Cause of Death in Follicular Lymphoma in the First Decade of the Rituximab Era: A Pooled Analysis of French and US Cohorts

Small sized centroblasts as poor prognostic factor in follicular lymphoma - Based on artificial intelligence analysis

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists. We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The 'excellent prognosis' group were without recurrence or progression of follicular lymphoma within 60 months, the 'poor prognosis' group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the 'indeterminate prognosis' group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 μm2 had poorer event-free survival than those with a mean nuclear area of ≥55 μm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

Lisocabtagene maraleucel in follicular lymphoma: the phase 2 TRANSCEND FL study

An unmet need exists for patients with relapsed/refractory (R/R) follicular lymphoma (FL) and high-risk disease features, such as progression of disease within 24 months (POD24) from first-line immunochemotherapy or disease refractory to both CD20-targeting agent and alkylator (double refractory), due to no established standard of care and poor outcomes. Chimeric antigen receptor (CAR) T cell therapy is an option in R/R FL after two or more lines of prior systemic therapy, but there is no consensus on its optimal timing in the disease course of FL, and there are no data in second-line (2L) treatment of patients with high-risk features. Lisocabtagene maraleucel (liso-cel) is an autologous, CD19-directed, 4-1BB CAR T cell product. The phase 2 TRANSCEND FL study evaluated liso-cel in patients with R/R FL, including 2L patients who all had POD24 from diagnosis after treatment with anti-CD20 antibody and alkylator ≤6 months of FL diagnosis and/or met modified Groupe d'Etude des Lymphomes Folliculaires criteria. Primary/key secondary endpoints were independent review committee-assessed overall response rate (ORR)/complete response (CR) rate. At data cutoff, 130 patients had received liso-cel (median follow-up, 18.9 months). Primary/key secondary endpoints were met. In third-line or later FL (n = 101), ORR was 97% (95% confidence interval (CI): 91.6‒99.4), and CR rate was 94% (95% CI: 87.5‒97.8). In 2L FL (n = 23), ORR was 96% (95% CI: 78.1‒99.9); all responders achieved CR. Cytokine release syndrome occurred in 58% of patients (grade ≥3, 1%); neurological events occurred in 15% of patients (grade ≥3, 2%). Liso-cel demonstrated efficacy and safety in patients with R/R FL, including high-risk 2L FL. ClinicalTrials.gov identifier: NCT04245839 .

Long-term survival for lymphoid neoplasms and national health expenditure (EUROCARE-6): a retrospective, population-based study

BACKGROUND

Management of lymphoid malignancies requires substantial health system resources. Total national health expenditure might influence population-based lymphoid malignancy survival. We studied the long-term survival of patients with 12 lymphoid malignancy types and examined whether different levels of national health expenditure might explain differences in lymphoid malignancy prognosis between European countries and regions.

METHODS

For this observational, retrospective, population-based study, we analysed the EUROCARE-6 dataset of patients aged 15 or older diagnosed between 2001 and 2013 with one of 12 lymphoid malignancies defined according to International Classification of Disease for Oncology (third edition) and WHO classification, and followed up to 2014 (Jan 1, 2001-Dec 31, 2014). Countries were classified according to their mean total national health expenditure quartile in 2001-13. For each lymphoid malignancy, 5-year and 10-year age-standardised relative survival (ASRS) was calculated using the period approach. Generalised linear models indicated the effects of age at diagnosis, gender, and total national health expenditure on the relative excess risk of death (RER).

FINDINGS

82 cancer registries (61 regional and 21 national) from 27 European countries provided data eligible for 10-year survival estimates comprising 890 730 lymphoid malignancy cases diagnosed in 2001-13. Median follow-up time was 13 years (IQR 13-14). Of the 12 lymphoid malignancies, the 10-year ASRS in Europe was highest for hairy cell leukaemia (82·6% [95% CI 78·9-86·5) and Hodgkin lymphoma (79·3% [78·6-79·9]) and lowest for plasma cell neoplasms (29·5% [28·9-30·0]). RER increased with age at diagnosis, particularly from 55-64 years to 75 years or older, for all lymphoid malignancies. Women had higher ASRS than men for all lymphoid malignancies, except for precursor B, T, or natural killer cell, or not-otherwise specified lymphoblastic lymphoma or leukaemia. 10-year ASRS for each lymphoid malignancy was higher (and the RER lower) in countries in the highest national health expenditure quartile than in countries in the lowest quartile, with a decreasing pattern through quartiles for many lymphoid malignancies. 10-year ASRS for non-Hodgkin lymphoma, the most representative class for lymphoid malignancies based on the number of incident cases, was 59·3% (95% CI 58·7-60·0) in the first quartile, 57·6% (55·2-58·7) in the second quartile, 55·4% (54·3-56·5) in the third quartile, and 44·7% (43·6-45·8) in the fourth quartile; with reference to the European mean, the RER was 0·80 (95% CI 0·79-0·82) in the first, 0·91 (0·90-0·93) in the second, 0·94 (0·92-0·96) in the third, and 1·45 (1·42-1·48) in the fourth quartiles.

INTERPRETATION

Total national health expenditure is associated with geographical inequalities in lymphoid malignancy prognosis. Policy decisions on allocating economic resources and implementing evidence-based models of care are needed to reduce these differences.

FUNDING

Italian Ministry of Health, European Commission, Estonian Research Council.

Treatment sequencing and impact of number of treatment lines on survival in follicular lymphoma: A national population-based study

Follicular lymphoma (FL) is a clinically heterogeneous disease. The need for treatment, treatment sequencing, number of treatment lines, and its association with survival have not been described in a population-based setting. We identified all patients diagnosed with FL in the Swedish Lymphoma register from 2007 to 2014, followed until 2020, with detailed data on progression/relapse, transformation, and 2nd and further lines of therapy. During a median follow-up of 6.8 years, 1226 patients (69%) received 1st systemic treatment, 358 patients (20%) were managed with watch-and-wait (WaW) only, and 188 (10%) patients were treated with radiotherapy and did not require additional therapy during the study period. Among patients starting systemic treatment, 496 (40%), 224 (18%), and 88 (7%) received 2nd-, 3rd-, or 4th-line therapy, respectively. The 10-year cause-specific cumulative incidence of transformation was 13%. Among patients managed with 1st line R-single, R-CHOP, or BR, 54%, 33%, and 29% required 2nd line, respectively. The cumulative probability of starting subsequent treatment within 2 years was 26% after 1st line and 35% after 2nd line treatment. Two-year OS following 1st, 2nd, 3rd, and 4th line systemic treatment was 84%, 70%, 52%, and 36%, respectively, and remained similar when excluding transformations. We conclude that a substantial proportion of FL patients can be managed with WaW for a long period of time, while patients who require multiple treatment lines constitute a group with a large clinical unmet need. These results constitute valuable real-world reference data for FL.

End-of-treatment 18[F]-FDG PET can predict early progression in patients receiving bendamustine-rituximab for follicular lymphoma in first relapse: a prospective West Japan hematology Study Group (W-JHS) NHL01 trial

Response determined by 18[F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)-CT after induction therapy can predict progression-free survival (PFS) in follicular lymphoma (FL). However, little prospective research has examined the significance of PET after second-line therapy. We conducted a prospective multicenter phase II trial (W-JHS NHL01) of bendamustine plus rituximab (BR) without rituximab maintenance for FL in first relapse. This study aimed to evaluate the usefulness of end-of-treatment (EOT)-PET for predicting PFS in FL patients in first relapse. EOT-PET examinations were performed between 6 and 8 weeks from the start of the last BR cycle. The primary endpoint was 1-year PFS. Key secondary endpoints were overall response rate (ORR), complete response rate (CRR), and 1-year overall survival (OS). Seventy-five patients were enrolled, and 8 were excluded from analysis. ORR was 86.6% and CRR was 59.7%. One-year PFS was 88.9% (95% confidence interval [CI] 80.7-94.3%) and 1-year OS in 75 patients was 97.3% (95% CI 89.6-99.3%). One-year PFS was significantly inferior in EOT-PET-positive patients (n = 9) compared with PET-negative patients (n = 58) (77.8% vs. 93.1%; p = 0.02). We confirmed that EOT-PET after second-line BR therapy could predict early progression in FL patients in first relapse.

