Romidepsin for the treatment of relapsed/refractory peripheral T-cell lymphoma: pivotal study update demonstrates durable responses

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.

Efficacy and safety of single-agent pralatrexate for treatment of angioimmunoblastic T-cell lymphoma after failure of first line therapy: a pooled analysis

Angioimmunoblastic T-cell lymphoma (AITL) is a histological subtype of peripheral T-cell lymphoma associated with a poor prognosis. This post-hoc pooled analysis aims to provide insight about the efficacy of pralatrexate monotherapy in a subset of twenty-nine patients with relapsed or refractory (r/r) AITL drawn from two prospective registration trials completed in China and Japan. After a median of two prior lines of therapy, an overall response rate of 52% (15/29 patients; 95% CI 0.34, 0.70) was demonstrated. The estimated median duration of response, progression free survival (PFS) and overall survival (OS) were 6.4 months (196 days), 5.0 months (151 days), and 18.0 months (548 days), respectively. Grades 1-3 mucositis was observed in twenty-three patients (79.3%); and hemato-toxicity in twenty-six (89.7%) patients. Results of this analysis corroborate with data from two previously reported US retrospective cohorts, supporting the potential benefits of pralatrexate monotherapy in patients with r/r AITL.

Biomarker-driven management strategies for peripheral T cell lymphoma

Peripheral T cell lymphomas are heterogeneous diseases which remain treatment challenges. Recent advances in molecular and genomic profiling have provided unprecedented insight into disease pathogenesis driven by distinct cells of origins and molecular pathways. The discovery and clinical application of molecular biomarkers in PTCL subtypes has the potential to transform personalized care for patients with PTCL in diagnosis, prognosis, and therapy. Targeting CD30+ PTCL with the antibody-drug conjugate brentuximab vedotin in the relapsed setting and in combination with chemotherapy in the frontline setting has improved patient survivals. Epigenetic modifying agents, including HDAC inhibitors and hypomethylating agents, have demonstrated broad clinical efficacy and durability and are in clinical development for combination strategies for both relapsed and frontline settings. Wide-ranging novel agents targeting critical intracellular pathways and tumor microenvironment are in active exploration to define clinical activities. This review summarizes PTCL-specific biomarkers which are increasingly incorporated in clinical practice to guide precision diagnosis and personalized treatment.

Assessing the efficacy-effectiveness gap for cancer therapies: A comparison of overall survival and toxicity between clinical trial and population-based, real-world data for contemporary parenteral cancer therapeutics

BACKGROUND

Although increasing evidence has suggested that an efficacy-effectiveness gap exists between clinical trial (CT) and real-world evidence (RWE), to the authors' knowledge, the magnitude of this difference remains undercharacterized. The objective of the current study was to quantify the magnitude of survival and toxicity differences between CT and RWE for contemporary cancer systemic therapies.

METHODS

Patients receiving cancer therapies funded under Cancer Care Ontario's New Drug Funding Program (NDFP) were identified. Landmark CTs with data regarding survival and adverse events (AEs) for each drug indication were identified. RWE for survival and hospitalization rates during treatment were ascertained through Canadian population-based databases. The efficacy-effectiveness gap for each drug indication was calculated as the difference between RWE and CT data for median overall survival (OS), 1-year OS, and generated hazard ratios (HRs) with 95% CIs from Kaplan-Meier OS curves. Toxicity differences were calculated as the difference between RWE of hospitalization rates and CT serious AE rates.

RESULTS

Twenty-nine indications from 20 systemic therapies were included. Twenty-eight of 29 indications (97%) demonstrated worse survival in RWE, with a median OS difference of 5.2 months (interquartile range, 3.0-12.1 months). Lower effectiveness in RWE also was demonstrated through a meta-analysis of an OS hazard ratio of 1.58 (95% CI, 1.39-1.80). The median difference between RWE for hospitalization rates and CT serious AEs was 14% (95% CI, 9%-22%).

CONCLUSIONS

An efficacy-effectiveness gap exists for contemporary cancer systemic therapies, with a 5.2-month lower median OS observed in RWE compared with CT data. These data supports the use of RWE to better inform real-world decision making regarding the use of cancer systemic therapies.

