Survival of patients with peripheral T-cell lymphoma after first relapse or progression: spectrum of disease and rare long-term survivors

Sintilimab for relapsed/refractory extranodal NK/T cell lymphoma: a multicenter, single-arm, phase 2 trial (ORIENT-4)

This study (ORIENT-4) aimed to assess the efficacy and safety of sintilimab, a humanized anti-PD-1 antibody, in patients with relapsed/refractory extranodal NK/T cell lymphoma (r/r ENKTL). ORIENT-4 is a multicenter, single-arm, phase 2 clinical trial (NCT03228836). Patients with r/r ENKTL who failed to at least one asparaginase-based regimen were enrolled to receive sintilimab 200 mg intravenously every 3 weeks for up to 24 months. The primary endpoint was the objective response rate (ORR) based on Lugano 2014 criteria. Twenty-eight patients with r/r ENKTL were enrolled from August 31, 2017 to February 7, 2018. Twenty-one patients (75.0%, 95% CI: 55.1-89.3%) achieved an objective response. With a median follow-up of 30.4 months, the median overall survival (OS) was not reached. The 24-month OS rate was 78.6% (95% CI, 58.4-89.8%). Most treatment-related adverse events (TRAEs) were grade 1-2 (71.4%), and the most common TRAE was decreased lymphocyte count (42.9%). Serious adverse events (SAEs) occurred in 7 (25.0%) patients, and no patient died of adverse events. Sintilimab is effective and well tolerated in patients with r/r ENKTL and could be a novel therapeutic approach for the control of ENKTL in patients.

Population-based cohort study of the efficacy of brentuximab vedotin in relapsed systemic anaplastic large-cell lymphoma using Public Health England data

Systemic anaplastic large-cell lymphoma (sALCL) is a rare T-cell lymphoma associated with poor prognosis after relapse. The immunoconjugate brentuximab vedotin (BV) first became available for relapsed sALCL in England in 2013, following the results of a pivotal phase II study. We present a population-based study describing outcomes of relapsed sALCL in England after BV, using Public Health England data. We obtained information on all relapsed/refractory (r/r) sALCL patients ≥18 years treated with BV monotherapy in England between 1 January 2014 and 31 December 2019. The final cohort comprised 127 patients with a median age of 60 years (range 19-89). Eighteen (14·2%) had received stem cell transplant in first remission. Median two-year overall survival (OS) was 46·6%. The vast majority of deaths (59) occurred within 18 months, with very few events after this. Receipt of BV as second line compared to third or fourth line was associated with significantly improved survival (two-year OS 50·3% vs 29·7%, P = 0·03). There was no difference in OS for different subgroups, including anaplastic lymphoma kinase status, age, gender, or receipt of stem cell transplantation in first response. We report excellent survival following treatment with BV in a real-world setting, comparable with previous clinical trial data.

RBMX Protein Expression in T-Cell Lymphomas Predicts Chemotherapy Response and Prognosis

Simple Summary

Patients with T-cell non-Hodgkin’s lymphomas (T-NHL) are often chemotherapy refractory and subsequently have poor prognosis. So far, mechanisms leading to this primary chemotherapy refractoriness and factors identifying such cases are not well established. This study investigated the prognostic relevance of the RNA binding protein X (RBMX) in 53 T-NHL cases using conventional immunohistochemistry. As shown, low RBMX expression was associated with better response to anthracycline-containing first-line treatment. Furthermore, low RBMX expression predicted an improved overall survival (OS) and progression-free survival (PFS). These results suggest that RBMX protein expression levels might be a contributing factor towards chemotherapy resistance and thus affect prognosis of patients with T-cell lymphomas.

Abstract

T-cell non-Hodgkin’s lymphomas (T-NHL) are a heterogeneous group of lymphomas with a mature T-cell phenotype. While in some hematological diseases the prognosis improved over the last decades, T-NHL cases often relapse early or present with an initially refractory course. Recently, it has been shown that RNA binding proteins have a crucial role for malignant tumor initiation, progression and treatment response while contributing to chemotherapy resistance. Therefore, we investigated the protein expression of the RNA binding protein X (RBMX), which has been shown to be of great relevance in disease initiation and progression in hematological diseases in 53 T-NHL cases using conventional immunohistochemistry. Low RBMX expression was associated with better response to anthracycline-containing first-line treatment. Furthermore, low RBMX expression predicted an improved overall survival and progression-free survival in univariate analysis. Multivariable Cox regression revealed RBMX as an independent prognostic marker for overall survival (p = 0.007; hazard ratio (HR) = 0.204; 95% confidence interval (CI): 0.064–0.646) and progression-free survival (p = 0.006; HR = 0.235; 95% CI: 0.083–0.666). The study identifies low RBMX expression to predict better chemotherapy response, overall survival and progression-free survival in patients with T-cell non-Hodgkin’s lymphomas. These results suggest that RBMX protein expression levels might be a contributing factor towards chemotherapy resistance and thus affect prognosis. Hence, RBMX may be a potential therapeutic target and prognostic marker in T-cell lymphomas.

The pivotal role of cytotoxic NK cells in mediating the therapeutic effect of anti-CD47 therapy in mycosis fungoides

CD47 is frequently overexpressed on tumor cells and is an attractive therapeutic target. The mechanism by which anti-CD47 immunotherapy eliminates cutaneous lymphoma has not been explored. We utilized CRISPR/Cas-9 CD47 knock-out, depletion of NK cells, and mice genetically deficient in IFN-γ to elucidate the mechanism of anti-CD47 therapy in a murine model of cutaneous T cell lymphoma (CTCL). CD47 was found to be a crucial factor for tumor progression since CD47 KO CTCL exhibited a delay in tumor growth. The treatment of CD47 WT murine CTCL with anti-CD47 antibodies led to a significant reduction in tumor burden as early as four days after the first treatment and accompanied by an increased percentage of cytotoxic NK cells at the tumor site. The depletion of NK cells resulted in marked attenuation of the anti-tumor effect of anti-CD47. Notably, the treatment of CD47 WT tumors in IFN-γ KO mice with anti-CD47 antibodies was efficient, demonstrating that IFN-γ was not required to mediate anti-CD47 therapy. We were able to potentiate the therapeutic effect of anti-CD47 therapy by IFN-α. That combination resulted in an increased number of cytotoxic CD107a + IFN-γ-NK1.1 cells and intermediate CD62L + NKG2a-NK1.1. Correlative data from a clinical trial (clinicaltrials.gov, NCT02890368) in patients with CTCL utilizing SIRPαFc to block CD47 confirmed our in vivo observations.

Comparison of chidamide-contained treatment modalities versus chemotherapy in the second-line treatment for relapsed or refractory peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is characterized by an aggressive clinical behavior. Chidamide has been approved for the treatment of relapsed/refractory (R/R) PTCL in China. We compared the efficacy of chidamide-contained regimens with chemotherapy (ChT) in R/R PTCL. Based on the second-line treatments, patients were divided into three groups, including ChT, ChT combined with chidamide (chidamide + ChT) and chidamide combined with or without other targeted agents (targeted therapy) group. Chidamide + ChT group had a better progression-free survival (PFS) compared with targeted therapy group (p = 0.013), and showed a trend towards superior PFS compared with ChT group (p = 0.079). Among patients with high second-line International Prognostic Index (IPI) (3-5), chidamide+ChT group had a longer PFS than ChT group(p = 0.018), and PFS in targeted therapy group was not inferior to that in chidamide+ChT group (p = 0.200). Among patients younger than 60 years, chidamide+ChT group demonstrated a PFS benefit over targeted therapy group (p = 0.010). Among CD30-negative patients, PFS was superior in the chidamide+ChT group compared with ChT group (p < 0.001). Conversely, results observed above were absent in patients with low second-line IPI or patients older than 60 years or CD30-positive patients. Overall, the combination of chidamide and ChT may be an effective treatment strategy for R/R PTCL.