Early histological transformation of follicular lymphoma to diffuse large B-cell lymphoma indicating adverse survival: A population-based analysis and validation

INTRODUCTION

The histological transformation (HT) of follicular lymphoma (FL) is a crucial biological event. The study aimed to evaluate the incidence, clinicial characteristics, prognosis and impact of HT time on survival of FL transforming to diffuse large B-cell lymphoma in population-based large-scale cohorts.

METHODS

A retrospective cohort study of FL with HT was performed in the Surveillance, Epidemiology, and End Results database. The Hematological Malignancy Research Network FL cohort and Aristotle study FL cohort were used to assess the external validity.

RESULTS

Among 44,127 FL cases from the Surveillance, Epidemiology, and End Results database, 1311 cases were pathology-proven recorded to transform to diffuse large B-cell lymphoma. The cumulative rates of HT at 5, 10, and 15 years after FL diagnosis were estimated to be 1.19%, 2.93%, and 5.01%, respectively. Significantly worse overall survival and cancer-specific survival were exhibited in patients with HT than those without HT. Early HT (transformation of FL within 48 months after FL diagnosis [TOD48]) was an independent predictor for adverse overall survival of HT patients, regardless of treatment modalities before transformation. The adverse prognostic effect of TOD48 was validated in the Hematological Malignancy Research Network cohort and Aristotle study cohort. Older age (>75 years) and B symptoms within FL at diagnosis were the independent risk factors of TOD48. Furthermore, a novel prognostic model combining TOD48 with Follicular Lymphoma International Prognostic Index (TOD48-FLIPI) was constructed and validated for risk stratification.

CONCLUSION

TOD48 was a risk indicator of HT, and the novel prognostic model "TOD48-FLIPI" for HT patients was proposed.

Causal relationship between circulating cytokines and follicular lymphoma: a two-sample Mendelian randomization study

Follicular lymphoma (FL), derived from germinal centre (GC) B cells, is a kind of systemic neoplasm. Even though FL is indolent, it remains an incurable haematology Neoplasm. Accumulating evidence has suggested that the circulating cytokine is associated with the development of FL, yet the causal relationship between FL and circulating cytokines remains undetermined. Therefore, we conducted a two-sample Mendelian randomization (MR) to confirm the causal link between FL and levels of circulating cytokines with the use of summary data on circulating cytokines and FL. All these data from genome-wide association study were derived from the Genome-wide pQTL mapping which contains 14,824 individuals. FL data were acquired exclusively from FinnGen, where 218,792 individuals (522 cases vs. 218,270 controls) were involved. Various statistical methods, including the inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model (WM) and MR-Egger, were used to evaluate the potential causal connection between circulating cytokines and FL. Sensitivity analysis, which involves the examination of the heterogeneity, pleiotropy, and leave-one-out method, was also performed to ensure more trustworthy results. A bidirectional MR test was performed to evaluate the direction of causal association between circulating cytokines and FL. Combining all the steps of MR analysis, we revealed four causal cytokines: C-X-C motif chemokine ligand 5 (CXCL5), interleukin-15 receptor A (IL15RA), interleukin-20 (IL20), and neurotrophin-3 (NT-3). The risk of FL may be inversely linked to CXCL5 (OR=0.73, CI: 0.545-0.979, P=0.036), IL-15RA (OR=0.669, CI: 0.451-0.993, P=0.046), and IL-20 (OR=0.565, CI: 0.325-0.981, P=0.043) but positively linked to NT-3 (OR=1.872, CI: 1.063-3.297, P=0.03). In addition, in our study, no causal effect of FL on cytokines was demonstrated and no significant heterogeneity and pleiotropy were found. Our research revealed the causal relationship between cytokines and FL, along with both the anti-protective effect of CXCL5, IL-15RA, and IL-20 and the protective effect of neurotrophin-3 on FL. These findings aim to provide new clues regarding the pathogenesis of FL and to extend the potential of circulating cytokines to therapeutic interventions.

Polatuzumab vedotin plus bendamustine and rituximab or obinutuzumab in relapsed/refractory follicular lymphoma: a phase Ib/II study

Follicular lymphoma (FL) is the most common type of indolent non-Hodgkin lymphoma. Despite treatment advances that have improved outcomes for patients with relapsed or refractory (R/R) FL, many patients still die from progressive disease or treatment-related toxicities. In the phase Ib/II GO29365 study (clinicaltrials.gov 02257567), the safety and efficacy of polatuzumab vedotin plus bendamustine and rituximab (Pola-BR) versus bendamustine and rituximab (BR) alone, and polatuzumab vedotin plus bendamustine and obinutuzumab (Pola-BG) as a single-arm cohort were evaluated in patients with R/R FL. Following the phase Ib safety run-in, patients were randomized 1:1 to receive Pola-BR or BR alone in the phase II stage; a separate non-randomized Pola-BG cohort was examined in the phase Ib/II expansion stage. Primary endpoints included safety and tolerability (phase Ib) and positron emission tomography complete response (PET-CR) rate by independent review committee (phase II). Overall, 112 patients were enrolled (phase Ib safety run-in: Pola-BR, N=6; phase II randomized cohort: Pola-BR, N=39; BR, N=41; phase Ib/II expansion cohort: Pola-BG, N=26). PET-CR rates were 66.7% (phase Ib safety run-in, Pola-BR); 69.2% (phase II randomized, Pola-BR); 63.4% (phase II randomized, BR); and 65.4% (phase Ib/II expansion Pola-BG). There was a higher occurrence of cytopenias with Pola-BR and Pola-BG than with BR; serious adverse events were more frequent with Pola-BR (61.4%) and Pola-BG (46.2%) than with BR (29.3%). Overall, this analysis does not demonstrate a benefit of adding Pola to BR or BG regimens for patients with R/R FL.

Comparing R-Bendamustine vs. R-CHOP Plus Maintenance Therapy as First-Line Systemic Treatment in Follicular Lymphoma: A Multicenter Retrospective GELTAMO Study

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and R-bendamustine (R-B) are the most common frontline treatment strategies for advanced-stage follicular lymphoma (FL). After R-CHOP induction therapy, using rituximab for maintenance therapy notably improves outcomes; however, whether this can be achieved by using the same approach after R-B therapy is still being determined. This retrospective analysis compared 476 FL patients from 17 GELTAMO centers who received R-based regimens followed by rituximab maintenance therapy for untreated advanced-stage FL. The complete response rate at the end of induction was higher with R-B and relapses were more frequent with R-CHOP. During induction, cytopenias were significantly more frequent with R-CHOP and so was the use of colony-stimulating factors. During maintenance therapy, R-B showed more neutropenia and infectious toxicity. After a median follow-up of 81 months (95% CI: 77-86), the 6-year rates of progression-free survival (PFS) were 79% (95% CI: 72-86) for R-bendamustine vs. 67% (95% CI: 61-73) for R-CHOP (p = 0.046), and 6-year overall survival (OS) values were 91% (95% CI: 86-96) for R-B vs. 91% (95% CI: 87-94) for R-CHOP (p = 0.49). In conclusion, R-B followed by rituximab maintenance therapy in patients with previously untreated FL resulted in significantly longer PFS than R-CHOP, with older patients also benefiting from this treatment without further toxicity. Adverse events during maintenance were more frequent with R-B without impacting mortality.

