Radiotherapy vs sequential pegaspargase, gemcitabine, cisplatin and dexamethasone and radiotherapy in newly diagnosed early natural killer/T-cell lymphoma: A randomized, controlled, open-label, multicenter study

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.

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.

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.

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.

EBV-associated NK and T-cell lymphoid neoplasms

PURPOSE OF REVIEW

Epstein-Barr virus (EBV)-associated neoplasms derived from natural killer (NK) or T cells comprise a group of clinically and biologically heterogenous disorders affecting children and adults, which are overall rare but more prevalent in Asia and South America. This review focuses on neoplasms presenting in the adulthood, addressing recent genomic discoveries as well as therapeutic developments in these highly aggressive disorders.

RECENT FINDINGS

Distinct molecular subtypes of extranodal NK/T-cell lymphomas (ENKTCLs) have been described, with differences in cell of origin, EBV pattern, genomic alterations, clinical characteristics, response to asparaginase-based therapies and to more recent approaches targeting molecular aberrations of the lymphoma. For the last two decades, progress in the clinical management of ENKTCL was based on L-asapraginase containing combinations and the incoroperation of radiotherapy. A subset of cases with PDL1-2 structural alterations may be more responsive to treatment with immune checkpoint inhibitors. Primary nodal EBV+ lymphomas derived from T or NK cells have distinctive features separating them from both peripheral T-cell lymphoma not otherwise specified and ENKTCL. Treatment algorithms correspond to those for advanced ENKTCL.

SUMMARY

With better understanding of lymphomagenesis, genomic landscape and immunologic aspects of the diseases, future treatment options will include targeted therapies including immune checkpoint inhibitors and novel antibodies.

18F-FDG PET/CT Plays a Limited Role in Replacing Bone Marrow Biopsy for Newly Diagnosed Advanced-Stage Patients With Extranodal Natural Killer/T-Cell Lymphoma

Purpose

The role of ¹⁸F-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in evaluating bone marrow (BM) involvement (BMI) among patients with extranodal natural killer/T-cell lymphoma (ENKTL) is poorly understood. This study investigated whether PET/CT could replace bone marrow biopsy (BMB) in treatment-naive ENKTL patients.

Methods

Newly diagnosed ENKTL patients (n = 356) who received BMB and PET/CT to evaluate BMI at the time of diagnosis were retrospectively reviewed at West China Hospital between August 2008 and January 2020. The BMI diagnosis was confirmed using BM histology. Clinical characteristics, survival outcomes, and prognostic indicators were summarized and analyzed.

Results

The cohort included 356 cases, of whom 261 were diagnosed with early-stage and 95 with advanced-stage ENKTL by PET/CT before initial treatment. No early-stage patients were identified with BMI by either BMB or PET/CT. Among the advanced-stage patients, 26 were BMB positive, and 12 of 22 patients (54.5%) with positive PET/BM results were also BMB positive. The sensitivity and specificity of PET/CT to detect BMI were 46% and 97%, respectively. The progression-free survival (PFS) and overall survival (OS) of PET/BM-negative patients were markedly longer (p = 0.010 and p = 0.001 for PFS and OS, respectively), which was consistent with the results of the BMB (p = 0.000 for both PFS and OS).

Conclusion

Although ¹⁸F-FDG PET/CT showed the potential to replace BMB in the initial staging of early-stage ENKTL patients, baseline PET/CT cannot provide an accurate BMI evaluation for advanced-stage patients. A prospective study is required to confirm the diagnostic performance of BMI identification by PET/CT, along with targeted BMB and MRI for advanced-stage patients.

Combination of atezolizumab and chidamide to maintain long-term remission in refractory metastatic extranodal natural killer/T-cell lymphoma: A case report

BACKGROUND

The prognosis of refractory extranodal natural killer/T-cell lymphoma (ENKTL) is poor. Recent data have indicated that immune checkpoint blockade with a programmed cell death protein-1 (PD-1) antibody in combination with administration of histone deacetylase inhibitors represents a potentially effective treatment strategy. Compared with PD-1 antibodies, programmed death-ligand 1 antibodies have fewer side effects. Here, we present a rare case of a patient with refractory metastatic ENKTL who achieved sustained remission of approximately 10 mo with minor adverse effects after combination therapy with atezolizumab, chidamide, and radiotherapy.

CASE SUMMARY

A 56-year-old woman underwent resection of a tumour in her left nasal cavity and was diagnosed with ENKTL (nasal type). Medical examination revealed tumours observed in the bilateral nasal mucosa, the subcutaneous soft tissue of the inner side of the left eye, the soft tissue of the nasopharynx, the bilateral tonsils, and the left preauricular, right hilar, bilateral neck lymph nodes and bone marrow. However, tomography/computed tomography showed increased metabolism of the bilateral nasal mucosa and subcutaneous soft tissue of the inner side of the left eye and newly increased metabolism of the left cervical lymph node after chemotherapy. Therefore, combination therapy with chidamide, atezolizumab, and radiotherapy was performed. Fortunately, the patient achieved a complete response following 10 mo of combination therapy.