T time: Emerging and new therapies for peripheral T-cell lymphoma

Peripheral T-cell Lymphomas (PTCL) are a heterogenous group of aggressive non-Hodgkin lymphomas that are far less sensitive to chemotherapy than their B-cell counterparts. Despite their poor prognosis, they are treated similarly to most aggressive B-cell lymphomas, heavily relying on CHOP or CHOP-like combination chemotherapy irrespective of their different subtypes or biology. The last decade has seen the emergence of many targeted therapies that include histone deacetylase inhibitors, hypomethylating agents, monoclonal antibodies and PIK3 inhibitors, among others. However, prognosis remains poor especially in the relapsed/refractory setting. Using an extensive pubmed search, the authors will be summarizing the different trials that led to these approved targeted agents as well as novel combination strategies. The fundamental recognition that different subtypes of PTCL have specific biological features that drive not only proliferation, but also responses to different treatment approaches, should be informing the design of future clinical trials.

Predictive Factors of Event-Free Survival at 24 Months in Patients with Peripheral T-cell Lymphoma: A Retrospective Study

Purpose

Event-free survival at 24 months (EFS24) is known to be a surrogate marker for overall survival (OS) for patients with peripheral T-cell lymphoma (PTCL). We examined the role of EFS24 in PTCL compared to diffuse large B-cell lymphoma (DLBCL), and then assessed the clinical predictive factors of achieving EFS24.

Materials and Methods

Patients with newly diagnosed PTCL treated with anthracycline-based chemotherapy were included. Subsequent OS was defined as the time elapsed from 24 months after diagnosis until death from any cause in those who achieved EFS24.

Results

Overall, 153 patients were evaluated, and 51 patients (33.3%) achieved EFS24. Patients who achieved EFS24 showed superior OS compared to patients who did not (p < 0.001). EFS24 could stratify the subsequent OS although it did not reach to that of the general population. After matching the PTCL group to the DLBCL group based on the international prognostic index, the subsequent OS in patients who achieved EFS24 was similar between the two groups (p=0.094). Advanced stage was a significant factor to predict the failing EFS24 by multivariable analysis (p < 0.001).

Conclusion

Patients with PTCL who achieve EFS24 could have a favorable subsequent OS. Since advanced disease stage is a predictor of EFS24 failure, future efforts should focus on developing novel therapeutic strategies for PTCL patients presenting with advanced disease.

Characterization of newly established Pralatrexate-resistant cell lines and the mechanisms of resistance

Background

Pralatrexate (PDX) is a novel antifolate approved for the treatment of patients with relapsed/refractory peripheral T-cell lymphoma, but some patients exhibit intrinsic resistance or develop acquired resistance. Here, we evaluated the mechanisms underlying acquired resistance to PDX and explored potential therapeutic strategies to overcome PDX resistance.

Methods

To investigate PDX resistance, we established two PDX-resistant T-lymphoblastic leukemia cell lines (CEM and MOLT4) through continuous exposure to increasing doses of PDX. The resistance mechanisms were evaluated by measuring PDX uptake, apoptosis induction and folate metabolism-related protein expression. We also applied gene expression analysis and methylation profiling to identify the mechanisms of resistance. We then explored rational drug combinations using a spheroid (3D)-culture assay.

Results

Compared with their parental cells, PDX-resistant cells exhibited a 30-fold increase in half-maximal inhibitory concentration values. Induction of apoptosis by PDX was significantly decreased in both PDX-resistant cell lines. Intracellular uptake of [¹⁴C]-PDX decreased in PDX-resistant CEM cells but not in PDX-resistant MOLT4 cells. There was no significant change in expression of dihydrofolate reductase (DHFR) or folylpolyglutamate synthetase (FPGS). Gene expression array analysis revealed that DNA-methyltransferase 3β (DNMT3B) expression was significantly elevated in both cell lines. Gene set enrichment analysis revealed that adipogenesis and mTORC1 signaling pathways were commonly upregulated in both resistant cell lines. Moreover, CpG island hypermethylation was observed in both PDX resistant cells lines. In the 3D-culture assay, decitabine (DAC) plus PDX showed synergistic effects in PDX-resistant cell lines compared with parental lines.

Conclusions

The resistance mechanisms of PDX were associated with reduced cellular uptake of PDX and/or overexpression of DNMT3B. Epigenetic alterations were also considered to play a role in the resistance mechanism. The combination of DAC and PDX exhibited synergistic activity, and thus, this approach might improve the clinical efficacy of PDX.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08607-9.

How to Sequence Therapies in Peripheral T Cell Lymphoma

OPINION STATEMENT

Peripheral T cell lymphoma (PTCL) represents a heterogeneous group of rare lymphoproliferative disorders. Historically, there has been a lack of pathobiological understanding of PTCL. With the exception of ALK-positive anaplastic large cell lymphoma, patients with PTCL have less favorable outcomes, with most patients relapsing shortly after conventional anthracycline-containing multi-agent chemotherapy. The standard management approach for PTCL involves induction therapy followed by autologous stem cell transplantation. Patients with relapsed/refractory PTCL have dismal outcomes and limited treatment options despite the available novel agents, therefore remaining a critical unmet need. By virtue of advancement in cancer biology over the recent years, the treatment landscape of PTCL has gradually evolved from conventional chemotherapy based on solely morphological diagnosis toward more individualized therapies by integrating molecular attributes of PTCL to the traditional treatment paradigm. We are at the edge of witnessing a paradigm shift in PTCL management.

Burden of illness and treatment patterns among patients with peripheral T-cell lymphoma in the US healthcare setting

OBJECTIVE

Limited real-world information exists on the characteristics or treatment patterns of patients with peripheral T-cell lymphoma (PTCL). We reported demographics, treatments and direct healthcare resource utilization (HRU) in a large cohort of US patients newly diagnosed with PTCL.

METHODS

Patients aged ≥18 years with a PTCL diagnosis between January 2011 and December 2016 were identified from the Inovalon MORE² Registry. Continuous medical/pharmacy enrollment 6-months prior to and ≥1-month after the first PTCL diagnosis was required. The main focus of this study was on newly diagnosed patients receiving cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) versus other chemotherapy.

RESULTS

A total 2971 patients with PTCL and chemotherapy information were included in the study; 1706 (57%) received CHOP and 1265 (43%) other chemotherapy. A majority of patients (51.7%) were female; mean (standard deviation) age at index was 61.0 (±16.0), Charlson score was 4.1 (±2.9), and follow-up time was 24.6 (±16.7) months. During the variable follow-up period, HRU was similar for the CHOP and other chemotherapy cohorts; 58.1% and 59.3% had ≥1 all-cause hospitalizations, respectively. The proportion of patients with ≥1 PTCL-related hospitalizations was higher in the CHOP than in the other chemotherapy cohort (40.3% vs. 9.7%, respectively) and mean length of stay was longer (4.6 vs. 3.7 days per patient per month, respectively).

CONCLUSIONS

This retrospective analysis of patients with PTCL revealed high levels of comorbidity and HRU; novel interventions that improve patient outcomes and reduce the HRU burden of PTCL are needed.

A multicenter retrospective study on the real-world outcomes of autologous vs. allogeneic hematopoietic stem cell transplantation for peripheral T-cell lymphoma in China

Background:

There were few studies on real-world data about autologous hematopoietic stem cell transplantation (auto-HSCT) or allogeneic HSCT (allo-HSCT) in peripheral T-cell lymphoma (PTCL). This study aimed to investigate the clinical outcomes of patients who received auto-HSCT or allo-HSCT in China.

Methods:

From July 2007 to June 2017, a total of 128 patients who received auto-HSCT (n = 72) or allo-HSCT (n = 56) at eight medical centers across China were included in this study. We retrospectively collected their demographic and clinical data and compared the clinical outcomes between groups.

