Concurrent pembrolizumab with AVD for untreated classic Hodgkin lymphoma

An updated review on immune checkpoint inhibitor-induced colitis: epidemiology, pathogenesis, treatment strategies, and the role of traditional Chinese medicine

Immune checkpoint inhibitor-induced colitis (irColitis) is a common and severe adverse reaction to immune checkpoint inhibitors (ICIs), significantly impacting the treatment outcomes and quality of life of cancer patients. Epidemiological studies indicate that the incidence of irColitis is associated with factors such as the type of ICIs, the patient's gender, age, and medical history. Although the exact pathophysiology remains unclear, irColitis is thought to be related to immune system activation and dysregulation, gut microbiota imbalance, and impaired epithelial barrier function. This review summarized the epidemiology, clinical presentation, diagnostic criteria, and pathogenesis of irColitis. Additionally, the standard and novel therapeutic strategies of irColitis, including corticosteroids, biologics, and gut microbiota interventions, more importantly the potential and application of Traditional Chinese Medicine (TCM). Future researches call for deeper mechanistic investigations, the development of biomarkers, and reveal the integration of TCM therapies within individual immunotherapy frameworks.

T-cell diversity and exclusion of blood-derived T-cells in the tumor microenvironment of classical Hodgkin Lymphoma

The Tumor Microenvironment (TME) in classical Hodgkin Lymphoma (HL) contains abundant immune cells and only few neoplastic Hodgkin and Reed-Sternberg cells (HRSC). We analyzed the T-cell receptor (TCR) repertoire to detect T-cell expansion in the TME and blood. In contrast to solid cancer tissue, T-cells in the TME of HL are highly polyclonal at first diagnosis and show only minor clonal expansion during anti-PD1 immune checkpoint blockade (ICB). At relapse and during ICB, pre-amplified T-cell populations increase in the TME of solid cancers but to a much lesser extent in HL. In contrast, T-cell populations in the peripheral blood of HL patients display higher clonality than healthy controls reaching clonality levels comparable to solid cancer. However, pre-amplified blood T-cells in HL patients show only minor additional clonal expansion during ICB. Moreover, blood-derived T-cells do not repopulate the TME of HL to the same extent as observed in solid cancers. Thus, the T-cell repertoire in the TME of HL appears unique by a relatively low clonal T-cell content and the exclusion of clonally expanded T-cells from the peripheral blood. Exclusion of clonally expanded tumor-specific T-cells from the TME may present a novel mechanism of immune evasion in HL.

Impact of immunological aging on T cell-mediated therapies in older adults with multiple myeloma and lymphoma

The treatment landscape for lymphoma and multiple myeloma, which disproportionally affect older adults, has been transformed by the advent of T cell-mediated immunotherapies, including immune checkpoint inhibition, T cell-engaging bispecific antibodies, and chimeric antigen receptor (CAR) T cell therapy, during the last decade. These treatment modalities re-enable the patient's own immune system to combat malignant cells and offer the potential for sustained remissions and cure for various diseases.Age profoundly affects the physiological function of the immune system. The process of biological aging is largely driven by inflammatory signaling, which is reciprocally fueled by aging-related alterations of physiology and metabolism. In the T cell compartment, aging contributes to T cell senescence and exhaustion, increased abundance of terminally differentiated cells, a corresponding attrition in naïve T cell numbers, and a decrease in the breadth of the receptor repertoire. Furthermore, inflammatory signaling drives aging-related pathologies and contributes to frailty in older individuals. Thus, there is growing evidence of biological aging modulating the efficacy and toxicity of T cell-mediated immunotherapies.Here, we review the available evidence from biological and clinical studies focusing on the relationship between T cell-mediated treatment of hematologic malignancies and age. We discuss biological features potentially impacting clinical outcomes in various scenarios, and potential strategies to improve the safety and efficacy of immune checkpoint inhibitors, T cell-engaging bispecific antibodies, and CAR-T cell therapy in older patients.

A phase 2 study of frontline pembrolizumab in follicular lymphoma

Background

The tumor microenvironment (TME), including infiltrating T-cells, is thought to play a major role in the pathogenesis and prognosis of follicular lymphoma (FL) and may contribute to its widely varied disease course. We hypothesized that programmed death-1 inhibition may be most effective in untreated, immunocompetent FL patients. Thus, we developed a phase 2 study to evaluate the efficacy of pembrolizumab as the initial treatment for indolent B-cell lymphoma.

