Avelumab for the treatment of relapsed or refractory extranodal NK/T-cell lymphoma: an open-label phase 2 study

Early growth response 1 as a key regulator of PD-L1 expression and immune evasion in extranodal NK/T-cell lymphoma

This study investigates the role of Early Growth Response 1 (EGR1) in extranodal natural killer/T-cell lymphoma (ENKTL) and its correlation with PD-L1 expression. Analysis of 62 ENKTL patient samples revealed that high EGR1 expression was linked to PD-L1 positivity, the immune evasion-A subtype, and early-stage disease. Although EGR1 expression was not an independent prognostic factor for overall survival, patients with higher EGR1 levels showed a trend toward better outcomes. In ENKTL cell lines (YT, SNK6), EGR1 positively regulated LMP1 and PD-L1 expression. Knockdown of EGR1 reduced PD-L1 levels, decreased PTEN, increased AKT phosphorylation, and abrogated STAT3 phosphorylation. Conversely, EGR1 overexpression enhanced PD-L1. Treatment with the histone deacetylase inhibitor entinostat upregulated both EGR1 and PD-L1, but this effect was lost in EGR1-depleted cells, indicating EGR1's necessity for HDAC inhibitor-induced PD-L1 expression. These findings reveal EGR1's pivotal role in tumor immune modulation and highlight potential combination therapies targeting EGR1, epigenetic regulators, and PD-1/PD-L1 checkpoints.

Efficacy and safety of PD-1/PD-L1 inhibitors for natural killer/T-cell lymphoma: a single-arm meta-analysis

BACKGROUND

With the advent of asparaginase-based drugs, patients with natural killer/T-cell lymphoma (NKTCL) have achieved excellent efficacy. However, the prognosis is poor in patients with advanced disease, and even worse in relapse/refractory patients. This meta-analysis aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitor monotherapy or combination treatment strategies in patients with NKTCL.

METHOD

Seven databases were extensively searched from inception to November 2023 and updated in April 2024, with no language restrictions. The pooled overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and treatment-related adverse events (AEs) were calculated via a random effects model. Heterogeneity was tested utilizing the I-square (I2) test and Cochrane's Q test. Subgroup analysis was used to compare the effects of single PD-1/PD-L1 inhibitors or combination treatment in NKTCL patients.

RESULTS

A total of thirteen single-arm studies involving 460 patients were enrolled. The results revealed that the pooled ORR was 62% (95% CI: 48-76%). In terms of survival outcomes, the pooled 1-year OS was 67% (95% CI: 47-87%) and the 2-year OS was 47% (95% CI: 24-69%). Moreover, the 1-year and 2-year PFS rates were 66% (95% CI: 48-84%) and 59% (95% CI: 34-84%), respectively. With regard to treatment toxicity, the pooled incidence of all-grade AEs was 86% (95% CI: 79-93%), and the pooled incidence of grade 3 or higher AEs was 29% (95% CI: 22-36%). Leukopenia and hypoalbuminemia were identified as the most common hematologic and non-hematologic adverse events, respectively.

CONCLUSION

Evidence suggests that PD-1/PD-L1 inhibitors are promising treatment options for newly diagnosed NKTCL patients. PD-1/PD-L1 inhibitors combined with chemotherapy or chidamide has demonstrated superior clinical efficacy in patients with relapsed/refractory NKTCL.

TRIAL REGISTERATION

Open Science Framwork: osf.io/2bwh3.

Immune checkpoints in B-cell Lymphoma: Still an Unmet challenge from Basic research to clinical practice

In the last decade, advancements in immunotherapy knowledge have highlighted CTLA-4, PD-1, LAG-3, TIM-3, and TIGIT, decisive immune checkpoints exhibiting within the tumor microenvironment (TME), as fundamental objects for cancer immunotherapy. The widespread clinical use of immune checkpoint inhibitors (ICls), employing PD-1/PD-L1 or CTLA-4 antibodies to obstruct crucial checkpoint regulators, is noted in treating B-cell lymphoma patients. Nevertheless, the prolonged advantages of the currently employed treatments against CTLA-4, PD-1, and PD-L1 are uncommon among patients. Thus, recent focus has been progressively moved to additional immune checkpoints on T cells, like LAG-3, TIM-3, and TIGIT, which are now seen as reassuring targets for treatment and broadly acknowledged. There are several types of immunecheckpoint molecules expressed by T cells, and inhibitors targeting immune checkpoints can revive and amplify the immune response of T lymphocytes against tumors, a crucial aspect in lymphoma therapy. However, there is little knowledge about their regulation. Herein, we discuss the anti-tumor effects and functions of ICIs in controlling T-cell activity, as well as the progress in combined application with other immunotherapies.

A prognostic index for advanced-stage extranodal natural killer/T-cell lymphoma: A multicenter study

Advanced-stage extranodal natural killer/T-cell lymphoma (ENKTL) is a highly heterogeneous disease with very poor prognosis. All commonly utilized prognostic models incorporated both early-stage and advanced-stage patients in the modeling process. This study aim to design a prognostic model specifically for advanced-stage ENKTL, providing risk stratification in affected patients. We analyzed 291 patients with stage III/IV ENKTL receiving asparaginase-based chemotherapy from 8 institutions to develop a new prognostic model and validate it in an independent cohort consisted of 221 patients from 4 additional hospitals. The prognostic model included three independent variables based on a multivariate analysis for overall survival (OS): age, bone marrow invasiveness and visceral organ involvement. We identified three different risk groups: group 1, no adverse factors; group 2, one factor; and group 3, two or three factors, which were associated with 5-year OS rates of 66.0%, 32.3%, and 20.0%, respectively (P < 0.001). The prognostic index of natural killer lymphoma (PINK) and nomogram-revised risk index (NRI) were unsatisfactory for stratifying these patients. These results were validated and confirmed in an independent cohort. This newly proposed model can be used to guide risk-adapted treatment for advanced stage ENKTL.

An evaluation of sugemalimab for the treatment of relapsed or refractory extranodal natural killer T-cell lymphoma

INTRODUCTION

Relapsed or refractory extranodal natural killer/T-cell lymphoma (R/R ENKTL) is a rare and aggressive subtype arising from natural killer or cytotoxic T-cells, predominantly affecting the nasal cavity and paranasal sinuses, lacking a standardized therapeutic approach. Sugemalimab, a fully human, full-length anti-PD-L1 immunoglobulin G4 (IgG4) monoclonal antibody (mAb), has been investigated in a Single-Arm, Multicenter, Phase II Study (GEMSTONE-201). The results demonstrated significant efficacy, favorable tolerability, and manageable adverse reactions of sugemalimab in R/R ENKTL. This study summarizes and compares the efficacy and safety profile of sugemalimab with several other PD-1/PD-L1 inhibitors in R/R ENKTL patients.

AREA COVERED

We included a Phase II study (GEMSTONE-201) of sugemalimab in R/R ENKTL.

EXPERT OPINION

The clinical trials have demonstrated superior efficacy of sugemalimab, evidenced by a complete response rate (CRR) of 35.9% and an overall response rate (ORR) of 44.9%. In comparison with other immune checkpoint inhibitors (ICIs), sugemalimab shows a notably higher CRR. Additionally, sugemalimab exhibits a manageable safety profile. Further evaluation of sugemalimab is required based on its efficacy and safety in real-world patient populations. Should sugemalimab be included in medical insurance in the future, it could potentially benefit a larger number of patients with R/R ENKTL.

Anti-PD-1 antibody (Tislelizumab) combined with gemcitabine and oxaliplatin for extranodal NK/T-cell lymphoma failing asparaginase: A multicenter phase II trial

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTCL) is almost always fatal after the failure of asparaginase. This phase II study aimed to investigate the efficacy and safety of tislelizumab combined with gemcitabine and oxaliplatin (Tisle-GemOx) in patients with ENKTCL failing asparaginase.

METHODS

Eligible patients received Tisle-GemOx as initial induction for 6-8 cycles at 21-day intervals. Responders continued tislelizumab maintenance every two months for two years. The primary endpoint was the best complete response rate (CRR).