Results:

Patients receiving allo-HSCT were more likely to be diagnosed with stage III or IV disease (95% vs. 82%, P = 0.027), bone marrow involvement (42% vs. 15%, P = 0.001), chemotherapy-resistant disease (41% vs. 8%, P = 0.001), and progression disease (32% vs. 4%, P < 0.001) at transplantation than those receiving auto-HSCT. With a median follow-up of 30 (2–143) months, 3-year overall survival (OS) and progression-free survival (PFS) in the auto-HSCT group were 70%(48/63) and 59%(42/63), respectively. Three-year OS and PFS for allo-HSCT recipients were 46%(27/54) and 44%(29/54), respectively. There was no difference in relapse rate (34%[17/63] in auto-HSCT vs. 29%[15/54] in allo-HSCT, P = 0.840). Three-year non-relapse mortality rate in auto-HSCT recipients was 6%(4/63) compared with 27%(14/54) for allo-HSCT recipients (P = 0.004). Subanalyses showed that patients with lower prognostic index scores for PTCL (PIT) who received auto-HSCT in an upfront setting had a better outcome than patients with higher PIT scores (3-year OS: 85% vs. 40%, P = 0.003). Patients with complete remission (CR) undergoing auto-HSCT had better survival (3-year OS: 88% vs. 48% in allo-HSCT, P = 0.008). For patients beyond CR, the outcome of patients who received allo-HSCT was similar to that in the atuo-HSCT group (3-year OS: 51% vs. 46%, P = 0.300).

Conclusions:

Our study provided real-world data about auto-HSCT and allo-HSCT in China. Auto-HSCT seemed to be associated with better survival for patients in good condition (lower PIT score and/or better disease control). For patients possessing unfavorable characteristics, the survival of patients receiving allo-HSCT group was similar to that in the auto-HSCT group.

What's new in peripheral T-cell lymphomas

Peripheral T‐cell lymphomas (PTCLs) are a rare, heterogeneous group of hematological malignancies with extremely poor prognosis for almost all subtypes. The diverse clinicopathological features of PTCLs make accurate diagnosis, prognosis, and choice of optimal treatment strategies difficult. Moreover, the best therapeutic algorithms are still under debate due to the extrapolated approaches developed for B‐cell lymphomas and to the absence of few treatment protocol specifically developed for PTCLs. Some advances have been made with CD30 monoclonal antibody, mainly for anaplastic large‐cell lymphomas, with improvements in progression‐free survival and overall survival. Several new drugs are under evaluation in clinical trials, although not all the results are as encouraging as expected. In this review, we briefly present the most updated information on diagnosis, prognostication, and treatment strategies in PTCLs.

Enteropathy-Associated T cell Lymphoma

PURPOSE OF REVIEW

Enteropathy-associated T cell lymphoma (EATL) is a rare subtype of mature T cell lymphoma. The available literature about this rare type T cell lymphoma is relatively limited. This article provides a summary and review of the available literature addressing this entity in terms of risk factors, pathogenesis, diagnostic, and therapeutic options.

RECENT FINDINGS

EATL has two distinct subtypes. Type I EATL, now known as EATL, is closely, but not exclusively linked to celiac disease (CD), and it is primarily a disease of Northern European origin. It accounts for < 5% of peripheral T cell lymphoma (PTCL). Risk factors for EATL include advanced age, male sex, and most importantly, genetic susceptibility in the form of HLA-DQ2 homozygosity. The pathogenesis of EATL is closely related to celiac disease as it shares common pathogenic features with refractory celiac disease. The gold standard of diagnosis is histological diagnosis. EATL carries an aggressive course and a poor prognosis. Treatment of EATL includes surgery, induction chemotherapy, and consolidation in first complete remission and autologous stem cell transplant. The role of targeted and biologic therapies in newly diagnosed EATL patients along with relapsed, refractory cases is evolving and discussed in this review. EATL is an aggressive peripheral T cell lymphoma with poor overall treatment outcome using currently available therapy options. Clinical trials are considered the best approach for treatment of EATL. Early diagnosis and early referral to specialized centers would be the best way to deal with such patients. Development of new prognostic models and early surgical intervention are warranted. Prevention is where all the efforts should be spent, by counseling patients with CD regarding the importance of adherence to gluten-free diet and development of periodic surveillance programs in celiac disease patients for early detection of pre-lymphoma lesions.

Diagnosis, Risk Stratification, and Treatment of Peripheral T-Cell Lymphomas: Past and Present

Peripheral T-cell lymphomas represent an evolving class of aggressive T-cell malignancies that are generally refractory to conventional treatments and historically carry a poor prognosis. Recent advances in gene expression profiling have begun to unravel the specific molecular mechanisms of tumorigenesis in these disease processes, allowing for discrete classification schemes that help guide discussions regarding prognosis and therapy options. We outline here a review of the histopathology, epidemiology, clinical features, and treatment strategies currently used in the management of these diseases.

Comparison of Allogeneic Stem Cell Transplant and Autologous Stem Cell Transplant in Refractory or Relapsed Peripheral T-Cell Lymphoma: A Systematic Review and Meta-analysis

IMPORTANCE

Hematopoietic stem cell transplant (HSCT) is an advisable option for refractory or relapsed peripheral T-cell lymphoma (R/R-PTCL), but whether allogeneic HSCT or autologous HSCT is more beneficial is unknown.

OBJECTIVE

To compare the effectiveness and safety of allogeneic HSCT vs autologous HSCT in patients with R/R-PTCL.

DATA SOURCES

A systematic search of the PubMed, Embase, the Cochrane Central Register of Controlled Trials, Wanfang, and China National Knowledge Infrastructure databases with the search items refractory or relapsed peripheral T-cell lymphoma, ASCT/autologous stem-cell transplantation, allo-HSCT/allogeneic stem-cell transplantation, therapeutic effect, and treatment was conducted for articles published from January 12, 2001, to October 1, 2020.

STUDY SELECTION

After duplicate and irrelevant publications were discarded, 329 were ineligible according to the inclusion (clinical trials or retrospective studies with >10 samples) and exclusion criteria (articles without overall survival [OS], progression-free survival [PFS], and transplantation-related mortality [TRM]). Thirty trials were included in the meta-analysis. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

DATA EXTRACTION AND SYNTHESIS

Data on study design, individual characteristics, and outcomes were extracted. All statistics were pooled by applying a random-effects model.

MAIN OUTCOMES AND MEASURES

The prespecified main outcomes were OS, PFS, and TRM.

RESULTS

Of 6548 articles, data extracted from the 30 studies (including 880 patients who underwent allogeneic HSCT and 885 who underwent autologous HSCT) were included in this meta-analysis. In the allogeneic HSCT group, a 3-year OS of 50% (95% CI, 41%-60%) and PFS of 42% (95% CI, 35%-51%), a 5-year OS of 54% (95% CI, 47%-62%) and PFS of 48% (95% CI, 40%-56%), and a 3-year TRM of 32% (95% CI, 27%-37%) were observed. In the autologous HSCT group, a 3-year OS of 55% (95% CI, 48%-64%) and PFS of 41% (95% CI, 33%-51%), a 5-year OS of 53% (95% CI, 44%-64%) and PFS of 40% (95% CI, 24%-58%), and a 3-year TRM of 7% (95% CI, 2%-23%) were observed.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, OS and PFS were similar in the allogeneic HSCT and autologous HSCT groups; however, allogeneic HSCT was associated with specific survival benefits among patients with R/R-PTCL.