CONCLUSION

The outcome in this case suggests that the combination of atezolizumab, chidamide, and radiotherapy is a promising regimen for treating refractory metastatic ENKTL following chemotherapy treatment failure.

Phase II Study of Gemcitabine, Peg-Asparaginase, Dexamethasone and Methotrexate Regimen for Newly Diagnosed Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type: Final Analysis With Long-Term Follow-Up and Rational Research for the Combination

Patients with extranodal natural killer/T-cell lymphoma (ENKTL), nasal type are benefit from peg-asparaginase, gemcitabine, and methotrexate. Therefore, we conducted a prospective phase II trial using a combination of these drugs as GAD-M regimen in naïve ENKTL patients, simultaneously, explored the combinational mechanism. The GAD-M regimen was administered for 6 cycles sandwiched by radiotherapy for stage I/II and 6 cycles for stage III/IV patients. After 6 cycles, the overall response rate of 36 patients was 91.6%, and the complete remission rate increased to 83.3%. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 74.8% and 77.8%, respectively. The 5-year PFS and OS were 68.3% and 77.8%. No patient suffered from the central nervous system (CNS) relapse. Most patients experienced recoverable liver dysfunction and anemia in this study. The plasma MTX concentration ratio at 12 to 24 hr during the first cycle could be an early predictor of outcomes in ENKTL (PFS, P=0.005; OS, P=0.002). Additionally, we found that high dose MTX (HD-MTX) and gemcitabine had the synergistic effect of ENKTL cell in vitro. Mechanistically, we demonstrated that the combination could lead to obviously apoptosis in ENKTL cell with extremely release of reactive oxygen spices (ROS), which mediated by endoplasmic reticulum stress. In conclusion, the GAD-M regimen could be a new choice to newly diagnosed ENKTL, especially for stage I/II patients. Furthermore, our results showed the synergy effect of HD-MTX with gemcitabine in ENKTL.

GELAD chemotherapy with sandwiched radiotherapy for patients with newly diagnosed stage IE/IIE natural killer/T-cell lymphoma: a prospective multicentre study

Early-stage natural killer/T-cell lymphoma (NK/TCL) patients usually receive a combination of chemotherapy and radiotherapy, but the optimal treatment approach has not yet been established. This study aimed to investigate the efficacy and safety profile of a novel chemotherapy regimen and sandwiched radiotherapy in early-stage NK/TCL. Patients with newly diagnosed stage IE/IIE disease were eligible. Patients were initially treated with two courses of the GELAD regimen (gemcitabine 1·0 g/m² day 1, etoposide 60 mg/m² days 1-3, pegaspargase 2000 units/m² day 4, and dexamethasone 40 mg days 1-4), followed by intensity-modulated radiotherapy (IMRT; 50-56 Gy in 25-28 fractions) and two additional courses of GELAD chemotherapy. A total of 52 patients were enrolled. The overall response rate and complete response rate per Lugano 2014 criteria were 94·2% and 92·3% respectively. With a median follow-up of 32 months, the estimated four-year overall survival rate and progression-free survival rate were 94·2% [95% confidence interval (CI), 83·2% to 93·1%] and 90·4% (95% CI, 78·4% to 95·9%) respectively. The most common adverse events were related to pegaspargase. Haematological toxicities were mild, with grade 3/4 neutropenia in 15·4% of patients. Our study provides a new approach with high activity and improved safety for the treatment of early-stage NK/TCL patients. This study was registered at www.clinicaltrials.gov as NCT02733458.

NK-/T-cell lymphomas

Natural killer/T-cell lymphoma (NKTL) is a sub-type of Epstein-Barr virus (EBV)-related non-Hodgkin lymphomas common in Asia and Latin America but rare elsewhere. Its pathogenesis is complex and incompletely understood. Lymphoma cells are transformed from NK- or T-cells, sometimes both. EBV-infection and subsequent genetic alterations in infected cells are central to NKTL development. Hemophagocytic syndrome is a common complication. Accurate staging is important to predict outcomes but there is controversy which system is best. More than two-thirds of NKTL lympohmas are localized at diagnosis, are frequently treated with radiation therapy only and have 5-year survival of about 70 percent. Persons with advanced NKTLs receive radiation therapy synchronously or metachronously with diverse multi-drug chemotherapy typically including L-asparginase with 5-year survival of about 40 percent. Some persons with widespread NKTL receive chemotherapy only. There are few data on safety and efficacy of high-dose therapy and a haematopoietic cell autotransplant. Immune therapies, histone deacetylase (HDAC)-inhibitors and other drugs are in early clinical trials. There are few randomized controlled clinical trials in NKTLs and no therapy strategy is clearly best; more effective therapy(ies) are needed. Some consensus recommendations are not convincingly evidence-based. Mechanisms of multi-drug resistance are considered. We discuss these issues including recent advances in our understanding of and therapy of NKTLs.