RESULTS

As of September 2023, 32 patients were enrolled in our study. Among the 30 efficacy-evaluable patients, the best CRR was 60 %, meeting the primary efficacy endpoint. With a median follow-up of 22.6 months, the median progression-free survival (PFS) was 7.4 months and the 1-year PFS rate was 46.4 %. Subgroup analyses showed that shorter PFS was associated with previous lines of chemotherapy ≥ 2 (P = 0.034) and concomitant hemophagocytic lymphohistiocytosis (P = 0.040). Pseudo-progression was observed in three patients (10 %). The most common grade ≥ 3 toxicities were lymphopenia (25 %) and anemia (15.6 %).

CONCLUSIONS

Tisle-GemOx exhibits promising anti-tumor activity and manageable toxicities as a salvage therapy for ENKTCL failing asparaginase. Further long-term follow-up is necessary to evaluate the durability of the response with tislelizumab maintenance in this patient population.

Phase II study of pegaspargase, etoposide, gemcitabine (PEG) followed by involved-field radiation therapy in early-stage extranodal natural killer/T-cell lymphoma

OBJECTIVE

The prognosis of extra-nodal NK/T cell lymphoma (ENKTL) is poor, and the optimal therapy remains controversial. This study aims to evaluate the safety and efficacy of a new combined modality therapy.

METHODS

Phase-2 study of pegaspargase, etoposide and gemcitabine (PEG) combined with involved field radiation therapy (IFRT) in newly-diagnosed patients with early-stage ENKTL. Patients received 4 course of PEG followed by IFRT. The primary endpoints were complete response (CR), partial response (PR), and objective response rate (ORR) after IFRT. Secondary endpoints included progression-free survival (PFS), overall survival (OS) and adverse events.

RESULTS

34 consecutive patients with Ann Arbor stage I/II were enrolled. 3 patients progressed on PEG, while the remaining 31 received IFRT. The ORR was 88.2% (30/34), included 28 (82.4%) complete and 2 (5.8%) partial responses. With a median follow-up of 56.0 months (Interquartile Range [IQR], 36.0-66.9 months), the estimated 5-year PFS and OS were 87.4% (95% Confidence Interval [CI],69.5%-94.8%) and 97.1% (95%CI, 80.1%-99.6%), respectively. Most adverse events were hematological and easily managed.

CONCLUSIONS

PEG followed by IFRT is a safe and effective initial therapy for early-stage ENKTL, demonstrating impressive PFS and OS rates. This promising approach warrants further validation in a randomized controlled trial (Registered at Clinicaltrials.gov NCT02705508).Trial registration: ClinicalTrials.gov identifier: NCT02705508.

Modeling NK-cell lymphoma in mice reveals its cell-of-origin and microenvironmental changes and identifies therapeutic targets

Extranodal NK/T-cell lymphoma (ENKTCL) is an Epstein-Barr virus (EBV)-related neoplasm preferentially involving the upper aerodigestive tract. Here we show that NK-cell-specific Trp53 disruption in mice leads to the development of NK-cell lymphomas after long latency, which involve not only the hematopoietic system but also the salivary glands. Before tumor onset, Trp53 knockout causes extensive gene expression changes, resulting in immature NK-cell expansion, exclusively in the salivary glands. Both human and murine NK-cell lymphomas express tissue-resident markers, suggesting tissue-resident NK cells as their cell-of-origin. Murine NK-cell lymphomas show recurrent Myc amplifications and upregulation of MYC target gene signatures. EBV-encoded latent membrane protein 1 expression accelerates NK-cell lymphomagenesis and causes diverse microenvironmental changes, particularly myeloid propagation, through interferon-γ signaling. In turn, myeloid cells support tumor cells via CXCL16-CXCR6 signaling and its inhibition is effective against NK-cell tumors in vivo. Remarkably, KLRG1-expressing cells expand in the tumor and are capable of repopulating tumors in secondary recipients. Furthermore, targeting KLRG1 alone or combined with MYC inhibition using an eIF4 inhibitor is effective against NK-cell tumors. Therefore, our observations provide insights into the pathogenesis and highlight potential therapeutic targets, including CXCL16, KLRG1, and MYC, in ENKTCL, which can help improve its diagnostic and therapeutic strategies.

Antibody-Based Therapies for Peripheral T-Cell Lymphoma

While antibody-based immunotherapeutic strategies have revolutionized the treatment of B-cell lymphomas, progress in T-cell lymphomas has suffered from suboptimal targets, disease heterogeneity, and limited effective treatment options. Nonetheless, recent advances in our understanding of T-cell biology, the identification of novel targets, and the emergence of new therapies provide hope for the future. In this review, we explore four areas of current and evolving antibody-based strategies for the treatment of peripheral T-cell lymphoma (PTCL): monoclonal antibodies (mAbs), bispecific antibodies (BsAs), chimeric antigen receptor T-cell therapy (CAR-T), and antibody-drug conjugates (ADCs). As part of this discussion, we will also include limitations, lessons learned, and potential future directions.

Resistance mechanisms and potential therapeutic strategies in relapsed or refractory natural killer/T cell lymphoma

ABSTRACT

Natural killer/T cell lymphoma (NKTCL) is a malignant tumor originating from NK or T cells, characterized by its highly aggressive and heterogeneous nature. NKTCL is predominantly associated with Epstein-Barr virus infection, disproportionately affecting Asian and Latin American populations. Owing to the application of asparaginase and immunotherapy, clinical outcomes have improved significantly. However, for patients in whom first-line treatment fails, the prognosis is exceedingly poor. Overexpression of multidrug resistance genes, abnormal signaling pathways, epigenetic modifications and active Epstein-Barr virus infection may be responsible for resistance. This review summarized the mechanisms of resistance for NKTCL and proposed potential therapeutic approaches.

Primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting

Posttransplantation primary cutaneous T-cell lymphomas (PT-CTCL) are a rare complication of sustained immunosuppression in the posttransplant setting. When present, PT-CTCLs are typically EBV- and exhibit features of mycosis fungoides/Sézary syndrome or CD30+ lymphoproliferative disorders. We present a case of a 75-year-old individual who developed skin lesions 30 years after liver transplantation. Pathologic evaluation of the skin biopsy revealed involvement by a clonal, EBV+ T-cell population of gamma/delta lineage with no evidence of systemic disease. Comprehensive genomic profiling was performed, confirming focal one-copy loss of 6q23.3, altogether consistent with the extremely rare and unusual diagnosis of primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting.

Optimization of immune checkpoint inhibitor treatment planning for relapsed or refractory extranodal NK/T cell lymphoma

Pembrolizumab (anti-programmed cell death-ligand 1 inhibitor) is a promising salvage therapeutic option for relapsed/refractory extranodal NK/T-cell lymphoma (R/R ENKTL). However, the appropriate duration of pembrolizumab use in R/R ENKTL patients and the optimal timing for administering pembrolizumab remain undetermined. We collected and analyzed clinical information on R/R ENKTL 58 patients who received pembrolizumab to evaluate the optimal treatment durations and clinical information for considering treatment interruption. Treatment outcomes were assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and Epstein Barr virus DNA (EBV DNA) every 3 months. Nineteen (32.8%) patients had been treated with more than three chemotherapies before pembrolizumab administration. The best response rate towards the first try of pembrolizumab was 38.9% (31.5% complete response rate (CR), 7.4% partial response (PR)). During the 41.8-month median follow-up duration, the median progression-free survival (PFS) was 3.1 months, and the median overall survival (OS) was 7.1 months. The failure group, which was characterized by Deaville score (DS) 3-4 and circulating EBV detection, or DS 5 with/without EBV detection, had the worst PFS (p < 0.001) and OS (p < 0.001), followed by the high (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected) and low-risk groups (DS 1-2 and EBV not detected). Among the 21 patients who achieved the best response at the first pembolizumab try, the patients who received planned 24 cycles presented better PFS than those who received incomplete cycles (57.6 months vs 20.9 months, P-value = 0.012). Among 13 patients who received avelumab or pembrolizumab in advance, a few who responded to the second trial of pembrolizumab administration had over one year of chemotherapy vacation. Determining the discontinuation or continuation of pembrolizumab would be considered in selected cases assessed by PET-CT and EBV monitoring. Disruption of pembrolizumab treatment may be advisable for the low-risk group(DS 1-2 and EBV not detected), whereas continuation could be warranted for the high-risk group (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected). Moreover, it might be critical to maintain over 24 cycles to improve the survival outcome of R/R ENKTL.