Combined oral 5-azacytidine and romidepsin are highly effective in patients with PTCL: a multicenter phase 2 study

Peripheral T-cell lymphomas (PTCLs) are uniquely vulnerable to epigenetic modifiers. We demonstrated in vitro synergism between histone deacetylase inhibitors and DNA methyltransferase inhibitors in preclinical models of T-cell lymphoma. In a phase 1 trial, we found oral 5-azacytidine and romidepsin to be safe and effective, with lineage-selective activity among patients with relapsed/refractory (R/R) PTCL. Patients who were treatment naïve or who had R/R PTCL received azacytidine 300 mg once per day on days 1 to 14, and romidepsin 14 mg/m2 on days 8, 15, and 22 every 35 days. The primary objective was overall response rate (ORR). Targeted next-generation sequencing was performed on tumor samples to correlate mutational profiles and response. Among 25 enrolled patients, the ORR and complete response rates were 61% and 48%, respectively. However, patients with T-follicular helper cell (tTFH) phenotype exhibited higher ORR (80%) and complete remission rate (67%). The most frequent grade 3 to 4 adverse events were thrombocytopenia (48%), neutropenia (40%), lymphopenia (32%), and anemia (16%). At a median follow-up of 13.5 months, the median progression-free survival, duration of response, and overall survival were 8.0 months, 20.3 months, and not reached, respectively. The median progression-free survival and overall survival were 8.0 months and 20.6 months, respectively, in patients with R/R disease. Patients with tTFH enjoyed a particularly long median survival (median not reached). Responders harbored a higher average number of mutations in genes involved in DNA methylation and histone deacetylation. Combined azacytidine and romidepsin are highly active in PTCL patients and could serve as a platform for novel regimens in this disease. This trial was registered at www.clinicaltrials.gov as #NCT01998035.

Targeted based therapy in nodal T-cell lymphomas

T-cell lymphomas (TCL) are a group of biologically and clinically heterogenous neoplasms derived from mature T lymphocytes. Recent findings in biology have advanced the classification of these neoplasms; however, clinical investigations based on biologic features have yet to be designed. Two biomarker-driven treatments for TCL are promising: brentuximab vedotin (BV) in combination with chemotherapy or as monotherapy is the standard treatment for newly diagnosed CD30-positive TCL and relapsed/refractory anaplastic large cell lymphoma (ALCL), while ALK inhibitors have induced responses in ALK+ ALCLs. Common genetic alterations in TCL, such as aberrations in PI3K/mTOR, JAK/STAT, and epigenetic regulators are also targetable by pathway inhibitors and HDAC/DNMT inhibitors; however, responses to these treatments as monotherapy are neither satisfactory nor durable, even in patients pre-stratified by several biomarkers. Additional work is needed to extend biology/biomarker-driven treatment in these neoplasms. As T-cell lymphomagenesis is multistep and multifactorial, trials are ongoing to evaluate combination treatments. The focus of this article is to summarize the status and the current role of targeted-based therapy in nodal TCL.

Conditional survival and hazards of death for peripheral T-cell lymphomas

Typically, peripheral T-cell lymphoma (PTCLs) prognosis is estimated using overall survival before treatment. However, these estimates cannot show how prognosis evolves with the changing hazard rate over time. Patients (n = 650) with newly diagnosed PTCLs were enrolled retrospectively. After a median follow-up of 5.4 years, angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) and NK/T cell lymphoma had initially lower 3-year conditional overall survival (COS3; i.e., the 3-year conditional overall survival was defined as the probability of surviving an additional 3 years) and higher hazards of death (26–44.3%). However, after 2 years, the COS3 increased and the death risk decreased over time, whereas anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma constantly had a lower risk over time (0–19.5%). For patients with complete remission after initial treatment, prognosis varied by histological subtypes, with PTCL, NOS having a negative impact. Our data suggested that the risk stratification using the International Prognostic Index might not accurately predict the COS3 for survivors of PTCLs. The COS3 provided time-dependent prognostic information for PTCLs, representing a possible surrogate prognosis indicator for long-term survivors after systemic chemotherapy.

Comprehensive analysis of peripheral T-cell and natural killer/T-cell lymphoma in Asian patients: A multinational, multicenter, prospective registry study in Asia

Background

Peripheral T-cell lymphomas (PTCLs) are uncommon and their frequency is regionally heterogeneous. Several studies have been conducted to evaluate the clinical features and treatment outcomes of this disease entity, but the majority of these were conducted in limited areas, making it difficult to comprehensively analyze their relative frequency and clinical features. Furthermore, no consensus treatment for PTCLs has been established. Therefore, we conducted an Asia-specific study to understand the relative frequency of PTCLs and assess treatments and their outcomes in Asian patients.

Methods

We performed a multinational, multicenter, prospective registry of adult patients with PTCLs that was named as the International Cooperative non-Hodgkin T-cell lymphoma prospective registry study where thirty-two institutes from six Asian countries and territories (Korea, China, Taiwan, Singapore, Malaysia, and Indonesia) participated.

Findings

A total of 486 patients were registered between April 2016 and February 2019, and more than a half of patients (57%) had stage III or IV. Extranodal natural killer (NK)/T- cell lymphoma was the most common subtype (n = 139,28.6%), followed by angioimmunoblastic T-cell lymphoma (AITL, n = 120,24.7%), PTCL-not otherwise specified (PTCL-NOS, n = 101,20.8%), ALK-positive anaplastic large cell lymphoma (ALCL, n = 34,6.9%), and ALK-negative ALCL (n = 30,6.2%). The median progression-free survival (PFS) and overall survival (OS) were 21.1 months (95% CI,10.6-31.6) and 83.6 months (95% CI, 56.7-110.5), respectively. Upfront use of combined treatment with chemotherapy and radiotherapy showed better PFS than chemotherapy alone in localized ENKTL whereas consolidation with upfront autologous stem cell transplantation (SCT) provided longer PFS in advance stage ENKTL. In patients with PTCLs other than ENKTL, anthracycline-containing chemotherapies were widely used, but the outcome of those regimens was not satisfactory, and upfront autologous SCT was not significantly associated with survival benefit, either. The treatment outcome of salvage chemotherapy was disappointing, and none of the salvage strategies showed superiority to one another.

Interpretation

This multinational, multicenter study identified the relative frequency of each subtype of PTCLs across Asian countries, and the survival outcomes according to the therapeutic strategies currently used.

Funding

Samsung Biomedical Research Institute.

Myeloablative Haploidentical Transplant as an Alternative to Matched Sibling Transplant for Peripheral T-Cell Lymphomas

The number of HLA-haploidentical allogeneic hematopoietic stem-cell transplantation (Haplo-HSCT) is increasing. Comparative studies about Haplo-HSCT versus allo-HSCT with HLA-matched sibling donors (MSD-HSCT) have been tried in leukemias and B-cell lymphomas. Few studies were reported in Peripheral T-cell lymphomas (PTCLs). We performed a multicenter retrospective study about 52 patients with PTCLs undergoing Haplo-HSCT (n = 20) or MSD-HSCT (n = 32). All Haplo-HSCT recipients received antithymocyte globulin (ATG) based graft versus host disease (GVHD) prophylaxis. The median follow-up for all survivors was 38 months. The 100-day cumulative incidence of grade II to IV acute GVHD was similar (19% in the MSD-HSCT group versus 28% in the Haplo-HSCT group, P = 0.52). The 2-year cumulative incidence of chronic GVHD (limited and extensive) after Haplo-HSCT (30%) was also similar with that in the MSD-HSCT group (50%, P = 0.15). The 3-year relapse rates (33% vs 27%, P = 0.84) and non-relapse mortality (21% vs 22%, P = 0.78) did not differ between these two groups. There were also no differences in 3-year overall survival (OS) (48% vs 50%, P = 0.78) and progression-free survival (47% vs 51%, P = 0.95) between these two groups. On multivariate analysis, prognostic index for T-cell lymphoma (PIT) score (higher than 1: hazard ratio [HR], 4.0; P = 0.003) and disease status (stable or progression disease before HSCT: HR, 2.8; P = 0.03) were independent variables associated with worse OS. We concluded that ATG-based haplo-HSCT platform could work as an alternative to MSD-HSCT for patients with PTCLs.