Research Advances in the Use of Histone Deacetylase Inhibitors for Epigenetic Targeting of Cancer

The causes and progression of cancer are controlled by epigenetic processes. The mechanisms involved in epigenetic regulation of cancer development, gene expression, and signaling pathways have been studied. Histone deacetylases (HDACs) have a major impact on chromatin remodeling and epigenetics, making their inhibitors a very interesting area of cancer research. This review comprehensively summarizes the literature regarding HDAC inhibitors (HDACis) as an anticancer treatment published in the past few years. In addition, we explain the mechanisms of their therapeutic effects on cancer. An analysis of the beneficial characteristics and drawbacks of HDACis also is presented, which will assist preclinical and clinical researchers in the design of future experiments to improve the therapeutic efficacy of these drugs and circumvent the challenges in the path of successful epigenetic therapy. Future therapeutic strategies may include a combination of HDACis and chemotherapy or other inhibitors to target multiple oncogenic signaling pathways.

Epidrugs: targeting epigenetic marks in cancer treatment

Growing evidence suggests that aberrant epigenetic regulation of gene function is strongly related to the genesis of cancer. Unlike genetic mutations, the ability to reprogram the epigenetic landscape in the cancer epigenome is one of the most promising target therapies in both treatment and reversibility of drug resistance. Epigenetic alterations in cancer development and progression may be the basis for the individual variation in drug response. Thus, this review focuses on the emerging area of pharmaco(epi)genomics, specifically highlighting epigenetic reprogramming during tumorigenesis and how epigenetic markers are targeted as a therapy (epidrugs) and the clinical implications of this for cancer treatment.

Aggressive T-cell lymphomas: 2019 updates on diagnosis, risk stratification, and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL) and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma. In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. The most promising is the CD30 directed antibody drug conjugate brentuximab vedotin. This has recently been approved by the Food and Drug Administration for the upfront treatment of CD30 expressing PTCLs in combination with cyclophosphamide, doxorubicin, and prednisone chemotherapy. Other notable targets are CD25, CCR4 tag, PI3kinase inhibitors, and JAK/STAT inhibitors. Anaplastic lymphoma kinase (ALK) inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell lymphomas and cutaneous T-cell lymphomas. For all other subtypes, immune checkpoint inhibitors should be used with extreme caution and only in the context of a clinical trial. Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL.

Prognostic factors and the impact of frontline therapy in peripheral T-cell lymphoma: 10 years of 'real-world' experience from Western Australia

We present an analysis of 98 consecutive patients with peripheral T-cell lymphoma (PTCL) treated over a 10-year period within Western Australia. The most common frontline therapies were CHO(E)P (47%), HyperCVAD (21%), and reduced intensity therapy or supportive care alone (19%). Median and 4-year overall survival (OS) for the whole cohort were 1.59 years and 34%. Amongst CHO(E)P and HyperCVAD-treated patients, elevated LDH, advanced stage, IPI >1, and non-ALK + ALCL histology predicted inferior progression-free survival (PFS). Inferior OS was predicted by elevated LDH, age >60, IPI >1, and non-ALK + ALCL histology. Response rates and PFS were not significantly different between patients treated with CHO(E)P or HyperCVAD. OS was longer in the HyperCVAD group, however this was not significant on multivariable analysis and appears to relate to the younger age and more aggressive therapy at relapse in this group. Our data confirmed the prognostic utility of the IPI in patients with PTCL and do not demonstrate a clear benefit of HyperCVAD.

A phase II trial of bendamustine, carboplatin, and dexamethasone for refractory or relapsed peripheral T-cell lymphoma (BENCART trial)

This trial was designed to investigate the efficacy and toxicity of bendamustine, carboplatin, and dexamethasone (BCD) for relapsed or refractory peripheral T-cell lymphomas (PTCLs), which would be expected to exhibit more promising clinical outcomes compared with bendamustine therapy alone. After treatments with BCD, eight patients exhibited a complete response (CR; 29%) and seven exhibited a partial response (PR; 25%). The overall response rate (ORR) was 54%. Five patients proceeded to ASCT and three patients finally achieved CR. The median progression-free survival (PFS) was 4.4 months (2.8-6.0, 95% CI). For a total of 85 cycles of BCD, grade 3 or 4 neutropenia, thrombocytopenia, and anemia occurred in 17.6, 38.8, and 16.5% of cycles, respectively. Only one patient experienced febrile neutropenia. BCD was a considerable salvage regimen for relapsed or refractory PTCLs with acceptable toxicity; AITL or ASCT eligible patients were more effective to BCD.ClinicalTrials.gov Identifier:NCT02424045.

