT2D (45%), CREBBP (40%), and TP53 (35%) in DLBCL. The applicability of the test (detection of at least one somatic mutation) was 100%. Nineteen patients presented a cfDNA evaluation between days +30 and +60 ( Figure, left). Twelve progressed and ten of them were CloneSight-positive. Patient FL107, negative at day 28, presented a positive result at progression (day 180). For patient DLBCL16, the last sample available was at day +30, but the progression occurred at day 80, highlighting the need for sequential response assessment. Regarding the remaining nine cases in CR, five were negative and two positives by the test (SE 83%, SP 71%, PPV 83%, NPV 67%). Of note, FL101 becomes CloneSight-negative in the next Time-point (TP) available (day 112) and maintains MRD negativity in three more TPs (last at day 907). The remaining discordant case, DLBCL21, has a follow-up of only 60 days. Of note, patient DLBCL3 did not respond to CART but achieved CR and Clonesight-negativity under immune checkpoint inhibitor therapy. The ctDNA surveillance highly correlated with the PET/CT results ( Figure, right). Remarkably, 27 out of 32 PET/CT-negative TPs (84%) were consistent with a CloneSight-negative determination on belong two patients that did not progress. Four of five TPs with PET/CT-negative and CloneSight-positive status were classified as false negative PET/CTs, as those patients finally progressed. On the other hand, 13 out of 16 positive PET/CT samples (81%) were CloneSight-positive and the patient progressed. Of the remaining three PET/CT positive CloneSight-negative, two belong to patients that also progressed. Conclusions: In CAR-T therapy, monitoring with MRD by ctDNA is consolidated as a useful and necessary tool. Our CloneSight test can predict DLBCL and FL outcomes in advance and could be of high utility to detect false positive or negative PET/CT assessments during follow-ups. However, dynamic response assessment is crucial to draw meaningful conclusions. Further research and a larger cohort will be presented at the meeting.

Metabolic bulk volume from FDG PET as an independent predictor of progression-free survival in follicular lymphoma.

Total metabolic tumor volume (TMTV) in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) predicts patient outcome in follicular lymphoma (FL); however, it requires laborious segmentation of all lesions. We investigated the prognostic value of the metabolic bulk volume (MBV) obtained from the single largest lesion. Pretreatment FDG PET/computed tomography (CT) scans of 201 patients were analyzed for TMTV and MBV using a 41% maximum standardized uptake value (SUVmax) threshold. During a median follow-up of 3.2 years, 54 events, including 14 deaths, occurred. Optimal cut-offs were 121.1 cm3 for TMTV and 24.8 cm3 for MBV. Univariable predictors of progression-free survival (PFS) included a high Follicular Lymphoma International Prognostic Index 2 (FLIPI2) score, TMTV, and MBV. In the multivariable analysis, high TMTV and MBV were independent predictors of worse PFS (P =0.015 and 0.033). Furthermore, in a sub-group with FLIP2 scores of 0-2 (n = 132), high MBV could identify patients with worse PFS (P = 0.007). . Readily measurable MBV is useful for stratifying risk in FL patients.

Retrospective Analysis of the Impact of Bendamustine Dose Reduction and Chemotherapy on the Outcomes of Follicular Lymphoma