Clinicopathological characteristics, prognostic factors, and outcomes of elderly patients with lymphoma-associated hemophagocytic lymphohistiocytosis: A multicenter analysis

BACKGROUND

Lymphoma is the most common secondary cause of hemophagocytic lymphohistiocytosis (HLH) in adults. Lymphoma-associated HLH (LA-HLH) in the elderly population is not rare, however, little has been reported regarding clinicopathological characteristics, prognostic factors, and outcomes of LA-HLH in the elderly population.

METHODS

We retrospectively analyzed a multicenter cohort of elderly patients with LA-HLH. Clinicopathological features and treatment information were collected. The impacts of baseline characteristics and treatments on survival outcomes were analyzed.

RESULTS

A total of 173 elderly patients with LA-HLH were included. Compared with young patients, elderly patients showed different clinical and laboratory features. Regarding lymphoma subtypes, B-cell lymphoma was more common in elderly patients (elderly 61.3% vs. young 32.3%, p < 0.001) while T/NK-cell lymphoma was more common in young patients (65.3% vs. 35.3%, p < 0.001). The median survival of elderly patients with LA-HLH was only 92 days. The prior use of HLH therapy or etoposide-containing HLH therapy was not associated with improved overall survival. T/NK-cell subtype, a lower platelet count (≤53 × 109/L), a lower albumin level (≤32.1 g/L), a higher LDH level (>1407 U/L), and a higher creatinine level (>96.8 μmol/L) were independent predictors of decreased overall survival and 60-day survival. A prognostic index was established and demonstrated to be robust in predicting the overall survival and 60-day survival of elderly patients with LA-HLH.

CONCLUSIONS

LA-HLH in elderly patients displayed heterogeneous clinicopathological features and survival outcomes. Treatments need to be optimized to improve the outcomes of elderly patients with LA-HLH.

Fifth Edition of the World Health Organization Classification of Tumors of the Hematopoietic and Lymphoid Tissues: Mature T-Cell, NK-Cell, and Stroma-Derived Neoplasms of Lymphoid Tissues

This review focuses on mature T cells, natural killer (NK) cells, and stroma-derived neoplasms in the fifth edition of the World Health Organization classification of hematolymphoid tumors, including changes from the revised fourth edition. Overall, information has expanded, primarily due to advancements in genomic understanding. The updated classification adopts a hierarchical format. The updated classification relies on a multidisciplinary approach, incorporating insights from a diverse group of pathologists, clinicians, and geneticists. Indolent NK-cell lymphoproliferative disorder of the gastrointestinal tract, Epstein-Barr virus-positive nodal T- and NK-cell lymphoma, and several stroma-derived neoplasms of lymphoid tissues have been newly introduced or included. The review also provides guidance on how the fifth edition of the World Health Organization classification of hematolymphoid tumors can be applied in routine clinical practice.

Increased coexpression of PD-L1 and IDO1 is associated with poor overall survival in patients with NK/T-cell lymphoma

Immunotherapy with programmed cell death 1 ligand 1 (PD-L1) blockade was effective in patients with NK/T-cell lymphoma. In addition to PD-L1, indoleamine 2,3-dioxygenase-1 (IDO1) is one of the most promising immunotherapeutic targets. High proportions of PD-L1 and IDO1 proteins were observed by immunohistochemistry (IHC) from 230 newly diagnosed patients with NK/T lymphoma with tissue samples from three cancer centers and were associated with poor overall survival (OS) in patients with NK/T lymphoma. Importantly, the coexpression of PD-L1 and IDO1 was related to poor OS and short restricted mean survival time in patients with NK/T lymphoma and was an independent prognostic factor in the training cohorts, and which was also validated in 58 NK/T lymphoma patients (GSE90597). Moreover, a nomogram model constructed with PD-L1 and IDO1 expression together with age could provide concise and precise predictions of OS rates and median survival time. The high-risk group in the nomogram model had a positive correlation with CD4 + T-cell infiltration in the validation cohort, as did the immunosuppressive factor level. Therefore, high PD-L1 and IDO1 expression was associated with poor OS in patients with NK/T lymphoma. PD-L1 and IDO1 might be potential targets for future immune checkpoint blockade (ICB) therapy for NK/T lymphoma.

Efficacy and safety analysis of combination therapy based on mitoxantrone hydrochloride liposome injection (Lipo-MIT) in relapsed/refractory NK/T-cell lymphoma

Background

Currently, there is no standard treatment for relapsed/refractory NK/T-cell lymphoma (NKTCL). Liposomal mitoxantrone (Lipo-MIT) showed good anti-tumor effect in patients with NKTCL, breaking the limitation of natural resistance of NKTCL to anthracyclines. To further improve the efficacy, we tried a combination therapy based on Lipo-MIT in patients with relapsed/refractory NKTCL.

Methods

12 patients with relapsed/refractory NKTCL were enrolled in this retrospective study, all of whom had previously received pegaspargase-based treatments. The salvage treatment was a combination regimen based on Lipo-MIT. The efficacy was evaluated after every two cycles.

Results

11 patients had stage IV NKTCL, and all but one patients had an NRI score of ≥3. The median previous lines of treatment was two (range, 1-4), and five patients were refractory to their last line of treatment. The best response rates were as follows: complete response (CR) in five (41.7%) patients, partial response in five (41.7%) patients, stable disease in one (8.3%) patient, and progressive disease in one (8.3%) patient. At a median follow-up of four months (range, 2-14), seven patients died, with a median PFS of five months and a median OS of seven months. The six-month PFS and OS rate was 44.4% and 52.1%, respectively. All patients had suffered from side effects, among which myelosuppression was most reported. Nine patients had grade three or more myelosuppression, and the median recovery time from myelosuppression was 14 days (2-35 days). Five patients had obvious skin hyperpigmentation, and the CR rate was significantly higher compared with those without skin hyperpigmentation (80% vs. 14.3%, p=0.023). Other side effects included liver insufficiency (N=4), coagulation dysfunction (N=4), acute pancreatitis (N=2), and immunotherapy-related adverse effects (irAEs, N=2).

Conclusion

Combination therapy based on Lipo-MIT has a high remission rate for relapsed/refractory NKTCL, but the duration of remission needs to be further extended. Lipo-MIT has obvious myelosuppression toxicity, and active supportive therapy should be given when combined with other cytotoxic drugs.

EBV-Positive Nodal T- and NK-Cell Lymphoma Mimicking Anaplastic Large Cell Lymphoma: A Case Report

EBV-positive nodal T- and NK-cell lymphoma (EBV+ NT/NKCL) is a recently recognized entity in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues. Notably, CD30 positivity is frequently observed in (EBV+ NT/NKCL), creating diagnostic challenges to distinguish it from ALK-negative anaplastic large cell lymphoma (ALCL). Furthermore, cases of EBV+ ALCL have been documented in the literature, predating the inclusion of EBV+ nodal cytotoxic T-cell lymphoma as a variant of peripheral T-cell lymphoma. We present a case of a 47-year-old male presenting with multiple lymphadenopathies. The histomorphologic and immunophenotypic features of the lymph node closely resemble ALK-negative ALCL, characterized by uniform CD30 expression and a subcapsular distribution of lymphoma cells. However, the lymphoma cells exhibit diffuse positivity for EBV, consistent with EBV+ NT/NKCL. A case of ALK-negative ALCL with an immunophenotype identical to the EBV-positive case is included for comparison. Given that EBV+ NT/NKCL represents an aggressive neoplasm requiring unique clinical management compared to ALK-negative ALCL, it is critical to accurately differentiate EBV+ NT/NKCL from ALK-negative ALCL with a cytotoxic T-cell immunophenotype.

Sintilimab (anti-PD-1 antibody) plus chidamide (histone deacetylase inhibitor) in relapsed or refractory extranodal natural killer T-cell lymphoma (SCENT): a phase Ib/II study

Anti-PD-1 antibodies are a favorable treatment for relapsed or refractory extranodal natural killer T cell lymphoma (RR-ENKTL), however, the complete response (CR) rate and the duration of response (DOR) need to be improved. This phase 1b/2 study investigated the safety and efficacy of sintilimab, a fully human anti-PD-1 antibody, plus chidamide, an oral subtype-selective histone deacetylase inhibitor in 38 patients with RR-ENKTL. Expected objective response rate (ORR) of combination treatment was 80%. Patients received escalating doses of chidamide, administered concomitantly with fixed-dose sintilimab in 21-days cycles up to 12 months. No dose-limiting events were observed, RP2D of chidamide was 30 mg twice a week. Twenty-nine patients were enrolled in phase 2. In the intention-to-treat population (n = 37), overall response rate was 59.5% with a complete remission rate of 48.6%. The median DOR, progression-free survival (PFS), and overall survival (OS) were 25.3, 23.2, and 32.9 months, respectively. The most common grade 3 or higher treatment-emergent adverse events (AEs) were neutropenia (28.9%) and thrombocytopenia (10.5%), immune-related AEs were reported in 18 (47.3%) patients. Exploratory biomarker assessment suggested that a combination of dynamic plasma ctDNA and EBV-DNA played a vital prognostic role. STAT3 mutation shows an unfavorable prognosis. Although outcome of anticipate ORR was not achieved, sintilimab plus chidamide was shown to have a manageable safety profile and yielded encouraging CR rate and DOR in RR-ENKTL for the first time. It is a promising therapeutic option for this population.