Peripheral T-Cell Lymphoma: Moving Toward Targeted Therapies

Therapeutic advances for peripheral T-cell non-Hodgkin lymphoma (PTCL) have lagged behind their B-cell NHL counterparts in part because novel agents to treat PTCL have been developed empirically. The recent clinical success of brentuximab-vedotin suggests that novel therapies for PTCL can significantly improve outcomes when properly targeted. Aberrancies in T-cell receptor, Jak/STAT, and DNA methylation pathways play critical roles in T-NHL pathogenesis based on genomic studies and preclinical experimental validation. New strategies targeting these pathways in patients with PTCL are underway, and this clinical trial experience will possibly contribute to additional improvements in outcome for patients with these diseases.

Developing Targeted Therapies That Exploit Aberrant Histone Ubiquitination in Cancer

Histone ubiquitination is a critical epigenetic mechanism regulating DNA-driven processes such as gene transcription and DNA damage repair. Importantly, the cellular machinery regulating histone ubiquitination is frequently altered in cancers. Moreover, aberrant histone ubiquitination can drive oncogenesis by altering the expression of tumor suppressors and oncogenes, misregulating cellular differentiation and promoting cancer cell proliferation. Thus, targeting aberrant histone ubiquitination may be a viable strategy to reprogram transcription in cancer cells, in order to halt cellular proliferation and induce cell death, which is the basis for the ongoing development of therapies targeting histone ubiquitination. In this review, we present the normal functions of histone H2A and H2B ubiquitination and describe the role aberrant histone ubiquitination has in oncogenesis. We also describe the key benefits and challenges associated with current histone ubiquitination targeting strategies. As these strategies are predicted to have off-target effects, we discuss additional efforts aimed at developing synthetic lethal strategies and epigenome editing tools, which may prove pivotal in achieving effective and selective therapies targeting histone ubiquitination, and ultimately improving the lives and outcomes of those living with cancer.

Treatment and prognosis of mature (non-anaplastic) T- and NK-cell lymphomas in childhood, adolescents, and young adults

Paediatric non-Hodgkin lymphomas (pNHL) are a diverse group of malignancies characterised by nodal and/or extranodal involvement. Less common pNHL forms include those derived from mature T- and natural killer (NK) cells. Much of our current understanding of paediatric mature (non-anaplastic) T/NK-cell lymphomas with respect to pathogenesis, diagnosis and treatment is extrapolated from adult literature. At the Sixth International Symposium on Childhood, Adolescent and Young Adult Non-Hodgkin Lymphoma, convened September 26-29, 2018 in Rotterdam, The Netherlands, some important aspects on diagnosis and outcomes of mature (non-anaplastic) T/NK-cell lymphoma in children and adolescents were discussed and will be reviewed in here.

Randomized Phase III Study of Alisertib or Investigator's Choice (Selected Single Agent) in Patients With Relapsed or Refractory Peripheral T-Cell Lymphoma

PURPOSE

The aim of this open-label, first-in-setting, randomized phase III trial was to evaluate the efficacy of alisertib, an investigational Aurora A kinase inhibitor, in patients with relapsed/refractory peripheral T-cell lymphoma (PTCL).

PATIENTS AND METHODS

Adult patients with relapsed/refractory PTCL—one or more prior therapy—were randomly assigned 1:1 to receive oral alisertib 50 mg two times per day (days 1 to 7; 21-day cycle) or investigator-selected single-agent comparator, including intravenous pralatrexate 30 mg/m² (once per week for 6 weeks; 7-week cycle), or intravenous gemcitabine 1,000 mg/m² or intravenous romidepsin 14 mg/m² (days 1, 8, and 15; 28-day cycle). Tumor tissue (disease subtype) and imaging were assessed by independent central review. Primary outcomes were overall response rate and progression-free survival (PFS). Two interim analyses and one final analysis were planned.