Methods

Adults with FL or marginal zone lymphoma and an indication for treatment were eligible. Patients received pembrolizumab 200 mg IV in 21-day cycles for up to 18 cycles, until progression or unacceptable toxicity. Early response assessment was obtained after cycle 3 with computed tomography (CT), and a fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET-CT) was obtained after cycle 6 to determine candidacy for continuation in the study. Immunosecretome profiling was performed at baseline and on cycle 2 day 1.

Results

Nine patients with FL were enrolled between February 2019 and April 2021, including eight (89%) with advanced stage, seven (78%) with intermediate/high Follicular Lymphoma International Prognostic Index, and six (67%) with high-tumor burden by Groupe d'Etude des Lymphomes Folliculaires. The best overall response rate by FDG PET-CT was 33% (three partial metabolic responses). Three patients (33%) had stable disease, and three (33%) had progressive disease (including one patient who only had a follow-up CT). By CT four (44%) experienced a reduction in target lesions, but all were less than partial responses. Grade 3 or higher immune-related adverse events (IRAEs) were seen in two (22%) patients, both with transaminitis and one of whom had concurrent hypophysitis. Another patient had grade 1 pneumonitis, requiring treatment with steroids. No associations between the immunosecretome profile and clinical outcomes could be detected.

Conclusion

Frontline pembrolizumab for FL is associated with limited responses and a clinically significant rate of IRAEs. Alternative strategies for targeting the TME in FL should be explored.

The evolving role of checkpoint inhibitors in the treatment of Hodgkin lymphoma

Since their initial approval as single agent therapy for multiply relapsed/refractory Hodgkin lymphoma (HL), the PD-1 inhibitors nivolumab and pembrolizumab have been incorporated into second-line salvage regimens, and they are being investigated in upfront therapy of newly diagnosed patients. As second-line therapy in combination with brentuximab vedotin or multi-agent chemotherapy, nivolumab and pembrolizumab provide high complete remission rates and durable progression-free survival after consolidative autologous stem cell transplant. Incorporation of these agents into frontline chemotherapy regimens is feasible, and early results from a Phase III trial of nivolumab-AVD compare favorably with the existing standard for advanced stage HL, brentuximab vedotin plus AVD. As nivolumab and pembrolizumab move into earlier lines of HL therapy, open research questions include the efficacy of checkpoint inhibitor regimens in patients who relapse after frontline exposure to nivolumab or pembrolizumab; the selection of patients with relapsed HL who can achieve durable remissions without autologous stem cell transplant; and the efficacy of the PD-1 inhibitors in the frontline therapy of patients with early stage Hodgkin lymphoma.

Emerging immunotherapies in the Hodgkin lymphoma armamentarium

INTRODUCTION

Brentuximab vedotin and PD-1 inhibitors have improved outcomes for classic Hodgkin lymphoma (cHL), but better therapies are needed for patients who relapse after these agents. Based on an improved understanding of cHL biology, there is a robust pipeline of novel therapies in development. In this review, we highlight emerging immunotherapeutic agents and combinations for cHL.

AREAS COVERED

We review clinical trials of novel PD-1/PD-L1 inhibitors beyond FDA-approved agents, checkpoint inhibitors targeting CTLA-4, LAG-3, TIM-3, TIGIT, and CD47/SIRPα, PD-1 inhibitor combinations with immunomodulatory agents and epigenetic modifying therapies, antibody-drug conjugates, bispecific antibodies, and cellular therapies including anti-CD30 CAR-T and allogeneic NK cell therapy. We review the key safety and efficacy data from published phase 1-2 studies and highlight trials in progress, including the first phase 3 trial for PD-1 inhibitor-refractory cHL.

EXPERT OPINION

Many novel immunotherapies hold great promise in cHL. Rational combinations with existing agents and next-generation antibody and CAR-T constructs may improve response rates and durability. Identifying biomarkers of response to these immunotherapies and using more sensitive tools to assess response, such as circulating tumor DNA, may further inform treatment decisions and enable a precision medicine approach in the future.