First-line sintilimab with pegaspargase, gemcitabine, and oxaliplatin in advanced extranodal natural killer/T cell lymphoma (SPIRIT): a multicentre, single-arm, phase 2 trial

BACKGROUND

Programmed cell death protein 1 (PD-1) inhibitor sintilimab is effective in relapsed and refractory extranodal natural killer/T cell lymphoma (ENKTL), nasal type. We aimed to assess the safety and activity of sintilimab plus P-GEMOX (pegaspargase, gemcitabine, and oxaliplatin) in the first-line setting for advanced ENKTL.

METHODS

The multicentre, single-arm, phase 2 trial was done at three medical centres in China. Patients aged 18-75 years with treatment-naive pathologically confirmed advanced ENKTL and an with Eastern Cooperative Oncology Group performance status score of 0-2 were eligible. Patients received intravenous sintilimab (200 mg on day 1), intramuscular pegaspargase (2000 U/m2 on day 1), intravenous gemcitabine (1 g/m2 on days 1 and 8), and intravenous oxaliplatin (130 mg/m2 on day 1) every 3 weeks for six cycles, followed by intravenous sintilimab (200 mg) every 3 weeks for up to 2 years or until disease progression or unacceptable toxicities. The primary endpoint was the complete response rate in the intention-to-treat population. The secondary endpoints were overall response rate (ORR), progression-free survival (PFS), disease-free survival (DFS), and overall survival. This trial is registered with ClinicalTrials.gov, NCT04127227. Enrolment has been completed, and follow-up is ongoing.

FINDINGS

Between Nov 29, 2019, and Sept 7, 2022, 34 eligible patients were enrolled (median age 39 years [IQR 32-55]; 25 [74%] of 34 patients were male; nine [26%] were female; and all were of Asian ethnicity). At the data cutoff (July 20, 2023), the median follow-up was 21 months (IQR 13-32). The complete response rate was 85% (29 of 34 patients, 95% CI 70-94). Five patients (15%; 95% CI 7-30) attained partial response and the ORR was 100% (34 of 34 patients). 24-month PFS was 64% (95% CI 48-86), 24-month DFS was 72% (54-95), and 36-month overall survival was 76% (52-100). The most common grade 3 or 4 treatment-related adverse events were neutropenia (17 [50%] of 34 patients), anaemia (10 [29%] patients), and hypertriglyceridemia (10 [29%] patients). Hypothyroidism was the most frequent immune-related adverse event (18 [53%]), including grade 3 hypothyroidism in one (3%) patient that caused treatment termination. No severe adverse events occurred. There were three deaths: one due to haemophagocytic syndrome, one due to disease progression, and one due to unknown cause, which were not considered to be treatment related.

INTERPRETATION

Combination of sintilimab with P-GEMOX seems to be an active and safe first-line regimen for patients with advanced ENKTL.

FUNDING

National Key Research and Development Program and National Natural Science Foundation of China, Guangzhou Science and Technology Program and the Clinical Oncology Foundation of Chinese Society of Clinical Oncology.

Counterproductive effects of anti-CD38 and checkpoint inhibitor for the treatment of NK/T cell lymphoma

Introduction

Natural killer/T cell lymphoma (NKTL) is an aggressive malignancy associated with poor prognosis. This is largely due to limited treatment options, especially for relapsed patients. Immunotherapies like immune checkpoint inhibitors (ICI) and anti-CD38 therapies have shown promising but variable clinical efficacies. Combining these therapies has been suggested to enhance efficacy.

Methods

We conducted a case study on a relapsed NKTL patient treated sequentially with anti-CD38 followed by ICI (anti-PD1) using cytometry analyses.

Results and Discussion

Our analysis showed an expected depletion of peripheral CD38+ B cells following anti-CD38 treatment. Further analysis indicated that circulating anti-CD38 retained their function for up to 13 weeks post-administration. Anti-PD1 treatment triggered re-activation and upregulation of CD38 on the T cells. Consequently, these anti-PD1-activated T cells were depleted by residual circulating anti-CD38, rendering the ICI treatment ineffective. Finally, a meta-analysis confirmed this counterproductive effect, showing a reduced efficacy in patients undergoing combination therapy. In conclusion, our findings demonstrate that sequential anti-CD38 followed by anti-PD1 therapy leads to a counterproductive outcome in NKTL patients. This suggests that the treatment sequence is antithetic and warrants re-evaluation for optimizing cancer immunotherapy strategies.

Pembrolizumab for Patients with Relapsed or Refractory Extranodal NK/T-Cell Lymphoma in Korea

PURPOSE

Programmed death-1 blockade with pembrolizumab has shown promising activity in relapsed/refractory (R/R) extranodal natural killer/T-cell lymphoma (NKTCL), but studies are limited, with small patient numbers.

MATERIALS AND METHODS

Thirteen institutes involved with the Consortium for Improving Survival of Lymphoma, a Korean lymphoma study group, collected the clinical data of 59 patients treated with pembrolizumab as salvage therapy between 2016 and 2022.

RESULTS

The median age of the patients was 60 years (range, 22 to 87 years), and 76.3% had advanced Ann Abor stage disease. Pembrolizumab was given to 35.6%, 40.7%, and 23.7% of the patients as second-, third-, and fourth- or higher-line chemotherapy, respectively. The overall response rate was 40.7%, with 28.8% having complete response. The estimated 2-year progression-free survival (PFS) and overall survival rates for all patients were 21.5% and 28.7%, respectively; for responders, the rates were 53.0% and 60.7%, respectively. Although not statistically significant, Eastern Cooperative Oncology Group performance status ≥ 2 (hazard ratio [HR], 1.91; 95% confidence interval [95% CI], 0.93 to 3.94; p=0.078) and stage III or IV disease (HR, 2.59; 95% CI, 0.96 to 6.96; p=0.060) were associated with a trend toward shorter PFS in multivariate analysis. Grade 3 or 4 adverse events (AEs) were noted in 12 patients (20.3%); neutropenia (10.2%), fatigue (6.8%), and pneumonitis (5.1%) were most common AEs.

CONCLUSION

In conclusion, while pembrolizumab had a modest effect on patients with R/R NKTCL, it may be a useful salvage therapy for patients with localized disease and good performance status.

Tislelizumab and radiation therapy in low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type: a phase II study protocol

Low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type has a favorable outcome with radiation therapy alone, and the addition of chemotherapy shows no survival benefit. Nonetheless, a proportion of patients will relapse or progress, with a dismal outcome, highlighting the need for a novel therapeutic strategy. Promising preliminary findings indicate the efficacy of PD-1/PD-L1 inhibitors in extranodal natural killer/T-cell lymphoma, nasal type, with good toxicity profiles. Here we describe the design of a phase II study (CLCG-NKT-2101), which is evaluating the safety and efficacy of adding anti-PD-1 antibody to the current radiation therapy regimen in low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type patients. Tislelizumab will be added in an inductive and concurrent way to radiation therapy. The primary end point will be the complete response rate after induction immunotherapy. Clinical trial registration: ClinicalTrials.gov (NCT05149170).