RESULTS

Between May 2012 and October 2014, 271 patients were randomly assigned (alisertib, n = 138; comparator, n = 133). Enrollment was stopped early on the recommendation of the independent data monitoring committee as a result of the low probability of alisertib achieving PFS superiority with full enrollment. Centrally assessed overall response rate was 33% for alisertib and 45% for the comparator arm (odds ratio, 0.60; 95% CI, 0.33 to 1.08). Median PFS was 115 days for alisertib and 104 days for the comparator arm (hazard ratio, 0.87; 95% CI, 0.637 to 1.178). The most common adverse events were anemia (53% of alisertib-treated patients v 34% of comparator-treated patients) and neutropenia (47% v 31%, respectively). A lower percentage of patients who received alisertib (9%) compared with the comparator (14%) experienced events that led to study drug discontinuation. Of 26 on-study deaths, five were considered treatment related (alisertib, n = 3 of 11; comparator, n = 2 of 15). Two-year overall survival was 35% for each arm.

CONCLUSION

In patients with relapsed/refractory PTCL, alisertib was not statistically significantly superior to the comparator arm.

Development of new agents for peripheral T-cell lymphoma

INTRODUCTION

Peripheral T-cell lymphoma (PTCL) is a relatively rare, heterogeneous group of mature T-cell neoplasms generally associated with poor prognosis, partly because of refractoriness against conventional cytotoxic chemotherapies. To improve the outcome of patients with PTCL, the clinical development of several novel agents is currently under investigation.

AREAS COVERED

Since the first approval of pralatrexate (dihydrofolate reductase inhibitor) by the US Food and Drug Administration, belinostat, romidepsin (histone deacetylase inhibitors), and brentuximab vedotin (anti-CD30 antibody-drug conjugate) have been approved in the US, and many other countries. In addition, mogamulizumab (anti-CC chemokine receptor 4 antibody), chidamide (histone deacetylase inhibitor), and forodesine (purine nucleoside phosphorylase inhibitor) have been approved in Asian countries, including China, and Japan. In this review, we have summarized the available data regarding these approved agents and new agents currently under development for PTCL.

EXPERT OPINION

Novel agents will be a promising therapeutic option in selected patients with relapsed/refractory PTCL and will change the daily clinical practice in the treatment of PTCL. However, these are not a curative option when used as a single agent. Further clinical developments are expected, comprising 1) combination therapies of new agents with cytotoxic chemotherapies; 2) 'novel-novel' combinations; 3) immune therapies, including chimeric antigen receptor T-cell therapy; and 4) predictive marker analysis.

Natural Products and Chemical Biology Tools: Alternatives to Target Epigenetic Mechanisms in Cancers

DNA methylation and histone acetylation are widely studied epigenetic modifications. They are involved in numerous pathologies such as cancer, neurological disease, inflammation, obesity, etc. Since the discovery of the epigenome, numerous compounds have been developed to reverse DNA methylation and histone acetylation aberrant profile in diseases. Among them several were inspired by Nature and have a great interest as therapeutic molecules. In the quest of finding new ways to target epigenetic mechanisms, the use of chemical tools is a powerful strategy to better understand epigenetic mechanisms in biological systems. In this review we will present natural products reported as DNMT or HDAC inhibitors for anticancer treatments. We will then discuss the use of chemical tools that have been used in order to explore the epigenome.

Efficacy of ESHAP Regimen in Transplant Ineligible Patients With Relapsed/Refractory T-Cell Lymphoma

Background

Salvage chemotherapy is the mainstay for the treatment of relapsed/refractory peripheral T-cell lymphomas (R/R PTCLs). ESHAP regimen, consisting of etoposide, methylprednisolone, high-dose Ara-C, and cisplatin is considered one of the well-accepted regimens for R/R lymphoma. Though, the evidence of long-term efficacy of ESHAP on R/R PTCLs is limited. This study aims to determine the efficacy and safety of ESHAP as a first salvage regimen, not followed by autologous stem cell transplantation (ASCT), in R/R PTCLs.

Methods

Patients with PTCLs, who progressed after one prior therapy and received ESHAP as a salvage treatment without subsequent ASCT, were recruited from the prospective observational study in the patients with lymphoma.