Management of Angioimmunoblastic T-Cell Lymphoma (AITL) and other T Follicular Helper Cell lymphomas (TFH PTCL)

Despite the remarkable improvements in the treatment and outcome of patients with aggressive B-cell lymphoma, the peripheral T-cell lymphomas (PTCL) continue to carry a poor prognosis with the presently available treatment options. The PTCL are very rare diseases that account for only 10,000 to 15,000 new cases per year in the United States. The World Health Organization's 2016 classification describes 29 distinct subtypes of PTCL, thus making these both rate and incredibly heterogenous. The 2 most common forms of PTCL, for example, peripheral T-cell lymphoma-not otherwise specified and angioimmunoblastic T-cell lymphoma , have an incidence of only 2500 and 1800 cases per year respectively, in the United States.

Management of ALCL and other CD30+ peripheral T-cell lymphomas with a focus on Brentuximab vedotin

Peripheral T-cell lymphomas (PTCL) are rare lymphoproliferative disorders with poor outcomes and high rates of relapse. Incidence varies although the most common subtypes include PTCL-not-otherwise specified, anaplastic large cell lymphoma, and angioimmunoblastic T-cell lymphoma. Anaplastic large cell lymphoma is characterized by near-universal CD30 expression and serves as a prototypic model for other CD30-expressing lymphomas. Historically, these neoplasms have been treated with regimens used in the treatment of aggressive B-cell lymphomas. Over the last decade, brentuximab vedotin, an antibody-drug conjugate, has been investigated to treat peripheral T-cell lymphomas expressing CD30. While first studied in the relapsed and refractory setting, it was later studied in the frontline setting in the ECHELON-2 trial with positive results and is now an approved treatment for CD30-expressing peripheral T-cell lymphomas. Other treatment options in the relapsed and refractory setting include histone deacetylase inhibitors, pralatrexate, and salvage multiagent chemotherapy regimens. Current research is underway regarding combination therapies and the use of other novel agents.

Primary and secondary central nervous system mature T- and NK-cell lymphomas

Primary central nervous system (CNS) mature T- and NK-cell lymphomas are rare, only comprising 2% to 3% of all primary CNS lymphomas. Among them, peripheral T-cell lymphoma, not otherwise specified, anaplastic large cell lymphoma (ALCL), and extranodal NK/T-cell lymphoma (ENKTL) are the commonly reported histological subtypes. Secondary CNS T-cell lymphoma generally affects about 5% of patients with T- or NK-cell lymphoma, with some exceptions. Acute and lymphomatous subtypes of adult T-cell leukemia/lymphoma (ATLL) have high risk of CNS progression, may affect up to 20% of patients; ALK-positive ALCL with extranodal involvement >1 also has high risk of CNS progression. However, the impact and the optimal methodology of CNS prophylaxis remain unclear in systemic T-cell lymphomas. There are little data on the treatment strategy of primary and secondary CNS T-cell lymphoma. Treatment strategy derived from B-cell CNS primary lymphoma is generally used; this includes induction therapy with high-dose methotrexate-based regimens, followed by high-dose chemotherapy with autologous stem cell transplant in fit patients. There are unmet needs for patients who are not fit for intensive chemotherapy. The prognosis after CNS progression in T-cell lymphoma is dismal with the median overall survival of less than 1 year. New agents targeting T-cell lymphomas are emerging and should be tested in patients with mature T- and NK-cell lymphoma who suffer from CNS involvement.

Phase I studies of darinaparsin in patients with relapsed or refractory peripheral T-cell lymphoma: a pooled analysis of two phase I studies conducted in Japan and Korea

OBJECTIVE

Two phase I studies of darinaparsin including Japanese and Korean patients with relapsed/refractory peripheral T-cell lymphoma were performed to evaluate its safety (primary purpose), efficacy and pharmacokinetic profile (ClinicalTrials.gov: NCT01435863 and NCT01689220).

METHODS

Patients received intravenous darinaparsin for 5 consecutive days at 200 mg/m2/day in 4-week cycles, 300 mg/m2/day in 4-week cycles or 300 mg/m2/day in 3-week cycles.

RESULTS

Seventeen Japanese and 6 Korean patients were enrolled and treated. Drug-related adverse events developed in 18 patients (78%). Dose-limiting toxicity, grade 3 hepatic dysfunction, was reported on Day 15 of cycle 1 in 1 Japanese patient who received 300 mg/m2/day. The most common drug-related, grade ≥ 3 adverse events were lymphopenia (9%), neutropenia (9%) and thrombocytopenia (9%). No deaths occurred. In 14 evaluable patients, 1 and 3 patients had complete response and partial response, respectively. The plasma concentration-time profiles of arsenic, a surrogate marker for darinaparsin, were similar between Japanese and Korean patients. No significant difference was found in its pharmacokinetic profile.

CONCLUSIONS

These data indicate the good tolerability and potential efficacy of darinaparsin in patients with relapsed/refractory peripheral T-cell lymphoma. Darinaparsin 300 mg/m2/day for 5 consecutive days in 3-week cycles is the recommended regimen for phase II study.

Esophageal peripheral T-cell lymphoma treated with radiotherapy: A case report

RATIONALE

The clinical prognosis of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) patients is poor. Therefore, effective treatment is still a challenge at present. Moreover, little is known about the value of radiotherapy in the treatment of PTCL-NOS.

PATIENT CONCERNS

A 55-year-old male patient with eating difficulties and progressive exacerbation for 3 months was diagnosed as non-Hodgkin's lymphoma. Airway compression occurred after 2 cycles of first line treatment with cyclophosphamide-Adriamycin-vincristine-prednisone regimen, radiotherapy (48Gy/24f) was given as the second line therapy.

DIAGNOSIS

After radiotherapy, the patient complained that mild intermittent dysphagia still existed. Endoscopic biopsy of the upper digestive tract confirmed necrotic material and superficial squamous epithelial mucosa, suggesting esophageal stricture after radiotherapy, which was indistinguishable from tumor residue.

INTERVENTIONS

The patient received anti-inflammatory treatment outside the hospital and did not receive any other special treatment.

OUTCOMES

The symptoms of dysphagia disappeared and the focus showed complete response (CR). As of October 1, 2020, the patient has been diagnosed with PTCL-NOS for more than 57 months and the overall survival (OS) have not been achieved.

LESSONS

Radiotherapy has obvious and rapid anti-tumor effect on cyclophosphamide-Adriamycin-vincristine-prednisone refractory PTCL-NOS. At the same time, hollow organs after radiotherapy can lead to lumen stenosis and the symptoms of suspected recurrence which is difficult to distinguish only from the imaging findings.

A pilot clinical trial of oral tetrahydrouridine/decitabine for noncytotoxic epigenetic therapy of chemoresistant lymphoid malignancies

One mechanism by which lymphoid malignancies resist standard apoptosis-intending (cytotoxic) treatments is genetic attenuation of the p53/p16-CDKN2A apoptosis axis. Depletion of the epigenetic protein DNA methyltransferase 1 (DNMT1) using the deoxycytidine analog decitabine is a validated approach to cytoreduce malignancy independent of p53/p16. In vivo decitabine activity, however, is restricted by rapid catabolism by cytidine deaminase (CDA). We, therefore, combined decitabine with the CDA-inhibitor tetrahydrouridine and conducted a pilot clinical trial in patients with relapsed lymphoid malignancies: the doses of tetrahydrouridine/decitabine used (∼10/0.2 mg/kg orally (PO) 2×/week) were selected for the molecular pharmacodynamic objective of non-cytotoxic, S-phase dependent, DNMT1-depletion, guided by previous Phase 1 studies. Patients with relapsed/refractory B- or T-cell malignancies (n = 7) were treated for up to 18 weeks. Neutropenia without concurrent thrombocytopenia is an expected toxicity of DNMT1-depletion and occurred in all patients (Grade 3/4). Subjective and objective clinical improvements occurred in 4 of 7 patients, but these responses were lost upon treatment interruptions and reductions to manage neutropenia. We thus performed parallel experiments in a preclinical in vivo model of lymphoma to identify regimen refinements that might sustain DNMT1-targeting in malignant cells but limit neutropenia. We found that timed-alternation of decitabine with the related molecule 5-azacytidine, and combination with inhibitors of CDA and de novo pyrimidine synthesis could leverage feedback responses of pyrimidine metabolism to substantially increase lymphoma cytoreduction but with less neutropenia. In sum, regimen innovations beyond incorporation of a CDA-inhibitor are needed to sustain decitabine DNMT1-targeting and efficacy against chemo-resistant lymphoid malignancy. Such potential solutions were explored in preclinical in vivo studies.

