Possible Association of CD3+CD4-CD8- Phenotype of T-Cell Lymphoma with Peripheral Blood Eosinophilia.

INTRODUCTION: Because the prognosis of patients with peripheral T-cell lymphoma is poor compared to that of patients with B-cell lymphoma, we want to avoid further organ damage by eosinophilia. Moreover, in patients with some types of lymphoma, blood eosinophilia is implicated in a worse prognosis. To study the risk factors of eosinophilia, the association between lymphoma type, immunophenotypic features, and peripheral blood eosinophil counts were examined in the patients with mature T-cell lymphoma. METHODS: We retrospectively examined 28 patients with mature T-cell lymphoma who were admitted to our hospital and whose immunophenotypic features were confirmed using flow cytometric, immunohistochemical analysis, or both between December 2012 and November 2023. RESULTS: We report a possible association between peripheral eosinophilia and peripheral T-cell lymphoma - not otherwise specified and CD3+CD4-D8- (double-negative) phenotypes. Mild eosinophilia was observed in various types, but moderate and severe eosinophilia were observed in patients with peripheral T-cell lymphoma - not otherwise specified. Double-negative phenotype was rarely observed; however, all patients with double-negative phenotype exhibited peripheral blood eosinophilia. In addition, four of the five cases of the double-negative type were peripheral T-cell lymphoma - not otherwise specified. CONCLUSION: Here, we retrospectively examined patients with peripheral T-cell lymphoma whose immunophenotypic features were confirmed and report a possible association between peripheral eosinophilia and peripheral T-cell lymphoma - not otherwise specified and CD3+CD4-CD8- (double-negative) phenotypes. In addition, clinicians should be aware of the possible risk that patients with lymphocytic hypereosinophilic syndrome of the double-negative phenotype may develop peripheral T-cell lymphoma.

A novel murine syngeneic CD8 peripheral T-cell lymphoma model with preclinical applications.

Peripheral T-cell Lymphoma (PTCL) represents a heterogenous group of aggressive non-Hodgkin Lymphomas with poor prognostic outcomes and limited treatment options. The development and refinement of therapeutic strategies for PTCL are impeded by a paucity of reliable preclinical models that accurately mimic the disease's pathophysiology. There is a dire need for more physiologically relevant models for PTCL. Here we describe a spontaneousCD8+ peripheral T-cell lymphoma cell line (LM-23) derived from a 12-week-old female Balb/cJ mouse. Both intravenous and subcutaneous administration of this cell line to syngeneic Balb/cJ mice resulted in rapid establishment of tumor growth. CHOP and anti-PD1 treatment both displayed no benefit to mice in regulating tumor growth. Such results along with its phenotypic characteristics, rapid growth, and metastatic behavior in syngeneic mice highlight its value in studying the elusive disease and discovery of novel therapeutics.

Mutations in Ras homolog family member A in patients with peripheral T-cell lymphoma and implications for personalized medicine.

Genome sequencing has revealed frequent mutations in Ras homolog family member A (RHOA) among various cancers with unique aberrant profiles and pathogenic effects, especially in peripheral T-cell lymphoma (PTCL). The discrete positional distribution and types of RHOA amino acid substitutions vary according to the tumor type, thereby leading to different functional and biological properties, which provide new insight into the molecular pathogenesis and potential targeted therapies for various tumors. However, the similarities and discrepancies in characteristics of RHOA mutations among various histologic subtypes of PTCL have not been fully elucidated. Herein we highlight the inconsistencies and complexities of the type and location of RHOA mutations and demonstrate the contribution of RHOA variants to the pathogenesis of PTCL by combining epigenetic abnormalities and activating multiple downstream pathways. The promising potential of targeting RHOA as a therapeutic modality is also outlined. This review provides new insight in the field of personalized medicine to improve the clinical outcomes for patients.

Possible role of a malfunctioning immune system in discordant lymphoma with peripheral T­cell lymphoma secondary to classical Hodgkin lymphoma: A case report.