Immune checkpoint blockade in hematological malignancies: current state and future potential

Malignant cells are known to evade immune surveillance by engaging immune checkpoints which are negative regulators of the immune system. By restoring the T-lymphocyte mediated anti-tumor effect, immune checkpoint inhibitors (ICI) have revolutionized the treatment of solid tumors but have met rather modest success in hematological malignancies. Currently, the only FDA approved indications for ICI therapy are in classic hodgkin lymphoma and primary mediastinal B cell lymphoma. Multiple clinical trials have assessed ICI therapy alone and in combination with standard of care treatments in other lymphomas, plasma cell neoplasms and myeloid neoplasms but were noted to have limited efficacy. These trials mostly focused on PD-1/PDL-1 and CTLA-4 inhibitors. Recently, there has been an effort to target other T-lymphocyte checkpoints like LAG-3, TIM-3, TIGIT along with improving strategies of PD-1/PDL-1 and CTLA-4 inhibition. Drugs targeting the macrophage checkpoint, CD47, are also being tested. Long term safety and efficacy data from these ongoing studies are eagerly awaited. In this comprehensive review, we discuss the mechanism of immune checkpoint inhibitors, the key takeaways from the reported results of completed and ongoing studies of these therapies in the context of hematological malignancies.

Immune Checkpoints and Their Inhibition in T-Cell Lymphomas

T-cell lymphomas (TCLs) are a rare and heterogeneous subgroup of non-Hodgkin lymphomas (NHLs), forming only 10 % of all NHL cases in Western countries. Resulting from their low incidence and heterogeneity, the current treatment outcome is generally unfavorable, with limited availability of novel therapeutic approaches. Therefore, the recent success of immune checkpoint inhibitors (ICIs) in cancer treatment motivated their clinical investigation in TCLs as well. Multiple studies showed promising results; however, cases of TCL hyperprogression following ICI treatment and secondary T-cell-derived malignancies associated with ICI treatment of other cancer types were also reported. In our review, we first briefly summarize classification of T-cell-derived malignancies, general anti-tumor immune response, immune evasion, and immune checkpoint signaling. Next, we provide an overview of immune checkpoint molecule deregulation in TCLs, summarize available studies of ICIs in TCLs, and review the above-mentioned safety concerns associa-ted with ICI treatment and T-cell-derived malignancies. Despite initial promising results, further studies are necessary to define the most suitable clinical applications and ICI therapeutic combinations with other novel treatment approaches within TCL treatment. ICIs, and their combinations, might hopefully bring the long awaited improvement for the treatment of T-cell-derived malignancies.

Use of PD-1 blockade in refractory/relapsed natural killer T-cell lymphomas: a systematic review and synthesis of case reports

Natural killer/T-cell lymphoma (NK/T-cellL) is an aggressive non-Hodgkin's lymphoma with limited treatment options for patients who experience disease progression or recurrence after second-line treatment. The use of new therapies, such as pembrolizumab, which involves immune checkpoint blockade mechanisms, is proposed. This systematic review followed the MOSE guidelines and searched PUBMED/MEDLINE, EMBASE, and Scopus databases. Fourteen articles were found, reporting on the use of pembrolizumab anti PD-1 in NK/T-cellL patients. The objective response rate was 84.50%, with disease-free survival ranging from two to 48 months. The complete response rate was 61.6%, and the quality of the reported studies was evaluated to be of high and moderate confidence bias levels in case reports and high bias in clinical trials. Pembrolizumab and others anti PD-1 are treatment options for refractory/recurrent NK/T-cellL, regardless of PD-L1 expression, with good short- and long-term results and low adverse events.

Biology and genetics of extranodal mature T-cell and NKcell lymphomas and lymphoproliferative disorders

The extranodal mature T-cell and NK-cell lymphomas and lymphoproliferative disorders represent a unique group of rare neoplasms with both overlapping and distinct clinicopathological, biological, and genomic features. Their predilection for specific sites, such as the gastrointestinal tract, aerodigestive tract, liver, spleen, and skin/soft tissues, underlies their classification. Recent genomic advances have furthered our understanding of the biology and pathogenesis of these diseases, which is critical for accurate diagnosis, prognostic assessment, and therapeutic decision-making. Here we review clinical, pathological, genomic, and biological features of the following extranodal mature T-cell and NK-cell lymphomas and lymphoproliferative disorders: primary intestinal T-cell and NK-cell neoplasms, hepatosplenic T-cell lymphoma, extranodal NK/T-cell lymphoma, nasal type, and subcutaneous panniculitis-like T-cell lymphoma.

Few and far between: clinical management of rare extranodal subtypes of mature T-cell and NK-cell lymphomas

While all peripheral T-cell lymphomas are uncommon, certain subtypes are truly rare, with less than a few hundred cases per year in the USA. There are often no dedicated clinical trials in these rare subtypes, and data are generally limited to case reports and retrospective case series. Therefore, clinical management is often based on this limited literature and extrapolation of data from the more common, nodal T-cell lymphomas in conjunction with personal experience. Nevertheless, thanks to tremendous pre-clinical efforts to understand these rare diseases, an increasing appreciation of the biological changes that underlie these entities is forming. In this review, we attempt to summarize the relevant literature regarding the initial management of certain rare subtypes, specifically subcutaneous panniculitis-like T-cell lymphoma, hepatosplenic T-cell lymphoma, intestinal T-cell lymphomas, and extranodal NK/T-cell lymphoma. While unequivocally established approaches in these diseases do not exist, we make cautious efforts to provide our approaches to clinical management when possible.

Single-Cell Analysis Reveals Malignant Cells Reshape the Cellular Landscape and Foster an Immunosuppressive Microenvironment of Extranodal NK/T-Cell Lymphoma

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive type of lymphoma associated with Epstein-Barr virus (EBV) and characterized by heterogeneous tumor behaviors. To better understand the origins of the heterogeneity, this study utilizes single-cell RNA sequencing (scRNA-seq) analysis to profile the tumor microenvironment (TME) of NKTCL at the single-cell level. Together with in vitro and in vivo models, the study identifies a subset of LMP1+ malignant NK cells contributing to the tumorigenesis and development of heterogeneous malignant cells in NKTCL. Furthermore, malignant NK cells interact with various immunocytes via chemokines and their receptors, secrete substantial DPP4 that impairs the chemotaxis of immunocytes and regulates their infiltration. They also exhibit an immunosuppressive effect on T cells, which is further boosted by LMP1. Moreover, high transcription of EBV-encoded genes and low infiltration of tumor-associated macrophages (TAMs) are favorable prognostic indicators for NKTCL in multiple patient cohorts. This study for the first time deciphers the heterogeneous composition of NKTCL TME at single-cell resolution, highlighting the crucial role of malignant NK cells with EBV-encoded LMP1 in reshaping the cellular landscape and fostering an immunosuppressive microenvironment. These findings provide insights into understanding the pathogenic mechanisms of NKTCL and developing novel therapeutic strategies against NKTCL.

Advances and challenges of immunotherapies in NK/T cell lymphomas

Natural killer (NK)/T cell lymphoma (NKTCL) is a rare subtype of Epstein-Barr virus (EBV)-associated non-Hodgkin lymphoma characterized by poor clinical outcomes. It is more common in East Asian and Latin American countries. Despite the introduction of asparaginase/pegaspargase-based chemotherapy, the prognosis of patients with advanced NKTCL needs to be improved, and few salvage treatment options are available for relapsed/refractory patients who fail chemotherapy. Although many unknowns remain, novel treatment strategies to further improve outcomes are urgently needed. Immunotherapy has emerged and shown favorable antitumor activity in NKTCL, including monoclonal antibodies targeting immune checkpoint inhibitors, other receptors on the cellular membrane, and cellular immunotherapy, which could enhance immune cells attack on tumor cells. In this review, we provide an overview of recent immunotherapy in NKTCL, focusing on programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), chimeric antigen receptor (CAR) T cells, EBV-specific cytotoxic T lymphocytes, immunomodulatory agents, and other targeted agents, as well as the current progress and challenges in the field.

Clinical PD-1/PD-L1 Blockades in Combination Therapies for Lymphomas

Immunotherapy with the programmed cell death protein 1 (PD-1)/PD-1 ligand (PD-L1) blockade has revolutionized the treatment of advanced solid cancers. However, these clinical benefits have been limited to cases of malignant lymphomas, showing promising results for only classic Hodgkin lymphoma (cHL) and primary mediastinal B-cell lymphoma (PMBCL). To bring clinical benefits to more patients with lymphoma, numerous combination therapies involving PD-1/PD-L1 blockade have been tested in clinical trials in both frontline and relapsed/refractory settings. This article reviews the current landscape of combination therapies with PD-1/PD-L1 blockade for lymphoma and discusses the potential therapeutic approaches. An interim analysis of a phase 3 study demonstrated increased progression-free survival with nivolumab combination therapy over the current frontline treatment in patients with advanced-stage cHL. The results of combination therapies for aggressive B-cell lymphomas, except for PMBCL, have been disappointing. Several clinical trials of combined PD-1/PD-L1 blockade and Bruton's tyrosine kinase inhibitors are exploring its efficacy in patients with chronic lymphocytic leukemia (CLL) with Richter transformation. Several T-cell lymphoma subtypes respond to PD-1/PD-L1 blockade monotherapy. Further clinical trials are underway to investigate appropriate combination regimens with PD-1/PD-L1 blockade, especially for cHL, CLL with Richter transformation, and T-cell lymphoma, in both frontline and relapsed/refractory settings.