Introduction Follicular lymphoma (FL) is the most common indolent non-Hodgkin's lymphoma and primarily affects the elderly population. While bendamustine serves as a pivotal drug in standard therapy, it is often not administered as planned due to side effects, especially among the elderly. Clinical studies have shown that dose reduction and chemotherapy delays in the treatment of diffuse large B-cell lymphoma are associated with lower survival rates. However, few studies have analyzed the impact of bendamustine delays and dose reduction on the outcome of FL. Thus, the aim of our study was to clarify the effect of bendamustine dose reduction and chemotherapy course delay on treatment outcomes and to evaluate the effects of chemotherapy modification on FL. Patients and Methods This is a retrospective pooled analysis of previously untreated patients with FL who underwent consecutive bendamustine-based regimens at our institute. Patients receiving less than four courses of bendamustine-based regimens were excluded. Bendamustine dose reduction was defined as a cumulative dose reduction of at least 20% of the total prescribed dose. The total dose was defined as the sum of six cycles administered at 100% of the prescribed dose. Chemotherapy delays were defined as the total number of days of delay exceeding 21 days. The main goal of the study was to assess the impact of the chemotherapy scheme modification (dose reduction or delay) on progression-free survival (PFS) and overall survival (OS). The Kaplan-Meier method was used for single-variable survival data analysis. Differences in survival rate were determined using the log-rank test. Comparison among subgroups was performed using ANOVA for continuous covariates and Fisher's exact test for categorical variables. Results From January 2016 to June 2023, 43 untreated FL patients (23 females and 20 males) were started on rituximab-bendamustine (R-B) or obinutuzumab-bendamustine (G-B) at our institution. Median patient age was 69 years (range, 41-90 years) and the median follow-up time was 44 months (range, 5-74 months). Thirteen patients were treated with R-B, and 30 with G-B. Only one patient received obinutuzumab maintenance therapy due to the COVID-19 pandemic. Patients were divided into for three bendamustine delay/reduction groups. No bendamustine dose reduction or chemotherapy delays was observed in 27 patients (62.7%). The chemotherapy scheme was modified in 16 patients (37.2%): 10 patients (23.2%) experienced a bendamustine-only dose reduction and 6 patients (13.9%) experienced chemotherapy-only delays. None of the patients experienced both bendamustine dose reduction and delays. The main reasons for bendamustine dose reductions were the following: elderly/ frailty (60.0%), neutropenia (10.0%), thrombocytopenia (10.0%), and patient request (10.0%). The main reasons for chemotherapy delays were the following: patient request (33.3%), thrombocytopenia (33.3%), infection (16.6%), and skin rash (16.6%). Baseline characteristics were summarized in Table 1. The PFS of the three groups was comparable (Figure. 1a). The OS of the group with chemotherapy delays was comparable to the group with no dose reduction or delay, while that of the group with dose reduction was inferior (Figure. 1b). There were no differences in objective response rate (Table1). Conclusion Our study showed that chemotherapy delays or bendamustine dose reduction did not adversely affect PFS, and only chemotherapy delays adversely affected OS. No clinically significant differences in PFS were observed among patients with chemotherapy delays, which could be attributed to insufficient statistical power. Our cohorts comprised a heterogeneous population, including patients treated with R-B and G-B. However, considering the lack of evidence regarding the optimal dose intensity or chemotherapy interval for different populations, reducing the bendamustine dose may be a valid option for vulnerable patients.

Time to Lymphoma Treatment within 24 Months in Watchful Waiting Follicular Lymphoma Defines Patients at High Risk for Progression: A Multicenter Analysis

Purpose Follicular lymphoma (FL) is a clinically and molecularly heterogeneous disease, watch and wait (W&W) remains a management therapeutic option in patients with advanced-stage, low-tumor-burden and asymptomatic FL in the rituximab era. We continue to use Groupe d'Etudes des Lymphomes Folliculaires criteria for active disease to initiate therapy. We sought to understand whether time to lymphoma treatment (TLT) after diagnosis in patients who managed by W&W was a factor affecting survival outcomes in FL. Patients and Methods Between 2008 and 2022, 411 FL patients from 16 institutions in China were managed by W&W strategy, and their TLT was retrospectively evaluated. Patients were further divided into training and validation Cohorts. Logistic regression was used to identify and incorporate independent predictors of early TLT into a model with variable scoring. Model performance was evaluated through the area under the receiver operating characteristic curve (AUC) and goodness-of-fit statistics. Results After a median follow-up of 46 months, 35 percent of W&W patients experience TLT within 24 months (TLT24) after diagnosis, and the 5-year progression free survival (PFS) rate was significantly lower than that of patients who were treatment-free at 24 months (62.3% vs. 89.5%). In multivariable analysis, five clinical factors were identified as independent predictors of TLT24: stage III-IV, β 2 microglobulin ≥ 3mg/L, lymphocyte-to-monocyte ratio＜3.8, bone marrow involved and spleen enlargement. We calculated risk scores (TLT24PI) for each patient and defined three risk groups: low (0-1 points), intermediate (2 points), or high (3-5 points). Its AUC for TLT24 was 0.761 (95% CI, 0.698 - 0.823) in the development cohort and 0.761 (95% CI, 0.698 - 0.823) in the validation cohort. Risk groups were also associated with PFS ( P<0.001). Conclusion In patients with FL who initially managed by W&W, TLT within 24 months after diagnosis was associated with poor outcomes. We developed a multivariable model that incorporates clinical and laboratory factors to identify patients at high risk for TLT24, which may be useful to identify candidates for early interventional treatment.