The follicular lymphoma tumor microenvironment at single-cell and spatial resolution

ABSTRACT

Follicular lymphoma (FL) is a generally incurable malignancy that originates from developmentally blocked germinal center B cells residing, primarily, within lymph nodes (LNs). During the long natural history of FL, malignant B cells often disseminate to multiple LNs and can affect virtually any organ. Nonmalignant LNs are highly organized structures distributed throughout the body, in which they perform functions critical for host defense. In FL, the malignant B cells "re-educate" the lymphoid environment by altering the phenotype, distribution, and abundance of other cells such as T cells, macrophages, and subsets of stromal cells. Consequently, dramatic anatomical changes occur and include alterations in the number, shape, and size of neoplastic follicles with an accompanying attenuation of the T-cell zone. Ongoing and dynamic interactions between FL B cells and the tumor microenvironment (TME) result in significant clinical heterogeneity observed both within and across patients. Over time, FL evolves into pathological variants associated with distinct outcomes, ranging from an indolent disease to more aggressive clinical courses with early death. Given the importance of both cell-intrinsic and -extrinsic factors in shaping disease progression and patient survival, comprehensive examination of FL tumors is critical. Here, we describe the cellular composition and architecture of normal and malignant human LNs and provide a broad overview of emerging technologies for deconstructing the FL TME at single-cell and spatial resolution. We additionally discuss the importance of capturing samples at landmark time points as well as longitudinally for clinical decision-making.

Anlotinib suppresses the DNA damage response by disrupting SETD1A and inducing p53-dependent apoptosis in Transformed Follicular Lymphoma

Purpose: The high tumor mutational burden (TMB) of transformed follicular lymphoma (tFL) leads to tumor heterogeneity and poor prognosis in follicular lymphoma, in which endogenous DNA damage and epigenetic modification are the key factors. This study aims to evaluate the efficacy of anlotinib in tFL and to investigate its potential therapeutic mechanism. Methods: Cell viability and apoptosis were tested with CCK-8 and annexin V/PI staining kits, respectively. The tumorigenicity test in mice was utilized to further confirm the efficacy of anlotinib in vivo. Western blotting was utilized to explore the molecular mechanisms. Results: Anlotinib induced G2/M phase arrest in tFL cells, inhibited the proliferation of tFL cells and promoted the apoptosis of tFL cells in a dose-dependent manner. Administration of anlotinib markedly reduced tumor mass and weight in an FL xenograft mouse model. The western blot and immunohistochemistry staining results confirmed that the mechanism by which anlotinib promoted tumor cell apoptosis was DNA damage. Further results showed that anlotinib significantly downregulated the expression of SETD1A, leading to its destruction. Anlotinib administration resulted in a significant dose-dependent increase in the level of p-p53. Furthermore, anlotinib greatly downregulated the antiapoptotic proteins Mcl-1 and in parallel upregulated the proapoptotic element BAX and Bak, accompanied by caspase-3 activation and PARP degradation. Conclusion: Anlotinib has a good proapoptotic effect on tumor cells in vitro and in vivo, and its possible mechanism is related to the inhibition of the DNA damage response by disrupting SETD1A.

Proteomics identifies apoptotic markers as predictors of histological transformation in patients with follicular lymphoma

Follicular lymphoma (FL) is an indolent lymphoma with a generally favorable prognosis. However, histological transformation (HT) to a more aggressive disease leads to markedly inferior outcomes. This study aims to identify biological differences predictive of HT at the time of initial FL diagnosis. We show differential protein expression between diagnostic lymphoma samples from patients with subsequent HT (subsequently-transforming FL [st-FL]; n = 20) and patients without HT (nontransforming FL [nt-FL]; n = 34) by label-free quantification nano liquid chromatography-tandem mass spectrometry analysis. Protein profiles identified patients with high risk of HT. This was accompanied by disturbances in cellular pathways influencing apoptosis, the cytoskeleton, cell cycle, and immune processes. Comparisons between diagnostic st-FL samples and paired transformed FL (n = 20) samples demonstrated differential protein profiles and disrupted cellular pathways, indicating striking biological differences from the time of diagnosis up to HT. Immunohistochemical analysis of apoptotic proteins, CASP3, MCL1, BAX, BCL-xL, and BCL-rambo, confirmed higher expression levels in st-FL than in nt-FL samples (P < .001, P = .015, P = .003, P = .025, and P = .057, respectively). Moreover, all 5 markers were associated with shorter transformation-free survival (TFS; P < .001, P = .002, P < .001, P = .069, and P = .010, respectively). Notably, combining the expression of these proteins in a risk score revealed increasingly inferior TFS with an increasing number of positive markers. In conclusion, proteomics identified altered protein expression profiles (particularly apoptotic proteins) at the time of FL diagnosis, which predicted later transformation.

Chimeric Antigen Receptor T-Cells in Indolent Lymphoma, Mantle Cell Lymphoma, Chronic Lymphocytic Leukemia

The advent of chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of several hematological malignancies. Although the initial benefit was mainly observed in aggressive leukemias and lymphomas, recent data have resulted in the approval of multiple CAR-T therapies in indolent lymphomas, with ongoing research showing great promise for further improvements and therapeutic optimizations. In this article, we review the published data and approved therapies for CAR-T cell therapy for indolent lymphomas focusing on mantle cell lymphoma and follicular lymphoma while describing the work in chronic lymphocytic leukemia and future strategies.

Multiple Real-World Data Sources in a Bayesian Framework to Inform Long-Term Survival Estimates of Mosunetuzumab in Patients with Follicular Lymphoma

INTRODUCTION

Patients with follicular lymphoma (FL) receiving third-line or later (3L +) therapy have long survival, which can make estimating long-term overall survival (OS) from trial data challenging. The objective of this study was to estimate long-term OS for mosunetuzumab from the GO29781 trial (NCT02500407) using multiple real-world databases (RWDs) in a Bayesian framework.

METHODS

Seven RWD sources for patients with FL receiving 3L + therapy and the expansion cohort in the GO29781 trial for mosunetuzumab were used. Hazard trends from the RWD sources were analyzed, and disease-wide pointwise OS and its corresponding uncertainty were estimated using Bayesian random-effects meta-analysis from the RWD sources. Pointwise OS obtained was used as an informative prior in Bayesian survival extrapolations to data from patients receiving mosunetuzumab. Results after adjusting for background mortality were compared to equivalent frequentist extrapolations using trial data only.

RESULTS

Hazard patterns from RWD sources supported a constant or linearly decreasing hazard. Mean pointwise OS for patients with FL receiving 3L + therapy was estimated at 0.52 (95% credible interval, 0.29-0.85) at 8 years. Bayesian extrapolations for mosunetuzumab produced median survival estimates of 11.6 (6.7-20.7) years to 17.0 (6.4-22.7) years depending on the distribution used, reducing uncertainty by 20% to 46% relative to the frequentist estimation.

CONCLUSION

Multiple RWD sources can be synthesized to augment the credibility of data with short follow-up, long patient survival, and few events to effectively estimate long-term survival and reduce estimated uncertainty. This method can be applied to other indications with similar characteristics.

CLINICAL TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

NCT02500407, July 16, 2015.

Measurable Residual Disease Monitoring in Lymphoma

PURPOSE OF REVIEW

The utility of analyzing circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and disease in the bone marrow as an adjunctive tool in caring for hematologic cancer patients is expanding. This holds true for lymphoma where these biomarkers are being explored as a means of genotyping and quantifying disease. Regarding the latter, they can be used to monitor measurable residual disease (MRD) during and after treatment. This holds potential for aiding clinical decisions amidst treatment, detecting earlier relapse, and improving prognostication. Here, we review the evidence to support these applications in a variety of lymphoma subtypes.

