ROSEWOOD: A Phase II Randomized Study of Zanubrutinib Plus Obinutuzumab Versus Obinutuzumab Monotherapy in Patients With Relapsed or Refractory Follicular Lymphoma

BTK inhibitors and next-generation BTK-targeted therapeutics for B-cell malignancies

Bruton's tyrosine kinase (BTK) is a therapeutically validated drug target. Small-molecule inhibitors of BTK have changed the treatment paradigms of multiple B-cell malignancies and evolved over three generations to overcome clinical challenges. Four drugs are now approved by the FDA, including the first-in-class drug ibrutinib and successively approved acalabrutinib, zanubrutinib, and pirtobrutinib. The third-generation drug pirtobrutinib, which binds non-covalently to BTK, is expected to overcome resistance mutations at the covalent binding Cys481 residue of the first and second-generation drugs that covalently bind to BTK. However, some newly identified non-Cys481 resistance mutations to pirtobrutinib have shown their co-resistance to some of the covalent inhibitors, and this leaves a major unmet need that is promoting the development of next-generation BTK-targeted therapeutics. More non-covalent BTK inhibitors with differentiated binding modes are under development, and the ongoing development focus of next-generation therapeutics involves new and alternative directions to target BTK using dual-binding inhibitors and degraders of BTK, as well as its allosteric inhibitors. Recent exploration of the differentiated features of BTK inhibitors in various aspects has shown the possible link between their different features and different functional and therapeutic consequences. This review summarizes the key differentiated features of the BTK inhibitors approved by the FDA and others under development to add knowledge for their therapeutic application and future development. Long-term follow-up updates of clinical outcomes of the earlier developed drugs are also included, together with direct and indirect comparisons of efficacy and safety between the different generations of drugs. The ongoing development status of next-generation BTK-targeted therapeutics is described, with a discussion on their therapeutic potential and some limitations.

Relapsed/Refractory Follicular Lymphoma: Current Advances and Emerging Perspectives

Follicular lymphoma (FL) is a prevalent indolent non-Hodgkin lymphoma (NHL) characterized by a relapsing course and eventual refractoriness to therapy. Despite advancements in treatment, FL remains incurable, necessitating ongoing research into novel therapeutic strategies. This review provides a comprehensive overview of current standard treatments for relapsed or refractory (R/R) FL, including chemoimmunotherapy and stem cell transplantation, and delves into emerging therapies such as chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies. We discuss the efficacy and safety profiles of these innovative treatments, their integration into existing treatment paradigms, and the potential they hold in altering the natural history of FL. Additionally, we explore the challenges associated with these therapies, including accessibility, cost, and long-term management of adverse effects. By examining the evolving therapeutic landscape, this review aims to provide insights into future directions for achieving sustained remission and improving the quality of life in patients with R/R FL.

Advances in the treatment of high burden Follicular lymphoma: a Comprehensive review

Follicular lymphoma (FL) represents the second most frequent type of non-Hodgkin lymphoma and the most common indolent histology. The disease course of FL is heterogeneous, likely resulting from diverse molecular and immunological features that drive a broad spectrum of clinical presentations. While some patients with low-volume and asymptomatic disease are suitable for observation, patients with high tumor burden, advanced-stage, or symptomatic disease more often necessitate treatment initiation. The decision to begin therapy is personalized and typically initiated when GELF criteria are met. The introduction of novel agents has modified the treatment landscape for FL, allowing for more personalized strategies based on the specific characteristics of patients and diseases. In this review, we discuss the indications for treatment initiation and optimization, focusing on long-term follow-up of pivotal studies and emerging non-chemotherapy regimens. We further consider effective novel combination regimens and future directions for the evolution of frontline immunotherapy for the treatment of patients with FL.

Bruton's tyrosine kinase inhibitor zanubrutinib-based regimens in relapsed/refractory primary diffuse large B-cell lymphoma of the central nervous system

Patients with relapsed/refractory primary central nervous system lymphoma (R/R PCNSL) usually have a poor prognosis and limited treatment options. We respectively reviewed 38 patients with R/R PCNSL treated with zanubrutinib-based regimens in our center. The overall response rate, complete response rate and disease control rate were 76.3%, 47.4% and 92.1%, respectively. The median progression-free survival (PFS) was 31.0 months, the median overall survival (OS) was not reached. Unitivariate analysis by Cox's proportional hazards model revealed that overall response (vs. no response, HR = 0.18, 95%CI:0.07,0.48, p = 0.001), long duration of zanubrutinib (≥6months vs 2-5 months, HR = 0.20, 95%CI:0.06,0.63, p = 0.006) were independent factors for prolonged PFS. The log-rank analysis indicated a prolongation of PFS among patients exhibiting a higher Tumor mutational burden (TMB, ≥14.75muts/Mb) following zanubrutinib-based treatment (p = 0.016). Our data showed promising efficacy with tolerable safety of zanubrutinib-based therapies in patients with R/R PCNSL. Long duration of zanubrutinib may be associated with prolonged PFS.

Follicular lymphoma: contemporary clinical management with a focus on recent therapeutic advances

Follicular lymphoma (FL) is the most common type of indolent lymphoma, and the prognosis is favorable for most patients. However, FL remains generally incurable, and relapse is common. Patients are at risk of developing treatment-resistant lymphoma, particularly when early disease progression occurs or transformation to aggressive lymphoma takes place. Furthermore, lymphoma is the leading cause of death among patients with FL, emphasizing the need for more effective treatment strategies. This review summarizes therapeutic approaches for FL, with a focus on therapies currently in development. Recent biological insights have driven the emergence of highly effective treatments, including novel immune and targeted therapies. Clinical trials are assessing the efficacy of these novel approaches, which are increasingly used in earlier line settings. In the future, FL therapy is expected to rely less on chemotherapeutic methods, extend remission, and potentially enable cures for a growing number of patients.

An evaluation of epcoritamab as a treatment for relapsed or refractory follicular lymphoma

INTRODUCTION

The treatment landscape for relapsed refractory (RR) follicular lymphoma (FL) is rapidly evolving, and chemo-free immunotherapeutic strategies represent the major players in the field. CD20×CD3 bispecific antibodies are effective and easily manageable agents that are able to redirect the cytotoxic activity of T-cells against lymphoma cells by creating an immunological synapse.