Prognosis of Progressive Follicular Lymphoma within 24 Months of First-Line Therapy Is Not Influenced By the Initial Regimen Intensity

CONCLUSIONS Progression of follicular lymphoma (FL) within 24 months of initiating first-line therapy (POD24) is a strong driver of poor outcomes and is associated with a high risk of transformation. Previous reports suggest that POD24 has less prognostic significance in patients treated with rituximab alone as front-line therapy. We aimed to evaluate the impact of POD24 on outcome as well as the influence of the intensity of front-line therapy on the prognosis of POD24 in our local cohort of FL patients. We included patients with FL grade 1, 2 or 3A and stages II to IV who received front line therapy between 01/01/2014 and 31/12/2020 at our centre, and excluded patients treated with radiotherapy alone. Our primary objective was to describe and compare the clinical outcomes following different front-line regimens used in FL at our center. Rituximab (R) alone and R-Cyclophosphamide, Vincristine and Prednisone (R-CVP) were defined as attenuated-intensity regimens and R-CHOP (R-CVP with adriamycin) and bendamustine-rituximab (BR) as high-intensity regimens. The following endpoints were analyzed: event-free survival (EFS), defined as time from therapy initiation (D1C1) to progression, relapse, transformation to an aggressive lymphoma, or death of any cause, progression-free survival (PFS), defined as time from D1C1 to progression or death and overall survival (OS), defined as time from D1C1 to death of any cause. POD24 was defined as progression or relapse within 24 months of D1C1. We identified 85 patients with FL. At diagnosis, median age was 61 years (range: 38-85), 86 % had an ECOG performance score of 0-1, 81% had grade 1-2 FL, 91% had stage III-IV and 27% had high LDH. FLIPI score was available for 82 patients and 54% had a FLIPI of 3-5. Seventy-eight patients (92%) received a combination of rituximab and chemotherapy (R-chemo) and 7 (8%) received rituximab alone (R). Front line BR is approved at our center since November 2019. R-chemo regimens included R-CVP (40 patients, 47%), R-CHOP (29 patients, 34%) and BR (9 patients, 11%). Fifty-four patients received rituximab maintenance. Rituximab maintenance was not offered following BR. Twenty-eight (33%) patients had POD24 and 57 patients (67%) did not (non-POD24 group). Median follow-up was 5 years. Median and 5-year results for the 85 patients are: EFS 4.2 years and 45%, PFS 4.2 years and 45% and OS not reached and 86%. Patients with POD24 and non-POD24 had a 5-year OS of 66% (38-84) and 94% (81-98) (p=0.007) respectively. The proportion of POD24 among patients treated with R-chemo or R alone was 32% (25/78) and 43% (3/7). The rates of POD24 after R-CVP, R-CHOP and BR were 25% (10/40), 38% (11/29) and 44% (4/9), respectively. Among patients treated with R-chemo, 5-year OS was 67% for POD24 and 93% for non-POD24 (p=0.01). Among patients treated with an attenuated-intensity regimen, 5-year OS was 85% for POD24 and 93% for non-POD24 (p=0.567). Among patients with POD24, 5-year OS with an attenuated-intensity regimen was 85%, whereas it was 33% in the group of patients treated with R-CHOP or BR (p=0.18). Transformation incidence to an aggressive lymphoma was 15% at 5 years for the whole cohort, 32% in the POD24 group and 6% in the non-POD24 group (p=0.0004). BR was the regimen associated with the highest rate of transformation reaching a rate of 83% compared to none with R, 8% with R-CVP and 14% with R-CHOP (p=0.0005). Median time to transformation in aggressive lymphoma from D1C1 was 329 days (range 140-2688). On multivariable analysis, no patient- or disease-related factor before the first line treatment was associated with the occurrence of POD24. Our real-world study highlights the inferior outcome of patients with POD24 retrieved in pooled analysis from larger cohorts, irrespective of the intensity of the induction regimen. The small number of patients is a limitation of our study. The identification of clinical features associated with POD24 before 1L initiation is needed to improve outcomes of FL. Acknowledgments The study has been supported by the C3i Lymphoma Registry

T-cell phenotype including CD57+ T follicular helper cells in the tumor microenvironment correlate with a poor outcome in follicular lymphoma

T-lymphocytes are prevalent in the tumor microenvironment of follicular lymphoma (FL). However, the phenotype of T-cells may vary, and the prevalence of certain T-cell subsets may influence tumor biology and patient survival. We therefore analyzed a cohort of 82 FL patients using CyTOF to determine whether specific T-cell phenotypes were associated with distinct tumor microenvironments and patient outcome. We identified four immune subgroups with differing T-cell phenotypes and the prevalence of certain T-cell subsets was associated with patient survival. Patients with increased T cells with early differentiation stage tended to have a significantly better survival than patients with increased T-cells of late differentiation stage. Specifically, CD57+ TFH cells, with a late-stage differentiation phenotype, were significantly more abundant in FL patients who had early disease progression and therefore correlated with an inferior survival. Single cell analysis (CITE-seq) revealed that CD57+ TFH cells exhibited a substantially different transcriptome from CD57− TFH cells with upregulation of inflammatory pathways, evidence of immune exhaustion and susceptibility to apoptosis. Taken together, our results show that different tumor microenvironments among FL patients are associated with variable T-cell phenotypes and an increased prevalence of CD57+ TFH cells is associated with poor patient survival.