The present case report investigated the clinicopathological features and potential mechanisms underlying the transformation to peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), following treatment for classical Hodgkin lymphoma (CHL) in a 73-year-old man. The patient was admitted to hospital in 2012 and underwent a left cervical lymph node biopsy, which confirmed CHL of the nodular sclerosing type, with evident bone marrow involvement. The patient received four cycles of doxorubicin, bleomycin, vinblastine and dacarbazine chemotherapy, after which they achieved complete remission. However, after 3 years, the patient presented with enlarged left inguinal lymph nodes and a biopsy revealed PTCL-NOS. Molecular studies indicated a T-cell receptor-γ gene rearrangement. A literature review, together with the current case, identified 11 patients with CHL that transformed into PTCL-NOS. Among these, nine patients (81.82%) were middle-aged or elderly (>45 years old), and eight (72.73%) experienced transformation within 3 years post-treatment of CHL. Among these eight patients, seven (87.50%) predominantly exhibited the nodular sclerosis subtype, with a median recurrence time of 26 months. Five (45.45%) patients died of the disease. The rare transformation of CHL to PTCL-NOS, primarily among men, underscores its clinical significance. Notably, nodular sclerosing-type CHL appears to be particularly prone to transformation into PTCL-NOS. The poor prognosis in such cases may be attributed to the complex tumor microenvironment of CHL.

Targeted agents plus CHOP compared with CHOP as the first-line treatment for newly diagnosed patients with peripheral T-cell lymphoma (GUIDANCE-03): an open-label, multicentre phase 2 clinical trial.

Background: Peripheral T-cell lymphoma (PTCL) is a heterogeneous disease with dismal outcomes. We conducted an open-label, phase 2 nonrandomised, externally controlled study to evaluate the efficacy and safety of targeted agents plus CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) (CHOPX) for PTCL in the front-line setting. Methods: Eligible patients were ≥18 years of age and newly diagnosed PTCL. Patients in the CHOPX group received standard CHOP at Cycle 1. Specific targeted agents were added from Cycle 2, decitabine if TP53 mut, azacytidine if TET2/KMT2D mut, tucidinostat if CREBBP/EP300 mut, and lenalidomide if without mutations above. Patients in the CHOP group received CHOP for 6 cycles. The primary endpoint was the complete response rate (CRR) at the end of treatment (EOT). Secondary endpoints included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety. The study was registered with ClinicalTrials.gov, NCT04480099. Findings: Between July 29, 2020, and Sep 22, 2022, 96 patients were enrolled and included for efficacy and safety analysis with 48 in each group. The study met its primary endpoint. CRR at EOT in the CHOPX group was superior to the CHOP group (64.6% vs. 33.3%, OR 0.27, 95%CI 0.12-0.64; p = 0.004). At a median follow-up of 24.3 months (IQR 12.0-26.7), improved median PFS was observed in the CHOPX group (25.5 vs. 9.0 months; HR 0.57, 95%CI 0.34-0.98; p = 0.041). The median OS was similar between two groups (not reached vs. 30.9 months; HR 0.55, 95%CI 0.28-1.10; p = 0.088). The most common grade 3-4 hematological and non-hematological adverse events in the CHOPX group were neutropenia (31, 65%) and infection (5, 10%). Interpretation: Targeted agents combined with CHOP demonstrated effective and safe as first-line treatment in PTCL. Biomarker-driven therapeutic strategy is feasible and may lead to promising efficacy specifically toward molecular features in PTCL. Funding: This study was supported by the National Key Research and Development Program (2022YFC2502600) and the General Program of the Shanghai Municipal Health Commission (202040400).

Response to Azacytidine in a Patient With Refractory Peripheral T-cell Lymphoma With TET2 Mutation.

Peripheral T-cell lymphomas (PTCLs) are an aggressive form of non-Hodgkin lymphomas. PTCLs have multiple subtypes, with PTCL not otherwise specified (PTCL-NOS) being the most common. This subtype usually has a high rate of relapse. Making an accurate diagnosis requires molecular genetic analyses, histopathological examination, and immunophenotyping. Treatment for PTCL traditionally starts with the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone). We present a case of a patient with PTCL-NOS who progressed despite multiple treatment regimens, including both traditional and novel therapeutic agents, and finally achieved good results with azacytidine, selected based on a TET2 mutation. This case proposes future research into Azacytidine's efficacy in this patient population and further exploration of the broader utility of epigenetic therapies in PTCL.

Unraveling clonal CD8 T cell expansion and identification of essential factors in γ-herpesvirus-induced lymphomagenesis.

