Integrative analysis reveals selective 9p24.1 amplification, increased PD-1 ligand expression, and further induction via JAK2 in nodular sclerosing Hodgkin lymphoma and primary mediastinal large B-cell lymphoma. Blood. 2010;116:3268-3277. [PMID: 20628145 DOI: 10.1182/blood-2010-05-282780]

Classic Hodgkin lymphoma: Pathobiological features that impact emerging therapies

Classic Hodgkin lymphoma (cHL) is defined by distinctive Hodgkin Reed-Sternberg (HRS) cells, which are CD30+/CD15+ multinucleated tumor cells lacking typical B-cell markers. These cells comprise <5 % of tumor mass but orchestrate an extensive immunosuppressive tumor microenvironment (TME). Classic HL was curable with radiation therapy and multi-agent chemotherapy. Despite high cure rates, treatment-related toxicities remain significant. The goals of multimodality therapy are to achieve a cure while minimizing treatment-associated toxicity. Advances in molecular insights into HRS cells have led to transformative therapies, including checkpoint inhibitors, antibody-drug conjugates like brentuximab vedotin, which have shown remarkable efficacy, especially in relapsed or refractory disease. However, challenges persist due to the heterogeneity of cHL, driven by the complex biology of HRS cells and their surrounding tumor microenvironment. Novel approaches such as single-cell RNA sequencing and circulating tumor DNA profiling provide promising strategies to address these challenges. This review examines the origin, morphology, phenotype, and genetic profiles of HRS cells, highlighting key pathobiological features, including biomarkers and Epstein-Barr Virus involvement. It also explores the biological mechanisms underlying HRS cell survival and evaluates standard and emerging therapies, offering insights into the rationale for novel treatment strategies.

High-accuracy Detection of PD-L1 3'-UTR Disruption by Immunohistochemistry and Fluorescence in Situ Hybridization on Formalin-fixed Paraffin-embedded Sections

Programmed death-ligand 1 (PD-L1/CD274) structural variation (SV) disrupting the 3'-untranslated region has been highlighted as being associated with PD-L1 overexpression. In the present study, we evaluated lymphoma tissue samples to investigate the applicability of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) for detecting the PD-L1 SV involving the 3'-untranslated region. In total, 1052 lymphoma samples were screened using IHC, and 99 IHC screening-positive samples were evaluated with FISH (non-Hodgkin lymphoma [NHL, n=58] and Hodgkin lymphoma [HL, n=41]). Of these, 92 samples showed strong PD-L1 expression with 2 PD-L1 antibodies (E1J2J and SP142) (concordant PD-L1 IHC), whereas 7 samples showed strong PD-L1 expression only with E1J2J (discordant PD-L1 IHC). Abnormal FISH findings for PD-L1 were detected in all evaluated samples (51 NHLs and 41 HLs). A structural abnormality pattern was observed in 17 of the 51 evaluated NHL samples (33%). In contrast, all 41 HL samples showed a copy number abnormality pattern, with 1 exhibiting a structural abnormality pattern. Target-capture sequencing of the PD-L1 gene was performed on 73 of the 99 IHC screening-positive samples, comprising 41 NHLs and 32 HLs. PD-L1 SVs were detected in 16 (39%) of the 41 NHL samples and in only one of the 32 HL samples (3%). Samples exhibiting discordant PD-L1 IHC and/or FISH structural abnormality patterns were shown to harbor PD-L1 SV by target-capture sequencing, with positive and negative predictive values of 94% and 96%, respectively. Our approach is an alternative to target-capture sequencing for evaluating PD-L1 gene abnormalities.

The PD-L1 Promoter Methylation Predicts Gene And Protein Expression Levels in Urothelial Carcinoma

We aimed to clarify the role of PD-L1 promoter methylation in bladder cancer by analyzing PD-L1 methylation and mRNA expression in FFPE samples, along with PD-L1 mRNA and protein levels in urine samples from bladder urothelial carcinoma patients. We analyzed PD-L1 promoter methylation in 43 bladder urothelial carcinoma tissue samples and 41 non-malignant bladder tissues using methylation-sensitive high-resolution melting analysis to assess two CpG islands (cg15837913, cg19724470). PD-L1 mRNA expression in tissues and urine samples, along with PD-L1 protein levels in urine, were evaluated. The bladder urothelial carcinoma group showed significantly higher methylation rates for cg19724470 and cg15837913 compared to controls (P = 0.016, P = 0.049 respectively). In the patient group, tissue PD-L1 mRNA expression was 15.22 times higher and urinary PD-L1 mRNA expression 6.56 times higher in the cg19724470 unmethylated group compared to the methylated group. Urinary PD-L1 protein concentration was twice as high in the cg19724470 unmethylated group compared to the methylated group. In the patients, tissue PD-L1 mRNA expression was 4.58 times higher and urinary PD-L1 mRNA expression 2.58 times higher in the cg15837913 unmethylated group compared to the methylated group. Moreover, the urinary PD-L1 protein concentration was 1.7 times higher in the cg15837913 unmethylated group than in the methylated group (P = 0.036). A positive correlation was observed between tissue PD-L1 mRNA and both urine PD-L1 mRNA and protein levels and between urine PD-L1 mRNA and protein levels. This study suggests that PD-L1 methylation may be a key epigenetic regulator influencing PD-L1 expression and disease pathogenesis in bladder urothelial carcinoma.

JAK3 A573V and JAK3 M511I mutations in peripheral T-cell lymphoma mediating resistance to anti-PD-1 therapy through the STAT3/PD-L1 pathway

BACKGROUND

Clinical evidence has established anti-PD-1 antibody as a transformative treatment modality for relapsed/refractory peripheral T-cell lymphoma (r/r PTCL), yet reveals a therapeutic plateau with drug resistance observed in 60% of r/r PTCL. The biological determinants underlying this resistance-particularly the complex interplay between tumor-intrinsic characteristics (including tumor mutation burden and oncogenic mutations) and immune microenvironment features (notably PD-L1 expression)-remain insufficiently illustrated. Therefore, we systematically depicted the comprehensive mutation profile of r/r PTCL patients and correlated them with the efficacy and prognosis of anti-PD-1 therapy.

METHODS

Here, we enrolled a cohort of 109 patients with r/r PTCL and performed targeted next-generation sequencing of 440 cancer-associated genes. Clinical information was collected and correlated with genetic mutations. We constructed JAK3 mutant models using Jurkat and BA/F3 cell lines. We performed single-cell transcriptomics, western blotting, and flow cytometry to elucidate the molecular mechanism. Additionally, we built a JAK3-mutant syngeneic mouse model to demonstrate in vivo antitumor efficacy of Tofacitinib and anti-PD-1 therapy.

RESULTS

We identified and validated that PD-L1 was a predictor for the efficacy of anti-PD-1 therapy in PTCL patients. The subset of PTCL patients (13.5%) characterized by enrichment of the APOBEC-related mutation signature had worse overall survival (p=0.031) compared with non-APOBEC-enriched samples. JAK3 and EZH2 mutations were associated with lower PD-L1 expression (p<0.05), and JAK3 mutations were independently correlated with shorter progression-free survival (HR=6.07, p=0.0144). Among all types of JAK3 mutations, single-cell transcriptomics, western blotting, and flow cytometry revealed that JAK3 p.A573V and p.M511I mutations led to decreased PD-L1 expression in Jurkat and BA/F3 cell lines through inactivation of STAT3. Compared with JAK3 wild-type syngeneic mouse models, JAK3 p.A573V and p.M511I mutant mice were more sensitive to Tofacitinib but not anti-PD-1 antibody.

CONCLUSIONS

In conclusion, we found that JAK3 mutations, especially JAK3 p.A573V and JAK3 p.M511I mutations, lead to poor prognosis of anti-PD-1 therapy through the STAT3/PD-L1 pathway. Tofacitinib is more suitable than anti-PD-1 antibody for JAK3 mutant PTCL patients.

TRIAL REGISTRATION NUMBER

NCT03502629.