Minimal residual disease detection in lymphoma: methods, procedures and clinical significance

Lymphoma is a highly heterogeneous lymphohematopoietic tumor. As our understanding of the biological and pathological characteristics of lymphoma improves, we are identifying an increasing number of lymphoma subtypes. Genotyping has enhanced our ability to diagnose, treat, and monitor the prognosis of lymphoma. Despite significant improvements in treatment effectiveness, traditional methods for assessing disease response and monitoring prognosis are imperfect, and there is no significant improvement in overall remission rates for lymphoma patients. Minimal Residual Disease (MRD) is often indicative of refractory disease or early relapse. For lymphoma patients, personalized MRD monitoring techniques offer an efficient means to estimate disease remission levels, predict early relapse risk, and assess the effectiveness of new drug regimens. In this review, we delve into the MRD procedures in lymphoma, including sample selection and requirements, detection methods and their limitations and advantages, result interpretation. Besides, we also introduce the clinical applications of MRD detection in lymphoma.

Hodgkin lymphoma and liquid biopsy: a story to be told

Hodgkin lymphoma (HL) represents a neoplasm primarily affecting adolescents and young adults, necessitating the development of precise diagnostic and monitoring tools. Specifically, classical Hodgkin lymphoma (cHL), comprising 90% of cases, necessitating tailored treatments to minimize late toxicities. Although positron emission tomography/computed tomography (PET/CT) has enhanced response assessment, its limitations underscore the urgency for more reliable progression predictive tools. Genomic characterisation of rare Hodgkin Reed-Sternberg (HRS) cells is challenging but essential. Recent studies employ single-cell molecular analyses, mass cytometry, and Next-Generation Sequencing (NGS) to unveil mutational landscapes. The integration of liquid biopsies, particularly circulating tumor DNA (ctDNA), extracellular vesicles (EVs), miRNAs and cytokines, emerge as groundbreaking approaches. Recent studies demonstrate ctDNA's potential in assessing therapy responses and predicting relapses in HL. Despite cHL-specific ctDNA applications being relatively unexplored, studies emphasize its value in monitoring treatment outcomes. Overall, this review underscores the imperative role of liquid biopsies in advancing HL diagnosis and monitoring.

Healthy tissue metabolism assessed by [18F]FDG PET/CT as a marker of prognosis and adverse events in advanced Hodgkin lymphoma patients

The aim of the study was to assess healthy tissue metabolism (HTM) using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) during chemotherapy in Hodgkin lymphoma (HL) and the association of HTM with baseline metabolic tumour volume (MTV), haematological parameters, adverse events (AEs), early response and progression-free survival (PFS). We retrospectively identified 200 patients with advanced HL from the RATHL trial with [18F]FDG-PET/CT before (PET0) and following 2 cycles of chemotherapy (PET2). [18F]FDG-uptake was measured in bone marrow (BM), spleen, liver and mediastinal blood pool (MBP). Deauville score (DS) 1-3 was used to classify responders and DS 4-5, non-responders. [18F]FDG-uptake decreased significantly in BM and spleen and increased in liver and MBP at PET2 (all p < 0.0001), but was not associated with MTV. Higher BM uptake at PET0 was associated with lower baseline haemoglobin and higher absolute neutrophil counts, platelets, and white blood cells. High BM, spleen, and liver uptake at PET0 was associated with neutropenia after cycles 1-2. BM uptake at PET0 was associated with treatment failure at PET2 and non-responders with higher BM uptake at PET2 had significantly inferior PFS (p = 0.023; hazard ratio = 2.31). Based on these results, we concluded that the change in HTM during chemotherapy was most likely a direct impact of chemotherapy rather than a change in MTV. BM uptake has prognostic value in HL.