Relationship between BCL2 mutations and follicular lymphoma outcome in the chemoimmunotherapy era

How to identify follicular lymphoma (FL) patients with low disease burden but high risk for early progression is unclear. Building on a prior study demonstrating the early transformation of FLs with high variant allele frequency (VAF) BCL2 mutations at activation-induced cytidine deaminase (AICDA) sites, we examined 11 AICDA mutational targets, including BCL2, BCL6, PAX5, PIM1, RHOH, SOCS, and MYC, in 199 newly diagnosed grade 1 and 2 FLs. BCL2 mutations with VAF ≥20% occurred in 52% of cases. Among 97 FL patients who did not initially receive rituximab-containing therapy, nonsynonymous BCL2 mutations at VAF ≥20% were associated with increased transformation risk (HR 3.01, 95% CI 1.04–8.78, p = 0.043) and a trend toward shorter event-free survival (EFS, median 20 months with mutations versus 54 months without, p = 0.052). Other sequenced genes were less frequently mutated and did not increase the prognostic value of the panel. Across the entire population, nonsynonymous BCL2 mutations at VAF ≥20% were associated with decreased EFS (HR 1.55, 95% CI 1.02–2.35, p = 0.043 after correction for FLIPI and treatment) and decreased overall survival after median 14-year follow-up (HR 1.82, 95% CI 1.05–3.17, p = 0.034). Thus, high VAF nonsynonymous BCL2 mutations remain prognostic even in the chemoimmunotherapy era.

Characterization and clinical significance of T follicular helper cells in follicular lymphoma

Abstract T follicular helper (T FH) cells are a subset of CD4 +T cells that reside within the follicles of secondary lymphoid organs and play an essential role in the germinal center (GC) reaction. To examine the role T FHcells in follicular lymphoma (FL), we first characterized T FHcells using single cell analysis with the high-throughput technologies of mass cytometry (CyTOF) and the Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq). Clustering analysis revealed that T FHcells form subsets with unique phenotypes, and the expression of many common markers including CXCR5, ICOS, IL-21, TOX2, CD57, GZMK, XCL1, XCL2, CXCL13 and CD40L varies on T FHsubsets. We found that T FHcells are phenotypically more heterogenous in FL than benign tonsil tissues by both proteomic (n=82) and transcriptomic (n=8) profiling. Each FL patient showed different dominant T FHsubsets, in contrast to tonsil donors which were highly homogenous. Some T FHsubsets were only present in FL and absent in tonsil tissues, suggesting the existence of FL-specific T FHcells. Cytokines (IL-2, IL12, IL-17 and IL-21) and activated B cells upregulated T FHmarkers including PD-1, CXCR5 and IL-21 to induce the development of T FHsubsets such as IL-21 +or IL-21 +IFN-g +T FHcells, which was inhibited by rapamycin, an immunosuppressor. We observed that the T FHcell frequency significantly correlated with the number of lymphoma B cells. Futhermore, while T FHcells as a whole showed no correlation with prognosis, T FHsubsets such as CD57 +T FHcells were significantly associated with an inferior patient outcome. Taken together, our results indicate that T FHcells are highly heterogenous with different tumor-specific T FHsubsets present in FL and associated with patient outcomes in FL.

A Genome-Wide Association Study (GWAS) of Event-Free Survival (EFS) in Follicular Lymphoma Patients Treated with Front-Line Immunochemotherapy: A Lysa, Iowa/Mayo MER, and FIL Study