Nivolumab in Relapsed or Refractory Primary Central Nervous System Lymphoma: Multicenter, Retrospective Study

PURPOSE

Given that 40%-50% of primary central nervous system lymphoma (PCNSL) tissues exhibit aberrancy on 9p24.1, immune checkpoint inhibitors (ICI) may work for the disease.

MATERIALS AND METHODS

To define the role of ICIs in PCNSL, we carried out a nationwide retrospect analysis for 22 patients who had been treated with nivolumab monotherapy for relapsed or refractory PCNSL.

RESULTS

The median age at diagnosis was 66, and male: female ratio was 1:1. Patients received nivolumab after a median of 3 lines (range, 2 to 6) of therapy and at the median age of 67 years (range, 37 to 82 years). Eleven patients (50%) were refractory to the last treatment prior to nivolumab. With a median follow-up duration of 22.3 months (95% confidence interval [CI], 13.1 to 31.5), nine patients (41%) had an objective response (6 complete responses, 3 partial responses), and the median duration of response was 20.9 months (95% CI, 1.7 to 40.0). The median progression-free survival and overall survival were 2.1 months (95% CI, 0.2 to 4.0) and 18.9 months (95% CI, 5.0 to 32.8), respectively. Nivolumab was generally well-tolerated as no patients required dose reduction and only two patients required delay of treatment.

CONCLUSION

Our study suggests that nivolumab can be a reasonable option with the durable response for RR PCNSL.

Advances in Hodgkin lymphoma research

Hodgkin lymphoma (HL) has been and still is the most enigmatic lymphoid malignancy in humans. Since the first molecular analysis of isolated Hodgkin and Reed-Sternberg (HRS) tumor cells of classic HL 30 years ago, substantial advances in our understanding of HL have been made. This review describes the cellular origin of HL, summarizes the current knowledge about the genetic lesions in HRS cells, and highlights the role of Epstein-Barr virus (EBV) in HL pathogenesis. Moreover, the pathobiological roles of altered gene expression and deregulated signaling pathways are discussed and key aspects of the HL microenvironment are presented.

Integrating Novel Agents Into the Clinical Management of Classic Hodgkin Lymphoma

Classic Hodgkin lymphoma (cHL) is highly curable at all stages. Research efforts over the past few decades have largely focused on interim PET-adapted strategies for therapy de-escalation or intensification. The overarching goals have been to increase cure rates, minimize potential therapy-related effects, and optimize survivorship. Better understanding of the biology of cHL has led to the development and approval of effective novel agents including the antibody-drug conjugate brentuximab vedotin and the checkpoint inhibitor immunotherapies. In this review, we discuss recent trial results and how these agents are integrated into clinical practice with the goal of further optimizing outcomes.

Loss of MNX1 Sensitizes Tumors to Cytotoxic T Cells by Degradation of PD-L1 mRNA

Immune checkpoint blockade (ICB) therapy, targeting programmed cell death ligand-1 (PD-L1)/programmed cell death protein 1 (PD-1) axis and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), has exhibited amazing clinical outcomes in various types of cancers. However, only a small portion of patients benefit from ICB therapy, indicating that the mechanism underlying immune checkpoint is still unclear. Here, it is reported that motor neuron and pancreas homeobox 1 (MNX1), a homeobox domain-containing transcription factor, contributes to the tumor immune escape. MNX1 increases PD-L1 expression in cancer cells by stabilizing PD-L1 mRNA rather than activating transcription. Mechanistically, MNX1 exists in the cytoplasm of cancer cells and interacts with Y-box binding protein 1 (YBX1), a multifunctional DNA/RNA-binding protein, to enhance the binding of YBX1 to PD-L1 mRNA. MNX1 ablation activates cytotoxic T cell-mediated anti-tumor immunity and sensitizes CTLA-4 blockade therapy. Moreover, MNX1 also facilitates tumor progression in an immune-independent manner in cancer cells. In addition, MNX1 is upregulated by its adjacent long non-coding RNA MNX1-AS1 via HECT and RLD domain containing E3 ubiquitin protein ligase 2 (HERC2). Together, these results reveal MNX1 as a novel immune checkpoint regulator with promising therapeutic potential.

SOHO State of the Art Updates and Next Questions | Latest Advances in the Management of Primary Mediastinal B-Cell Lymphoma

Primary mediastinal B-cell lymphoma (PMBCL) is recognized as a distinct clinicopathologic entity that predominantly affects adolescents and young adults (AYA) and is more common in females. Although PMBCL was previously considered to be a subtype of diffuse large B-cell lymphoma, the clinical, histological, and biological characteristics overlap significantly with those of nodular-sclerosing Hodgkin lymphoma (NS-HL). Over recent years, the shared biology of these 2 entities has been highlighted in several studies, and mediastinal gray zone lymphoma, with features intermediate between PMBCL and NS-HL, has been recognized as a unique molecular entity. Although there is a lack of consensus about the optimal therapeutic strategy for patients with newly diagnosed PMCBL, highly curative treatment regimens that obviate the need for mediastinal radiation therapy (RT) are favored by most. Recently, the results from IELSG-37 were presented and demonstrated that patients with a negative PET/CT scan at the completion of treatment do not require consolidative RT. Progress in understanding the biology of PMBCL and its close relationship to NS-HL have helped pave the way for the investigation of novel strategies, including immune checkpoint inhibitors (ICI), CD30-targeting agents and adoptive T-cell approaches. Currently, a clinic trial is ongoing that is evaluating the role of nivolumab with chemo-immunotherapy for the frontline treatment of PMBCL, after ICI have shown robust responses in patients with relapsed and refractory (R/R) PMBCL. In the R/R setting, studies with anti-CD19 CAR-T-cell therapies and treatments with bispecific antibodies have shown good activity.

Flow Cytometry for B-Cell Non-Hodgkin and Hodgkin Lymphomas

Multi-parametric flow cytometry is a powerful diagnostic tool that permits rapid assessment of cellular antigen expression to quickly provide immunophenotypic information suitable for disease classification. This chapter describes the classification of B-cell non-Hodgkin lymphoma (B-NHL) by flow cytometry suitable for the clinical and research environment. In addition to describing the immunophenotypic patterns of the most common B-NHL (including examples of common B-NHL), the effect of anti-CD19, -CD20, and -CD38 therapies on the evaluation of flow cytometric data is also discussed. Over the last 15 years, our laboratory has developed flow cytometry combinations that can immunophenotype classic Hodgkin lymphoma (CHL), nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), and T-cell/histocyte-rich large B-cell lymphoma (THRLBCL) and the use of these assays will be presented. The CHL assay combination is also particularly well suited to immunophenotype primary mediastinal large B-cell lymphoma (PMLBCL) and our experience immunophenotyping PMLBCL by flow cytometry will be discussed. Finally, an approach to the evaluation of the reactive infiltrate of CHL, NLPHL, and THRLBCL that can provide diagnostic information will also be provided.

Aberrantly Expressed Mitochondrial Lipid Kinase, AGK, Activates JAK2-Histone H3 Axis and BCR Signal: A Mechanistic Study with Implication in CLL Therapy

PURPOSE

Although the B-cell receptor (BCR) signal plays a critical role in chronic lymphocytic leukemia (CLL) cell survival and a target of current therapies (ibrutinib targets Bruton's tyrosine kinase; idelalisib targets PI3Kδ), contribution of the cytokine-driven JAK2 pathway to the "CLL cell-survival signaling network" is largely undefined.

EXPERIMENTAL DESIGN

Patients with CLL were enrolled to investigate expression/activation of JAK2 and acylglycerol kinase (AGK), and their functional implication in primary CLL cell survival. A series of biochemical and molecular biology assays were employed to uncover the underlying mechanism.