AREAS COVERED

In this paper we will review the efficacy and safety profile of the bispecific antibody epcoritamab in RR FL, either as monotherapy (as it was recently approved in the United States and Europe) and in combination with other agents. We will discuss its potential role among the existing treatment options in this setting, particularly in relation with other approved bispecific antibodies and with CAR-T cell therapy. Presented data were obtained by literature search on PubMed and updated with most recent evidence presented at international hematology meetings (2022-2024).

EXPERT OPINION

The optimal treatment sequencing in FL is still an open issue; however, epcoritamab effectively combines key aspects such as high, rapid and durable responses, good tolerability, predictable cytokine release syndrome (CRS) kinetics, and ease of administration, representing an appealing option for patients and clinicians. Future efforts should aim at positioning epcoritamab-based treatments in earlier lines of FL.

Ibrutinib and Venetoclax in Relapsed and Refractory Follicular Lymphoma

BACKGROUND

Bruton tyrosine kinase (BTK) inhibitors are approved in several B-cell malignancies, including the recent authorization of zanubrutinib for relapsed or refractory follicular lymphoma (FL).

METHODS

Based on preclinical studies demonstrating synergy with ibrutinib and the B-cell lymphoma (BCL)-2 inhibitor, venetoclax, in FL cell lines, we conducted a multicenter phase Ib/II study evaluating this combination in relapsed or refractory FL.

RESULTS

The recommended phase 2 dose was ibrutinib 560 mg and venetoclax 600 mg. There was no evidence of clinical tumor lysis syndrome, despite the omission of a venetoclax ramp up. At a median duration of therapy of 6 months, the most common adverse events were low grade diarrhea (83%), infection (75%), and rash (58%). Amongst the 24 patients enrolled, the overall and complete response (CR) rates were 63% and 21%. At a median follow up of 6.9 months, the median progression-free survival was 8.2 months, and the median duration of CR (n = 5) was 38 months.

CONCLUSION

The combination of a BTK and BCL2 inhibitor is efficacious in relapsed/refractory FL and represents a unique dual-targeted approach warranting further investigation.

The bispecific antibody AZD0486: an overview of the clinical journey to date with a focus on follicular lymphoma

INTRODUCTION

Follicular lymphoma (FL) is the most common indolent lymphoma. Patients with advanced-stage FL typically respond to therapy, then follow a relapsing/remitting course, with shorter progression-free survival with each subsequent line of therapy. Whilst existing CD19-directed therapies such as CAR T-cell therapy have shown promising efficacy in the management of relapsed/refractory FL, immune-mediated adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity (ICANS), are well described. AZD0486 is a fully human bispecific (CD19×CD3) T-cell engager (TCE) that induces T cell-mediated cytotoxicity but with low-affinity binding of CD3, resulting in a reduction in cytokine release.

AREAS COVERED

In this review, we describe the key preclinical data for AZD0486 and evaluate in detail the available clinical data from the ongoing phase 1 first-in-human study, including safety, efficacy, pharmacokinetics, and future development plans.

EXPERT OPINION

Bispecific TCEs are among the most promising novel therapies in use for the management of relapsed/refractory B-cell lymphomas. AZD0486 results in high complete response rates with low incidence of high-grade immune-mediated toxicity compared to alternative TCE therapies. Importantly, it remains active in patients with lymphomas that have lost CD20 expression, an important mechanism of treatment failure following CD20 targeting TCEs.

Advances in Personalized Treatment and Prognostic Factors of Follicular Lymphoma

OPINION STATEMENT

Follicular lymphoma is the most prevalent form of indolent B-cell lymphoma, characterized by gradual disease progression and potential survival over several decades. Although the overall prognosis is typically favorable, some patients remain at risk for disease progression or transformation into a more aggressive variant. Recent advancements in the treatment of relapsed or refractory follicular lymphoma include cereblon modulators, kinase inhibitors, chimeric antigen receptor (CAR) T-cell therapies, and antibody-drug conjugates. Ongoing research into novel prognostic markers may improve the identification of patients at high risk for early progression, multiple relapses, or histological transformation, facilitating more precise and individualized treatment strategies.

Current treatment approach and future perspectives in B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) represent the two major subtypes of mature B cell lymphoma. A deeper understanding of tumor biology, as well as molecular classification characterized by targetable gene alterations, and the introduction of novel treatment options, including targeted drugs (e.g., antibody-drug conjugates and small molecules [e.g., Bruton tyrosine kinase inhibitor]) and immune therapies (e.g., chimeric antigen receptor [CAR] T cell therapy and bispecific antibody [BsAb]), has changed the treatment paradigms for DLBCL and FL. In clinical practice, however, treatment regimens are determined mainly based on prior treatment history, duration of response after previous treatment, patient age, and patient frailty because there have been few randomized trials to inform treatment selection for patients with relapsed or refractory disease and because there is no single prognostic index that guides suitable treatment for each patient. In this review, we summarize the treatment options for DLBCL and FL and discuss the treatment strategies for these two subtypes. We also discuss future perspectives for the treatment of these subtypes.

Acalabrutinib in combination with rituximab and lenalidomide in patients with relapsed or refractory follicular lymphoma: Results of the phase 1b open-label study (ACE-LY-003)

Patients with relapsed/refractory (R/R) follicular lymphoma (FL) have limited effective treatment options. Bruton tyrosine kinase inhibitors (BTKis) increase the anti-tumoural phenotype of tumour-associated macrophages, providing rationale to combine them with rituximab and lenalidomide (R2). Acalabrutinib, a second-generation BTKi, has potential to improve R2 efficacy without increasing T-cell-mediated toxicity due to its lack of interleukin-2-inducible T-cell kinase inhibition. Here, we report safety and efficacy from a phase 1b dose-finding study (NCT02180711) evaluating acalabrutinib plus R2 in patients with R/R FL. Overall, 29 patients received acalabrutinib plus R2 (lenalidomide 15 mg, n = 8; lenalidomide 20 mg, n = 21). At a median acalabrutinib exposure of 21 months, the most common grade ≥3 treatment-emergent adverse event (TEAE) was neutropenia (37.9%). The incidence of grade ≥3 serious TEAEs was 37.5% and 52.4% in the lenalidomide 15-mg and 20-mg cohorts, respectively; overall, the most common were COVID-19 pneumonia, COVID-19 infection and pneumonia. Earlier treatment withholdings/reductions were observed in the 20-mg cohort. With a median follow-up of 34.1 months, the overall response rate was 75.9%. The complete response rate was 25.0% and 42.9% in the lenalidomide 15- and 20-mg cohorts, respectively. Due to acceptable toxicity and preliminary efficacy, the lenalidomide 20-mg dose was selected for further investigation.