Checkpoint inhibition in hematologic malignancies

Checkpoint inhibitor therapy has emerged as an effective therapeutic strategy for many types of malignancies, especially in solid tumors. Within the last two decades, numerous monoclonal antibody drugs targeting the CTLA-4 and PD-1/PD-L1 checkpoint pathways have seen FDA approval. Within hematologic malignancies, Hodgkin Lymphoma has seen the greatest clinical benefits thus far with more recent data showing efficacy in the front-line setting. As our understanding of checkpoint inhibition expands, using these pathways as a therapeutic target has shown some utility in the treatment of other hematologic malignancies as well, primarily in the relapsed/refractory settings. Checkpoint inhibition also appears to have a role as a synergistic agent to augment clinical responses to other forms of therapy such as hematopoietic stem cell transplant. Moreover, alternative checkpoint molecules that bypass the well-studied CTLA-4 and PD-1/PD-L1 pathways have emerged as exciting new therapeutic targets. Most excitingly is the use of anti-CD47 blockade in the treatment of high risk MDS and TP-53 mutated AML. Overall, there has been tremendous progress in understanding the benefits of checkpoint inhibition in hematologic malignancies, but further studies are needed in all areas to best utilize these agents. This is a review of the most recent developments and progress in Immune Checkpoint Inhibition in Hematologic Malignancies in the last decade.

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus (HBV) reactivation can be serious and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving chemotherapy, especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation. Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver. The expression of these silent genomes is controlled by the immune system. Suppression or ablation of immune cells, most importantly B cells, may lead to reactivation of seemingly resolved HBV infection. Thus, all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen. Patients found to be positive for HBsAg should be given prophylactic antiviral therapy. For patients with resolved HBV infection, there are two approaches. The first is pre-emptive therapy guided by serial HBV DNA monitoring, and treatment with antiviral therapy as soon as HBV DNA becomes detectable. The second approach is prophylactic antiviral therapy, particularly for patients receiving high-risk therapy, especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation. Entecavir and tenofovir are the preferred antiviral choices. Many new effective therapies for hematological malignancies have been introduced in the past decade, for example, chimeric antigen receptor (CAR)-T cell therapy, novel monoclonal antibodies, bispecific antibody drug conjugates, and small molecule inhibitors, which may be associated with HBV reactivation. Although there is limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBsAg-positive patients receiving novel treatments, including Bruton's tyrosine kinase inhibitors, B-cell lymphoma 2 inhibitors, and CAR-T cell therapy. Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

Targeting Bcl-xL is a potential therapeutic strategy for extranodal NK/T cell lymphoma

Extranodal natural killer/T cell lymphoma, nasal type (ENKTL) is an aggressive lymphoid malignancy with a poor prognosis and lacks standard treatment. Targeted therapies are urgently needed. Here we systematically investigated the druggable mechanisms through chemogenomic screening and identified that Bcl-xL-specific BH3 mimetics effectively induced ENKTL cell apoptosis. Notably, the specific accumulation of Bcl-xL, but not other Bcl-2 family members, was verified in ENKTL cell lines and patient tissues. Furthermore, Bcl-xL high expression was shown to be closely associated with worse patient survival. The critical role of Bcl-xL in ENKTL cell survival was demonstrated utilizing selective inhibitors, genetic silencing, and a specific degrader. Additionally, the IL2-JAK1/3-STAT5 signaling was implicated in Bcl-xL dysregulation. In vivo, Bcl-xL inhibition reduced tumor burden, increased apoptosis, and prolonged survival in ENKTL cell line xenograft and patient-derived xenograft models. Our study indicates Bcl-xL as a promising therapeutic target for ENKTL, warranting monitoring in ongoing clinical trials by targeting Bcl-xL.

First-line immunotherapy with anti-PD-1 antibody for extranodal NK/T-cell lymphoma: A retrospective study

Anti-PD-1 antibody has shown certain effects in patients with newly diagnosed extranodal NK/T-cell lymphoma (ENKTL). Here, we evaluated the clinical efficacy and safety of first-line anti-PD-1 antibody for the treatment of patients with ENKTL and explored biomarkers for treatment response. The clinical data of 107 patients with newly diagnosed ENKTL were retrospectively analysed. Patients received either first-line anti-PD-1 antibody induction treatment or anti-PD-1 antibody combined with asparaginase-based chemotherapy (immunochemotherapy). We found that immunochemotherapy was an independent prognostic factor for longer PFS (p < 0.001). The overall response rate and complete remission rate of immunochemotherapy group was higher than immunotherapy induction group (86.11% vs. 62.86% and 72.22% vs. 52.29%, respectively, p = 0.013). We also observed pretreatment CD4/CD8 ratio >0.83 was significant associated with better response and longer PFS in ENKTL patients received first-line anti-PD1-antibody. Plasma copy number of EBV decreased more significantly in patients with CD4/CD8 ratio >0.83 after treatment. PD-L1 expression was associated with better response and PFS, while elevated plasma IL-6, IL-10 and IFN-γ were associated with poor prognosis. Anti-PD-1 antibody treatment showed promising results in newly diagnosed ENKTL patients. The assessment of pretreatment CD4/CD8 ratio in ENKTL seems feasible for identifying responders to anti-PD-1 antibody treatment.

Extranodal NK-/T-cell lymphoma, nasal type: what advances have been made in the last decade?

Extranodal NK-/T-cell lymphoma (ENKTCL) is a rare and highly aggressive malignancy with significant racial and geographic variations worldwide. In addition to the formerly "nasal-type" initial description, these lymphomas are predominantly extranodal in origin and typically cause vascular damage and tissue destruction, and although not fully understood, Epstein-Barr virus (EBV) has an important role in its pathogenesis. Initial assessment must include a hematopathology review of representative and viable tumor areas without necrosis for adequate immunohistochemistry studies, including EBV-encoded small RNA (EBER) in situ hybridization (ISH). Positron emission tomography with 18-fluorodeoxyglucose (¹⁸F-FDG-PET/CT) for accurate staging is essential, and most patients will have localized disease (IE/IIE) at diagnosis. Apart from other T-cell malignancies, the best treatment even for localized cases is combined modality therapy (chemotherapy plus radiotherapy) with non-anthracycline-based regimens. For advanced-stage disease, l-asparaginase-containing regimens have shown improved survival, but relapsed and refractory cases have very poor outcomes. Nowadays, even with a better understanding of pathogenic pathways, up-front therapy is completely based on chemotherapy and radiotherapy, and treatment-related mortality is not low. Future strategies targeting signaling pathways and immunotherapy are evolving, but we need to better identify those patients with dismal outcomes in a pre-emptive way. Given the rarity of the disease, international collaborations are urgently needed, and clinical trials are the way to change the future.

Efficacy of Immune Checkpoint Blockade and Biomarkers of Response in Lymphoma: A Narrative Review

Immune checkpoint blockade (ICB) has revolutionized the prognosis of several advanced-stage solid tumors. However, its success has been far more limited in hematological malignancies and is mostly restricted to classical Hodgkin lymphoma (cHL) and primary mediastinal B cell lymphoma (PMBCL). In patients with non-Hodgkin lymphoma (NHL), response to PD-1/PD-L1 ICB monotherapy has been relatively limited, although some subtypes are more sensitive than others. Numerous predictive biomarkers have been investigated in solid malignancies, such as PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability (MSI), among others. This review aims to appraise the current knowledge on PD-1/PD-L1 ICB efficacy in lymphoma when used either as monotherapy or combined with other agents, and describes potential biomarkers of response in this specific setting.