Combination treatment of copanlisib and gemcitabine in relapsed/refractory PTCL (COSMOS): an open-label phase I/II trial

BACKGROUND

Current treatment options for peripheral T-cell lymphomas (PTCLs) in the relapsed/refractory setting are limited and demonstrate modest response rates with rare achievement of complete response (CR).

PATIENTS AND METHODS

This phase I/II study (NCT03052933) investigated the safety and efficacy of copanlisib, a phosphatidylinositol 3-kinase-α/-δ inhibitor, in combination with gemcitabine in 28 patients with relapsed/refractory PTCL. Patients received escalating doses of intravenous copanlisib on days 1, 8, and 15, administered concomitantly with fixed-dose gemcitabine (1000 mg/m² on days 1 and 8) in 28-day cycles.

RESULTS

Dose-limiting toxicity was not observed in the dose-escalation phase and 60 mg copanlisib was selected for phase II evaluation. Twenty-five patients were enrolled in phase II of the study. Frequent grade ≥3 adverse events (AEs) included transient hyperglycemia (57%), neutropenia (45%), thrombocytopenia, (37%), and transient hypertension (19%). However, AEs were manageable, and none were fatal. The overall response rate was 72% with a CR rate of 32%. Median duration of response was 8.2 months, progression-free survival was 6.9 months, and median overall survival was not reached. Combination treatment produced a greater CR rate in patients with angioimmunoblastic T-cell lymphoma than those with PTCL-not otherwise specified (55.6% versus 15.4%, respectively, P = 0.074) and progression-free survival was significantly longer (13.0 versus 5.1 months, respectively, P = 0.024). In an exploratory gene mutation analysis of 24 tumor samples, TSC2 mutation was present in 25% of patients and occurred exclusively in responders.

CONCLUSION

The combination of copanlisib and gemcitabine is a safe and effective treatment option in relapsed/refractory PTCLs and represents an important new option for therapy in this rare group of patients.

Combination of brentuximab-vedotin and ifosfamide, carboplatin, etoposide in relapsed/refractory peripheral T-cell lymphoma

OBJECTIVES

Relapsed/refractory peripheral T-cell lymphomas (PTCL) have a poor prognosis. We aimed at assessing efficacy of ifosfamide, carboplatin, etoposide (ICE) regimen, a known therapeutic option, to which we added brentuximab-vedotin (BV).

METHODS

In this study, we retrospectively analyzed patients with PTCL treated with BV-ICE in our center between July 2014 and March 2018.

RESULTS

Fourteen patients received BV-ICE. Median age was 62 years (range, 31-73). Main histological subtypes were PTCL-not otherwise specified (29%), angioimmunoblastic T-cell lymphoma (21%), follicular-T helper (21%), or anaplastic large-cell (15%) lymphomas, all were CD30 positive. Overall response was seen in four (29%) patients, and complete response (CR) in two (14%). Most frequent adverse events were infections, and cytopenia. 2-year progression-free and overall survival were 14% and 17.5%, respectively.

CONCLUSION

Patients with relapsed/refractory PTCL treated with BV-ICE can achieve CR, but few had a sustained response. This association should preferably be used as a bridge to stem cell transplant or be followed by maintenance therapy.

Brentuximab Vedotin in the Treatment of Peripheral T Cell Lymphoma and Cutaneous T Cell Lymphoma

PURPOSE OF REVIEW

The recent development of brentuximab vedotin (BV), an antibody-drug conjugate targeting CD30-positive cells, has led to therapeutic advances in the treatment of T cell lymphomas. In this review, we discuss key studies of BV in peripheral T cell lymphoma (PTCL) and cutaneous T cell lymphoma (CTCL) and highlight important questions for further investigation.

RECENT FINDINGS

Monotherapy with BV has proven to be effective and well tolerated in patients with relapsed/refractory (R/R) CD30-positive CTCL. BV has shown significant activity in R/R PTCL as well, with particularly durable responses in patients with anaplastic large cell lymphoma (ALCL). In a landmark phase III study (ECHELON-2), BV + CHP demonstrated superior progression-free and overall survival relative to CHOP as frontline therapy for patients with CD30-expressing PTCL, representing the first randomized trial demonstrating an overall survival benefit in PTCL. Though BV is overall well tolerated, peripheral neuropathy remains a clinically significant adverse effect. BV is a major therapeutic advance in the treatment of patients with R/R CTCL and of those with PTCL in both the R/R and frontline settings. Key ongoing areas of investigation include optimization of CD30 expression as a predictive biomarker as well as the role of BV in consolidation therapy.

Strategies for introducing palliative care in the management of relapsed or refractory aggressive lymphomas

Recent advances in treatment of patients with aggressive lymphomas ranging from chimeric antigen receptor T-cell therapy to combination of antibody-drug conjugates with chemotherapy have improved survival outcomes. Despite these significant advances, patients with relapsed or refractory disease experience high physical and psychological symptom burden, and a substantial proportion still die of their lymphoma. In addition, end-of-life care outcomes are suboptimal with high rates of intensive end-of-life health care use and low rates of timely hospice enrollment. Integrating palliative care concurrently with disease-directed care for this patient population has strong potential to improve their symptom burden, quality of life, and end-of-life care. Multiple factors, including heightened prognostic uncertainty in the setting of relapsed/refractory disease, pose challenges to timely provision of palliative care. This article reviews benefits of primary and specialty palliative care for patients with relapsed/refractory aggressive lymphomas and barriers to such care. It also highlights strategies for effectively integrating palliative care for patients with relapsed/refractory aggressive lymphomas.

Allogeneic stem cell transplantation in poor prognosis peripheral T-cell lymphoma: the impact of different donor type on outcome

We report the outcome of 68 patients with advanced peripheral T-cell lymphoma receiving transplantation from haploidentical or from conventional donors. The 4-year OS, PFS, 2-year cumulative incidence of relapse and 2-year GRFS was 75%, 70%, 21%, and 51%, respectively. Survival was not affected by donor type. The 2-year NRM was 9%, lower after related or haploidentical donor (21% vs 0% vs 7%; p = 0.06). Grade 2-4 aGVHD cumulative incidence was significantly different after transplantation from haploidentical vs matched sibling vs unrelated donor, and (24% vs 35% vs 58%, p = 0.024). The familial donor cohort was compared to the unrelated cohort. Familial donor induced less grade 2-4 aGVHD, with a trend to less grade 3-4 aGVHD or moderate-severe cGVHD. The OS and PFS were not different, while the relapse risk and NRM were reduced. Allo-SCT is highly effective in T-cell lymphoma, with low NRM and low relapse rate. The incidence of aGVHD was lower after haploidentical transplantation. Related donor may challenge unrelated transplant reducing the risk of relapse and NRM.