Long-term 3-year follow-up of mosunetuzumab in relapsed or refractory follicular lymphoma after ≥2 prior therapies

ABSTRACT

Mosunetuzumab, a CD20×CD3 T-cell engaging bispecific antibody, redirects T cells to eliminate malignant B cells. We present updated efficacy and safety data of a pivotal phase 1/2 study after a median follow-up of 37.4 months in 90 patients with relapsed/refractory (R/R) follicular lymphoma (FL) and ≥2 prior lines of therapy treated with fixed-duration mosunetuzumab. Investigator-assessed complete response (CR) rate and objective response rate were 60.0% (95% confidence interval [CI], 49.1-70.2) and 77.8% (95% CI, 67.8-85.9), respectively. Among 70 responders, median duration of response was 35.9 months (95% CI, 20.7 to not estimable [NE]). Among 54 patients who achieved CR, 49 remained in CR at the end of treatment; median duration of CR was not reached (NR; 95% CI, 33.0 to NE); Kaplan-Meier-estimated 30-month remission rate was 72.4% (95% CI, 59.2-85.6). Estimated 36-month overall survival (OS) rate was 82.4% (95% CI, 73.8-91.0); median OS was NR (95% CI, NE to NE). Median progression-free survival was 24.0 months (95% CI, 12.0 to NE). Median time to CD19+ B-cell recovery was 18.4 months (95% CI, 12.8-25.0) after 8 cycles of mosunetuzumab treatment. No new cytokine release syndrome events or fatal, serious, or grade ≥3 adverse events were reported. With extended follow-up, mosunetuzumab demonstrated high response rates, durable remissions, and manageable safety with no long-term concerns. This supports outpatient mosunetuzumab administration as an off-the-shelf, fixed-duration, safe, and effective treatment for patients with R/R FL, including those with high-risk disease. This trial was registered at www.clinicaltrials.gov as #NCT02500407.

Covalent Bruton tyrosine kinase inhibitors across generations: A focus on zanubrutinib

Bruton tyrosine kinase (BTK), the primary target of BTK inhibitors, is a key enzyme in the proliferation and survival pathway of neoplastic B-cells. BTK inhibitors are approved in many hematologic malignancies: chronic lymphocytic leukaemia, mantle cell lymphoma, marginal zone lymphoma, Waldenström macroglobulinaemia and follicular lymphoma. Second-generation BTK inhibitors display high target selectivity thus resulting in a reduction in off-target and off-tissue effects, better therapeutic index and improved tolerability. This paper summarizes the mechanisms of action of first and second generation BTK inhibitors and elucidates results in any disease setting, with a precise focus on zanubrutinib.

SOHO State of the Art Updates and Next Questions | Novel Immunotherapy Combinations for the Treatment of Indolent B-Cell Lymphoma

Chemoimmunotherapy (CIT) is the standard frontline treatment for advanced indolent non-Hodgkin lymphomas (iNHL). While lenalidomide-based immunotherapy remains the standard of care for relapsed iNHL, its frontline use is limited, due to nonsuperiority as compared to CIT. Agents that engage T-cells, polarize macrophage phenotype to a more antitumoral phenotype, and/or to target epigenetic pathways could enhance immunotherapy. We summarize in this review safety plus efficacy data from published and/or ongoing clinical trials investigating the combination of lenalidomide-based immunotherapy with T-cell engagers (including anti-CD3/CD20 bispecific antibodies), macrophage-targeting agents (including BTK inhibitors and anti-CD47 antibodies), and epigenetic modifiers (including EZH2 inhibitors). We also summarize the activity in iNHL of agents targeting antigens other than CD20 (including CD19 and CD79b), and novel immunotherapies and cellular therapies (including NK-cell based treatments). The therapeutic landscape of iNHL is soon to significantly change.

Indolent lymphoma: addressing the needs of survivors

Over the past two decades, there has been a continuous improvement in outcome for patients with indolent lymphoma (iNHL) resulting in a gradual accumulation of survivors. While life expectancy in the current era approaches that of the lymphoma-free population, patients continue to experience lifelong complications of the disease and its treatment affecting general health, emotional, psychological and social wellbeing, relationships, employment, finances, and fitness. Contemporary care models while suited to the management of lymphoma are often lacking when it comes to identification and management of these additional needs. Given improvements in physical survival achieved over the past decades, it is timely for us to focus on other issues affecting patient wellbeing including immunodeficiency and infection, second cancers, cardiovascular disease, bone health, psychological wellbeing, and sexual health. Many of these aspects are in the domain of the primary care physician; however, there is limited guidance on how these issues should be addressed. It is now time for us to engage our patients, their caregivers, and other healthcare providers in care aspects beyond the lymphoma diagnosis, so they can anticipate a rich and full life, free from both direct and indirect consequences of the lymphoma diagnosis.

Building the future management of follicular lymphoma with T-cell-redirecting strategies

ABSTRACT

Follicular lymphoma (FL) usually requires multiple lines of therapy, and disease control remains largely insufficient with conventional chemoimmunotherapy. Several T-cell-redirecting strategies recently approved in the relapsed/refractory setting have the potential to improve outcomes and change the treatment algorithm in FL. This review focuses on the role of chimeric antigen receptor T cells and bispecific antibodies in FL, paying special attention to sequencing approaches and future directions.