RECENT FINDINGS

Numerous clinical trials across a variety of lymphomas have demonstrated value in MRD monitoring. MRD monitoring is often prognostic for progression free survival (PFS) and even overall survival (OS) at several time points in a disease course, particularly when utilizing serial measurements. With regards to tailoring treatment, there are a growing number of trials examining MRD-adaptive treatment strategies to intensify or de-escalate treatment to individualize care. Lastly, MRD monitoring has been utilized successfully in detecting earlier relapse when compared to more standard methods of clinical surveillance such as radiographic assessment. Although not routinely implemented into clinical practice, MRD monitoring in lymphoma is helping shape the future landscape of this disease by aiding in prognostication, guiding therapy, and detecting earlier relapse. Steps to standardize and further examine this technology prospectively are being taken to bring MRD monitoring to the forefront of the field.

Immune dysregulation as a leading principle for lymphoma development in diverse immunological backgrounds

Lymphoma is a heterogeneous group of malignancies arising from lymphocytes, which poses a significant challenge in terms of diagnosis and treatment due to its diverse subtypes and underlying mechanisms. This review aims to explore the shared and distinct features of various forms of lymphoma predisposing conditions, with a focus on genetic, immunological and molecular aspects. While diseases such as autoimmune disorders, inborn errors of immunity and iatrogenic immunodeficiencies are biologically and immunologically distinct, each of these diseases results in profound immune dysregulation and a predisposition to lymphoma development. Interestingly, the increased risk is often skewed towards a particular subtype of lymphoma. Patients with inborn errors of immunity in particular present with extreme forms of lymphoma predisposition, providing a unique opportunity to study the underlying mechanisms. External factors such as chronic infections and environmental exposures further modulate the risk of lymphoma development. Common features of conditions predisposing to lymphoma include: persistent inflammation, recurrent DNA damage or malfunctioning DNA repair, impaired tumor surveillance and viral clearance, and dysregulation of fundamental cellular processes such as activation, proliferation and apoptosis. Our growing understanding of the underlying mechanisms of lymphomagenesis provides opportunities for early detection, prevention and tailored treatment of lymphoma development.

DLBCL arising from indolent lymphomas: How are they different?

Transformation to diffuse large B-cell lymphoma (DLBCL) is a recognized, but unpredictable, clinical inflection point in the natural history of indolent lymphomas. Large retrospective studies highlight a wide variability in the incidence of transformation across the indolent lymphomas and the adverse outcomes associated with transformed lymphomas. Opportunities to dissect the biology of transformed indolent lymphomas have arisen with evolving technologies and unique tissue collections enabling a growing appreciation, particularly, of their genetic basis, how they relate to the preceding indolent lymphomas and the comparative biology with de novo DLBCL. This review summarizes our current understanding of both the clinical and biological aspects of transformed lymphomas and the outstanding questions that remain.

Management and clinical outcomes of follicular lymphoma across continuous lines of treatments: a retrospective analysis in China

Background

Follicular lymphoma (FL) is characterized by an incurable course that frequently necessitates multiple lines of treatment. While a range of new approaches have broadened therapeutic options for patients in later lines, data regarding treatment patterns and outcomes of Chinese patients with relapsed/refractory(R/R) FL was scarcely reported.

Methods

This retrospective single-center study included patients diagnosed with FL grades 1-3a at our institution between January 2002 and December 2019. Endpoints of interest were analyzed according to lines and types of interventions. The endpoints mainly included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results

The study enrolled 566 biopsy-proven patients. Among them, 544 patients initiated the first line of treatment, followed by 240 initiating the second line, 146 initiating the third line, 88 initiating the fourth line, 47 initiating the fifth line, and 28 initiating the sixth line. In terms of treatment patterns, anti-CD20 chemotherapy was a major modality in the first and second lines. However, for patients in the third line and subsequent lines, treatment approaches were diverse, and participation in clinical trials for new medications was common, which correlated with a survival benefit. The study also revealed that clinical indicators (such as ORR, PFS, and OS) gradually decreased with each subsequent line of treatment. The ORR at the first line was 86.6%, but decreased to 48.6% at the third line and 40.4% at the sixth line, respectively. Similarly, median OS and PFS decreased to 88.8 and 7.1 months at the third line and further reduced to 21.7 and 2.8 months at the sixth line, respectively. A total of 133 patients developed progression within 24 months from the initiation of first line anti-CD20 chemotherapy (POD24), and these patients exhibited poorer response rates and outcomes in subsequent lines of therapycompared to the non-POD24 group.

Conclusion

This study revealed the clinical routine practices and prognosis of R/R FL patients within the Chinese population. It underscored the unmet need for optimal strategies to improve survival and also served as a benchmark for future trials.

Mosunetuzumab and the emerging role of T-cell-engaging therapy in follicular lymphoma

Follicular lymphoma (FL) is the most common indolent lymphoma. Since the advent of rituximab, FL has seen a progressive improvement in patient prognosis. While chemotherapy combined with an anti-CD20 monoclonal antibody remains standard first-line therapy, most patients will relapse and require subsequent therapy. T-cell-redirecting therapies can be very potent and are transforming the therapeutic landscape in the relapsed and refractory (R/R) setting. T-cell-dependent bispecific antibodies, of which mosunetuzumab is the first to be approved for R/R FL, are proving to be a highly effective, 'off-the-shelf' option with manageable toxicities. This review covers approved treatments for R/R FL and focuses on preclinical and clinical data available for mosunetuzumab (Lunsumio™), with the goal of determining its role in the treatment of R/R FL.

Follicular lymphoma microenvironment: insights provided by single-cell analysis

Follicular lymphoma (FL) is the most frequent indolent lymphoma and is characterized by the abundant infiltration of tumor microenvironment (TME) cells. The activity of TME cells reportedly plays an important role in the biology of FL. TME cells that reside within neoplastic follicles, such as T-follicular helper cells and follicular dendritic cells, have been shown to aid in FL development and progression through interactions with malignant B cells, whereas regulatory T cells have unexpectedly shown an apparently favorable prognostic impact in FL. Unfortunately, the understanding of the FL TME, particularly regarding minor cell subsets, has been hampered by unknown cell heterogeneity. As with other solid and hematologic cancers, novel single-cell analysis technologies have recently been applied to FL research and have uncovered previously unrecognized heterogeneities, not only in malignant B cells but also in TME cells. These reports have greatly increased the resolution of our understanding of the FL TME and, at the same time, raised questions about newly identified TME cells. This review provides an overview of the unique aspects of FL TME cells with a clinical viewpoint and highlights recent discoveries from single-cell analysis, while also suggesting potential future directions.

Thinking "outside the germinal center": Re-educating T cells to combat follicular lymphoma

There have been significant advancements in the management of follicular lymphoma (FL), the most common indolent lymphoma. These include immunomodulatory agents such as lenalidomide, epigenetic modifiers (tazemetostat), and phosphoinotiside-3 kinase inhibitors (copanlisib). The focus of this review is T cell-engager therapies, namely chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies, have recently transformed the treatment landscape of FL. Two CAR T cell products, axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel), and one bispecific antibody, mosunetuzumab, recently received FDA approvals in FL. Several other new immune effector drugs are being evaluated and will expand the treatment armamentarium. This review focuses on CAR T-cell and bispecific antibody therapies, details their safety and efficacy and considers their evolving role in the current treatment landscape of FL.