RESULTS

We detected that compared with normal B cells, CLL cells aberrantly express constitutively active JAK2. Mechanistically, HSP90 forms a chaperoning complex with JAK2, resulting in its aberrant accumulation in CLL cells. We also discovered aberrant upregulation of a novel mitochondrial lipid kinase, AGK, which remains complexed with HSP90 in CLL cells activating JAK2. Although AGK is typically mitochondrial, we detected its nuclear localization in association with JAK2 in some CLL cells. Functionally, JAK2 phosphorylates its noncanonical substrate, histone H3(Y41), but not STAT3, activating transcription of diverse sets of genes in a patient-specific manner. Additionally, JAK2 activates the BCR signal in CLL cells via LYN/Bruton's tyrosine kinase axis. Targeted inhibition of JAK2 as monotherapy, or in combination with the BCR inhibitors or venetoclax (a BCL2 inhibitor), induced apoptosis synergistically in CLL cells.

CONCLUSIONS

These findings suggest that aberrantly expressed AGK activates JAK2, independent of cytokine, leading to activation of diverse sets of gene transcription in CLL cells. Combined targeting of JAK2 and BCR signals or BCL2 may be effective in some patients with CLL.

Phase 2 study of alemtuzumab and dose-adjusted EPOCH-R in relapsed or refractory aggressive B-cell lymphomas

Immune cells within the lymphoma tumor microenvironment promote immune evasion and are rational therapeutic targets. Alemtuzumab targets CD52 expressed on malignant B-cells and infiltrating nonmalignant T-cells. We evaluated the safety and efficacy of alemtuzumab with DA-EPOCH-R in 48 patients with relapsed/refractory aggressive B-cell lymphoma. Febrile neutropenia occurred in 18% of cycles and serious infections in 21% of patients. Responses were observed in 30 (62%) patients, including 12 (80%) patients with classical HL and 3 (75%) patients with T-cell/histiocyte-rich large B-cell lymphoma (THRLCL). Seventeen (35%) patients achieved complete responses, and 12 (25%) were bridged to consolidation. The 2-year progression-free survival (PFS) and overall survival were 22.1% (95% CI, 11.5-34.7%) and 45.2% (95% CI, 34.3-58.9%), respectively. The 2-year PFS for HL and THRLCL patients was 35% and 50%, respectively. Alemtuzumab can be safely combined with DA-EPOCH-R in relapsed/refractory aggressive B-cell lymphomas and can induce durable responses in patients with T-cell-rich microenvironments.

Getting the right combination to break the epigenetic code

Rapid advances in the field of epigenetics have facilitated the development of novel therapeutics targeting epigenetic mechanisms that are hijacked by cancer cells to support tumour growth and progression. Several epigenetic agents have been approved by the FDA for the treatment of cancer; however, the efficacy of these drugs is dependent on the underlying biology and drivers of the disease, with inherent differences between solid tumours and haematological malignancies. The efficacy of epigenetic drugs as single agents remains limited across most cancer types, which has spurred the clinical development of combination therapies, with the hope of attaining synergistic activity and/or overcoming treatment resistance. In this Review we discuss clinical advances that have been achieved with the use of epigenetic agents in combination with chemotherapies, immunotherapies or other targeted agents, including epigenetic-epigenetic combinations, as well as limitations and challenges associated with these combinatorial strategies. So far, the success of combination therapies targeting epigenetic mechanisms has generally been confined to haematological malignancies, with limited efficacy observed in patients with solid tumours. Nevertheless, this Review captures the field of epigenetic combination therapies across the spectra of haematology and oncology, highlighting opportunities for precision therapy to effectively harness the potential of epigenetic agents and produce meaningful improvements in clinical outcomes.

Primary mediastinal large B-cell lymphoma from the clinic to genomics: Insights for pathologists

Primary mediastinal large B-cell lymphoma (PMBL) is a mature aggressive B-cell lymphoma that arises in the anterior mediastinum, likely originating from thymic B cells. Initially considered a subtype of diffuse large B-cell lymphoma, PMBL has since been established as a distinct clinicopathologic entity due to its unique clinical, morphologic, immunophenotypic and genetic characteristics. PMBL primarily affects young adults, especially women, and manifests as a bulky mediastinal mass that can invade adjacent structures, often causing respiratory symptoms. The genomic landscape of PMBL includes alterations in the JAK-STAT, NF-κB signaling pathways, and immune evasion mechanisms. This review explores the clinical presentation, pathogenesis and genetic landscape of PMBL, highlighting its morphologic and immunophenotypic characteristics and differences from related mediastinal lymphomas such as classic Hodgkin lymphoma and mediastinal grey zone lymphoma. We also discuss the implications of these findings on diagnosis, management and personalized treatment approaches.

Genome-scale spatial mapping of the Hodgkin lymphoma microenvironment identifies tumor cell survival factors

A key challenge in cancer research is to identify the secreted factors that contribute to tumor cell survival. Nowhere is this more evident than in Hodgkin lymphoma, where malignant Hodgkin Reed Sternberg (HRS) cells comprise only 1-5% of the tumor mass, the remainder being infiltrating immune cells that presumably are required for the survival of the HRS cells. Until now, there has been no way to characterize the complex Hodgkin lymphoma tumor microenvironment at genome scale. Here, we performed genome-wide transcriptional profiling with spatial and single-cell resolution. We show that the neighborhood surrounding HRS cells forms a distinct niche involving 31 immune and stromal cell types and is enriched in CD4+ T cells, myeloid and follicular dendritic cells, while being depleted of plasma cells. Moreover, we used machine learning to nominate ligand-receptor pairs enriched in the HRS cell niche. Specifically, we identified IL13 as a candidate survival factor. In support of this hypothesis, recombinant IL13 augmented the proliferation of HRS cells in vitro. In addition, genome-wide CRISPR/Cas9 loss-of-function studies across more than 1,000 human cancer cell lines showed that IL4R and IL13RA1, the heterodimeric partners that constitute the IL13 receptor, were uniquely required for the survival of HRS cells. Moreover, monoclonal antibodies targeting either IL4R or IL13R phenocopied the genetic loss of function studies. IL13-targeting antibodies are already FDA-approved for atopic dermatitis, suggesting that clinical trials testing such agents should be explored in patients with Hodgkin lymphoma.

Successful Treatment of a Patient Presenting with Simultaneous Diffuse Large B-Cell Lymphoma and Hodgkin Lymphoma: A Case Report

BACKGROUND Simultaneously occuring diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma (HL) is extremely rare. Generally, patients with CD20-positive DLBCL receive rituximab, cyclophosphamide, vincristine, doxorubicin, prednisone (R-CHOP) regimen, while those with HL receive brentuximab vedotin, doxorubicin, vinblastine, dacarbazine (A-AVD) regimen as first-line therapy. Establishing a strategy for treating both lymphoma subtypes concurrently is thus very difficult. We report successful treatment of a patient simultaneously diagnosed with advanced DLBCL and HL. CASE REPORT A 20-year-old man visited the Hematology Department of Kyungpook National University Hospital after the diagnosis of germinal center B-cell DLBCL in the kidney and HL (nodular sclerosis type) in the neck lymph node. His DLBCL was classified as Ann Arbor stage IV with an International Prognostic Index score of 4, a high-risk group. Six cycles of R-CHOP therapy were planned, and central nervous system prophylaxis with intrathecalmethotrexate was added because of the high-risk features of central nervous system involvement. After completing 6 cycles of chemotherapy, without significant adverse events (Deauville score of 1), complete remission was confirmed. Then, the patient decided to undergo consolidative autologous stem cell transplantation (auto-SCT). He received busulfan, cyclophosphamide, and etoposide conditioning regimen, after which auto-SCT was conducted in April 2021. After auto-SCT, the patient was undergoing regular check-ups and doing well, without obvious disease relapse or specific symptoms. He maintained a disease-free status for 40 months to date. CONCLUSIONS Our case showed that R-CHOP regimen was effective not only for DLBCL but also for HL. Notably, consolidative upfront auto-SCT should be considered for a deeper response.