Efficacy, safety and cost-effectiveness of obinutuzumab in patients with follicular lymphoma: a rapid review

Background

Obinutuzumab was approved in China in June 2021 used in combination with chemotherapy (followed by obinutuzumab maintenance) for the treatment of adult patients with previously untreated stage II bulky, III, or IV follicular lymphoma (FL). The clinical application of obinutuzumab has recently begun in China, but there is a lack of evidence to determine under which circumstances it should be considered the treatment of choice. A comprehensive assessment is necessary to evaluate the efficacy, safety, and cost-effectiveness of obinutuzumab in adult patients with FL.

Objective

To summarize the evidence on the efficacy, safety, and cost-effectiveness of obinutuzumab in adult patients with FL, aiming to provide medical professionals with evidence for informed choices in clinical practice.

Methods

The approach to this evidence synthesis was a rapid review of systematic reviews/meta-analyses (SR/meta-analyses), health technology assessment (HTA) reports, and pharmacoeconomic studies that brings together and summarizes the efficacy, safety, and cost-effectiveness of obinutuzumab in adult patients with FL. A literature search was conducted across multiple databases, including PubMed, Embase, Wanfang, CNKI, Weipu database, the Cochrane Library, the Centre for Reviews and Dissemination (CRD) database, International Network of Agencies for Health Technology Assessment (INAHTA) and Canada's Drug Agency (CDA-AMC), International Society for Pharmacoeconomics and Outcomes Research (ISPOR), National Institute For Health and Care Excellence (NICE), Institute For Clinical And Economic Review (ICER), Grey Literature Database and Grey Net International. The studies on obinutuzumab for FL were searched in full text with obinutuzumab, systematic review, meta-analysis, economics, cost, and health technology assessment as keywords, with a search time frame from the date of database creation to 29 November 2024. The literature was screened based on predefined inclusion and exclusion criteria, and data were meticulously extracted and synthesized by two authors. Simultaneously, the quality of the literature was thoroughly assessed.

Results

Obinutuzumab based chemotherapy (the chemotherapy regimen-cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP); cyclophosphamide, vincristine, and prednisone (CVP); or bendamustine) significantly prolonged progression free survival (PFS) compared to other chemotherapy regimen at primary and updated analyses. The incidence of grade 3-5 AEs, infusion-related reactions (IRRs), and infection were higher in the obinutuzumab based chemotherapy group compared to other chemotherapies. The economic researches conducted in China, United States, Japan, Italy and Norway had demonstrated that obinutuzumab-based chemothrepy was cost-effective compared to other chemothrepies. Although obinutuzumab significantly prolonged PFS and was cost-effective, its safety profile was considered lower.

Conclusion

Compared with other chemothrapy regimen, obinutuzumab based chemotherapy significantly prolonged PFS and was cost-effective, while its safety profile was considered lower. Therefore, medical professionals should be caution when using or introducing obinutuzumab treatment for FL patients.

Bispecific antibodies for the treatment of hematologic malignancies: The magic is T-cell redirection

Bispecific antibody therapy has revolutionized the treatment of hematologic malignancies. There are currently 7 FDA approved products with 4 different targets covering 5 indications in 4 diseases. Products include blinatumomab targeting B-cell ALL in MRD detectable first remission and in relapsed and/or refractory disease, elranatamab and teclistamab targeting BCMA in relapsed/refractory multiple myeloma, talquetamab targeting GPCR5D in multiple myeloma, and mosunetuzumab, epcoritamab and glofitamab which all target CD20 in follicular lymphoma, both follicular and large B cell lymphoma, or large B cell lymphoma alone, respectively. Each product utilizes the strategy of T-cell redirection by binding CD3 on the effector cell to target immune cells toward a tumor associated antigen. There are overlapping toxicities related to activation of the immune system and inflammation. The role of these agents in earlier lines of therapy and in novel combinations are under heavy investigation and their full utility and benefit in the treatment of hematologic malignancies is yet to be fully realized.

Comparative Analysis of Bispecific Antibodies and CAR T-Cell Therapy in Follicular Lymphoma

The treatment landscape for relapsed/refractory follicular lymphoma (RR-FL) is marked by a pivotal debate between chimeric antigen receptor T-cell (CAR-T) therapy and bispecific antibodies (BsAbs). While both CAR-T therapy and BsAbs target similar immunobiology and molecular markers, their efficacy comparisons are hindered by the lack of direct clinical trial comparisons. Key trials, such as the ZUMA-5 study, underscore axicabtagene ciloleucel (axi-cel)'s efficacy in treating RR-FL, achieving a 79% complete response rate with a median duration of response exceeding 3 years. Similarly, lisocabtagene maraleucel (liso-cel) in the TRANSCEND FL study reports a 94% complete response rate, emphasizing robust outcomes in heavily pretreated patients. Among BsAbs, mosunetuzumab showed promise in the GO29781 trial, with a 62% overall response rate in heavily pretreated RR-FL patients. Thus, CAR-T therapy offers potential curative benefits with a single infusion. However, its efficacy is tempered by significant adverse events such as cytokine release syndrome (CRS), neurotoxicity, and cytopenias, requiring specialized management and patient monitoring. In contrast, BsAbs provide a more tolerable treatment option counterbalancing by lower response rates and frequent dosing requirements. Personalized treatment strategies are crucial because of these distinct efficacy and safety profiles. When considering cost-effectiveness, both therapies need to be evaluated in the context of their clinical outcomes and quality of life improvements. Cost-effectiveness considerations are essential; while CAR-T therapies incur higher initial costs, their potential for long-term remission may mitigate expenses associated with repeated treatments or hospitalizations. Future research into resistance mechanisms and optimal therapeutic sequencing will further refine RR-FL management strategies.

Loncastuximab tesirine with rituximab in patients with relapsed or refractory follicular lymphoma: a single-centre, single-arm, phase 2 trial

BACKGROUND

Preliminary data suggest promising activity of loncastuximab tesirine in follicular lymphoma, and synergistic activity between rituximab-induced cytotoxicity and loncastuximab tesirine. In this study, we evaluated loncastuximab tesirine combined with rituximab for second-line and later treatment of follicular lymphoma.