Background: Few studies have evaluated the role of host (germline) genetics in predicting outcome in follicular lymphoma (FL) patients. Using patients treated with rituximab (R) based immunochemotherapy (IC) from 3 clinical trials and one prospective observational study, we conducted the first genome-wide association study (GWAS) of prognosis in FL patients to identify germline genetic predictors of event-free survival (EFS) overall as well as failure within the first 24 months after treatment initiation (EFS24). Methods: We conducted a GWAS study of FL patients (n=1,054) treated in first-line therapy with R-CHOP (n=726, 69%), R-CVP (n=255, 24%) and R-FM (fludarabine and mitoxantrone) (n=73, 7%) from the following studies: PRIMA (n=391) and RELEVANCE (n=205) of the Lymphoma Study Association; FOL05 (n=199) of the Fondazione Italiana Linfomi; and the University of Iowa/Mayo Clinic Molecular Epidemiology Resource (MER) (n=259). After IC, 437 patients (41%) received R-maintenance. Genotyping was performed using Human Core exome (PRIMA, RELEVANCE, FOL05) and 660 Quad (MER) BeadChips. Minimac4/1000G was used to impute additional SNPs. After stringent quality control measures, 1,287,537 SNPs across the 4 cohorts with a minor allele frequency (MAF) >0.05 were evaluated. Association testing was conducted assuming a log-additive genetic model. We calculated the hazard ratios (HR) by Cox regression analysis for EFS. Results were adjusted for FLIPI score, sex, cohort, principal component analysis of population stratification, treatment (R-CHOP/R-FM vs. R-CVP), and use of R-maintenance (modeled as a time-dependent variable). To identify early clinical failures, we conducted a GWAS using a piecewise Cox model to find SNPs associated with events within the first 24 months (EFS24) vs after 24 months. Because of the heterogeneity of our prognostic cohorts, we utilized a cross-validation statistical technique to identify robust findings that replicate across cohorts. The data were iteratively analyzed in discovery and validation blocks using a "leave-one-cohort-out" (LOCO) strategy: in each round, one cohort was left for validation while the other three cohorts were combined for discovery. Top SNPs were selected from each discovery block of three cohorts with an inclusive p<0.0001 threshold to move to validation in the remaining cohort. SNPs were considered validated with a p<0.1 threshold and a consistent HR direction between discovery and validation blocks. Validated SNPs were then combined into a final pooled analysis and were ranked based on p-value and number of cross validations in the context of standard pooled GWAS results. Results: In the final analysis for EFS prediction, the top SNP was rs72625024 at 3q27.3 (MAF=0.11; HR=0.62, p=9.37x10-8), which was discovered and validated in all 4 LOCO rounds. Figure 1 shows this and other top SNPs from the LOCO analysis mapped onto traditional pooled GWAS results. This SNP also predicted overall survival (OS) in a model independent of FLIPI and other prognostic factors (HR=0.69, p=0.013). rs72625024 is near FETUB (fetuin B), which is involved in the inactivation of the PI3K/AKT signaling pathway. The other top SNPs for EFS were at 3q21.1 and 8p23.2, but they did not reach statistical significance and showed weak validation in the LOCO design. In the analysis of EFS24, rs114695031 at 14q32.13 predicted events during the first 24 months and was discovered and validated in all 4 LOCO rounds (MAF=0.20; HR=0.58, p=1.93x10-8) (Figure 2). This variant is an intronic SNP localized in T Cell Leukemia/Lymphoma 6 gene, a long non-coding RNA and putative tumor suppressor. Suggestive associations for early failure were observed for rs12824955 at 12q24.11 (MAF=0.27; HR=0.60, p=1.46x10-7) and validated in 3 of 4 LOCO rounds, while rs333302 at 3q21.1 (MAF=0.42; HR=1.61, p=1.15x10-6) did not reach statistical significance. For events after 24 months, no SNPs were statistically significant. Conclusions: In this large GWAS study, a locus at 3q27.3 (near FETUB) was associated with EFS after adjustment for other prognostic factors and treatment. Furthermore, a genome-wide significant locus (p<5x10-8) at 14q32.13 (near TCL6) predicted EFS24, suggesting a specific role in early failures. These results, requiring additional external validation, support a role for inherited susceptibility impacting outcomes in IC-treated FL and that may vary by timing of failures. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

FLIPI24: An Improved International Prognostic Model Developed on Early Events in Follicular Lymphoma