Efficacy and safety of programmed cell death receptor 1 inhibition-based regimens in patients with pediatric malignancies: the real-world study in China

Background

Programmed death receptor 1 (PD-1) inhibition has shown durable response and mild adverse events (AEs) in adult malignancies. However, data on the clinical activity of PD-1 inhibition in pediatric patients are lacking. We comprehensively assessed the efficacy and safety of PD-1 inhibitor-based regimens for pediatric malignancies.

Methods

We conducted a real-world, multi-institutional, retrospective analysis of pediatric malignancies treated with PD-1 inhibitor-based regimens. The primary endpoints were objective response rate (ORR) and progression-free survival (PFS). The secondary endpoints included disease control rate (DCR), duration of response (DOR), and AEs. The Kaplan-Meier method was used to calculate PFS and DOR. The National Cancer Institute Common Toxicity Criteria for AEs (version 5.0) were used to grade toxicity.

Results

A total of 93 and 109 patients were evaluated for efficacy and safety, respectively. For all efficacy-evaluable patients, PD-1 inhibitor monotherapy, combined chemotherapy, combined histone deacetylase inhibitor, and combined vascular endothelial growth factor receptor tyrosine kinase inhibitor cohorts, the ORR and DCR were 53.76%/81.72%, 56.67%/83.33%, 54.00%/80.00%, 100.00%/100.00%, and 12.50%/75.00%, respectively; the median PFS and DOR were 17.6/31.2 months, not achieved/not achieved, 14.9/31.2 months, 17.6/14.9 months, and 3.7/1.8 months, respectively; the incidence rate of AEs were 83.49%, 55.26%, 100.00%, 80.00%, and 100.00%, respectively. One patient in the PD-1 inhibitor-combined chemotherapy cohort discontinued treatment due to diabetic ketoacidosis.

Conclusions

This largest retrospective analysis demonstrate that PD-1 inhibitor-based regimens are potentially effective and tolerable in pediatric malignancies. Our findings provide references for future clinical trials and practice of PD-1 inhibitors in pediatric cancer patients.

Sugemalimab Monotherapy for Patients With Relapsed or Refractory Extranodal Natural Killer/T-Cell Lymphoma (GEMSTONE-201): Results From a Single-Arm, Multicenter, Phase II Study

PURPOSE

Relapsed or refractory extranodal natural killer/T-cell lymphoma (R/R ENKTL) is a rare and aggressive type of non-Hodgkin lymphoma with limited treatment options. This phase II study evaluated the efficacy and safety of sugemalimab, an anti-PD-L1 monoclonal antibody, in R/R ENKTL.

METHODS

Eligible patients received sugemalimab 1,200 mg intravenously once every 3 weeks for up to 24 months or until progression, death, or study withdrawal. The primary end point was objective response rate (ORR) assessed by an independent radiologic review committee. Key secondary end points included ORR assessed by the investigators, complete response rate, duration of response, and safety.

RESULTS

At the data cutoff (February 23, 2022), 80 patients were enrolled and followed for a median of 18.7 months. At baseline, 54 (67.5%) had stage IV disease and 39 (48.8%) had received ≥2 lines of prior systemic therapy. Independent radiologic review committee-assessed ORR was 44.9% (95% CI, 33.6 to 56.6); 28 (35.9%) patients achieved a complete response and seven (9.0%) achieved a partial response, with a 12-month duration of response rate of 82.5% (95% CI, 62.0 to 92.6). Investigator-assessed ORR was 45.6% (95% CI, 34.3 to 57.2), and 24 (30.4%) patients achieved a complete response. Most treatment-emergent adverse events were grade 1-2 in severity, and grade ≥ 3 events were reported in 32 (40.0%) patients.

CONCLUSION

Sugemalimab showed robust and durable antitumor activity in R/R ENKTL. Treatment was well tolerated with expected safety profile for this drug class.

Education and Empowering Special Forces to Eradicate Secret Defectors: Immune System-Based Treatment Approaches for Mature T- and NK-Cell Malignancies

Mature T- and NK-cell leukemia/lymphoma (MTCL/L) constitute a heterogeneous group of, currently, 30 distinct neoplastic entities that are overall rare, and all present with a challenging molecular markup. Thus, so far, the use of first-line cancer treatment modalities, including chemotherapies, achieve only limited clinical responses associated with discouraging prognoses. Recently, cancer immunotherapy has evolved rapidly, allowing us to help patients with, e.g., solid tumors and also relapsed/refractory B-cell malignancies to achieve durable clinical responses. In this review, we systematically unveiled the distinct immunotherapeutic approaches available, emphasizing the special impediments faced when trying to employ immune system defense mechanisms to target 'one of their own-gone mad'. We summarized the preclinical and clinical efforts made to employ the various platforms of cancer immunotherapies including antibody-drug conjugates, monoclonal as well as bispecific antibodies, immune-checkpoint blockades, and CAR T cell therapies. We emphasized the challenges to, but also the goals of, what needs to be done to achieve similar successes as seen for B-cell entities.

Antitumor activity and safety of camrelizumab combined with apatinib in patients with relapsed or refractory peripheral T-cell lymphoma: An open-label, multicenter, phase II study

Introduction

The treatment for relapsed/refractory peripheral T-cell lymphoma (r/r PTCL) is suboptimal. This open-label, multicenter, single-arm study aimed to investigate the antitumor activity and safety of camrelizumab (a PD-1 blockade) plus apatinib (an antiangiogenic agent) for patients with r/r PTCL.

Methods

Eligible patients with r/r PTCL were enrolled and received camrelizumab 200 mg intravenously every 2 weeks and apatinib 500 or 250 mg orally once daily, 4 weeks as a cycle. The primary endpoint was overall response rate (ORR).

Results

A total of 20 patients were enrolled and received study medications in the study, with a median number of prior treatment line of 3 (range 1-6). At the cutoff date of March 4, 2022, the median follow-up was 27.2 months (range: 0.5-39.9), and three patients remained on treatment. Six patients had early discontinuation without tumor response evaluation. For all patients, the ORR was 30% (6/20) (95% confidence interval [CI], 11.9% to 54.3%), with two patients (10%) achieving complete response. The median progression-free survival (PFS) and median overall survival for all patients were 5.6 months (95% CI, 1.8 to not reached) and 16.7 months (95% CI, 2.8 to not reached), respectively. Patients with PD-L1 expression ≥50% (3 patients) had a numerically higher ORR and longer median PFS than those with PD-L1 expression &lt; 50% (5 patients). The most commonly reported grade 3 or higher adverse events were hyperlipidemia (15%), hypokalemia (15%) and anemia (15%). No treatment-related deaths occurred.

Discussion

In this study, PD-1 inhibitors plus low-dose antiangiogenic drugs presented preliminary antitumor activity and manageable toxicity in patients with r/r PTCL.

Outcomes of programmed death protein-1 inhibitors treatment of chronic active Epstein Barr virus infection: A single center retrospective analysis

Introduction

Chronic active Epstein-Barr virus (CAEBV) disease is a high-mortality disease, which is characterized by persistent infectious mononucleosis-like symptoms. There is no standard treatment for CAEBV and allogeneic hematopoietic stem cell transplantation (HSCT) was considered the only potentially therapeutic approach. PD-1 inhibitors have achieved high response in many Epstein-Barr virus-related diseases. In this single-center retrospective analysis, we report the outcomes of PD-1 inhibitors treatment of CAEBV.

Methods

All CAEBV patients without hemophagocytic lymphohistiocytosis (HLH), who were treated with PD-1 inhibitors in our center between 6/1/2017 and 12/31/2021, were retrospectively analyzed. The efficacy and safety of the PD-1 inhibitors were evaluated.

Results

Among the sixteen patients with a median age at onset of 33 years (range, 11-67 years), twelve patients responded to PD-1 inhibitors and the median progression-free survival (PFS) was 11.1 months (range, 4.9-54.8 months). Three achieved clinical complete response (clinical CR), as well as molecular CR. Five patients achieved and remained partial response (PR), and four converted from PR to no response (NR). For three CR patients, the median time and cycles from the first application of PD-1 inhibitor to clinical CR were 6 weeks (range, 4-10 weeks) and 3 cycles (range, 2-4 cycles), and molecular CR was achieved after a median of 16.7 weeks (range, 6.1-18.4 weeks) and 5 cycles (range, 3-6 cycles) of PD-1 inhibitor infusion. No immune-related adverse events have been observed except for one patient who suffered immune-related pancreatitis. There was no correlation of treatment outcome with blood count, liver function, LDH, cytokine or ferritin levels. NK cell function, PD-L1 expression in tumor tissue and gene mutation possibly correlated with treatment response.