Integrative genomic and transcriptomic analysis reveals genetic alterations associated with the early progression of follicular lymphoma

Follicular lymphoma (FL), the most common indolent lymphoma, is a clinically and genetically heterogeneous disease. However, the prognostic value of driver gene mutations and copy number alterations has not been systematically assessed. Here, we analysed the clinical-biological features of 415 FL patients to identify variables associated with disease progression within 24 months of first-line therapy (POD24). Patients with B symptoms, elevated lactate dehydrogenase and β2-microglobulin levels, unfavourable baseline haemoglobin levels, advanced stage, and high-risk FL International Prognostic Index (FLIPI) scores had an increased risk of POD24, with FLIPI being the most important factor in logistic regression. HIST1H1D, identified as a driver mutation, was correlated with POD24. Gains of 6p22.2 (HIST1H1D) and 18q21.33 (BCL2) and loss of 1p36.13 (NBPF1) predicted POD24 independent of FLIPI. Gene expression profiling of FL samples showed that the POD24 cohort was significantly enriched in the inflammatory response (mediated by interferon and tumour necrosis factor), cell cycle regulation (transcription, replication and proliferation) sets and PI3K-AKT-mTOR signalling. This result was further validated with transcriptome-wide information provided by RNA-seq at single-cell resolution. Our study, performed on a large cohort of FL patients, highlights the importance of distinctive genetic alterations and gene expression relevant to disease diagnosis and early progression.

Personalised therapy in follicular lymphoma - is the dial turning?

Follicular lymphoma is the most common indolent lymphoma accounting for approximately 20%-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Whilst outcomes are mostly favorable, the spectrum of clinical phenotypes includes high-risk groups with significantly inferior outcomes. This review discusses recent updates in risk stratification and treatment approaches from upfront treatment for limited and advanced stage follicular lymphoma to the growing options for relapsed, refractory disease with perspectives on how to approach this from a personalized lens. Notable gaps remain on how one can precisely and prospectively select optimal treatment for patients based on varying risks, with an anticipation that an increased understanding of the biology of these different phenotypes and increasing refinement of imaging- and biomarker-based tools will, in time, allow these gaps to be closed.

Recent advances in treatment of nodal and gastrointestinal follicular lymphoma

Follicular lymphoma (FL) is the most common low-grade lymphoma, and although nodal FL is highly responsive to treatment, the majority of patients relapse repeatedly, and the disease has been incurable with a poor prognosis. However, primary FL of the gastrointestinal tract has been increasingly detected in Japan, especially due to recent advances in small bowel endoscopy and increased opportunities for endoscopic examinations and endoscopic diagnosis. However, many cases are detected at an early stage, and the prognosis is good in many cases. In contrast, in Europe and the United States, gastrointestinal FL has long been considered to be present in 12%-24% of Stage-IV patients, and the number of advanced gastrointestinal cases is expected to increase. This editorial provides an overview of the recent therapeutic advances in nodal FL, including antibody-targeted therapy, bispecific antibody therapy, epigenetic modulation, and chimeric antigen receptor T-cell therapy, and reviews the latest therapeutic manuscripts published in the past year. Based on an understanding of the therapeutic advances in nodal FL, we also discuss future possibilities for gastroenterologists to treat gastrointestinal FL, especially in advanced cases.

IDO1 Protein Is Expressed in Diagnostic Biopsies from Both Follicular and Transformed Follicular Patients

Follicular lymphoma (FL) is a lymphoid neoplasia characterized by an indolent clinical nature. Despite generally favorable prognoses, early progression and histological transformation (HT) to a more aggressive lymphoma histology remain the leading causes of death among FL patients. To provide a basis for possible novel treatment options, we set out to evaluate the expression levels of indoleamine 2,3-dioxygenase 1 (IDO1), an immunoinhibitory checkpoint molecule, in follicular and transformed follicular biopsies. The expression levels of IDO1 were assessed using immunohistochemical staining and digital image analysis in lymphoma biopsies from 33 FL patients without subsequent HT (non-transforming FL, nt-FL) and 20 patients with subsequent HT (subsequently transforming FL, st-FL) as well as in paired high-grade biopsies from the time of HT (transformed FL, tFL). Despite no statistical difference in IDO1 expression levels seen between the groups, all diagnostic and transformed lymphomas exhibited positive expression, indicating its possible role in novel treatment regimens. In addition, IDO1 expression revealed a positive correlation with another immune checkpoint inhibitor, namely programmed death 1 (PD-1). In summary, we report IDO1 expression in all cases of FL and tFL, which provides the grounds for future investigations of anti-IDO1 therapy as a possible treatment for FL patients.

Leukemic phase follicular lymphoma in a young adult

BACKGROUND

Leukemic presentation of follicular lymphoma (FL) is uncommon, with most cases reported in older adults.

DESIGN

This report describes an unusual case of a young adult diagnosed with leukemic phase of FL. We reviewed the existing literature on this rare presentation of the disease and its potential impact on patient outcomes.

RESULTS

Leukemic phase of FL in young adults can be mistaken for other high-grade hematologic malignancies. Morphology assessment and ancillary testing, such as flow cytometry and FISH analysis, can assist in achieving an accurate diagnosis of the leukemic phase of FL. Notably, our young patient responded well to therapy, which is different from what is typically observed in older patients who have a poorer prognosis. Further cases are needed to investigate the prognostic impact of the leukemic phase of FL in younger patients.

Differences in clinical characteristics and outcomes between patients with grade 3a and grades 1-2 follicular lymphoma: a real-world multicenter study

BACKGROUND

The difference between clinical characteristics and outcomes between follicular lymphoma grade 1-2 (FL1-2) and FL3a defined pathologically remains unclear, resulting in uncertainty how to treat FL3a. However, it may be crucial for clinicians to discriminate grade 3a and grade 1-2 for predicting prognosis and thus making treatment decisions.

METHODS

We compared 1403 patients with FL1-2 and 765 patients with FL3a diagnosed between January 2000 and December 2020 from fifteen centers nationwide in China to describe differences in clinical characteristics and outcomes.

RESULTS

Compared with FL1-2 patients, FL3a subgroup had a higher percentage of elderly patients (P = 0.003), and relatively more FL3a patients presented with increased levels of LDH (P < 0.0001) and higher Ki-67 indexs greater than 30% (P < 0.001). More FL3a patients were treated with CHOP ± R (P < 0.0001), and fewer were treated with the watchful-waiting approach (P < 0.0001). The results showed a higher incidence of relapse among FL3a patients, in which more patients underwent histological transformation (HT) when compared to FL1-2 (P = 0.003). 1470 (76.2%) patients of the entire cohort received R-CHOP therapy; survival analysis revealed that FL3a patients had a worse progression-free survival (PFS) rate than FL1-2 patients. Survival of FL3a patients with respect to FLIPI showed an inferior PFS in the intermediate and high-risk groups than FL1-2 patients. FL3a patients had a much worse prognosis than FL1-2 with or without progression of disease within 24 months (POD24). FL3a patients had higher likelihood of lymphoma-related death (LRD, P < 0.05), whereas the rates for non-LRD were comparable.

CONCLUSION

In conclusion, this study demonstrates a marked difference in clinical features and outcomes in FL3a patients compared with FL1-2 patients. The results highlight the need for applying therapeutic approaches distinct from FL1-2 when treating FL3a patients.

Evaluating patterns of care for early-stage low-grade follicular lymphoma in the rituximab era

Radiotherapy (RT) utilization for early-stage, low-grade follicular lymphoma (FL) is low despite treatment guideline recommendations. We compare treatment trends for early-stage FL in the era of involved-site RT and rituximab. We identified 11,645 patients in the National Cancer Database (NCDB) with stage I-II, grade 1-2 nodal or extranodal FL diagnosed 2011-2017, with median follow-up of 44 months. From 2011 to 2017, RT utilization rates decreased from 33.4% to 22.4%, observation decreased from 65.3% to 49.7%, chemoimmunotherapy increased from 0.5% to 15.0%, immuno-monotherapy increased from 0.6% to 10.2%, and RT + systemic therapy increased from 0.6% to 2.5%. RT utilization remains low in the involved-site RT and rituximab era.