Background: Early events are associated with inferior outcomes in follicular lymphoma (FL) and increased risk of death due to refractory FL. Risk prediction of early events prior to the start of therapy may enhance clinical management and research strategies. We report the FL International Prognostic Index model developed specifically to predict the risk of event within 24 months (EFS24) of starting first-line immunochemotherapy (IC) (FLIPI24). Methods: Modeling was performed using individual patient data from 10 observational cohorts from Europe, North America, and Australia. Eligible patients were diagnosed with grades 1-3A FL and initiated frontline R-CHOP, R-CVP, R-bendamustine (B-R), or like therapies. Event-free survival (EFS) was defined as time from start of IC to progression, retreatment, transformation, or death due to any cause. Model development utilized a truncated Cox model stratified on IC type and cohort with a time-dependent adjustment for maintenance therapy. Multiple imputation was implemented to address missing data. Functional forms of variables were assessed using splines. Model selection was based on model performance, clinical relevance, and parsimony. Gradient boosting machines were evaluated as a complementary approach and used to inform model selection. Model building was performed on an 80% split sample with 20% held for internal testing. External validation occurred in an independent cohort. FLIPI24 risk scores assumed B-R or R-CHOP based chemotherapy and 50% likelihood of maintenance. Results: 4485 patients initiating frontline IC between 2002 and 2018 were utilized in the analysis; 3577 patients were utilized for model building and 908 for internal model testing. Median age at diagnosis in the model build dataset was 61 years (IQR 53-69) and 51% were male. FLIPI was 21%, 32%, and 48% for low, intermediate, and high risk, respectively. IC type was 1874 R-CHOP or like (52%), 730 B-R or like (20%), and 973 R-CVP (27%); 2164 received CD20 antibody maintenance (61%). At median follow-up of 77 months (IQR 48-115), EFS24 estimate was 81% (95% CI: 79-82) and 835 patients (23%) died. 5-year survival after an early (non-death) event was 46% (95% CI: 42-50). The FLIPI24 model utilizes 5 continuous variables: age (linear 60-90 years with inflection at age 75), hemoglobin (linear 8-17 g/dL), white blood cell count (linear 4-11 109/L), normalized lactate dehydrogenase (linear 0.5-5), and beta-2-microglobulin (linear 1-10 mg/L). Linear variables and valid ranges were utilized based on close examination of functional forms across potential models. Continuous FLIPI24 risk scores were grouped for visualization in K-M curves as follows: very low risk (0-0.10), low risk (0.10-0.15), average risk (0.15-0.20), high risk (0.20-0.40), very high risk (>0.40), Figure 1. Internal validation was performed on the 20% holdout set (N=908). The FLIPI24 had superior concordance (c-stat) for EFS24 (c-stat=0.666) compared to FLIPI (c-stat=0.630) and PRIMA-PI (c-stat=0.590) models, Table 1. Importantly, FLIPI24 also improved prognostic ability for 10-year OS following IC (c-stat = 0.672) vs FLIPI (c-stat=0.629) or PRIMA-PI (c-stat=0.595). External validation was performed in a prospective cohort of 1438 newly diagnosed patients with FL (558 treated with IC) enrolled in the multicenter US LEO Cohort between 2015 and 2020. The FLIPI24 had superior c-stats compared to the FLIPI and PRIMA-PI for EFS24 (0.671 vs 0.600 vs 0.602) and OS (0.732 vs. 0.652 vs 0.635) in IC treated patients and for OS (0.785 vs 0.703 vs 0.662) when assessed in all patients. Conclusion: The FLIPI24 model provides an individual risk score at diagnosis for the likelihood of experiencing an event within 24 months from starting IC. The FLIPI24 was rigorously developed, tested, and externally validated using large harmonized and pooled international observational cohorts from the IC era. The FLIPI24 utilizes objective variables easily and reliably measured at diagnosis. A novel feature of the model is the significance of established blood-based measurements in the model, which appears to capture underlying tumor and host biology. Model performance for FLIPI24 was superior to standard clinical models for prediction of both EFS24 and OS in internal and external validation sets. Elevated FLIPI24 risk represents a patient population for further biologic studies and who should be considered for novel frontline therapies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

External Validation of the FLIPI Risk Score Measured at Initial Diagnosis and POD24 Among Previously Treated Individuals with Progressed Follicular Lymphoma in Alberta, Canada