Combination of crizotinib and chemotherapy in patients with relapsed or refractory anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL)

Our aim was to explore the role of crizotinib, targeted anaplastic lymphoma kinase (ALK), on r/r systemic anaplastic large cell lymphoma (sALCL). The treated group prospectively screened 20 patients. After taking crizotinib in the first week, 16 patients who were tolerant and sensitive received the combination of crizotinib with chemotherapy. The control group included 27 patients receiving chemotherapy in the same hospital during the same period. The objective remission rates of the treated and control group were 81.3% and 74.1% (p = .869), respectively. The progression-free survival rates at two years in treated and control group were 68.7% and 45.0% (HR = 0.42, 95% CI 0.17-0.99, p < .05), respectively. The overall survival rates at two years in the treated and control group were 86.1% and 78.9% (p = .385, HR = 0.51, 95% CI 0.11-2.30), respectively. The main adverse events included elevated transaminase, diarrhea, and vision abnormalities. Thus, the combination of crizotinib with chemotherapy might be effective in ALK-positive and crizotinib sensitive r/r sALCL patients.

All-oral metronomic DEVEC schedule in elderly patients with peripheral T cell lymphoma

Purpose

Peripheral T cell lymphomas (PTCLs) have an overall poor prognosis. Indeed, registry data in elderly patients show that the median progression-free survival (mPFS) following first- and second-line therapies are only 6.7 and 3.1 months, respectively. The aim of the study is to show the activity of metronomic chemotherapy, a regular administration of low chemotherapeutic drug doses allowing a favourable toxicity profile, on elderly PTCL patients.

Methods

We report a series of 17 PTCL patients, treated with the all-oral metronomic schedule DEVEC (prednisolone–etoposide–vinorelbine–cyclophosphamide) in four Italian centres. Patients 5/17 (29.4%) were treatment-naïve (naïve) and 12/17 (70.6%) were relapsed-refractory (RR), respectively. The median age was 83 years (range 71–87) and 71.5 years (range 56–85) for naïve and RR, respectively. In vitro activity of metronomic vinorelbine (VNR), etoposide (ETO) and their concomitant combination on HH, a PTCL cell line, was also assessed.

Results

Histology: PTCL-not-otherwise-specified = 12; angioimmunoblastic = 2; NK/T nasal type = 1; adult-type leukaemia lymphoma = 1, transformed Mycosis Fungoides = 1. The overall response rate was 80 and 58% in naïve and RR, respectively; whereas the PFS was 20 in naïve (95% CI 0–43) and 11 months (95% CI 4.2–17.8) in RR. The occurrence of relevant adverse events was 23.5%, which was managed with ETO dose reduction. In vitro experiments showed that both metronomic VNR and ETO caused a significant inhibitory activity on HH cells and a strong synergism when administered concomitantly.

Conclusion

All-oral DEVEC showed an encouraging activity and acceptable toxicity. This schedule deserves further studies in elderly PTCL also for assessing combinations with targeted drugs.

Electronic supplementary material

The online version of this article (10.1007/s00280-020-04172-3) contains supplementary material, which is available to authorized users.

Pralatrexate in relapsed/refractory T-cell lymphoma: a retrospective multicenter study

We present a retrospective multicenter study of pralatrexate treatment outcomes in an Australian practice setting for patients with relapsed/refractory T-cell lymphoma who had failed 1+ systemic therapies, treated via a compassionate access program. Endpoints assessed included response rates, toxicities, and subsequent therapies. Progression-free survival (PFS), time to next treatment (TTNT), event-free survival (EFS), overall survival (OS), and time to best response, were assessed by Kaplan-Meier analysis. The study included 31 patients, with median age 69 years. We demonstrated ORR of 35.5% (n = 11), including 4 complete responses (13%) and 7 partial responses (23%). The predicted median OS was 10 months, with EFS of 9 months, and PFS of 9 months. Median TTNT was 8 months. Mucositis was the most commonly observed toxicity. This study - the second largest real-world cohort reported to date - underscores the importance of pralatrexate in relapsed/refractory T-cell lymphoma, as well as its acceptable toxicity profile.

Evaluation of prognosis following early disease progression in peripheral T-cell lymphoma

Recently, progression of disease within 24 months (POD24) has been demonstrated as a strong prognostic indicator in various types of malignant lymphoma. Peripheral T-cell lymphoma (PTCL) has an aggressive course and poor clinical outcomes. In this multicenter retrospective study, 111 consecutively registered patients with newly diagnosed PTCL were analyzed. Of these patients, 72 (64.9%) experienced POD24 (POD24 group), and the other 39 patients (35.1%) were analyzed as the no POD24 group. In the POD24 group, overall survival (OS) was significantly inferior to all patients, and in the no POD24 group, subsequent OS was significantly superior to the POD24 group, although the clinical characteristics between the POD24 group and no POD24 group were not significantly different. Twenty-three patients (20.7%) showed primary refractory disease to first-line therapy, and the prognosis was poor. The International Prognostic Index score and POD24 were identified as independent predictors in multivariate analysis for OS in all patients, and only performance status was an independent prognostic factor for OS in the POD24 group in multivariate analysis. In conclusion, the clinical significance of assessing POD24 in PTCL and the poor prognosis in patients with early disease progression were demonstrated.

Treatment approaches in relapsed or refractory peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of rare and aggressive non-Hodgkin’s lymphomas. Clinical staging, prognostic scoring, and initial treatment strategies have historically been based on paradigms developed in B-cell lymphomas. Despite primary treatment protocols that are typically anthracycline-based and frequently involve consolidative autologous stem cell transplantation in first remission, many patients develop disease progression. There remains a high unmet medical need for improved treatment strategies in the relapsed or refractory setting. Salvage chemotherapy and stem cell transplantation in those who are suitable has traditionally been the accepted approach, but this remains a minority of the total patient population. As increasing knowledge is gleaned regarding the biological heterogeneity within the various PTCL subtypes, newer targeted agents have been developed, studied, and approved in this small, heterogeneous population of relapsed or refractory disease. Given its success and tolerability in this pretreated population, brentuximab vedotin, an anti-CD30 antibody drug conjugate, was brought earlier in the disease course and is a model for advances in the targeted treatment of PTCL. As others undergo further development in the relapsed setting and successes are brought earlier in the disease course, the outcome for PTCL patients is likely to improve. However, innovative clinical trial designs are crucial for the assessment of targeted agents in this highly heterogeneous population. This review explores the current treatment environment for patients with relapsed and refractory PTCL, including newer strategies such as targeted agents and immunotherapy.

Controversies in the Treatment of Peripheral T-cell Lymphoma

Peripheral T-cell lymphomas are a heterogeneous group of rare diseases with an aggressive behavior and dismal prognosis. Their classification is complex and still evolving, and several biomolecular markers now help refine the prognosis of specific disease entities, although still have limited impact in tailoring the treatment. First-line treatment strategies can cure only a minority of patients and relapsed-refractory disease still represents the major cause of failure. Frontline autologous transplantation may have an impact in the consolidation of response; however, its role is still questioned as far as complete responses obtained after induction chemotherapy are concerned. Newer drugs are now being evaluated in clinical trials, but effective salvage strategies for those who experience treatment failures are lacking. Here we review and discuss the most controversial aspects of diagnosis and treatment of peripheral T-cell lymphomas.

Phase I/Ib Study of Tenalisib (RP6530), a Dual PI3K δ/γ Inhibitor in Patients with Relapsed/Refractory T-Cell Lymphoma

Tenalisib (RP6530), a dual phosphoinositide 3-kinase δ/γ inhibitor was evaluated in a phase I/Ib study for maximum tolerated dose (MTD), pharmacokinetics, and efficacy in patients with relapsed/refractory peripheral and cutaneous T-Cell Lymphoma (TCL). Histologically confirmed (TCL) patients, with ≥1 prior therapy received Tenalisib orally in a 28-day cycle in doses of 200 to 800 mg twice daily (800 mg in fasting and fed state) in escalation phase (n = 19) and 800 mg twice daily (fasting) in expansion phase (n = 39). The most frequently reported treatment emergent adverse events (TEAE) and related TEAE were fatigue (45%) and transaminase elevations (33%), respectively. Most frequently reported related Grade ≥3 TEAE was transaminase elevation (21%). Two dose-limiting toxicities occurred in the 800 mg fed cohort; hence, 800 mg fasting dose was deemed MTD. Tenalisib was absorbed rapidly with a median half-life of 2.28 h. Overall response rate in 35 evaluable patients was 45.7% (3 complete response (CR); 13 partial response (PR)) and median duration of response was 4.9 months. Responding tumors showed a marked downregulation of CD30, IL-31 and IL-32α. With an acceptable safety and promising clinical activity, Tenalisib can be a potential therapeutic option for relapsed/refractory TCL. Currently, a phase I/II combination study with romidepsin is ongoing.