METHODS

We did a single-arm, investigator-initiated, phase 2 trial at Sylvester Comprehensive Cancer Center in Miami, FL, USA. We recruited patients aged 18 years or older with histologically confirmed relapsed or refractory follicular lymphoma (grade 1-3A) treated with one or more lines of therapy and presenting with progression or relapse of disease within 24 months (POD24) after the first line of treatment, one or more Groupe d'Etude des Lymphomes Folliculaires (GELF) criteria, or second relapse, and with an Eastern Cooperative Oncology Group performance status of 0-2. Intravenous loncastuximab tesirine was administered on day 1 of a 21-day cycle, at 0·15 mg/kg for two cycles, then 0·075 mg/kg thereafter. Intravenous rituximab was administered on day 1 of cycle 1, at 375 mg/m2 for four once-weekly doses, followed by one dose every 8 weeks on cycles 5, 6, and 7. At week 21, patients with a complete response discontinued loncastuximab tesirine and received two more doses of rituximab once every 8 weeks. Patients with a partial response at week 21 continued both agents for 18 more weeks. The primary endpoint was complete response rate at week 12 assessed by the Lugano 2014 classification in patients who had received at least three doses of loncastuximab tesirine. The safety analysis included all patients who received one or more doses of loncastuximab tesirine. The trial is registered with ClinicalTrials.gov, NCT04998669, and is ongoing (open to recruitment); the data cutoff for this analysis was Sept 13, 2024.

FINDINGS

Between Jan 28, 2022, and June 3, 2024, we enrolled 39 patients (median age 68 years [IQR 58-77]; 21 [54%] male patients and 18 [46%] female patients). All patients presented with one or more GELF criteria (n=36 [92%]) or POD24 after the first line of treatment (n=20 [51%]) at baseline. As of Sept 13, 2024, the median follow-up was 18·2 months (95% CI 12·0-19·3). Week 12 complete response rate was 67% (n=26 of 39). The most common grade 3 or worse treatment-emergent adverse events (TEAEs) were lymphopenia (eight [21%] of 39 patients) and neutropenia (five [13%] patients; one of whom had a serious grade 3 TEAE of febrile neutropenia that was considered to be related to study treatment). Generalised and peripheral oedema was predominantly grade 1-2 and all cases of oedema were treatable with diuretics. Serious TEAEs that were considered to be related to study drugs occurred in four (10%) of 39 patients. No fatal TEAEs occurred.

INTERPRETATION

Loncastuximab tesirine with rituximab showed clinically meaningful activity in relapsed or refractory follicular lymphoma, and had a manageable safety profile.

FUNDING

ADC Therapeutics and Sylvester Comprehensive Cancer Center.

Follicular lymphoma research: an open dialogue for a collaborative roadmap

Follicular lymphoma (FL) is the second most common type of lymphoma (20% of all non-Hodgkin lymphomas), derived from germinal centre (GC) B cells, and is characterised by its significant clinical, prognostic and biological heterogeneity, leading to complexity in management. Despite significant biological investigation and indisputable clinical progress since the advent of the immunotherapy era more than 20 years ago, much remains to be done to understand and cure this lymphoma. Today, FL is metaphorically a giant puzzle on the table with patches of sky, landscape and foliage clearly appearing. However, many of the remaining pieces are held by various stakeholders (e.g. clinicians, pathologists, researchers, drug developers) without global agreement on what the gaps are, or any clear blueprint on how to solve the puzzle of understanding the heterogeneity of this disease and create curative and tailored therapies. With the advent of new investigation and drug technologies, together with recent advances in our capacity to manage big data, the time seems ripe for a change of scale. More than ever, this will require collaboration between and within all stakeholders to overcome the current bottlenecks in the field. As for every investigator, we acknowledge that this first draft is necessarily biased, incomplete and some FL expert readers might recognise some remaining gaps not addressed. We hope they will reply to make this effort a collaborative one to assemble all the pieces in the most ideal fashion. As such, this review intends to be a first step and an interactive platform to a collaborative roadmap towards better understanding and care of FL.

The POD24 challenge: where do we go from here for early progressors?

Follicular lymphoma is the most common indolent lymphoma, with a favorable prognosis and survival measured in decades. However, approximately 15% to 20% of patients encounter early disease progression, termed POD24, within 24 months from diagnosis or treatment initiation. Recognizing the correlation between POD24 and a heightened risk of lymphoma-related death has sparked intensive investigations into the clinical and biological determinants of POD24 and the development of innovative treatment strategies targeting this group. Research is also ongoing to understand the varying impact of POD24 based on different clinical contexts and the implications of early histologic transformation on POD24 prognosis. Recent investigations have uncovered potential new predictors of POD24, including genetic and nongenetic alterations as well as some conflicting F-fludeoxyglucose-positron emission tomography characteristics such as maximum standardized uptake value and total metabolic tumor volume. These developments, together with clinical predictors, have led to the emergence of several clinicopathologic tools to help identify at diagnosis patients who may be at higher risk for POD24. As these models are not routinely used, more work is needed to develop new risk-stratification strategies integrating clinical and molecular risk profiling that can be easily implemented in clinical practice to drive therapeutic choice. This review aims to delineate the modest but incremental progress achieved in our understanding of POD24, both clinically and biologically. Furthermore, we offer insights into the best practices to approach POD24 in the current era, aspiring to chart a new path forward to optimize patient outcomes.

Navigating the changing landscape of BTK-targeted therapies for B cell lymphomas and chronic lymphocytic leukaemia

The B cell receptor (BCR) signalling pathway has an integral role in the pathogenesis of many B cell malignancies, including chronic lymphocytic leukaemia, mantle cell lymphoma, diffuse large B cell lymphoma and Waldenström macroglobulinaemia. Bruton tyrosine kinase (BTK) is a key node mediating signal transduction downstream of the BCR. The advent of BTK inhibitors has revolutionized the treatment landscape of B cell malignancies, with these agents often replacing highly intensive and toxic chemoimmunotherapy regimens as the standard of care. In this Review, we discuss the pivotal trials that have led to the approval of various covalent BTK inhibitors, the current treatment indications for these agents and mechanisms of resistance. In addition, we discuss novel BTK-targeted therapies, including covalent, as well as non-covalent, BTK inhibitors, BTK degraders and combination doublet and triplet regimens, to provide insights on the best current treatment paradigms in the frontline setting and at disease relapse.