Cancer-specific innate and adaptive immune rewiring drives resistance to PD-1 blockade in classic Hodgkin lymphoma

Hodgkin Reed-Sternberg (HRS) cells of classic Hodgkin lymphoma (cHL), like many solid tumors, elicit ineffective immune responses. However, patients with cHL are highly responsive to PD-1 blockade, which largely depends on HRS cell-specific retention of MHC class II and implicates CD4+ T cells and additional MHC class I-independent immune effectors. Here, we utilize single-cell RNA sequencing and spatial analysis to define shared circulating and microenvironmental features of the immune response to PD-1 blockade in cHL. Compared with non-responders, responding patients have more circulating CD4+ naïve and central memory T cells and B cells, as well as more diverse CD4+ T cell and B cell receptor repertoires. Importantly, a population of circulating and tumor-infiltrating IL1β+ monocytes/macrophages is detectable in patients with cHL but not healthy donors, and a proinflammatory, tumor-promoting signature of these circulating IL1β+ monocytes is associated with resistance to PD-1 blockade in cHL. Altogether, our findings reveal extensive immune rewiring and complementary roles of CD4+ T cells, B cells and IL1β+ monocytes in the response to PD-1 blockade and suggest that these features can be captured with a peripheral blood test.

Primary large B-cell lymphomas of immune-privileged sites

ABSTRACT

Diffuse large B-cell lymphoma (DLBCL) encompasses a diverse spectrum of aggressive B-cell lymphomas with remarkable genetic heterogeneity and myriad clinical presentations. Multiplatform genomic analyses of DLBCL have identified oncogenic drivers within genetic subtypes that allow for pathologic subclassification of tumors into discrete entities with shared immunophenotypic, genetic, and clinical features. Robust classification of lymphoid tumors establishes a foundation for precision medicine and enables the identification of novel therapeutic vulnerabilities within biologically homogeneous entities. Most cases of DLBCL involving the central nervous system (CNS), vitreous, and testis exhibit immunophenotypic features suggesting an activated B-cell (ABC) origin. Shared molecular features include frequent comutations of MYD88 (L265P) and CD79B and frequent genetic alterations promoting immune evasion, which are hallmarks of the MCD/C5/MYD88 genetic subtype of DLBCL. Clinically, these lymphomas primarily arise within anatomic sanctuary sites and have a predilection for remaining confined to extranodal sites and strong CNS tropism. Given the shared clinical and molecular features, the umbrella term primary large B-cell lymphoma of immune-privileged sites (IP-LBCL) was proposed. Other extranodal DLBCL involving the breast, adrenal glands, and skin are often ABC DLBCL but are more heterogeneous in their genomic profile and involve anatomic sites that are not considered immune privileged. In this review, we describe the overlapping clinical, pathologic, and molecular features of IP-LBCL and highlight important considerations for diagnosis, staging, and treatment. We also discuss potential therapeutic vulnerabilities of IP-LBCL including sensitivity to inhibitors of Bruton tyrosine kinase, immunomodulatory agents, and immunotherapy.

Immune checkpoints and ncRNAs: pioneering immunotherapy approaches for hematological malignancies

Hematological malignancies are typically treated with chemotherapy and radiotherapy as the first-line conventional therapies. However, non-coding RNAs (ncRNAs) are a rapidly expanding field of study in cancer biology that influences the growth, differentiation, and proliferation of tumors by targeting immunological checkpoints. This study reviews the results of studies (from 2012 to 2024) that consider the immune checkpoints and ncRNAs in relation to hematological malignancies receiving immunotherapy. This article provides a summary of the latest advancements in immunotherapy for treating hematological malignancies, focusing on the role of immune checkpoints and ncRNAs in the immune response and their capacity for innovative strategies. The paper also discusses the function of immune checkpoints in maintaining immune homeostasis and how their dysregulation can contribute to developing leukemia and lymphoma. Finally, this research concludes with a discussion on the obstacles and future directions in this rapidly evolving field, emphasizing the need for continued research to fully harness the capacity of immune checkpoints and ncRNAs in immunotherapy for hematological malignancies.

Antibody-Based Immunotherapies for the Treatment of Hematologic Malignancies

Despite the great advancements in treatment strategies for hematological malignancies (HMs) over the years, their effective treatment remains challenging. Conventional treatment strategies are burdened with several serious drawbacks limiting their effectiveness and safety. Improved understanding of tumor immunobiology has provided novel anti-cancer strategies targeting selected immune response components. Currently, immunotherapy is counted as the fourth pillar of oncological treatment (together with surgery, chemo- and radiotherapy) and is becoming standard in the treatment regimen, alone or in combination therapy. Several categories of immunotherapies have been developed and are currently being assessed in clinical trials for the treatment of blood cancers, including immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. However, monoclonal antibodies (mAbs) and their derivatives have achieved the most notable clinical outcome so far. Since the approval of rituximab for treating B-cell malignancies, the availability of mAbs against tumor-specific surface molecules for clinical use has flourished. Antibody-based therapy has become one of the most successful strategies for immunotherapeutic cancer treatment in the last few decades, and many mAbs have already been introduced into standard treatment protocols for some hematologic malignancies. To further increase the efficacy of mAbs, they can be conjugated to radioisotopes or cytostatic drugs, so-called antibody-drug conjugates. Moreover, with the growing recognition of T-cell immunity's role in cancer development, strategies aimed at enhancing T cell activation and inhibiting mechanisms that suppress T cell function are actively being developed. This review provides a comprehensive overview of the current status of immunotherapeutic strategies based on monoclonal antibodies and their derivatives, including antibody-drug conjugates, bispecific T-cell engagers, and checkpoint inhibitors, approved for the treatment of various HMs.

Circulating Tumor DNA Sequencing for Biologic Classification and Individualized Risk Stratification in Patients With Hodgkin Lymphoma

PURPOSE

Current clinical challenges in Hodgkin lymphoma (HL) include difficult-to-treat relapsed/refractory disease and considerable long-term toxicities of treatment. Since clinical risk factors lack discriminatory power, intensity of therapy is mainly based on tumor burden. Exploring HL genetics and tumor microenvironment (TME) might provide valuable insights for improved risk stratification.

MATERIALS AND METHODS

In this study, we applied circulating tumor DNA sequencing to 243 patients obtained from pivotal German Hodgkin Study Group trials to identify subtypes of HL. Independent validation of the subtypes was performed in 96 patients treated in the EuroNet-PHL-C2 study. Outcome differences of subtypes were assessed in an event-enriched clinical validation cohort comprising 72 patients from the HD21 trial, using a refined, validated, and clinically feasible assay.

RESULTS

We propose a biologic classification of HL consisting of three distinct subtypes: inflammatory immune escape HL is characterized by frequent copy-number variations including immune escape variants such as high-level amplifications of the PD-L1 locus and an inflammatory TME. Virally-driven HL is associated with Epstein-Barr virus and/or human herpesvirus 6 and an inflammatory TME with neutrophils and macrophages, while the tumor mutational burden (TMB) is low. Oncogene-driven HL is defined by a high TMB, recurrent mutations in oncogenic drivers such as TNFAIP3, ITPKB, and SOCS1, and a cold TME. A refined and validated assay version aiming at clinically feasible risk stratification showed significant progression-free survival differences between subtypes. In addition, assessment of minimal residual disease (MRD) allowed for the detection of patients at very high risk of relapse within the subtypes.

CONCLUSION

We propose a clinically feasible, noninvasive method for individualized risk stratification and MRD monitoring in patients with HL on the basis of circulating tumor DNA sequencing.

Research progress on the mechanism of common inflammatory pathways in the pathogenesis and development of lymphoma

In recent years, the incidence and mortality rates of lymphoma have gradually increased worldwide. Tumorigenesis and drug resistance are closely related to intracellular inflammatory pathways in lymphoma. Therefore, understanding the biological role of inflammatory pathways and their abnormal activation in relation to the development of lymphoma and their selective modulation may open new avenues for targeted therapy of lymphoma. The biological functions of inflammatory pathways are extensive, and they are central hubs for regulating inflammatory responses, immune responses, and the tumour immune microenvironment. However, limited studies have investigated the role of inflammatory pathways in lymphoma development. This review summarizes the relationship between abnormal activation of common inflammatory pathways and lymphoma development to identify precise and efficient targeted therapeutic options for patients with advanced, drug-resistant lymphoma.