Alcelaphine gammaherpesvirus 1 (AlHV-1) asymptomatically persists in its natural host, the wildebeest. However, cross-species transmission to cattle results in the induction of an acute and lethal peripheral T cell lymphoma-like disease (PTCL), named malignant catarrhal fever (MCF). Our previous findings demonstrated an essential role for viral genome maintenance in infected CD8+ T lymphocytes but the exact mechanism(s) leading to lymphoproliferation and MCF remained unknown. To decipher how AlHV-1 dysregulates T lymphocytes, we first examined the global phenotypic changes in circulating CD8+ T cells after experimental infection of calves. T cell receptor repertoire together with transcriptomics and epigenomics analyses demonstrated an oligoclonal expansion of infected CD8+ T cells displaying effector and exhaustion gene signatures, including GZMA, GNLY, PD-1, and TOX2 expression. Then, among viral genes expressed in infected CD8+ T cells, we uncovered A10 that encodes a transmembrane signaling protein displaying multiple tyrosine residues, with predicted ITAM and SH3 motifs. Impaired A10 expression did not affect AlHV-1 replication in vitro but rendered AlHV-1 unable to induce MCF. Furthermore, A10 was phosphorylated in T lymphocytes in vitro and affected T cell signaling. Finally, while AlHV-1 mutants expressing mutated forms of A10 devoid of ITAM or SH3 motifs (or both) were able to induce MCF, a recombinant virus expressing a mutated form of A10 unable to phosphorylate its tyrosine residues resulted in the lack of MCF and protected against a wild-type virus challenge. Thus, we could characterize the nature of this γ-herpesvirus-induced PTCL-like disease and identify an essential mechanism explaining its development.

Application patterns and outcomes of hematopoietic stem cell transplantation in peripheral T-cell lymphoma patients: a multicenter real-world study in China.

The optimal timing and type of hematopoietic stem cell transplantation (HSCT) for treating peripheral T-cell lymphoma (PTCL) remain controversial. This retrospective real-world study investigated the application pattern and outcomes of HSCT in China. The analysis encompassed 408 PTCL patients with a median age of 45.5 years, all of whom received initial adequate therapy at five hospitals. Among patients with nodal PTCL who responded effectively to first-line therapy (the "responders", n = 127) and subsequently underwent HSCT consolidation (n = 47, 37.0%), 93.6% received auto-HSCT, while 6.4% underwent allo-HSCT. Front-line auto-HSCT showed potential for long-term disease control in nodal PTCL responders. Among non-nodal PTCL responders (n = 80) with HSCT (n = 26, 32.5%), 46.2% underwent allo-HSCT and 53.8% received auto-HSCT. Upfront allo-HSCT provides longer progression-free survival (PFS) for non-nodal PTCL responders, with lower 3-year cumulative incidence of relapse (CIR) (16.7% vs. 56.0%) and comparable non-relapse mortality (NRM) (10.4% vs. 11.0%) compared to auto-HSCT. For patients who achieved remission with second-line salvage regimens, allo-HSCT was the primary choice (82.4%) for non-nodal PTCL, while auto-HSCT was more common (82.4%) in nodal PTCL. Nodal PTCL patients underwent auto-HSCT after ≥ 3 lines of treatment had a higher 3-year CIR (81.0%) compared to those treated in the first (26.0%) or second line (26.0%). Non-nodal PTCL patients underwent allo-HSCT after ≥ 3 lines had a higher 3-year NRM (37.5%) compared to after first (10.4%) or second line treatment (8.5%). These findings highlight distinct HSCT application patterns for PTCL in China, emphasizing the impact of early disease control and upfront consolidative HSCT.

Standardization of CD30 immunohistochemistry staining among three automated immunostaining platforms.

The identification of CD30 expression by immunohistochemistry is essential for the treatment of lymphomas using an antibody-drug conjugate targeting CD30. However, no standardized protocol for CD30 staining has been available. In this study, we compared three common automated immunostaining platforms {Bond III (B III), Dako Omnis (DO) and Ventana BenchMark ULTRA (VBMU)}. A primary antibody for CD30, the Ber-H2 clone, was diluted 50- to 400-fold for B III and DO, and ready-to-use antibody was used for VBMU. An enhancement step using a linker was introduced in all protocols. First, several candidate dilutions were selected for each platform by staining six cases. These candidate conditions were then confirmed with 60 cases of various types of peripheral T-cell lymphomas (PTCLs). The concordance rates of CD30 expression among platforms differed depending on cutoff values and antibody dilutions, except for anaplastic large cell lymphoma. The concordance rates among three platforms in the evaluation of "positive" or "negative" were 100% and 97% when the cutoff values were 1% and 10% respectively, if using 400-diluted antibody in B III and 100-diluted antibody in DO. This study demonstrated the feasibility of equalizing CD30 staining of PTCLs among different platforms by adjusting protocols.