Acalabrutinib alone or in combination with rituximab for follicular lymphoma: An open-label study

Acalabrutinib is a selective, second-generation Bruton tyrosine kinase inhibitor. In this open-label, parallel-group study, patients with relapsed/refractory (R/R) follicular lymphoma (FL) were randomised to either acalabrutinib monotherapy or acalabrutinib plus rituximab. An additional cohort of patients with treatment-naive (TN) FL received only the acalabrutinib-rituximab combination. Acalabrutinib-rituximab was well tolerated and active in R/R and TN FL; in the TN cohort the overall response rate was 92.3% with most remissions lasting over 4 years. Acalabrutinib monotherapy was also well tolerated and active in R/R FL. These results support further study of acalabrutinib alone and in combination with rituximab in FL.

Patient-reported outcomes in patients with relapsed or refractory follicular lymphoma treated with zanubrutinib plus obinutuzumab versus obinutuzumab monotherapy: results from the ROSEWOOD trial

OBJECTIVE

We report patient-reported outcomes (PROs) measuring health-related quality of life (HRQoL) from the ROSEWOOD trial (NCT03332017), which demonstrated superior efficacy and a manageable safety profile with zanubrutinib plus obinutuzumab (ZO) versus obinutuzumab (O) in patients with heavily pretreated relapsed/refractory follicular lymphoma (R/R FL).

METHODS

PROs were assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-C30) and EQ-5D-5L questionnaires at baseline and subsequently every 12 weeks. All QLQ-C30 domains and EQ-5D-5L visual analog scale (VAS) scores were analyzed descriptively. At the key clinical timepoints (weeks 12 and 24), a mixed model for repeated measures (MMRM) analysis was used to evaluate the key PRO endpoints, including global health status, physical and role functioning, and symptoms of fatigue, pain, diarrhea, and nausea/vomiting. Clinically meaningful change was defined as a ≥ 5-point mean difference from baseline and between the ZO and O arms.

RESULTS

Patients were randomized to ZO (n = 145) or O (n = 72). By week 48, descriptive analysis results indicated that patients in the ZO arm demonstrated improved outcomes in role functioning and fatigue and nausea/vomiting symptoms, compared with those in the O arm. Both groups experienced improvements in pain symptoms. EQ-5D-5L VAS scores showed no observable differences between treatment arms through week 48. MMRM analysis revealed that the global health status/quality of life of patients treated with ZO improved, as did fatigue, at week 12. At week 24, patients in the ZO arm experienced a clinically meaningful improvement in role functioning, pain, and fatigue.

CONCLUSIONS

In patients with R/R FL, ZO was associated with improved PROs compared with O. These findings suggest that zanubrutinib contributed clinically meaningful benefits to patient HRQoL when added to obinutuzumab.

TRIAL REGISTRATION

The ROSEWOOD trial is registered on ClinicalTrials.gov (BGB-3111-212; ClinicalTrials.gov identifier: NCT03332017).

Safety and efficacy of odronextamab in patients with relapsed or refractory follicular lymphoma

BACKGROUND

Odronextamab, a CD20×CD3 bispecific antibody that engages cytotoxic T cells to destroy malignant B cells, has demonstrated encouraging activity across multiple subtypes of relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma.

PATIENTS AND METHODS

This phase II study (ELM-2; NCT03888105) evaluated odronextamab in patients with R/R follicular lymphoma after two or more lines of systemic therapy. Patients received intravenous odronextamab in 21-day cycles, with step-up dosing in cycle 1 to help mitigate the risk of cytokine release syndrome, until disease progression or unacceptable toxicity. The primary endpoint was objective response rate by independent central review.

RESULTS

Among 128 patients evaluated, 95% completed cycle 1, and 85% completed four or more cycles. At 20.1 months' efficacy follow-up, objective response rate was 80.0% and complete response rate was 73.4%. Median duration of complete response was 25.1 months. Median progression-free survival was 20.7 months, and median overall survival was not reached. Discontinuation of odronextamab due to adverse events occurred in 16% of patients. The most common treatment-emergent adverse events were cytokine release syndrome [56%; grade ≥3 1.7% (1/60) with 0.7/4/20 mg step-up], neutropenia (39%), and pyrexia (38%).

CONCLUSIONS

Odronextamab achieved high complete response rates with generally manageable safety in patients with heavily pretreated R/R follicular lymphoma.

Advances in Targeted Therapy: Addressing Resistance to BTK Inhibition in B-Cell Lymphoid Malignancies

B-cell lymphoid malignancies are a heterogeneous group of hematologic cancers, where Bruton's tyrosine kinase (BTK) inhibitors have received FDA approval for several subtypes. The first-in-class covalent BTK inhibitor, Ibrutinib, binds to the C481 amino acid residue to block the BTK enzyme and prevent the downstream signaling. Resistance to covalent BTK inhibitors (BTKi) can occur through mutations at the BTK binding site (C481S) but also other BTK sites and the phospholipase C gamma 2 (PLCγ2) resulting in downstream signaling. To bypass the C481S mutation, non-covalent BTKi, such as Pirtobrutinib, were developed and are active against both wild-type and the C481S mutation. In this review, we discuss the molecular and genetic mechanisms which contribute to acquisition of resistance to covalent and non-covalent BTKi. In addition, we discuss the new emerging class of BTK degraders, which utilize the evolution of proteolysis-targeting chimeras (PROTACs) to degrade the BTK protein and constitute an important avenue of overcoming resistance. The moving landscape of resistance to BTKi and the development of new therapeutic strategies highlight the ongoing advances being made towards the pursuit of a cure for B-cell lymphoid malignancies.