Hodgkin lymphoma: 2025 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Hodgkin lymphoma (HL) is an uncommon B-cell lymphoid malignancy affecting 8570 new patients annually and representing ~10% of all lymphomas in the United States.

DIAGNOSIS

HL is composed of two distinct disease entities: classical HL and nodular lymphocyte predominant HL (also called nodular lymphocyte predominant B-cell lymphoma). Nodular sclerosis, mixed cellularity, lymphocyte depletion, and lymphocyte-rich HL are subgroups of classical HL.

RISK STRATIFICATION

An accurate assessment of the stage of disease in patients with HL is critical for the selection of the appropriate therapy. Prognostic models that identify patients at low or high risk for recurrence, as well as the response to therapy as determined by positron emission tomography (PET) scan, are used to optimize therapy.

RISK-ADAPTED THERAPY

Initial therapy for HL patients is based on the histology of the disease, the anatomical stage and the presence of poor prognostic features. Patients with early-stage disease are typically treated with combined modality strategies utilizing abbreviated courses of combination chemotherapy followed by involved-field radiation therapy, whereas those with advanced stage disease receive a longer course of chemotherapy often without radiation therapy. However, newer agents including brentuximab vedotin and anti-PD-1 antibodies are now standardly incorporated into frontline therapy.

MANAGEMENT OF RELAPSED/REFRACTORY DISEASE

High-dose chemotherapy (HDCT) followed by an autologous stem cell transplant (ASCT) is the standard of care for most patients who relapse following initial therapy. For patients who fail HDCT with ASCT, brentuximab vedotin, PD-1 blockade, non-myeloablative allogeneic transplant or participation in a clinical trial should be considered.

Advanced stage classic Hodgkin lymphoma (cHL): biology, clinical features, therapeutic approach, and management at relapse

As the integration of novel agents in the frontline therapy has primarily impacted upfront therapy of advanced stage classic Hodgkin lymphoma (cHL), this review will outline current management of advanced stage cHL at first line and at progression and relapse, focusing on the biology, clinical features, and therapeutic approaches. Due to S1826, HD21, and ECHELON-1, the first-line treatment of advanced cHL has dramatically changed, with novel agents part of standard frontline therapy. BV-AVD, BrECADD, and Nivo-AVD are now standard first-line regimens for patients with stage III-IV cHL, with improved outcomes compared to historical data in cHL. The addition of BV and PD-1 inhibitors to relapsed/refractory (r/r) cHL chemotherapy regimens improved outcomes in this population. Now, there is a paradigm shift with PD-1 moving into frontline therapy, so new studies to evaluate the role of these novel agents in salvage will be required to determine the optimal salvage approach in r/r cHL.

PD-1/PD-L1 immune checkpoint blockade in breast cancer: research insights and sensitization strategies

Immunotherapy targeting programmed cell death-1 (PD-1) and PD-L1 immune checkpoints has reshaped treatment paradigms across several cancers, including breast cancer. Combining PD-1/PD-L1 immune checkpoint blockade (ICB) with chemotherapy has shown promising efficacy in both early and metastatic triple-negative breast cancer, although only a subset of patients experiences durable responses. Identifying responders and optimizing immune drug selection are therefore critical. The effectiveness of PD-1/PD-L1 immunotherapy depends on both tumor-intrinsic factors and the extrinsic cell-cell interactions within the tumor microenvironment (TME). This review systematically summarizes the key findings from clinical trials of ICBs in breast cancer and examines the mechanisms underlying PD-L1 expression regulation. We also highlight recent advances in identifying potential biomarkers for PD-1/PD-L1 therapy and emerging evidence of TME alterations following treatment. Among these, the quantity, immunophenotype, and spatial distribution of tumor-infiltrating lymphocytes stand out as promising biomarkers. Additionally, we explore strategies to enhance the effectiveness of ICBs in breast cancer, aiming to support the development of personalized treatment approaches tailored to the unique characteristics of each patient's tumor.

Intra-tumoral and peripheral blood TIGIT and PD-1 as immune biomarkers in nodular lymphocyte predominant Hodgkin lymphoma

In classical Hodgkin lymphoma (cHL), responsiveness to immune-checkpoint blockade (ICB) is associated with specific tumor microenvironment (TME) and peripheral blood features. The role of ICB in nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is not established. To gain insights into its potential in NLPHL, we compared TME and peripheral blood signatures between HLs using an integrative multiomic analysis. A discovery/validation approach in 121 NLPHL and 114 cHL patients highlighted >2-fold enrichment in programmed cell death-1 (PD-1) and T-cell Ig and ITIM domain (TIGIT) gene expression for NLPHL versus cHL. Multiplex imaging showed marked increase in intra-tumoral protein expression of PD-1+ (and/or TIGIT+) CD4+ T-cells and PD-1+CD8+ T-cells in NLPHL compared to cHL. This included T-cells that rosetted with lymphocyte predominant (LP) and Hodgkin Reed-Sternberg (HRS) cells. In NLPHL, intra-tumoral PD-1+CD4+ T-cells frequently expressed TCF-1, a marker of heightened T-cell response to ICB. The peripheral blood signatures between HLs were also distinct, with higher levels of PD-1+TIGIT+ in TH1, TH2, and regulatory CD4+ T-cells in NLPHL versus cHL. Circulating PD-1+CD4+ had high levels of TCF-1. Notably, in both lymphomas, highly expanded populations of clonal TIGIT+PD-1+CD4+ and TIGIT+PD-1+CD8+ T-cells in the blood were also present in the TME, indicating that immune-checkpoint expressing T-cells circulated between intra-tumoral and blood compartments. In in vitro assays, ICB was capable of reducing rosette formation around LP and HRS cells, suggesting that disruption of rosetting may be a mechanism of action of ICB in HL. Overall, results indicate that further evaluation of ICB is warranted in NLPHL.

Molecular and Clinicopathologic Characterization of HER2-overexpressed Squamous Cell Carcinoma of the Cervix

HER2 amplification in cervical cancer has been associated with worse clinical prognosis and a potential favorable response to HER2 inhibitors. Immunohistochemistry for the HER2 receptor is a universally accepted surrogate test for HER2 amplification, but no standardized scoring system currently exists for cervical carcinomas. In this study, we investigated HER2 overexpression in cervical squamous cell carcinoma and correlated it with HER2 amplification using fluorescence in situ hybridization (FISH) and molecular methods. Seventy-two cases of human papillomavirus-associated cervical cancer were retrospectively reviewed, and at least 2 representative tumor sections were stained for HER2. HER2 scoring was performed using the 2018 American Society of Clinical Oncology/College of American Pathologist breast cancer criteria, and cases with equivocal (2+) to positive (3+) expression were analyzed for HER2 amplification using FISH and next-generation sequencing. The average patient age was 50 yrs (range: 27-85 yr), with most patients being African American (73.6%) and diagnosed at FIGO stage I (65.3%). Nineteen (26.4%) had equivocal HER2 expression and 4 (5.5%) showed positive expression. Three of the 4 cases with positive expression had enough tumors for FISH, and all 3 were amplified. Three cases with equivocal expression showed HER2 polysomy on FISH, and none showed HER2 amplification. Late clinical stage, high tumor grade, and regional lymph node metastasis were significantly correlated with HER2 overexpression and HER2 amplification. Next-generation sequencing of the 3 HER2-amplified tumors showed amplification of various genes, including CD274, JAK2, BIRC3, and ERBB2, and a PIK3CA missense mutation. In summary, HER2 immunohistochemistry is a reliable predictive marker of HER2 amplification in cervical cancer.

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.

Mapping the Spatial Dynamics of the CD4+ T Cell Spectrum in Classical Hodgkin Lymphoma

As around 25% to 30% of classical Hodgkin lymphoma (cHL) patients with advanced stages do not respond to standard therapies, the tumor microenvironment of cHL is one avenue that may be explored with the aim of improving risk stratification. CD4+ T cells are thought to be one of the main cell types in the tumor microenvironment. However, few immune signatures have been studied, and many of these lack related spatial data. Thus, our aim is to spatially resolve the CD4+ T cell subtypes that influence cHL outcome, depicting new immune signatures or transcriptional patterns that are in crosstalk with the tumor cells. This study was conducted using the NanoString GeoMx digital spatial profiling technology, based on the selection of distinct functional areas of patients' tissues followed by gene-expression profiling. The goals were to assess the differences in CD4+ T cell populations between tumor-rich and immune-predominant areas defined by different CD30 and PD-L1 expression levels and seek correlations with clinical metadata. Our results depict a complex map of CD4+ T cells with different functions and differentiation states that are enriched at distinct locations, the flux of cytokines and chemokines that could be related to these, and the specific relationships with the clinical outcome.