Long-term follow-up demonstrates curative potential of autologous stem cell transplantation for relapsed follicular lymphoma

Although autologous stem cell transplantation (ASCT) can achieve durable responses in eligible patients with follicular lymphoma (FL), long-term follow-up is needed to determine if it has curative potential. This retrospective, multicenter study included 162 patients who received ASCT for relapsed FL in Alberta, Canada. With a median (range) follow-up time of 12.5 years (0.1-27.9), the 12-year time-to-progression (TTP) was 57% (95% confidence interval [CI] 49%-65%), time-to-next-treatment was 61% (95% CI 52%-69%), progression-free survival was 51% (95% CI 42%-59%) and overall survival was 69% (95% CI 60%-76%). A plateau emerged on the TTP curve at 57% starting 9 years after ASCT with no relapses occurring beyond this timepoint. Ten patients remained in remission 20 years or more after ASCT. Patients undergoing ASCT at first or second relapse had superior outcomes compared to third or later relapse (12-year TTP 61% vs. 34%), as did patients without progression of disease within 24 months (POD24) of frontline treatment versus those with POD24 (12-year TTP 67% vs. 50%). ASCT achieves high rates of durable remission in relapsed FL, with long-term follow-up revealing that more than 50% of transplanted patients may be functionally cured of their lymphoma. The optimal timing to consider ASCT is at first or second relapse, regardless of POD24 status.

Novel targeted drugs for follicular and marginal zone lymphoma: a comprehensive review

Although mostly incurable, indolent non-Hodgkin lymphomas (iNHL) are chronic diseases with a median overall survival approaching 20 years. In recent years, important advances in the knowledge of the biology of these lymphomas have led to the development of new drugs, mostly chemotherapy-free, with promising outcomes. With a median age of around 70 years at diagnosis, many patients with iNHL suffer from comorbid conditions that may limit treatment options. Therefore, nowadays, in the transition towards personalized medicine, several challenges lie ahead, such as identifying predictive markers for the selection of treatment, the adequate sequencing of available therapies, and the management of new and accumulated toxicities. In this review, we include a perspective on recent therapeutic advances in follicular and marginal zone lymphoma. We describe emerging data on approved and emerging novel therapies, such as targeted therapies (PI3K inhibitors, BTK inhibitors, EZH2 inhibitors), monoclonal antibodies and antibody-drug conjugates. Finally, we describe immune-directed approaches such as combinations with lenalidomide or the even more innovative bispecific T-cell engagers and chimeric antigen receptor T-cell therapy, which can achieve a high rate of durable responses with manageable toxicities, further obviating the need for chemotherapy.

Risk Factors for and Outcomes of Follicular Lymphoma Histological Transformation at First Progression in the GALLIUM Study

BACKGROUND

Although advanced‑stage follicular lymphoma (FL) is considered incurable, survival has improved with the introduction of the anti-CD20 antibodies, rituximab (R) and obinutuzumab (G). However, FL can undergo histological transformation (HT) to a more aggressive disease, and a validated model for predicting HT risk is not yet available.

PATIENTS AND METHODS

We assessed HT incidence, risk factors and outcomes in the phase III, GALLIUM study evaluating R- or G-chemotherapy in patients with previously untreated, advanced-stage FL (ClinicalTrials.gov NCT01332968). HT rates were assessed by repeat tumour biopsy at disease progression or relapse, at the investigator's discretion.

RESULTS

Of 1202 patients enrolled, 315 (26.2%) experienced progressive disease; 46 (14.6%) had a biopsy at first progression, 40 of whom had biopsy-confirmed HT. HT risk factors were male sex (subdistribution hazard ratio [sHR], 2.21; 95% confidence interval [CI], 1.16-4.20), elevated baseline serum lactate dehydrogenase (sHR, 3.97; 95% CI, 2.03-7.76), and elevated baseline serum β₂-microglobulin (sHR, 1.96; 95% CI, 1.02-3.79). Patients with HT at first progression had poorer post-progression survival than those with relapsed FL (2-year rate: 55.9% vs. 83.1%). Relapse with HT occurred earlier than FL relapse (median time from randomisation: 0.8 vs. 2.3 years).

CONCLUSION

HT was a low-frequency event associated with poor survival outcomes in the GALLIUM study. Male sex and elevated baseline levels of serum LDH and B2M were significant risk factors for HT. Further research is required to develop validated prognostic indices for HT risk and guide treatment decisions.

Follicular lymphoma: The long and winding road leading to your cure?

Follicular lymphoma, the most common indolent lymphoma, though highly responsive to therapy is coupled with multiple relapses for the majority of patients. Advances in biologic understanding of molecular events in lymphoma cells and the tumor microenvironment, along with novel cellular and targeted therapies, suggest this may soon change. Here we first review the development of the molecular concepts and classification of follicular lymphoma, along with therapeutic development of treatments based on chemotherapy plus monoclonal antibodies targeting CD20. We then focus on developments over the last decade in further defining follicular lymphoma pathophysiology, leading to targeted therapeutics, as well as novel immunotherapeutic strategies effective against B cell lymphomas including follicular, particularly patients with advanced stage disease. Additional alterations beyond the hallmark t(14;18) translocation are necessary for development of follicular lymphoma. Epigenetic mutations are almost universally identified in follicular lymphoma, most commonly involving histone-lysine N-methyltransferase 2D (KMT2D, the histone acetyltransferases, cAMP response element-binding protein binding protein (CREBBP) and E1A binding protein P300 (EP300) and the histone methyltransferase enhancer of zeste homologue 2 (EZH2). Mutations are also commonly identified in other proliferation/survival pathways such as B-cell receptor, RAS, mTOR and JAK-STAT pathways, as well as immune escape mutations. The host immune response plays a key role as well, based on studies correlating various immune cell subsets and gene expression signatures with outcomes. Over the last decade, many therapeutic options beyond the commonly used bendamustine-rituximab induction regimen have become available or are being investigated. We focus on these newer agents in the relapsed setting. New antibody-based agents include the naked CD19 directed antibody tafasitamab, the CD79b directed antibody drug conjugate (ADC) polatuzumab vedotin and the CD47 directed antibody magrolimab that targets macrophages rather than FL cells directly. Immune modulation by lenalidomide has moved to earlier lines of therapy and in combinations. Several small molecule inhibitors of proliferation signal pathways involving PI3kinase and BTK have activity against FL. Apoptotic pathway modulators also have activity. With increasing recognition of the high rate of epigenetic mutations in FL, HDAC inhibition has a role. More importantly, the EZH2 inhibitor tazemetostat is FDA approved for FL after 2 prior lines of therapy. The most exciting data currently involve immune attack against follicular lymphoma by chimeric antigen receptor T-cells (CART) or bispecific antibody constructs. Given these multiple potentially non-crossreactive mechanisms, studies of rationally designed combination strategies hold the promise of improving outcomes and possibly cure of follicular lymphoma.

Biology of follicular lymphoma: insights and windows of clinical opportunity

Follicular lymphoma (FL) is a heterogeneous disease, both clinically and biologically. The biological behavior and development of FL is a culmination of complex multistep processes underpinned by genetic and nongenetic determinants. Epigenetic deregulation through recurrent genetic alterations is now a recognized major biological hallmark of FL, alongside the t(14;18) translocation. In parallel, there is a strong interplay between the lymphoma B cells and the immune microenvironment, with the microenvironment serving as a critical enabler by creating a tumor-supportive niche and modulating the immune response to favor survival of the malignant B cells. A further layer of complexity arises from the biological heterogeneity that occurs between patients and within an individual, both over the course of the disease and at different sites of disease involvement. Altogether, taking the first steps to bridge the understanding of these various biological components and how to evaluate these clinically may aid and inform future strategies, including logical therapeutic interventions, risk stratification, therapy selection, and disease monitoring.