Mosunetuzumab for the treatment of follicular lymphoma

INTRODUCTION

Follicular lymphoma (FL) is an indolent non-Hodgkin lymphoma that shows a progressive increase in relapses and refractory in its natural history and a median survival of approximately 18-20 years. The advent of anti-CD20 monoclonal antibodies has changed the FL therapeutic algorithm, with an increase in progression-free survival. T-cell-dependent bispecific antibodies (BsAbs) represent an emerging drug class against FL.

AREAS COVERED

In this review, we selected papers from the principal databases (PubMed, Medline, Medscape, ASCO, ESMO) between January 2021 and June 2024, using the keywords 'mosunetuzumab' and 'follicular lymphoma' to provide an overview of mosunetuzumab-axgb, a pioneering BsAb. Its mechanism of action, efficacy, safety, and future perspectives were analyzed.

EXPERT OPINION

Mosunetuzumab grants a directing T-cell mediated cytotoxicity and allows a step-up dosing that reduces adverse events, such as cytokine release syndrome, with promising tolerability. At the same time, it improves outcomes in the evolving landscape of FL management, even in post-CAR-T FL patients. Prognostic factors and targetable mechanisms of resistance need to be explored.

[Chinese expert consensus on the diagnosis and management of elderly patients with follicular lymphoma (2024)]

In the general population of China, the number of older patients with follicular lymphoma (FL) will continue to increase with age. The treatment of elderly patients with FL is based on individual principles, which focuses on the improvement of tumor-related symptoms and quality of life. To improve the diagnosis and treatment of elderly patients with FL in China, several organizations (i.e., Hematology Oncology Committee of China Anti-Cancer Association, etc.) have gathered relevant experts to formulate this consensus.

Current and future therapies for follicular lymphoma

Follicular lymphoma (FL) is an indolent, germinal center B cell-derived lymphoid neoplasm, for which recent advances in treatment have substantially improved patient survival. However, FL remains an incurable and heterogeneous disease, with groups of patients experiencing early disease progression, histologic transformation, or a high risk of treatment-related toxicity. Additionally, FL is a continually relapsing disease, and response rates and disease-control intervals decrease with each subsequent line of therapy. In this review, we explore the current treatment landscape for relapsed or refractory FL and promising therapies in development, highlighting the efficacy and potential risks of each treatment. We provide a real-world perspective on the unmet needs of patients with FL. Novel therapeutic approaches in development offer a wide array of options for clinicians when treating relapsed or refractory FL. A nuanced approach is required to address the needs of individual patients, taking into consideration both the risks and benefits of each treatment option, as well as patient preferences.

Safety and activity of lenalidomide in combination with obinutuzumab in patients with relapsed indolent non-Hodgkin lymphoma: a single group, open-label, phase 1/2 trial

Background

Rituximab and lenalidomide is a preferred option for relapsed indolent B cell non-Hodgkin lymphoma. Obinutuzumab may be a superior combination partner with lenalidomide given enhanced antibody dependent cellular cytotoxicity and phagocytosis compared to rituximab. Our aim was to determine the recommended phase 2 dose, safety, and activity of lenalidomide in combination with fixed dose of obinutuzumab in relapsed and refractory indolent B cell non-Hodgkin lymphoma.

Methods

In this single-arm, open-label, phase 1/2 trial, we enrolled patients with relapsed or refractory WHO Grade 1-3A follicular lymphoma, marginal zone lymphoma and small lymphocytic lymphoma and adequate performance status (ECOG 0-2) at the MD Anderson Cancer Center. We excluded patients with evidence of ongoing transformation to aggressive lymphoma. During phase 1, 1000 mg intravenous obinutuzumab was administered with three predefined levels of oral lenalidomide in a 3 + 3 dose escalation design to establish lenalidomide 20 mg as the recommended phase 2 dose. During phase 2, patients received induction therapy with six 28-day cycles of lenalidomide 20 mg with intravenous obinutuzumab 1000 mg. In accordance with our prior experience with lenalidomide plus rituximab, patients who were responding to the combination could receive up to 6 additional cycles (up to 12 cycles in total) of combination therapy. Dosing of obinutuzumab was continued in all responding patients after cycle 6 every 2 months for a total of 30 months from the start of therapy. The decision of number of cycles of combination therapy beyond 6 was at discretion of the investigator and was included to allow individualisation of therapy to maximise response while minimising exposure. The co-primary objectives were to evaluate the safety and overall response, defined as the proportion of patients who achieved a complete or partial response in relapsed and refractory indolent non-Hodgkin lymphoma at the end of induction therapy, according to Cheson and colleagues (2007 criteria). The secondary endpoints were complete response after induction therapy and time to event endpoints including time to progression, progression free survival, and overall survival. Analyses were intent to treat in the efficacy cohort and per-treated in the safety population in all patients who received at least one dose of either investigational agent. This trial is registered with ClinicalTrials.gov, NCT01995669.

Findings

Between June 03, 2014, and 07 March 2019, we completed planned enrolment, and 66 patients started therapy including 9 patients in phase 1 and 57 patients in phase 2. All patients were evaluated for safety and the 60 patients treated at the recommended phase 2 dose of lenalidomide 20 mg were evaluable for activity. Grade 3-4 haematological toxicities included neutropenia 21% (14/66) and thrombocytopenia 11% (7/66) with no cases of febrile neutropenia. Grade 3-4 non-haematological toxicities included lung infection 8% (5/66), fatigue 8% (5/66) and rash 6% (4/66). By Cheson 2007 criteria, 90% (54/60, 95% CI: 79-96) achieved an overall response at the end of induction meeting the prespecified activity endpoint. Complete responses were seen in 33% (20/60, 95% CI: 22-47) at the end of induction. Median progression free survival, time to progression and overall survival have not been reached after median follow-up of 41.7 months. Estimated 4-year progression free survival rates were 55% (95% CI: 42-73), time to progression of 56% (95% CI: 43-74) and overall survival of 84% (95% CI: 74-95).

Interpretation

Our findings suggest that oral lenalidomide with obinutuzumab is safe and highly active in patients with relapsed and refractory indolent B cell non-Hodgkin lymphoma and is associated with prolonged remission duration. The study is limited by the lack of a control arm leading to cross-trial comparisons to evaluate activity. Future randomised trials comparing this regime to rituximab and lenalidomide are warranted.