Single-cell RNA sequencing of pediatric Hodgkin lymphoma to study the inhibition of T cell subtypes

Pediatric classic Hodgkin lymphoma (cHL) patients have a high survival rate but suffer from severe long-term side effects induced by chemo- and radiotherapy. cHL tumors are characterized by the low fraction (0.1%-10%) of malignant Hodgkin and Reed-Sternberg (HRS) cells in the tumor. The HRS cells depend on the surrounding immune cells for survival and growth. This dependence is leveraged by current treatments that target the PD-1/PD-L1 axis in cHL tumors. The development of more targeted therapies that are specific for the tumor and are therefore less toxic for healthy tissue compared with conventional chemotherapy could improve the quality of life of pediatric cHL survivors. Here, we applied single-cell RNA sequencing (scRNA-seq) on isolated HRS cells and the immune cells from the same cHL tumors. Besides TNFRSF8 (CD30), we identified other genes of cell surface proteins that are consistently overexpressed in HRS cells, such as NRXN3 and LRP8, which can potentially be used as alternative targets for antibody-drug conjugates or CAR T cells. Finally, we identified potential interactions by which HRS cells inhibit T cells, among which are the galectin-1/CD69 and HLA-II/LAG3 interactions. RNAscope was used to validate the enrichment of CD69 and LAG3 expression on T cells near HRS cells and indicated large variability of the interaction strength with the corresponding ligands between patients and between tumor tissue regions. In conclusion, this study identifies new potential therapeutic targets for cHL and highlights the importance of studying heterogeneity when identifying therapy targets, specifically those that target tumor-immune cell interactions.

Higher tumor mutational burden and PD-L1 expression correlate with shorter survival in hematologic malignancies

Background

The prognostic implications of tumor mutational burden (TMB) and programmed death ligand 1 (PD-L1) expression are poorly studied in hematologic malignancies.

Objectives

This study aimed to better understand the characteristics and prognostic value of TMB and PD-1/PD-L1 in hematologic malignancies.

Design

This real-world study was conducted among patients with hematologic malignancies who had next-generation sequencing (NGS) (Foundation Medicine) at the University of California San Diego Moores Cancer Center (2014-2018).

Methods

TMB was measured by NGS. PD-L1 expression (tumor proportion score, TPS) was measured by immunohistochemistry (classified as high (⩾50%), low (1-49%), and negative (<1%)). Data was curated from the electronic medical records.

Results

In 388 evaluable patients, the most common diagnoses were B-cell non-Hodgkin lymphoma (NHL) (35%) and Philadelphia chromosome-negative myeloproliferative disorders (16%). Median TMB was 1.6 mutations/Mb (range, 0-46.83). Forty-eight patients (12%) had TMB ⩾10 mutations/Mb, 90% of which were B-cell or T-cell NHL. In 85 samples with available PD-L1 scores, 11 were high; 26, low; and 48, no tumor cell expression. PD-L1 TPS positive (⩾1%) was most common in T-cell NHL (7/9 (77%) cases) followed by B-cell NHL (21/51 (41%) cases). TMB ⩾4 mutations/Mb and PD-L1 score ⩾1% were significantly associated with shorter overall survival (OS) from diagnosis, with hazard ratio (HR) = 1.46 (p = 0.02, 95% confidence interval (CI) 1.05-2.03) and HR = 2.11 (p = 0.04, 95% CI 1.04-4.30), respectively; the relationship was more pronounced when PD-L1 ⩾50% versus <50% was used (HR = 2.80, p = 0.02, 95% CI 1.19-6.59). Higher TMB and higher PD-L1 positivity correlation were significant but weak (Pearson correlation coefficient R 2 = 0.04, p = 0.04).

Conclusion

TMB ⩾4 mutations/Mb and positive PD-L1 TPS are poor prognostic factors, correlating with shorter OS across hematologic malignancies.

Trial registration

ClinicalTrials.gov NCT02478931.

Circulating Multiple Myeloma Cells (CMMCs) as Prognostic and Predictive Markers in Multiple Myeloma and Smouldering MM Patients

In recent years, liquid biopsy has emerged as a promising alternative to the bone marrow (BM) examination, since it is a minimally invasive technique allowing serial monitoring. Circulating multiple myeloma cells (CMMCs) enumerated using CELLSEARCH® were correlated with patients' prognosis and measured under treatment to assess their role in monitoring disease dynamics. Forty-four MM and seven smouldering MM (SMM) patients were studied. The CMMC medians at diagnosis were 349 (1 to 39,940) and 327 (range 22-2463) for MM and SMM, respectively. In the MM patients, the CMMC count was correlated with serum albumin, calcium, β2-microglobulin, and monoclonal components (p < 0.04). Under therapy, the CMMCs were consistently detectable in 15/40 patients (coMMstant = 1) and were undetectable or decreasing in 25/40 patients (coMMstant = 0). High-quality response rates were lower in the coMMstant = 1 group (p = 0.04), with a 7.8-fold higher risk of death (p = 0.039), suggesting that continuous CMMC release is correlated with poor responses. In four MM patients, a single-cell DNA sequencing analysis on residual CMMCs confirmed the genomic pattern of the aberrations observed in the BM samples, also highlighting the presence of emerging clones. The CMMC kinetics during treatment were used to separate the patients into two subgroups based on the coMMstant index, with different responses and survival probabilities, providing evidence that CMMC persistence is associated with a poor disease course.

García J. Multiplex spatial analysis reveals increased CD137 expression and m-MDSC neighboring tumor cells in refractory classical Hodgkin Lymphoma

The Hodgkin and Reed - Sternberg (HRS) cells in classical Hodgkin Lymphoma (cHL) actively modify the immune tumor microenvironment (TME) attracting immunosuppressive cells and expressing inhibitory molecules. A high frequency of myeloid cells in the TME is correlated with an unfavorable prognosis, but more specific and rare cell populations lack precise markers. Myeloid-derived suppressor cells (MDSCs) have been identified in the peripheral blood of cHL patients, where they appear to be correlated with disease aggressiveness. TNFRSF9 (CD137) is a T cell co-stimulator expressed by monocytic and dendritic cells. Its expression has also been described in HRS cells, where it is thought to play a role in reducing antitumor responses. Here, we perform qualitative and quantitative analyses of lymphocytic and MDSC subtypes and determine the CD137 cell distribution in cHL primary tumors using multiplex immunofluorescence and automated multispectral imaging. The results were correlated with patients' clinical features. Cells were stained with specific panels of immune checkpoint markers (PD-1, PD-L1, CD137), tumor-infiltrating T lymphocytes (CD3, PD-1), and monocytic cells/MDSCs (CD68, CD14, CD33, Arg-1, CD11b). This approach allowed us to identify distinct phenotypes and to analyze spatial interactions between immune subpopulations and tumor cells. The results confirm CD137 expression by T, monocytic and HRS cells. In addition, the expression of CD137, T exhausted cells, and monocytic MDSCs (m-MDSCs) in the vicinity of malignant HRS cells were associated with a worse prognosis. Our findings reveal new elements of the TME that mediate immune escape, and confirm CD137 as a candidate target for immunotherapy in cHL.

Real-World Multicenter Study of PD-1 Blockade in HIV-Associated Classical Hodgkin Lymphoma Across the United States

BACKGROUND

Despite a higher risk of classical Hodgkin lymphoma (cHL) in people with HIV and the demonstrated safety and efficacy of PD-1 blockade in cHL, there are limited data on the use of these agents in HIV-associated cHL (HIV-cHL).