Follicular lymphoma: 2023 update on diagnosis and management

DISEASE OVERVIEW

Follicular lymphoma (FL) is generally an indolent B cell lymphoproliferative disorder of transformed follicular center B cells. FL is characterized by diffuse lymphadenopathy, bone marrow involvement, and splenomegaly. Extranodal involvement is less common. Cytopenias are relatively common but constitutional symptoms of fever, night sweats, and weight loss are uncommon in the absence of transformation to diffuse large B cell lymphoma.

DIAGNOSIS

The diagnosis is based on histology from a biopsy of a lymph node or other affected tissue. Incisional biopsy is preferred over needle biopsies in order to give adequate tissue to assign grade and assess for transformation. Immunohistochemical staining is positive in virtually all cases for cell surface CD19, CD20, CD10, and monoclonal immunoglobulin, as well as cytoplasmic expression of bcl-2 protein. The overwhelming majority of cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes.

RISK STRATIFICATION

The Follicular Lymphoma International Prognostic Index (FLIPI) uses five independent predictors of inferior survival: age >60 years, hemoglobin <12 g/dL, serum LDH > normal, Ann Arbor stage III/IV, number of involved nodal areas >4. The presence of 0-1, 2, and ≥3 adverse factors defines low, intermediate, and high-risk disease. There are other clinical prognostic models but the FLIPI remains the most common. Other factors such as time to relapse of less than 2 years from chemoimmunotherapy and specific gene mutations may also be useful for prognosis. Regardless of the prognostic model used, modern therapies have demonstrably improved prognosis.

RISK-ADAPTED THERAPY

Observation continues to be appropriate for asymptomatic patients with low bulk disease and no cytopenias. There is no overall survival (OS) advantage for early treatment with either chemotherapy or single-agent rituximab. For patients needing therapy, most patients are treated with chemoimmunotherapy, which has improved overall response rates (ORR), DOR, and OS. Randomized studies have shown additional benefits for maintenance of rituximab. Lenalidomide was non-inferior to chemoimmunotherapy in a randomized front-line study and, when combined with rituximab, was superior to rituximab alone in relapsed FL. Kinase inhibitors, stem cell transplantation (SCT), and chimeric antigen receptor T cells (CAR-T) are also considered for recurrent disease.

Allogeneic Hematopoietic Stem Cell Transplantation in Transformed Follicular Lymphoma (tFL): Results of a Retrospective Multicenter Study from GELTAMO/GETH-TC Spanish Groups

BACKGROUND

Transformation of follicular lymphoma into an aggressive lymphoma (tFL) worsens the prognosis and the standard treatment is not completely defined. Allogeneic hematopoietic stem cell transplantation (alloSCT) could be a potentially curative option for these patients, but it has not been widely explored.

METHODS

We designed a retrospective multicenter study to analyze the efficacy and toxicity of alloSCT in tFL patients and potential prognostic factors of survival.

RESULTS

A total of 43 patients diagnosed with tFL who underwent alloSCT in 14 Spanish centers between January 2000 and January 2019 were included. Median age was 44 (31-67) years. After a median follow-up of 58 months, estimated 5-year overall survival (OS) and progression-free survival (PFS) were both 35%. Estimated 100-day and 1-year non-relapse mortality (NRM) were 20% and 34%, respectively. The type of conditioning regimen (3-year OS of 52% vs. 20%, respectively, for reduced-intensity vs. myeloablative conditioning) and development of chronic graft versus host disease (cGVHD) (3-year OS of 75% vs. 40%) were the only factors significantly associated with OS. The only variable with an independent association with OS was cGVHD (HR, 3.4; 95% CI, 1.2-9.6).

CONCLUSIONS

Our results indicate that alloSCT continues to be a potentially curative option for patients with tFL.

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

INTRODUCTION/BACKGROUND

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSION

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 Sequence of Therapy for Older Patients With Follicular Lymphoma: SEER-Medicare Analysis

BACKGROUND

One key clinical challenge remains in how to sequence treatments in follicular lymphoma (FL). The chemoimmunotherapy rituximab cyclophosphamide, doxorubicin, vincristine (Oncovin), and prednisone (R-CHOP) has been a standard treatment option for two decades. However, there are limited data to suggest in which line R-CHOP should be used for older patients.

PATIENTS AND METHODS

We leveraged population-based surveillance, epidemiology, and end results-medicare data and identified 675 patients aged ≥65 years newly diagnosed with FL from 2000 to 2009 who received R-CHOP in either the first or second line. We estimated restricted mean survival time using Kaplan-Meier curves, propensity scores (PS), and regression models comparing patients who received R-CHOP as a first versus second line.

RESULTS

We found that patients who received R-CHOP as first line had significantly longer 9-year RMST than those who received R-CHOP in the second line using Kaplan-Meier curves (P = .01), PS stratification (P = .002), PS matching (P = .005), and the inverse of PS as the treatment weight (P < .0001). The subgroup analyses using linear regression models showed that the 9-year restricted mean survival time of patients who received R-CHOP as the first line was longer in patients aged ≥80 years (P = .002) and with histological grade 1 or 2 (P = .02), compared to those who received R-CHOP as second line.

CONCLUSION

R-CHOP given in the first line was associated with longer overall survival compared to R-CHOP given as second line for older patients with FL.

Genetics of Transformed Follicular Lymphoma

Histological transformation (HT) to a more aggressive disease–mostly diffuse large B-cell lymphoma–is considered one of the most dismal events in the clinical course of follicular lymphoma (FL). Current knowledge has not found a single biological event specific for HT, although different studies have highlighted common genetic alterations, such as TP53 and CDKN2A/B loss, and MYC translocations, among others. Together, they increase genomic complexity and mutational burden at HT. A better knowledge of HT pathogenesis would presumably help to find diagnostic biomarkers allowing the identification of patients at high-risk of transformation, as well as the discrimination from patients with FL recurrence, and those who remain in remission. This would also help to identify new drug targets and the design of clinical trials for the treatment of transformation. In the present review we provide a comprehensive overview of the genetic events frequently identified in transformed FL contributing to the switch towards aggressive behaviour, and we will discuss current open questions in the field of HT.

Clinical features and outcomes of patients with follicular lymphoma: A real-world study of 926 patients in China

Background

The data about the clinical features and outcomes of Chinese patients with follicular lymphoma (FL) are limited. Here, we conducted a retrospective study to explore the initial treatment strategies and clinical outcomes of Chinese patients with FL in the real world.

Method

This study included FL patients who were newly diagnosed in Tianjin Medical University Cancer Institute and Hospital from March 2002 to August 2020.

Results

A total of 926 FL patients were enrolled. The median age was 54 years old, and the majority of the Chinese FL patients had advanced-stage disease and Eastern Cooperative Oncology Group(ECOG) <1 but less frequently infiltrated bone marrow. After a median of 38-month follow-up, the 5-year progressive-free survival (PFS) and overall survival (OS) of grade1-3a were 57.8% and 88.7%, respectively, which both are similar to those reported in previous Chinese and Western studies. The co-existence at diagnosis of FL and diffuse large B-cell lymphoma (DLBCL) components (FL/DLBCL) was associated with poor outcomes. The FL grades and proportion of DLBCL component in FL/DLBCL did not have an impact on PFS and OS. The most common regimen with great efficacy and risk-benefit was RCHOP-like followed by R maintenance regimen. The 5-year cumulative hazard of histological transformation (HT) was 4.7% (95% CI, 3.5-5.9); median time to transformation was 23.5 months (range, 2-146 months) after diagnosis. Three-year survival following transformation was 55% (95% CI, 40-70). Patients with stage III-IV, elevated β2 microglobulin (β2-MG), and B symptoms seemed to be more prone to progress within 24 months of frontline therapy (POD24). The FLIPI-2 showed the highest specificity to predict POD24, reflecting the prediction of correctly classifying as low-risk patients, but the FLIPI had the highest sensitivity to predict the risk of progression for critical patients.