New preclinical models for angioimmunoblastic T-cell lymphoma: filling the GAP

Mouse models are essential to study and comprehend normal and malignant hematopoiesis. The ideal preclinical model should mimic closely the human malignancy. This means that these mice should recapitulate the clinical behavior of the human diseases such as cancer and therapeutic responses with high reproducibility. In addition, the genetic mutational status, the cell phenotype, the microenvironment of the tumor and the time until tumor development occurs, should be mimicked in a preclinical model. This has been particularly challenging for human angioimmunoblastic lymphoma (AITL), one of the most prominent forms of peripheral T-cell lymphomas. A complex network of interactions between AITL tumor cells and the various cells of the tumor microenvironment has impeded the study of AITL pathogenesis in vitro. Very recently, new mouse models that recapitulate faithfully the major features of human AITL disease have been developed. Here, we provide a summary of the pathology, the transcriptional profile and genetic and immune-phenotypic features of human AITL. In addition, we give an overview of preclinical models that recapitulate more or less faithfully human AITL characteristics and pathology. These recently engineered mouse models were essential in the evaluation of novel therapeutic agents for possible treatment of AITL, a malignancy in urgent need of new treatment options.

Targeting CD47 in Sézary syndrome with SIRPαFc

Sézary syndrome (SS), the leukemic variant of cutaneous T-cell lymphoma, has limited treatment options and rare occurrences of long-term remission, thus warranting research into new treatment approaches. CD47 has emerged as a promising target for multiple tumor types, but its role in SS remains unknown. Here, we show that CD47 is highly expressed on Sézary cells in the peripheral blood and skin, and the high level of CD47 expression correlates with worse overall survival (OS) in patients with SS. We also demonstrate that CD47 expression on Sézary cells is under the influence of interleukin 4 (IL-4), IL-7, and IL-13. Signal regulatory protein αFc (SIRPαFc; TTI-621), a novel CD47 decoy receptor, triggers macrophage-mediated phagocytosis of Sézary cells and, when administered in clinical trial settings, results in significant tumor load reduction. We conclude that inhibition of the CD47-SIRPα signaling pathway has therapeutic benefit for patients with SS. This trial was registered at www.clinicaltrials.gov as #NCT02663518.

DT2216-a Bcl-xL-specific degrader is highly active against Bcl-xL-dependent T cell lymphomas

BACKGROUND

Patients with advanced T cell lymphomas (TCLs) have limited therapeutic options and poor outcomes in part because their TCLs evade apoptosis through upregulation of anti-apoptotic Bcl-2 proteins. Subsets of TCL cell lines, patient-derived xenografts (PDXs), and primary patient samples depend on Bcl-xL for survival. However, small molecule Bcl-xL inhibitors such as ABT263 have failed during clinical development due to on-target and dose-limiting thrombocytopenia.

METHODS

We have developed DT2216, a proteolysis targeting chimera (PROTAC) targeting Bcl-xL for degradation via Von Hippel-Lindau (VHL) E3 ligase, and shown that it has better anti-tumor activity but is less toxic to platelets compared to ABT263. Here, we examined the therapeutic potential of DT2216 for TCLs via testing its anti-TCL activity in vitro using MTS assay, immunoblotting, and flow cytometry and anti-TCL activity in vivo using TCL cell xenograft and PDX model in mice.

RESULTS

The results showed that DT2216 selectively killed various Bcl-xL-dependent TCL cells including MyLa cells in vitro. In vivo, DT2216 alone was highly effective against MyLa TCL xenografts in mice without causing significant thrombocytopenia or other toxicity. Furthermore, DT2216 combined with ABT199 (a selective Bcl-2 inhibitor) synergistically reduced disease burden and improved survival in a TCL PDX mouse model dependent on both Bcl-2 and Bcl-xL.

CONCLUSIONS

These findings support the clinical testing of DT2216 in patients with Bcl-xL-dependent TCLs, both as a single agent and in rational combinations.

[Peripheral T cell lymphomas: diagnosis and treatment]

Peripheral T cell lymphomas are rare malignancies with aggressive course, with several different subtype described in the 2016 WHO classification. Their distribution across the world is heterogenous, with marked difference between Western and Asian country. Their clinical presentation often comprise extra-nodal involvement, B symptoms and immune system disorder which can lead to wrong diagnosis orientation. Make a right diagnosis need a experienced pathologist in close collaboration with clinical datas. Peripheral T cell lymphomas are in general associated with poor prognosis when treated with anthracyclines-based regimen, and several studies and trials focused on the use of intensified regimen or novel targeted agents, whose proper indication still remain to be clarified.

Epigenetic targeting in lymphoma

Despite considerable progress in the treatment of patients with lymphoid malignancies in recent decades, the prognosis of patients with relapsed or refractory lymphomas often remains disappointing. Increasing evidence has established the relevance of epigenetic alterations in the pathogenesis of lymphoid malignancies, and a succession of agents has been evaluated in clinical studies with varying efficacy. In the present review, we outline the importance of epigenetic modifications in lymphoma biology and discuss the published experience with epigenetic modifying agents by lymphoma subtype before considering ongoing clinical studies in this area.

Hypomethylating Agents in Lymphoma

OPINION STATEMENT

Epigenetic mutations are frequent and pathogenic in select subtypes of lymphoma, and agents modulating DNA and histone methylation-such as inhibitors of DNMT and EZH2, respectively-have demonstrated promise in treating these diseases. In particular, lymphomas derived from the germinal center-GC-DLBCL, FL, and AITL-are all characterized by epigenetic derangements. In an effort to target these derangements, DNMT inhibitors have been investigated as a means of improving responsiveness to chemotherapy in DLBCL patients, or as monotherapy or in combination with other epigenetic agents in the treatment of TCL. Histone methyltransferase inhibitors have demonstrated effectiveness in R/R FL patients with EZH2-activating mutations. New treatment options that target the pathogenesis of disease are needed. HDAC inhibitors have been in the clinic for over a decade for the treatment of lymphoma, and now methyltransferase inhibitors are finding their niche for this disease.

Contemporary strategies to improve outcomes for peripheral T-cell lymphoma patients following the failure of first-line therapy

INTRODUCTION

T cell lymphomas are a heterogeneous group, with varying incidences, geographic patterns, and risk factors. Although until recently approached in a manner similar to B cell lymphomas, the treatment outcomes are poor and this disease is characterized by high relapse rates. The treatment advances in PTCL have been slow compared to B cell lymphomas. The outcomes of patients who progress following stem cell transplantation are worse.

AREAS COVERED

This review focuses on the novel targeted agents that are approved and/or are under investigation for patients with relapsed/refractory PTCL. We conducted an electronic literature search of the studies using PubMed, clincaltrials.gov, MEDLINE, using the key words 'PTCL,' 'second line therapy,' and 'targeted agents.' Studies published before January 2020 were included in the search criteria.

EXPERT OPINION

Development of newer therapies such as HDAC inhibitors and kinases are promising new agents with activity in relapsed/refractory PTCL. Combination therapy using novel agents may be the future for treatment of PTCL. Therapies in the next few years may take a more personalized approach taking into consideration not just the histology, but also the epigenomic landscape.