PATIENTS/METHODS

We retrospectively identified patients with HIV-cHL from the "Cancer Therapy using Checkpoint inhibitors in People with HIV-International (CATCH-IT)" database who received nivolumab or pembrolizumab, alone or in combination with other agents, and reviewed records for demographics, disease characteristics, immune-mediated adverse events (imAEs), and treatment outcomes. Changes in CD4+ T-cell counts with treatment were measured via Wilcoxon signed-rank tests. Overall response rate (ORR) was defined as the proportion of patients with partial or complete response (PR/CR) per 2014 Lugano classification.

RESULTS

We identified 23 patients with HIV-cHL who received a median of 6 cycles of PD-1 blockade: 1 as 1st-line, 6 as 2nd-line, and 16 as ≥3rd-line therapy. Seventeen (74%) patients received monotherapy, 5 (22%) received nivolumab plus brentuximab vedotin, and 1 received nivolumab plus ifosfamide, carboplatin, and etoposide. The median baseline CD4+ T-cell count was 155 cells/µL, which increased to 310 cells/µL at end-of-treatment (P = .009). Three patients had grade 3 imAEs; none required treatment discontinuation. The ORR was 83% with median duration of response of 19.7 months. The median progression-free survival was 21.2 months and did not differ between patients with <200 versus ≥200 CD4+ cells/µL (P = .95).

CONCLUSION

Our findings support the use of PD-1 blockade in HIV-cHL for the same indications as the general population with cHL.

JAK inhibition enhances checkpoint blockade immunotherapy in patients with Hodgkin lymphoma

Unleashing antitumor T cell activity by checkpoint inhibitor immunotherapy is effective in cancer patients, but clinical responses are limited. Cytokine signaling through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway correlates with checkpoint immunotherapy resistance. We report a phase I clinical trial of the JAK inhibitor ruxolitinib with anti-PD-1 antibody nivolumab in Hodgkin lymphoma patients relapsed or refractory following checkpoint inhibitor immunotherapy. The combination yielded a best overall response rate of 53% (10/19). Ruxolitinib significantly reduced neutrophil-to-lymphocyte ratios and percentages of myeloid suppressor cells but increased numbers of cytokine-producing T cells. Ruxolitinib rescued the function of exhausted T cells and enhanced the efficacy of immune checkpoint blockade in preclinical solid tumor and lymphoma models. This synergy was characterized by a switch from suppressive to immunostimulatory myeloid cells, which enhanced T cell division.

Novel Targets and Advanced Therapies in Diffuse Large B Cell Lymphomas

Since the introduction of rituximab in the late 1990s, significant progress has been made in advancing targeted therapies for B cell lymphomas, improving patients' chance of being cured and clinicians' therapeutic armamentarium. A better understanding of disease biology and pathogenic pathways, coupled with refinements in immunophenotypic and molecular diagnostics, have been instrumental in these achievements. While traditional chemotherapy remains fundamental in most cases, concerns surrounding chemorefractoriness and cumulative toxicities, particularly the depletion of the hemopoietic reserve, underscore the imperative for personalized treatment approaches. Integrating targeted agents, notably monoclonal antibodies, alongside chemotherapy has yielded heightened response rates and prolonged survival. A notable paradigm shift is underway with innovative-targeted therapies replacing cytotoxic drugs, challenging conventional salvage strategies like stem cell transplantation. This review examines the landscape of emerging targets for lymphoma cells and explores innovative therapies for diffuse large B cell lymphoma (DLBCL). From Chimeric Antigen Receptor-T cells to more potent monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, checkpoint inhibitors, and small molecules targeting intracellular pathways, each modality offers promising avenues for therapeutic advancement. This review aims to furnish insights into their potential implications for the future of DLBCL treatment strategies.

Programmed Death Ligand 1 (PD-L1) Expression in Lymphomas: State of the Art

The interaction of programmed death-1 (PD-1) on T lymphocytes with its ligands Programmed Death Ligand 1 (PD-L1) and Programmed Death Ligand 2 (PD-L2) on tumor cells and/or tumor-associated macrophages results in inhibitory signals to the T-cell receptor pathway, consequently causing tumor immune escape. PD-L1/PD-L2 are currently used as predictive tissue biomarkers in clinical practice. Virtually PD-L1 levels expressed by tumor cells are associated with a good response to immune checkpoint blockade therapies targeting the PD-1/PD-L1 axis. These therapies restore T-cell antitumor immune response by releasing T-lymphocytes from the inhibitory effects of tumor cells. Immune checkpoint therapies have completely changed the management of patients with solid cancers. This therapeutic strategy is less used in hematological malignancies, although good results have been achieved in some settings, such as refractory/relapsed classic Hodgkin lymphoma and primary mediastinal large B-cell lymphoma. Variable results have been obtained in diffuse large B-cell lymphoma and T-cell lymphomas. Immunohistochemistry represents the main technique for assessing PD-L1 expression on tumor cells. This review aims to describe the current knowledge of PD-L1 expression in various types of lymphomas, focusing on the principal mechanisms underlying PD-L1 overexpression, its prognostic significance and practical issues concerning the evaluation of PD-L1 immunohistochemical results in lymphomas.

Partial remission with sintilimab monotherapy in a patient carrying a CD274 amplification in refractory diffuse large B‑cell lymphoma: A case report

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying characteristics, in terms of genomic variation, cell morphology and clinical presentation. At present, only ~66% of patients are cured with initial treatment and those with refractory DLBCL exhibit a poor prognosis. Thus, further investigations into novel effective treatment options for DLBCL are required. The present study reports the case of a patient resistant to multiple therapies, including rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) plus enzastaurin (trial no. CTR20171560), GemOx plus lenalidomide and selinexor (trial no. ATG-010-DLBCL-001). The patient harbored a CD274 amplification, as identified via next-generation sequencing (NGS), and exhibited a high programmed death-ligand 1 Tumor Proportion Score of up to 95%. Consequently, the patient was treated with sintilimab monotherapy and the response lasted for 12 months of follow-up without major immune-related adverse events. This case highlights the role of NGS technology in selecting treatment options for refractory DLBCL. Furthermore, the results of the present study suggest that sintilimab may have potential in the treatment of patients with refractory DLBCL.

Histopathologic Features and Differential Diagnosis in Challenging Cases of Nodular Lymphocyte Predominant B-cell Lymphoma/Nodular Lymphocyte Predominant Hodgkin Lymphoma

Nodular lymphocyte predominant Hodgkin lymphoma was termed "nodular lymphocyte predominant B-cell lymphoma" in the International Consensus Classification (ICC), to emphasize clinical and biological differences from classic Hodgkin lymphoma (CHL). The abbreviation "NLP" represents both terms in the ICC and World Health Organization classifications. Variations in the growth pattern, originally reported as Fan patterns A-F, are designated as either grade 1 or grade 2 in the ICC. NLP is uncommon, and in some cases an accurate diagnosis is challenging. The objectives of this article were to review the histopathologic features of NLP and the differential diagnosis from other key entities including de novo T-cell/histiocyte-rich large B-cell lymphoma (THRLBL) and lymphocyte-rich classic Hodgkin lymphoma (LRCHL). Histologically, NLP Fan pattern E (THRLBL-like) can be indistinguishable from de novo THRLBL. However, focal nodular areas, clustering of tumor cells, presence of few admixed small B-cells or FDC meshworks, and T-cell rosettes favor NLP Fan pattern E and argue against de novo THRLBL. NLP may also be confused with LRCHL. Patients with NLP are younger than those with LRCHL, and LRCHL may show mediastinal involvement. In LRCHL, the nodular pattern often contains eccentrically located small regressed germinal centers and intact small dense FDC meshworks, in contrast to the expanded, and fragmented FDC meshworks in NLP. Neoplastic cells that are positive for CD30 and CD15 but negative for CD20 and CD79a are characteristic of LRCHL. Additionally, Fascin and Gata3 are commonly positive in LRCHL but usually negative in NLP.