Nodal T follicular helper cell lymphoma with aberrant CD20 expression and monoclonal TCR, IG rearrangements secondary to Classical Hodgkin Lymphoma: a case report.

Classical Hodgkin Lymphoma (CHL) is a rare malignant neoplasm of the lymphatic system. While CHL typically responds well to conventional treatments, some cases may experience relapse to other subtypes, with the development of secondary peripheral T-cell lymphoma (PTCL) being relatively uncommon. Herein, we report a rare case of nodal T follicular helper cell lymphomas,nos (nTFHL-NOS) secondary to CHL, accompanied by aberrant CD20 expression and clonal rearrangements of T-cell receptor (TCR) and immunoglobulin (IG). A 74-year-old male, was diagnosed with CHL, leaning toward the mixed cell type, 6 years ago. He received six cycles of the Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD) regimen, achieving complete clinical remission. The patient was admitted to our hospital due to the appearance of multiple skin nodules 66 months later. Histopathological analysis revealed nTFHL-NOS, with aberrant CD20 expression and clonal rearrangements of TCR and IG. The patient underwent two cycles of chemotherapy with brentuximab vedotin and the Gemcitabine-Oxaliplatin (G-mox) regimen, resulting in a reduction of the skin lesions to 2 cm × 1 cm. We discuss this rare case and review related literature.

A Case Report on a Rare Type of Lymphoma: Angioimmunoblastic T-cell Lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) is a rare type of non-Hodgkin lymphoma (NHL). We present a case of a 60-year-old female who attended the emergency department (ED) with fatigue, recurrent fever, weight loss, and adenopathy for six months. Laboratory findings showed anemia, lymphocytosis, eosinophilia, thrombocytosis, cholestasis, hypoproteinemia, and hypoalbuminemia. Abdominopelvic computed tomography (CT) revealed multiple adenopathies. A lymph node biopsy yielded inconclusive results in the outpatient clinic. Later, during admission, the patient underwent a positron emission tomography-computed tomography (PET-CT), revealing a cervical adenopathy cluster that was excised en bloc. Histology confirmed the diagnosis of AITL. The medical team initiated chemotherapy but opted for exclusive symptomatic treatment due to disease progression. The patient died six months after diagnosis. The fluctuating and nonspecific presentation of AITL can hinder and delay definitive diagnosis, therefore impacting treatment and prognosis.

TP53 and KMT2D mutations associated with worse prognosis in peripheral T-cell lymphomas.

There are limited studies on mutation profiling for Peripheral T-cell lymphomas (PTCL) in the Chinese population. We retrospectively analyzed the clinical and genetic landscape of 66 newly diagnosed Chinese patients. Targeted next-generation sequencing (NGS) was performed for tissues from these patients. At least one mutation was detected in 60 (90.9%) patients, with a median number of 3 (0-7) mutations, and 32 (48.5%) cases detected with more than 4 mutations. The genes with higher mutation frequencies were TET2, RHOA, DNMT3A, IDH2, TP53, STAT3, and KMT2D respectively. When mutant genes are classified by functional group, the most prevalent mutations are related to epigenetics and signal transduction. IPI ≥2, PIT ≥2, and failure to achieve partial remission (PR) were factors for inferior progression-free survival (PFS) and overall survival (OS). Multivariate analysis showed TP53 was an adverse factor for PFS (HR, 3.523; 95% CI, 1.262-9.835; p = 0.016), and KMT2D was an adverse factor for OS (HR, 10.097; 95% CI, 1.000-101.953; p = 0.048). Mutation profiling could help differentiate distinct types of PTCL and serve as a useful tool for determining treatment options and prognoses.

Peripheral T-cell lymphoma: From biology to practice to the future.