Conclusions

We revealed the clinical characteristics and outcomes of FL patients in the real world in China, which may provide novel data on prognostic factors and primary treatment of FL, applicable to routine clinical practice.

Improving the prognostic ability of PET/CT SUVmax to identify follicular lymphoma with early treatment failure

Follicular lymphoma (FL) has a high degree of heterogeneity both clinically and molecularly. Early treatment failure (ETF), progression or relapse within 24 months of frontline immunochemotherapy is associated with a poor prognosis in FL. However, the clinical utility of ETF at diagnosis is limited. The maximum standardized uptake value (SUVmax) is a metabolic parameter for positron emission tomography/computed tomography (PET/CT); nevertheless, the relationship between SUVmax and ETF remains unclear. Thus, identifying early biomarkers that incorporate SUVmax and other clinical correlative variables could be helpful in identifying patients at high risk of ETF. A nomogram consisted of three independent variables, including SUVmax ≥ 12, beta-2 microglobulin > 3 mg/L, and Ki67 > 40%, was established to predict ETF in 127 patients with grade 1, 2, or 3a FL from the First Hospital of Jilin University (training cohort) and was validated using data from the Duke University Medical Center (validation cohort, n=95). The nomogram demonstrated prognostic accuracy in predicting ETF (sensitivity 70.8% and specificity 83.5% in the training cohort; sensitivity 84.2% and specificity 68.4% in the validation cohort). The patients were stratified into three groups: low-, intermediate-, and high-risk. In the training cohort, the corresponding 5-year progression-free survival (PFS) rates were 81.7%, 73.4%, and 34.9%, and the 5-year overall survival (OS) rates were 97.4%, 87.4%, and 62.3%, respectively. In the validation cohort, the 5-year PFS rates were 77.7%, 52.9%, and 34.8%, and the 5-year OS rates were 96.4%, 94.1%, and 73.7%, respectively. This was the first study to use a nomogram with SUVmax to predict ETF in FL to identify a subset of patients who might benefit from individualized targeted therapy.

Current trends in diagnosis and management of follicular lymphoma

Follicular lymphoma (FL) originates from germinal center B cells, is the most prevalent form of indolent non-Hodgkin's lymphoma. Upfront management is based on stage, grade, and disease burden. Radiotherapy may be curative in limited disease while chemoimmunotherapy is preferred in advanced disease. Maintenance therapy is routinely administered but its role is debatable. Relapses are common and interval from initial therapy to relapse is most important prognostic factor for relapsed FL. Management of relapsed patients is based on the initial management, the interval from prior therapies, and the toxicity of available therapies. Multiple agents are available for patients after two or more lines of therapy, but sequencing remains poorly defined.

High baseline total lesion glycolysis predicts early progression of disease within 24 months in patients with high-tumor-burden follicular lymphoma

Despite the introduction of rituximab-containing regimens, approximately 20% of patients with follicular lymphoma (FL) still experience progression of disease within 24 months (POD24) and have poor overall survival. Therefore, a more accurate risk assessment tool is required. We investigated the predictive value of two new volume-based parameters determined from baseline 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT), baseline total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG), in 45 patients with high-tumor-burden FL who underwent baseline PET/CT. We observed that high TMTV, high TLG, and poor initial treatment response (less than complete [metabolic] response [non-CR/CMR] at the end of induction therapy) independently predicted poor PFS. Notably, POD24-positive patients were more common in the high-TLG group than in the high-TMTV group, which suggests that TLG is a stronger predictor of outcomes than TMTV. Combining baseline TLG and initial treatment response showed that patients with both high TLG and non-CR/CMR experienced significantly poorer outcomes, with a 2 year PFS of 0% (hazard ratio 60.39, P = 0.000002). This combination had 56% sensitivity and 100% specificity for detecting patients who would experience POD24. Baseline TLG and initial treatment response can precisely identify patients at high risk of POD24.

Causes of Death in Low Grade B-Cell Lymphomas in the Rituximab Era: A Prospective Cohort Study

Mortality for patients with marginal zone and indolent B-cell lymphoma is largely unrelated to lymphoma in the first decade from diagnosis.

Early progression or retreatment within 24 months of diagnosis is strongly associated with increased risk of lymphoma-related mortality.

Low-grade B-cell lymphomas other than follicular and small lymphocytic lymphoma (LGBCL) account for 10% of all B-cell non-Hodgkin lymphomas. Despite improvements in survival outcomes for these patients, little is known about cause of death (COD) in the rituximab era. For a better understanding, we studied 822 newly diagnosed patients with marginal zone, lymphoplasmacytic, and unclassifiable low-grade B-cell lymphoma prospectively enrolled in the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource from 2002 to 2015. COD was assigned based on medical record review using a standard protocol. At a median follow-up of 107 months, 219 (27%) patients had died. The incidence of lymphoma-related deaths when pooling across subtypes was lower than non–lymphoma-related deaths (10-year incidence, 8.0%; 95% confidence interval [CI]: 6.2-10.4 vs 13.6%; 95% CI: 11.2-16.6). The incidence of lymphoma-related deaths varied by subtype, ranging from 3.7% at 10 years in extranodal marginal zone lymphoma to 19.3% in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Patients with early progression or retreatment events, defined using event-free survival at 24 months from diagnosis, had significantly higher likelihood of lymphoma-related death compared with patients without early events (10-year estimate: 19.1% vs 5.1%, respectively; P < .001), whereas the rates for non–lymphoma-related death were comparable in patients with or without early events (10-year estimates: 11.0% vs 15.3%, respectively). In conclusion, the most common COD in LGBCLs in the first decade after diagnosis was for causes other than lymphoma. Progression or retreatment within the first 2 years of diagnosis was a strong predictor for risk of lymphoma-related death.

Comparative analysis of rituximab or obinutuzumab combined with CHOP in first-line treatment of follicular lymphoma

Purpose

Rituximab (R) or obinutuzumab (G) combined with CHOP chemotherapy are used in previously untreated follicular lymphoma (FL). The aim is to compare in real life setting the efficacy and safety of these therapeutic strategies and assess the economic impact of introducing G.

Methods

This retrospective study, performed in 3 centers, included data from all patients who received R-CHOP or G-CHOP for previous untreated FL from June 1st, 2016 to December 31st, 2020. Progression-Free Survival (PFS) were estimated according to the Kaplan–Meier method. A budgetary impact model was performed from the French health care system’s perspective.

Results

N = 124 patients were included (58 G-CHOP; 66 R-CHOP). Fifty-one and 57 patients achieved a complete response at the end of induction in the G-CHOP and R-CHOP group, respectively. PFS was not significantly longer in the G-CHOP group (HR 0.28; 95% CI 0.08–0.97; p value = 0.14). Hematological toxicity occurred more frequently with G-CHOP than R-CHOP during induction treatment (n = 58; 100% vs. n = 61; 92%), including higher severe neutropenia (grade ≥ 3) (n = 26; 45% vs. n = 23; 35%). Infusion-related reactions during the first infusion occurred more frequently with G-CHOP (n = 19; 33% vs. n = 16; 24%). The introduction of a completed G treatment (induction and maintenance) results in an additional cumulative cost per patient estimated at more than €30,000.

Conclusion

Similar results were found in the GALLIUM subgroup analysis study, suggesting that at this time there is no absolute benefit to administer G-CHOP instead of R-CHOP in all patients with previously untreated FL and may encourage clinical and economic trials including quality of life data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-022-04155-2.