Introduction: A number of variables have been shown to predict survival outcomes in follicular lymphoma (FL), including the Follicular Lymphoma International Prognostic Index (FLIPI) score measured at initial diagnosis and progression of disease within 24 months (POD24). However, there exists little research aimed at informing prognosis in a cohort comprised exclusively of FL patients whose disease has relapsed after prior therapy. To address this gap, we assessed the FLIPI score measured at diagnosis and POD24 with respect to their ability to stratify survival outcomes measured from the time of first progression in a group of individuals with FL who experienced disease progression after initial treatment. Methods: An external validation of the FLIPI score measured at diagnosis and POD24 was conducted using population-level data from Alberta, Canada. The study cohort was comprised of individuals diagnosed with FL between 2004-2010 who received either systemic therapy and/or radiation within 180 days of diagnosis and who subsequently had disease progression. Individuals were followed until death or last-known contact with the healthcare system. Relevant data were identified through record linkage of the provincial cancer registry and electronic medical records along with a manual chart review conducted by trained medical doctors. Outcomes were examined from the time of first progression and included time to death (OS), time to death after first progression or second progression (PFS2), and time to death or initiation of third line treatment (TTNT2). For each outcome, Kaplan-Meier curves were estimated stratified by FLIPI and by POD24. To quantify the degree of separation of the Kaplan-Meier curves, we estimated hazard ratios (HRs) using a Cox proportional hazards model and Harrell's concordance statistic (c-statistic) for both the FLIPI index and POD24. Results: 910 individuals were diagnosed with FL between 2004-2010, of which 584 received systemic or radiation therapy. 527 individuals initiated front-line therapy within 180 days of diagnosis, of which 216 experienced progression during the follow-up period and were included in these analyses. Among the 216 individuals, 162 (75%) received front-line systemic therapy which was primarily R-CVP (n=57; 35%) or R-CHOP (n=78; 48.1%). From the time of disease progression, median OS was 11.7 years (95% CI: 8.9-NA). POD24 status was available for all 216 individuals, with 90 (42%) individuals having evidence of progression of disease within 24 months of initiating front-line therapy (POD24+). Overall, 129 of the 216 (60%) individuals had complete information required to derive the FLIPI risk score with 43 (33%) being classified as high-risk, 46 (36%) intermediate-risk, and 40 (31%) low-risk. OS estimates stratified by FLIPI score and by POD24 are presented in Table 1. POD24 was not highly predictive of OS from the time of disease progression (c-statistic: 0.55; HR [POD24+ vs. POD24-]: 1.42; 95% CI: 0.93 to 2.15; p = 0.10). Conversely, the FLIPI score measured at diagnosis was highly predictive of OS from the time of disease progression (c-statistic 0.70; HR [High vs. Low]: 7.38; 95% CI: 3.05 to 17.88, p < 0.01; HR [Int. vs. Low]: 3.70; 95% CI: 1.51 to 9.10, p < 0.01; ; HR [High vs. Int.]: 1.99; 95% CI: 1.15 to 3.47, p = 0.01; Figure 1). These findings were similar when examining PFS2 and TTNT2. In sensitivity analysis, findings were similar when restricting to individuals who received front-line systemic therapy. In addition, the classification of individuals by both POD24 and FLIPI did not meaningfully improve discrimination over FLIPI alone. Conclusions: The FLIPI score measured at initial diagnosis can be used for risk stratification at the time of disease progression among previously treated FL patients. In contrast, POD24 was not highly predictive of survival outcomes from the time of disease progression within this population of FL patients who all had disease progression. Future research is needed to determine if the prognostic utility of the FLIPI risk score measured at initial diagnosis can be improved upon by incorporating variables assessed at the time of relapse. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Trial in Progress: Follicular Lymphoma Outcomes in Relapsed/Refractory Patients Treated with Systemic Therapy in a Real-World Assessment (FLORA)

Trial in Progress: Follicular Lymphoma Outcomes in Relapsed/Refractory Patients Treated with Systemic Therapy in a Real-World Assessment (FLORA)

MRD Status By Clonoseq ® Is a Poor Predictor of Long-Term Outcomes after Bispecific LV20.19 CAR T-Cell Therapy for Relapsed, Refractory B-Cell NHL

INTRODUCTION: The clonoSEQ® Assay (Adaptive Biotechnologies Corporation, Seattle, USA) uses next-generation sequencing (NGS) based testing to identify disease-specific immunoglobulin sequences and detect evidence of minimal residual disease (MRD). MRD assessments have been shown to predict progression-free survival and overall survival in non-Hodgkin's lymphoma (NHL) patients. We report MRD results via the commercially available clonoSEQ® assay and its association with durability of response in patients treated with bispecific LV20.19 CAR in our phase 1/2 trial (NCT04186520). METHODS: We conducted a phase 1/2 single-center prospective trial (NCT04186520) to evaluate the efficacy and safety of LV20.19 CAR T-cells in patients with NHL at 2.5x106 cells/kg dose. LV20.19 CAR T-cells were manufactured onsite at varying lengths of manufacturing (8 vs 12 days) in the CliniMACS Prodigy device with IL7+15 for cell expansion, with the goal of fresh infusion. The commercial clonoSEQ® assay (by Adaptive Biotechnologies) was used to identify and track tumor clonotypes in responding patients at first assessment performed between Day 28-60. We evaluated associations between MRD status and long-term response post LV20.19 CAR-T cell therapy. Descriptive statistics were utilized for baseline characteristics. Survival analyses were calculated utilizing the Kaplan-Meier method and differences between groups were evaluated via the log-rank test. RESULTS: Among the 32 patients enrolled in the trial, there were 26 responders on Day 28. Of these responders, 23 patients had clonoSEQ® B-cell MRD assay done between Day 28-60 post CAR infusion (Table 1). MRD was performed in 11 patients with Diffuse Large B-cell Lymphoma (DLBCL), 3 patients with Follicular lymphoma (FL), and 9 patients with Mantle Cell Lymphoma (MCL). The median age was 64 years (45-74) and the median lines of prior therapy were 4 (2-11). Of the 23 patients with early MRD status available, the day 28 objective response rate (ORR) was 100% (complete response=57%, n=13 and partial response=43%, n=10). Eighteen patients (78%) were MRD negative at first assessment between days 28-60 and 5 (22%) were MRD positive. Of the 5 patients who were MRD positive, 3 became MRD negative at day 90, 1 patient was non-evaluable due to a non-relapse mortality event, and the remaining patient remains positive but with decreasing MRD status at Day 90. None of the patients with MRD positivity at day 28 have relapsed to date. Among patients who achieved early MRD negativity (n=18), 7 (39%) have relapsed, and all were patients with either DLBCL or FL. No MRD-negative MCL patient has relapsed to date. The duration of response in MRD-negative patients was significantly improved in MCL patients compared to DLBCL/FL patients (Figure 1), p=0.02. Among the 7 MRD negative patients who relapsed, only 1 patient was detected to have disease relapse by MRD positivity, 2 were detected simultaneously on MRD testing and imaging, while 3 were detected by physical exam or imaging findings and did not have MRD testing. Interestingly, 1 patient had a central nervous system relapse while being MRD negative. CONCLUSION: Relapse after CAR T-cell therapy remains a significant clinical challenge. New predictors are indicated to determine which responding patients after CAR-T cell therapy are more likely to relapse. Utilizing the commercially available Adaptive clonoSEQ® assay, early MRD assessment was not predictive of long-term clinical outcomes in DLBCL and FL. MRD positive patients maintained durable remission and converted to MRD negativity, while early MRD negative patients continued to relapse. In contrast, MRD negativity post-CAR-T therapy did appear to predict durable clinical remission in MCL patients. Newer assays, including cell-free technologies, may be more informative for non-MCL histologies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Factors Affecting the Clinical Course of Follicular Lymphoma: A Multistate Survival Analysis Using Individual Patient Data from Eight Multicenter Randomized Clinical Trials.