Recent advancements in comprehending peripheral T-cell lymphomas (PTCLs) validate and broaden our perspective, highlighting their diverse nature and the varying molecular mechanisms underlying the entities. Based on a comprehensive accumulated understanding, the PTCLs currently overcome the most challenging features of any disease: rarity, incredible heterogeneity, and a lack of any established standard of care. The treatments deployed in the front-line are extrapolated from regimens developed for other diseases. The recent approval of the three drugs brentuximab vedotin (BV), pralatrexate, and belinostat for patients with relapsed or refractory disease has provided clues about pathophysiology and future directions, though challenges satisfying post-marketing requirements (PMR) for those accelerated approvals have led to one of those drugs being withdrawn and put the other two in jeopardy. Edits of the front-line regimens, often called CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-plus approaches, look more like CHOP-minus strategies, as the toxicity of five-drug regimens often reduces the dose intensity of the added 'novel' drug, nullifying any hope of an advance. The turmoil in the field produced by the aforementioned, coupled with an ever-changing classification, has left the field uncertain about the path forward. Despite these challenges, empiric findings from studies of novel drug approaches, coupled with a logic emerging from studies of PTCL lymphomagenesis, have begun to illuminate, albeit faintly for some, a potential direction. The empiric finding that drugs targeting the discrete components of the PTCL epigenome, coupled with the description of multiple mutations in genes that govern epigenetic biology, offers, at the very least, an opportunity to finally be hypothesis-driven. The most recent recognition that the only combination of drugs shown to markedly improve progression-free survival (PFS) in patients with relapsed disease is one based on dual targeting of different and discrete components of that epigenetic biology has established a possibility that circumnavigating chemotherapy addition studies is both plausible, feasible, and likely the best prospect for a quantum advance in this disease. Herein, we analyze PTCL through a 2025 lens, highlighting and underscoring walls that have impeded progress. We will critically explore all the clues and the panoramic view of PTCL research.

Phase II Trial of Romidepsin as Consolidation Therapy after Gemcitabine, Dexamethasone, and Cisplatin in Elderly Transplant-Ineligible Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma.

Romidepsin is an important therapeutic option for patients with peripheral T-cell lymphoma (PTCL). However, the timing of romidepsin administration remains controversial. The objective of this study was to characterize the safety and efficacy of romidepsin as consolidation therapy after gemcitabine, dexamethasone, and cisplatin (GDP) therapy (GDPR). This study of patients treated between March 2019 and March 2021 was registered with the Japan Registry of Clinical Trials (registration number: jRCT0000000519). If complete response, partial response, or stable disease was confirmed after 2-4 GDP cycles, romidepsin was administered every 4 weeks for 1 year. Seven patients with relapsed/refractory (R/R) PTCL (T-follicular helper phenotype [n = 1] and angioimmunoblastic T-cell lymphoma [n = 6]) were included in this prospective study (PTCL-GDPR). After a median follow-up of 34 months of patients in PTCL-GDPR, the 2-year overall survival rate was 71%, and the overall response rate after treatment was 57%. Common adverse events in patients with PTCL-GDPR included hematological toxicities such as neutropenia, which improved with supportive treatment. There were no treatment-related mortalities. GDPR might be safe and effective in elderly transplant-ineligible patients with R/R PTCL; however, further investigation is required.

Chidamide in combination with azacitidine for an elderly patient with peripheral T cell lymphoma­not otherwise specified: A case report.

Peripheral T cell lymphoma (PTCL) is a type of aggressive non-Hodgkin's lymphoma with poor prognosis. PTCL-not otherwise specified (PTCL-NOS) is one of its most common pathological types. PTCL is not sensitive to conventional chemotherapy regimens and treatment is particularly limited in elderly patients due to their poor tolerance to chemotherapy. The present report shares the treatment experience of one elderly PTCL-NOS case, which achieved complete remission by reduced-intensity chemotherapy with chidamide in combination with azacitidine following the onset of organ failure and chemotherapy insensitivity. The 9-month follow-up showed sustained remission and the long-term efficacy of this regimen is also promising.

Exploratory screening for micro-RNA biomarkers in canine multicentric lymphoma.