Distinct Hodgkin lymphoma subtypes defined by noninvasive genomic profiling

The scarcity of malignant Hodgkin and Reed-Sternberg cells hampers tissue-based comprehensive genomic profiling of classic Hodgkin lymphoma (cHL). By contrast, liquid biopsies show promise for molecular profiling of cHL due to relatively high circulating tumour DNA (ctDNA) levels1-4. Here we show that the plasma representation of mutations exceeds the bulk tumour representation in most cases, making cHL particularly amenable to noninvasive profiling. Leveraging single-cell transcriptional profiles of cHL tumours, we demonstrate Hodgkin and Reed-Sternberg ctDNA shedding to be shaped by DNASE1L3, whose increased tumour microenvironment-derived expression drives high ctDNA concentrations. Using this insight, we comprehensively profile 366 patients, revealing two distinct cHL genomic subtypes with characteristic clinical and prognostic correlates, as well as distinct transcriptional and immunological profiles. Furthermore, we identify a novel class of truncating IL4R mutations that are dependent on IL-13 signalling and therapeutically targetable with IL-4Rα-blocking antibodies. Finally, using PhasED-seq5, we demonstrate the clinical value of pretreatment and on-treatment ctDNA levels for longitudinally refining cHL risk prediction and for detection of radiographically occult minimal residual disease. Collectively, these results support the utility of noninvasive strategies for genotyping and dynamic monitoring of cHL, as well as capturing molecularly distinct subtypes with diagnostic, prognostic and therapeutic potential.

The shifting roles and toxicities of cellular therapies in B-cell malignancies

Cellular therapies provide a curative-intent option for patients with relapsedand refractory lymphomas. Current options including high dose chemotherapyfollowed by autologous or allogeneic hematopoietic stem cell transplantation or CD19 chimericantigen receptor T-cell (CART) therapy. The indication varies according to lymphoma sub-type and line oftherapy. The sequencing of these therapies and their use in second-line orlater settings to manage these diseases is undergoing significant changes, withCD19 CAR T becoming a preferred option for relapsed aggressive B-cell lymphoma.The mechanism of both therapies causes significant yet distinctlymphodepletion, infectious, and inflammatory toxicities. The resulting patternand timing of immune reconstitution helps guide risk-mitigating strategies,revaccination, and infectious prophylaxis. In this review, we discuss theindication, efficacy, toxicity and immune reconstitution of autologoushematopoietic stem cell transplantation and CAR T therapy for use in thetreatment of lymphoma.

Quantitative PET-based biomarkers in lymphoma: getting ready for primetime

The use of functional quantitative biomarkers extracted from routine PET-CT scans to characterize clinical responses in patients with lymphoma is gaining increased attention, and these biomarkers can outperform established clinical risk factors. Total metabolic tumour volume enables individualized estimation of survival outcomes in patients with lymphoma and has shown the potential to predict response to therapy suitable for  risk-adapted treatment approaches in clinical trials. The deployment of machine learning tools in molecular imaging research can assist in recognizing complex patterns and, with image classification, in tumour identification and segmentation of data from PET-CT scans. Initial studies using fully automated approaches to calculate metabolic tumour volume and other PET-based biomarkers have demonstrated appropriate correlation with calculations from experts, warranting further testing in large-scale studies. The extraction of computer-based quantitative tumour characterization through radiomics can provide a comprehensive view of phenotypic heterogeneity that better captures the molecular and functional features of the disease. Additionally, radiomics can be integrated with genomic data to provide more accurate prognostic information. Further improvements in PET-based biomarkers are imminent, although their incorporation into clinical decision-making currently has methodological shortcomings that need to be addressed with confirmatory prospective validation in selected patient populations. In this Review, we discuss the current knowledge, challenges and opportunities in the integration of quantitative PET-based biomarkers in clinical trials and the routine management of patients with lymphoma.

Sequencing novel agents in the treatment of classical Hodgkin lymphoma

INTRODUCTION

Classical Hodgkin lymphoma (cHL) is a curable disease, with durable remission achieved in about 80% of patients following first-line treatment. Three new drugs were introduced to the daily use in cHL: brentuximab vedotin (BV), nivolumab, and pembrolizumab. All three drugs were initially approved for the treatment of relapsed/refractory cHL (RRHL) and with their promising outcomes, they are now incorporated in different stages of the treatment.

AREAS COVERED

We performed a literature search using PubMed on all cHL studies investigating BV and CPIs within the past 10 years. We analyzed literature to presume the sequencing of these novel agents.

EXPERT OPINION

Addition of BV or nivolumab to AVD backbone in the frontline setting showed promising activity in advanced stage cHL. BV and CPIs combined with chemotherapy in the second-line treatment of cHL are evaluated in phase 2 studies and comparable results are reported. The results of BrECADD, with good efficacy and toxicity profile, should be followed. Pembrolizumab was shown to be more effective in RRHL compared to BV in patients who have relapsed post-ASCT or ineligible for ASCT. BV is used in post-ASCT maintenance in high-risk cases, although its role will be questioned as it is increasingly used in the frontline treatment.