Leveraging the Follicular Lymphoma Analysis of Surrogacy Hypothesis database of individual patient data from first-line clinical trials, we studied the clinical course of follicular lymphoma (FL) and investigated clinical factors associated with FL outcomes. We examined 2428 patients from 8 randomized trials using multistate survival models with 4 states: induction treatment, progression, death from FL, and death from other causes. We utilized Aalen-Johansen estimator and Cox models to assess the likelihood of FL outcomes and quantify predictors' effects. Two-year progression, FL-related death, and death from other causes estimates were 26.5%, 3.4% and 1.4%, respectively. FL-associated deaths were the primary cause of mortality within 10 years of follow-up. Male sex (hazard ratio: 1.25; 95% confidence interval: 1.05-1.47), > 4 involved nodal areas (1.51; 1.23-1.86), elevated LDH (1.20; 1.01-1.43), low hemoglobin (1.44; 1.15-1.81), and elevated β-2 levels (1.23; 1.02-1.47) increased risk of progression. CD20-targeting agents reduced risks for progression (0.29; 0.22-0.39), death from FL (0.05; 0.01-0.20), and death from other causes without progression (0.13; 0.05-0.33) and following progression (0.52; 0.30-0.92). Estimated 2-year progression rates were 22.3% and 43.5% with or without CD20-targeting agents, respectively. Two-year FL-associated mortality rate was 8.3% among patients without CD20-targeting agents, 5.4% with B-symptoms, 4.9% with elevated LDH, and 9.1% with low hemoglobin. This study identified independent contributions of baseline clinical factors to distinct outcomes for patients with FL following first-line therapy on a clinical trial. Similar analytical approaches are needed to increase understanding of factors that influence FL outcomes in other settings.

The impact of histological grade on outcomes in follicular lymphoma: An analysis of patients in the SEER database in the context of evolving disease classification and treatment.

Currently, there is no convincing evidence that the grade of follicular lymphoma (FL) impacts patient outcome. We correlated grades in 33 925 patients with nodal FL during 1992-2018 in the SEER database with disease-specific survival (DSS) and overall survival (OS). Patients with FL grade 3 had lower DSS and OS as compared to FL grades 1-2. During 1992-2005, the 10-year DSS for patients with FL grades 3 and grades 1-2 were 68.6%, and 71.4%, respectively, and in 2006-2018, they were 77.7% and 82.6%, respectively. The 10-year OS estimates in 1992-2005 were 49.9% and 54.2% for grade 3 and grades 1-2 respectively, and in 2006-2018, they were 59.1% and 63.5% for grade 3 and grades 1-2, respectively. After adjustment for stage and age, the hazard ratios for death due to FL and death from any cause for patients with FL grade 3 during 1992-2005 were 1.09 (1.02-1.16) and 1.07 (1.02-1.12), respectively, compared to FL grades 1-2; and during 2006-2018, the hazard ratios for death due to FL and death from any cause for patients with FL grade 3 were 1.34 (1.22-1.45) and 1.16 (1.10-1.23), respectively compared to FL grades 1-2. The grade of FL is an important determinant of disease biology.