Discussion

In patients with CAEBV, PD-1 inhibitors have tolerable toxicity and comparable outcomes while improving quality of life and financial toxicity. Larger prospective studies and longer follow-up time is needed to be conducted.

Rational Targets of Therapy in Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma (ENKTL) is an aggressive extranodal non-Hodgkin lymphoma (NHL) with poor outcomes, particularly in advanced-stage and relapsed/refractory disease. Emerging research on molecular drivers of ENKTL lymphomagenesis by next-generation and whole genome sequencing has revealed diverse genomic mutations in multiple signaling pathways, with the identification of multiple putative targets for novel therapeutic agents. In this review, we summarize the biological underpinnings of newly-understood therapeutic targets in ENKTL with a focus on translational implications, including epigenetic and histone regulatory aberrations, activation of cell proliferation signaling pathways, suppression of apoptosis and tumor suppressor genes, changes in the tumor microenvironment, and EBV-mediated oncogenesis. In addition, we highlight prognostic and predictive biomarkers which may enable a personalized medicine approach toward ENKTL therapy.

A systematic review and meta-analysis of immune checkpoint therapy in relapsed or refractory non-Hodgkin lymphoma; a friend or foe?

Over the last decades, a revolution has occurred in oncology with the development of immune checkpoint inhibitors (ICIs). Following tremendous successes in solid tumors, interest has risen to explore these inhibitors in hematologic malignancies; while Hodgkin's lymphoma (HL) has shown overwhelming achievements, available data on different types of non-Hodgkin's lymphoma (NHL) vary considerably. To the best of our knowledge, no meta-analysis has assessed the efficacy and safety of ICI therapy in relapsed or refractory NHL patients. Meta-analysis of the included studies (n = 29) indicated PD-1 may probably be the more attractive ICI target rather than PD-L1 and CTLA-4 in NHL patients. Also, there is a plausible correlation between NHL subtypes and response to ICI therapy. While MF, ENKTL, RT, and PMBCL showed promising responses to ICI monotherapy, neither FL nor DLBCL had satisfactory responses; further necessitating novel strategies such as the application of ICIs in combination with other treatment strategies. Notably, among different combinations, BTK inhibitors showed an obvious improvement as compared to ICI monotherapy in both FL and DLBCL, however, the best results were obtained when ICI was combined with anti-CD20 monoclonal antibodies. Finally, while most NHL patients who received ICI treatment have experienced mild AEs, larger trials with long-term follow-up are required to confirm the safety, as well as the efficacy, of ICI therapy in NHL patients.

Emerging predictive biomarkers for novel therapeutics in peripheral T-cell and natural killer/T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are rare subtypes of non-Hodgkin's lymphoma that are typically associated with poor treatment outcomes. Contemporary first-line treatment strategies generally involve the use of combination chemoimmunotherapy, radiation and/or stem cell transplant. Salvage options incorporate a number of novel agents including epigenetic therapies (e.g. HDAC inhibitors, DNMT inhibitors) as well as immune checkpoint inhibitors. However, validated biomarkers to select patients for individualized precision therapy are presently lacking, resulting in high treatment failure rates, unnecessary exposure to drug toxicities, and missed treatment opportunities. Recent advances in research on the tumor and microenvironmental factors of PTCL and NKTCL, including alterations in specific molecular features and immune signatures, have improved our understanding of these diseases, though several issues continue to impede progress in clinical translation. In this Review, we summarize the progress and development of the current predictive biomarker landscape, highlight potential knowledge gaps, and discuss the implications on novel therapeutics development in PTCL and NKTCL.

Mature T-cell and NK-cell lymphomas: updates on molecular genetic features

Mature T-cell and NK-cell lymphomas are a heterogeneous group of rare and typically aggressive neoplasms. Diagnosis and subclassification have historically relied primarily on the integration of clinical, histologic, and immunophenotypic features, which often overlap. The widespread application of a variety of genomic techniques in recent years has provided extensive insight into the pathobiology of these diseases, allowing for more precise diagnostic classification, improved prognostication, and development of novel therapies. In this review, we summarize the genomic features of the most common types of mature T-cell and NK-cell lymphomas with a particular focus on the contribution of genomics to biologic insight, classification, risk stratification, and select therapies in the context of the recently published International Consensus and updated World Health Organization classification systems.

Reactivation of natural killer cells with monoclonal antibodies in the microenvironment of malignant neoplasms

Natural killer cells are critical players in the antitumor immune response due to their ability to destroy target cells through cytotoxic activity and other means. However, this response is inhibited in the tumor microenvironment, where a crippling hypoxic environment and several inhibitory molecules bind to NK cells to trigger an anergic state. Inhibitory receptors such as PD-1, NK2GA, KIR, TIGIT, and LAG-3 have been associated with inhibition of NK cells in multiple cancer types. Binding to these receptors leads to loss of cytotoxicity, lower proliferation and metabolic rates, and even apoptosis. While these receptors are important for avoiding auto-immunity, in a pathological setting like malignant neoplasms they are disadvantageous for the individual's immune system to combat cancer cells. The use of monoclonal antibodies to block these receptors contributes to cancer therapy by preventing the inhibition of NK cells. In this review, the impact of NK cell inhibition and activation on cancer therapy was summarized and an overview of the blockade of inhibitory pathways by monoclonal antibodies was provided.

Treatment of extranodal NK/T-cell lymphoma: From past to future

Extranodal NK/T-cell lymphoma (ENKTCL) is the most common subtype of T/NK-cell lymphoma in Asia and Latin America, but very rare in North American and Europe. Patient survival has improved significantly over the past two decades. However, standard treatment has not yet been established, although dozens of prospective trials have been conducted. To help understand how the treatment of ENKTCL has evolved in the past and what trends lie ahead, we have comprehensively reviewed the treatment of this aggressive malignancy, with a particular focus on neglected or unanswered issues, such as the optimal staging method, the best partner of asparaginase (Asp), the individualized administration of Asp, the preferred sequence of CT and RT and so on. Overall, the 5-year overall survival (OS) of patients with Ann Arbor stage I/II disease increased from < 50% in the early 20th century to > 80% in recent years, and the median OS of patients with Ann Arbor stage III/IV disease increased from < 1 year to more than 3 years. The improvement in patient survival is largely attributable to advances in radiation technology and the introduction of Asp and anti-PD-1/PD-L1 immunotherapy into practice. Radiotherapy is essential for patients with early-stage disease, while Asp-based chemotherapy (CT) and PD-1/PD-L1 inhibitors significantly improved the prognosis of patients with advanced-stage disease. ENKTCL management is trending toward simpler regimens, less toxicity, and higher efficacy. Novel drugs, such as manufactured T cells, monoclonal antibodies, and small molecule inhibitors, are being intensively investigated. Based on the fact that ENKTCL is highly resistant to cytotoxic drugs except Asp, and aggressive CT leads to higher toxicity rather than better outcomes, we recommend it is unnecessary to expend additional resources to compare different combinations of Asp with cytotoxic agents. Instead, more efforts should be made to optimize the use of Asp and immunotherapy to maximize efficacy and minimize toxicity, explore ways to overcome resistance to Asp and immunotherapy, identify novel treatment targets, and define subpopulations who may benefit more from specific treatments.

Therapeutic Potential of Targeting Transforming Growth Factor-beta (TGF-β) and Programmed Death-ligand 1 (PD-L1) in Pancreatic Cancer

Pancreatic cancer (PC) is one the most lethal malignancies worldwide affecting around half a million individuals each year. The treatment of PC is relatively difficult due to the difficulty in making an early diagnosis. Transforming growth factor-beta (TGF-β) is a multifunctional factor acting as both a tumor promoter in early cancer stages and a tumor suppressor in advanced disease. Programmed death-ligand 1 (PD-L1) is a ligand of programmed death-1 (PD-1), an immune checkpoint receptor, allowing tumor cells to avoid elimination by immune cells. Recently, targeting the TGF-β signaling and PD-L1 pathways has emerged as a strategy for cancer therapy. In this review, we have summarized the current knowledge regarding these pathways and their contribution to tumor development with a focus on PC. Moreover, we have reviewed the role of TGF-β and PD-L1 blockade in the treatment of various cancer types, including PC, and discussed the clinical trials evaluating TGF-β and PD-L1 antagonists in PC patients.