Funding

Genentech and an MD Anderson Core grant.

Moving T-Cell Therapies into the Standard of Care for Patients with Relapsed or Refractory Follicular Lymphoma: A Review

Patients with follicular lymphoma, an indolent form of non-Hodgkin lymphoma, typically experience multiple relapses over their disease course. Periods of remission become progressively shorter with worse clinical outcomes after each subsequent line of therapy. Currently, no clear standard of care/preferred treatment approach exists for patients with relapsed or refractory follicular lymphoma. As novel agents continue to emerge for treatment in the third-line setting, guidance is needed for selecting the most appropriate therapy for each patient. Several classes of targeted therapeutic agents, including monoclonal antibodies, phosphoinositide 3-kinase inhibitors, enhancer of zeste homolog 2 inhibitors, chimeric antigen receptor (CAR) T-cell therapies, and bispecific antibodies, have been approved by regulatory authorities based on clinical benefit in patients with relapsed or refractory follicular lymphoma. Additionally, antibody-drug conjugates and other immunocellular therapies are being evaluated in this setting. Effective integration of CAR-T cell therapy into the treatment paradigm after two or more prior therapies requires appropriate patient selection based on transformation status following a rebiopsy; a risk evaluation based on age, fitness, and remission length; and eligibility for CAR-T cell therapy. Consideration of important logistical factors (e.g., proximity to the treatment center and caregiver support during key periods of CAR-T cell therapy) is also critical. Overall, an individualized treatment plan that considers patient-related factors (e.g., age, disease status, tumor burden, comorbidities) and prior treatment types is recommended for patients with relapsed or refractory follicular lymphoma. Future analyses of real-world data and a better understanding of mechanisms of relapse are needed to further refine patient selection and identify optimal sequencing of therapies in this setting.

Translational insights into the genetics and immunobiology of relapsed/refractory follicular lymphoma

Although follicular lymphoma (FL) is traditionally classified as an indolent subtype of B cell non-Hodgkin lymphoma, clinical trajectories are often diverse based on unique disease biology, and many patients will eventually experience relapse of their disease. Furthermore, progression of disease within 24 months is associated with increased mortality rates for FL. In the last five years, we have witnessed an upsurge in the commercial availability of targeted therapies for relapsed/refractory (R/R) FL, including chimeric antigen receptor-T (CAR-T) products, bispecific T cell engagers (BiTEs), epigenetic modifier therapies, and next-generation Bruton tyrosine kinase (BTK) inhibitors. Furthermore, clinical trial options have increased tremendously and now include combinatorial strategies that exert synergy against malignant germinal center B cells. Here, we provide a 2024 update of novel therapeutic agents whose development has been informed by recent advances in the genetics and immunobiology of R/R FL. Specifically, we emphasize high-value targeted therapeutics, including anti-CD3 x anti-CD20 BiTEs and adoptive T cell therapies. We discuss prospects on selection and sequencing of BiTEs and CAR-T therapies for patients with R/R FL. We underscore the principles of FL pathobiology that are paving way for future drug discovery and shed insight into therapeutic targeting within nodal basins based on our increasing understanding of the FL microenvironment. Finally, we summarize how a greater knowledge of FL immunobiology can inform risk stratification and therapy selection on a personalized basis for R/R FL in 2025.

BTK inhibitors in CLL: second-generation drugs and beyond

ABSTRACT

BTK inhibitors (BTKis) are established standards of care in multiple B-cell malignancies including chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom macroglobulinemia. The first-generation BTKi ibrutinib demonstrated superiority over standard chemoimmunotherapy regimens in multiple randomized trials but is limited by cardiovascular side effects such as atrial fibrillation and hypertension. Second-generation BTKis have improved selectivity and demonstrate reduced rates of cardiovascular complications in 3 head-to-head ibrutinib studies. The emergence of BTK C481S mutation has led to the development of noncovalent, "reversible" BTKis, such as pirtobrutinib, which are agnostic to the C481S mutation. However, these inhibitors are associated with resistant mutations outside the C481 hot spot. These variant non-C481 mutations are of great clinical interest because some are shared among pirtobrutinib, zanubrutinib, and acalabrutinib, with potential implications for cross resistance and treatment sequencing. Finally, BTK protein degraders with in vitro activity against C481 and non-C481 mutations are currently in clinical development. Here, we review the evolution of therapeutic BTK-targeting and discuss future directions for clinical research.

Learnings from phosphatidylinositol 3-kinase inhibitors in lymphoma-Moving to a model where less can be more

The role of Pi3K inhibitors in lymphoma is diminishing due to the adverse results from trials in indolent lymphoma, but is a one-size-fits-all approach to drug development penalising some lymphoma subtypes and the newer generation of Pi3K inhibitors? The report by Soumerai et al. of zandelisib with zanubrutinib in follicular and mantle cell lymphoma is an important addition to the data. Commentary on: Soumerai et al. Safety and efficacy of zandelisib plus zanubrutinib in previously treated follicular and mantle cell lymphomas. Br J Haematol 2024;204:1762-1770.

Beyond Chemotherapy: Present and Future Perspectives in the Treatment of Lymphoproliferative Disorders

Over the past three decades, the treatment of lymphoproliferative disorders has undergone profound changes, notably due to the increasing availability of innovative therapies with the potential to redefine clinical management paradigms. A major impact is related to the development of monoclonal antibodies, checkpoint inhibitors, bispecific antibodies, and chimeric antigen receptor T (CAR-T) cell therapies. This review discusses the current landscape of clinical trials targeting various hematological malignancies, highlighting promising early-phase results and strategies to overcome resistance. Lymphoproliferative disorders encompass a range of conditions: while in Hodgkin lymphoma (HL) the goal is to reduce chemotherapy-related toxicity by integrating immunotherapy into the frontline setting, peripheral T cell lymphoma (PTCL) lacks effective targeted therapies. The review emphasizes a shifting therapeutic landscape towards precision medicine and treatment modalities that are less toxic yet more effective.