Lymphoma is one of the most frequent hematopoietic tumors in dogs and shares similar features with human counterparts. MicroRNAs (miRNA, small non-coding RNAs) are pivotal in gene regulation fine tuning and cancer hallmarks are influenced by their aberrant expression. Consequently, miRNA biomarkers may assist predicting therapeutic response and clinical outcome by providing less-invasive novel diagnostics tools. The aim of this study was to detect dysregulated miRNAs in lymphomatous lymph node tissues in comparison to lymph node material or PBMCs from healthy control dogs. Potential significant differences in miRNA expression profiles between four lymphoma entities were evaluated. A customized PCR array was utilized to profile 89 canine target miRNAs. Quantification was performed using qPCR, relative expression was determined by the delta-delta Ct method, and p-values were calculated with student's t-test. In the 14 diffuse large B-cell lymphoma (DLBCL) patients, 28 and 24 different miRNAs were significantly dysregulated compared to lymph node material or PBMCs. Sixteen miRNAs occurred in both control groups, with 12 miRNAs being down- and four miRNAs being upregulated. The six peripheral T-cell lymphoma (PTCL) samples showed 24 and 25 dysregulated miRNAs when compared to the healthy controls. A combined analysis of DLBCL and PTCL samples revealed seven shared and 19 differently expressed miRNAs. Potential biomarkers in T- and B-cell lymphoma could be the miRNA-17/92 cluster and miRNA-181-family together with miRNA-34a and miRNA-150. Diagnostic utility of potential biomarkers must be validated in larger, prospective cohorts of canine lymphoma cases and in higher numbers of physiological patient material.

[Prognostic Factors Affecting Recurrence in Peripheral T-Cell Lymphoma Patients with Different HDAC Levels].

OBJECTIVE: To analyze the distribution characteristics of prognostic factors affecting recurrence in peripheral T-cell lymphoma (PTCL) patients with different levels of histone deacetylase (HDAC) based on latent class analysis. METHODS: 112 PTCL patients who were treated in our hospital from September 2012 to September 2019 were selected and divided into recurrence group and non-recurrence group. The clinical data of the two groups of patients were compared. Multivariate logistic regression was used to analyze the risk factors for recurrence. Latent class analysis was used to compare the distribution characteristics of prognostic factors affecting recurrence between the high-risk group and the low-risk group. RESULTS: There were 87 patients (77.68%) in recurrence group and 25 patients (22.32%) in non-recurrence group. The result of multivariate logistic regression showed that ECOG score ≥2, Ann Arbor stage III-IV, IPI score >2, bone marrow involvement, elevated serum ß2-microglobulin (ß2-MG), short-term efficacy not reaching complete remission (CR) or partial remission (PR), and the high expression of HDAC were all independent risk factors for recurrence in patients with PTCL (P <0.05). The recurrence rate of patients with high HDAC levels was significantly higher than that of patiens with low HDAC levels (P <0.05). The results of cluster analysis showed that the risk of recurrence was obviously clustered, and the patients could be divided into high recurrence risk group (HDAC＞5 points) and low recurrence risk group (HDAC≤5 points). The results of latent class analysis showed that patients with multiple risk factors account for a higher proportion in the high recurrence risk group, compared with the low recurrence risk group (P <0.05). CONCLUSION: There are differences in recurrence rates among PTCL patients with different HDAC levels and in distribution characteristics of risk factors between high recurrence risk and low recurrence risk groups.

Safety and effectiveness of mogamulizumab in relapsed or refractory CC chemokine receptor 4-positive peripheral T-cell lymphoma and relapsed or refractory cutaneous T-cell lymphoma: A post-marketing surveillance in Japan.

Mogamulizumab is a humanized antibody targeting CC chemokine receptor 4 (CCR4). This post-marketing surveillance was conducted in Japan as a regulatory requirement from 2014 to 2020 to ensure the safety and effectiveness of mogamulizumab in patients with relapsed or refractory (r/r) CCR4-positive peripheral T-cell lymphoma (PTCL) or r/r cutaneous T-cell lymphoma (CTCL). Safety and effectiveness data were collected for up to 31 weeks after treatment initiation. A total of 142 patients were registered; safety was evaluated in 136 patients. The median number of doses was 8.0 (range, 1-18). The main reasons for treatment termination were insufficient response (22.1%) and adverse events (13.2%). The frequency of any grade adverse drug reaction was 57.4%, including skin disorders (26.5%), infections and immune system disorders (16.2%), and infusion-related reactions (13.2%). Graft-versus-host disease, grade 2, developed in one of two patients who underwent allogeneic-hematopoietic stem cell transplantation after receiving mogamulizumab. Effectiveness was evaluated in 131 patients (103 with PTCL; 28 with CTCL). The best overall response rate was 45.8% (PTCL, 47.6%; CTCL, 39.3%). At week 31, the survival rate was 69.0% (95% confidence interval, 59.8%-76.5%) [PTCL, 64.4% (54.0%-73.0%); CTCL, 90.5% (67.0%-97.5%)]. Safety and effectiveness were comparable between patients <70 and ≥ 70 years old and between those with relapsed and refractory disease. The safety and effectiveness of mogamulizumab for PTCL and CTCL in the real world were comparable with the data reported in previous clinical trials. Clinical Trial Registration.