Post-marketing surveillance of the safety and effectiveness of nivolumab for classic Hodgkin lymphoma in Japan

Nivolumab was approved for relapsed/refractory classic Hodgkin lymphoma (cHL) in Japan in 2016. After its approval, a prospective, non-interventional, observational post-marketing surveillance was initiated to evaluate the safety and effectiveness of nivolumab treatment for up to 12 months in patients with relapsed/refractory cHL. Of 304 registered patients, 288 were included in safety analyses and 282 in effectiveness analyses. There were 191 (66.3%) male patients, median age was 64.0 years, and 54 patients (18.8%) had performance status ≥ 2. Treatment-related adverse events (TRAEs) were reported in 183 (63.5%) patients, with grade 3-5 TRAEs in 86 (29.9%). The most common TRAEs were infusion reaction (14.6%), hepatic function abnormal (5.9%), interstitial lung disease (ILD) (5.6%), and hypothyroidism (5.2%). TRAEs of special interest in ≥ 5% of patients were infusion reaction (15.6%), hepatic failure/hepatic dysfunction/hepatitis/cholangitis sclerosing (13.2%), thyroid dysfunction (9.7%), and ILD (7.3%). In multivariable analyses, prior allogeneic hematopoietic stem cell transplantation was a risk factor for hepatic failure/hepatic dysfunction/hepatitis/cholangitis sclerosing, and prior thyroid gland disorders was a risk factor for thyroid dysfunction. The overall response rate was 61.7%. In conclusion, nivolumab showed a similar safety profile and comparable effectiveness to that reported in clinical trials for relapsed/refractory cHL (CheckMate 205, ONO-4538-15).

TRAF6 enhances PD-L1 expression through YAP1-TFCP2 signaling in melanoma

Immunotherapy represented by programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) monoclonal antibodies has led tumor treatment into a new era. However, the low overall response rate and high incidence of drug resistance largely damage the clinical benefits of existing immune checkpoint therapies. Recent studies correlate the response to PD-1/PD-L1 blockade with PD-L1 expression levels in tumor cells. Hence, identifying molecular targets and pathways controlling PD-L1 protein expression and stability in tumor cells is a major priority. In this study, we performed a Stress and Proteostasis CRISPR interference screening to identify PD-L1 positive modulators. Here, we identified TRAF6 as a critical regulator of PD-L1 in melanoma cells. As a non-conventional E3 ubiquitin ligase, TRAF6 is inclined to catalyze the synthesis and linkage of lysine-63 (K63) ubiquitin which is related to the stabilization of substrate proteins. Our results showed that suppression of TRAF6 expression down-regulates PD-L1 expression on the membrane surface of melanoma cells. We then used in vitro and in vivo assays to investigate the biological function and mechanism of TRAF6 and its downstream YAP1/TFCP2 signaling in melanoma. TRAF6 stabilizes YAP1 by K63 poly-ubiquitination modification, subsequently promoting the formation of YAP1/TFCP2 transcriptional complex and PD-L1 transcription. Inhibition of TRAF6 by Bortezomib enhanced cytolytic activity of CD8+ T cells by reduction of endogenous PD-L1. Notably, Bortezomib enhances anti-tumor immunity to an extent comparable to anti-PD-1 therapies with no obvious toxicity. Our findings reveal the potential of inhibiting TRAF6 to stimulate internal anti-tumor immunological effect for TRAF6-PD-L1 overexpressing cancers.

A first-in-class inhibitor of HSP110 to potentiate XPO1-targeted therapy in primary mediastinal B-cell lymphoma and classical Hodgkin lymphoma

BACKGROUND

Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations.

METHODS

To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo.

RESULTS

We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels.

CONCLUSIONS

These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy.

Regulatory mechanisms of PD-1/PD-L1 in cancers

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

The pediatric approach to Hodgkin lymphoma

Hodgkin lymphoma (HL) occurs throughout the lifespan but is one of the most common cancers in adolescents and young adults (AYA; 15-39 years). HL has become a highly curable disease with survival rates surpassing 90%, including patients with high-risk and advanced stage disease. Unfortunately, intensive treatment carries a risk of short- and long-term toxicity. Given the decades pediatric HL survivors are expected to live after treatment, the pediatric approach to treatment has focused on improving the therapeutic index through response adapted treatment and more recently the incorporation of novel agents. The efforts of pediatric and medical oncologists in research and clinical trial development have long occurred in parallel, but recent efforts have laid the foundation for collaboration with the goal of standardizing AYA care and allowing earlier incorporation of novel therapy for younger patients. This review focuses on the evolution of the management of pediatric HL including epidemiology, biology, and approaches to upfront and salvage treatment regimens.

The biology of classical Hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is distinguished by several important biological characteristics. The presence of Hodgkin Reed Sternberg (HRS) cells is a defining feature of this disease. The tumor microenvironment with relatively few HRS cells in an expansive infiltrate of immune cells is another key feature. Numerous cell-cell mediated interactions and a plethora of cytokines in the tumor microenvironment collectively work to promote HRS cell growth and survival. Aberrancy and constitutive activation of core signal transduction pathways are a hallmark trait of cHL. Genetic lesions contribute to these dysregulated pathways and evasion of the immune system through a variety of mechanisms is another notable feature of cHL. While substantial elucidation of the biology of cHL has enabled advancements in therapy, increased understanding in the future of additional mechanisms driving cHL may lead to new treatment opportunities.

A genetic profiling guideline to support diagnosis and clinical management of lymphomas

The new lymphoma classifications (International Consensus Classification of Mature Lymphoid Neoplasms, and 5th World Health Organization Classification of Lymphoid Neoplasms) include genetics as an integral part of lymphoma diagnosis, allowing better lymphoma subclassification, patient risk stratification, and prediction of treatment response. Lymphomas are characterized by very few recurrent and disease-specific mutations, and most entities have a heterogenous genetic landscape with a long tail of recurrently mutated genes. Most of these occur at low frequencies, reflecting the clinical heterogeneity of lymphomas. Multiple studies have identified genetic markers that improve diagnostics and prognostication, and next-generation sequencing is becoming an essential tool in the clinical laboratory. This review provides a "next-generation sequencing" guide for lymphomas. It discusses the genetic alterations of the most frequent mature lymphoma entities with diagnostic, prognostic, and predictive potential and proposes targeted sequencing panels to detect mutations and copy-number alterations for B- and NK/T-cell lymphomas.

Immune checkpoint inhibitors in advanced and relapsed/refractory Hodgkin lymphoma: current applications and future prospects

Classic Hodgkin lymphoma (cHL) treatment paradigms are undergoing a shift with the integration of immune checkpoint inhibitors (ICIs) into both first-line and relapsed/refractory (R/R) regimens. In first-line therapy, the synergy between ICIs and chemotherapy may surpass the previous standards of ABVD and BV-AVD established by landmark trials including RATHL and ECHELON-1. In R/R disease, the combination of ICIs with chemotherapy has begun to challenge the paradigm of chemotherapy as a bridge to consolidative autologous stem cell transplantation. The clinical advances heralded by ICI offer unique challenges to management. ICI treatment and the associated inflammatory response can make the traditional timing and modalities of treatment response assessment difficult to interpret. In contrast to ABVD and BV-AVD, pembrolizumab-AVD results in PET2 positivity rates that are higher and less predictive of treatment response even when ultimate outcomes may be superior. This suggests that the predictive value of PET2 may be less reliable in the ICI era, prompting a reevaluation of response assessment strategies. Looking forward, circulating tumor DNA (ctDNA) may be a promising tool in response-adapted therapy. Its potential to complement or even supersede PET scans in predicting response to ICIs represents a critical advancement. The integration of ctDNA analysis holds the promise of refining response-adapted approaches and enhancing precision in therapeutic decision-making for patients with cHL. This review navigates the evolving landscape of cHL therapy, emphasizing the paradigmatic shift brought about by ICIs. This article explores the impact of combining ICIs with chemotherapy in both relapsed/refractory and first-line settings, scrutinizes the challenges posed to response-adapted therapy by ICIs, and highlights the potential role of ctDNA as an adjunct in refining response-adapted strategies for cHL.