Single-cell landscape reveals the immune heterogeneity of bone marrow involvement in peripheral T-cell lymphoma.

The prognosis of patients with peripheral T-cell lymphoma (PTCL) depends on bone marrow involvement (BMI). The bone marrow (BM) tumor microenvironment in PTCL remains unclear. We performed single-cell RNA sequencing (scRNA-seq) on 11 fresh BM samples from patients with BMI to reveal the associations of immune landscape and genetic variations with the prognosis of PTCL patients. Compared with PTCL not otherwise specified (NOS), angioimmunoblastic T-cell lymphoma (AITL) had a higher number of T cells, lower number of lymphocytes, and greater inflammation. Immune heterogeneity in AITL is associated with prognosis. In particular, specific T-cell receptor (TCR) T cells are enriched in patients with good response to anti-CD30 therapy. We observed RhoA mutation-associated neoantigens. Chidamide-treated patients had a higher number of CD4+ regulatory cells and a better treatment response compared with other patients. In the nonresponder group, T-cell enrichment progressed to secondary B-cell enrichment and subsequently diffuse large B-cell lymphoma. Moreover, AITL patients with lymphoma-associated hemophagocytic syndrome had more T follicular helper (Tfh) cells with copy number variations in CHR5. To our knowledge, this study is the first to reveal the single-cell landscape of BM microenvironment heterogeneity in PTCL patients with BMI. scRNA-seq can be used to investigate the immune heterogeneity and genetic variations in AITL associated with prognosis.

Phase I/II clinical trial of brentuximab vedotin for pretreated Japanese patients with CD30-positive cutaneous T-cell lymphoma.

Brentuximab vedotin (BV), a conjugate of anti-CD30 antibody and monomethyl auristatin E, has emerged as a promising treatment option for refractory CD30+ mycosis fungoides (MF) and primary cutaneous anaplastic large-cell lymphoma (pcALCL). BV has been shown to be safe and effective in treating Hodgkin's lymphoma and peripheral T-cell lymphoma. This multicenter, prospective, single-arm phase I/II study evaluated the efficacy of BV in Japanese patients with CD30+ cutaneous lymphomas, namely CD30+ cutaneous T-cell lymphoma. Participants were divided into two groups: those with CD30+ MF or pcALCL (cohort 1, n = 13) and those with CD30+ lymphoproliferative disorders other than those in cohort 1 (cohort 2, n = 3). The studied population included the full analysis set (FAS), modified FAS (mFAS), and safety analysis set (SAF). These sets were identified in cohorts 1 and 1 + 2 and labeled FAS1 and FAS2, mFAS1 and mFAS2, and SAF1 and SAF2, respectively. Each treatment cycle lasted 3 weeks, and BV was continued for up to 16 cycles after the third cycle based on treatment response. The primary endpoint was the 4-month objective response rate (ORR4) determined by the Independent Review Forum (IRF). ORR4 was 69.2% for FAS1 and 62.5% for FAS2 (P < 0.0001). Secondary endpoints of ORR, assessed using the global response score (53.8% in FAS1) and modified severity-weighted assessment tool (62.5% in FAS1), using the IRF, provided results comparable to the primary findings. The incidence of ≥grade 3 adverse events (≥15%) in SAF1 was peripheral neuropathy in three patients (23%) and fever and eosinophilia in two patients (15%). In conclusion, BV showed favorable efficacy, tolerability, and safety profile in Japanese patients with relapsed or refractory CD30+ primary cutaneous T-cell lymphoma. The trial was registered with University Hospital Medical Information Network Clinical Trials Registry, Japan (protocol ID: UMIN000034205).