Results

From January 2005 to April 2015, 33 patients with R/R PTCLs received ESHAP as first salvage regimen at Chiang Mai University Hospital. The overall response rate was 46% (complete remission (CR) 39%). The median duration of response was 18 months. Median second progression-free survival (PFS) and overall survival (OS) were 8.0 and 11.0 months, respectively. Patients having late relapse had more favorable OS than those having early relapsed or refractory disease with a median OS of 21, 17 and 3 months, respectively (P = 0.001). Patients achieving CR after ESHAP had significantly better median OS (39, 7 and 5 months, P < 0.0001) and second PFS (33, 2 and 2 months, P < 0.0001) than those achieving PR or having progressive disease. Grade 3-4 neutropenia (45.5%) and thrombocytopenia (33.4%) were common but manageable.

Conclusions

ESHAP offers a long-term survival in some transplant ineligible patients with PTCLs who were chemosensitive with late relapse after front-line therapy. These results require further investigation in a prospective study.

Recent Advances in the Treatment of Peripheral T-Cell Lymphoma

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of clinically aggressive diseases associated with poor outcome. Despite progress in the last several years, resulting in a deeper understanding of the natural history and biology of PTCL based on molecular profiling and next-generation sequencing, there is a need for improvement in efficacy of chemotherapeutic regimens for newly diagnosed patients. Treatment in the front-line setting is most often cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like regimens, which are associated with a high failure rate and frequent relapses. Trials evaluating intensive chemotherapy have resulted in variable success in prolonging event-free survival, but overall survival has remained unchanged. Furthermore, this strategy is limited to patients who are in complete remission after initial anthracycline-based chemotherapy. Many patients are ineligible for hematopoietic stem cell transplantation because of age or failure to achieve remission. For relapsed disease, advances have been made in the therapeutic arsenal for PTCL. New drugs investigated in phase II studies have achieved response rates between 10% and 30%. However, to date the identification of new therapies has been largely empiric, and long-term remissions are the exception to the rule. Current patient outcomes suggest the need for the identification and development of active and biologically rational therapies to improve disease management and to extend the duration of response with iterative biomarker evaluation. This review covers the management of PTCL and focuses on new agents and therapeutic combinations, based on a better understanding of biology and pathogenesis of the disease.

IMPLICATIONS FOR PRACTICE

Recent progress in understanding of the biology and pathogenesis of peripheral T-cell lymphoma has led to the emergence of new drugs. Unfortunately, this has not been met with similar advances in outcome improvement. Anthracycline-containing regimens, mostly cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), are considered the standard of care, although the best first-line approach remains to be defined. In the relapsed and refractory settings, several new agents achieved response rates between 10% and 30%, although these drugs do not significantly affect survival rates. Therapeutic options based on better molecular characterization of various histological types and combinations with the CHOP regimen or synergic combinations of new drugs may lead to better outcomes.

Peripheral T-cell lymphoma - are we making progress?

Peripheral T cell lymphoma (PTCL) is a rare subtype of non-Hodgkin lymphoma. PTCLs are heterogeneous in terms of biology, but generally have more aggressive features and poorer outcomes than aggressive B-cell lymphomas when treated with combination chemotherapy. While the best long-term results are still seen with intensive chemotherapeutic approaches, significant progress has been made with molecular profiling identifying genetic drivers of PTCL that could serve as therapeutic targets. Tailoring therapy to different subtypes of PTCL may lead to more individualized approaches with the hope of improved outcomes. In this paper, we review current therapies for treatment of PTCL, newly identified molecular markers, and the role of emerging therapy and novel combinations of existing agents.

Forodesine in the treatment of relapsed/refractory peripheral T-cell lymphoma: an evidence-based review

T-cell lymphoma is a rare hematologic malignancy with an incidence rate between 10% and 20% of that of non-Hodgkin lymphomas. Patients with peripheral T-cell lymphoma (PTCL) generally have a poor prognosis when treated with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)/CHOP-like chemotherapy; once relapse occurs, it is mostly regarded as an incurable disease. To overcome the chemorefractoriness of PTCL, several novel agents have been developed. Since the first approval of pralatrexate, a dihydrofolate reductase inhibitor, for relapsed/refractory PTCL by the US Food and Drug Administration, several new agents, such as romidepsin (histone deacetylase inhibitor), brentuximab vedotin (antibody–drug conjugate targeting CD30), chidamide (histone deacetylase inhibitor), and mogamulizumab (anti-CC chemokine receptor 4 monoclonal antibody), have been approved as a therapeutic option for relapsed/refractory PTCL in several countries, including the US, Europe, China, and Japan. Forodesine is a novel, potent purine nucleoside phosphorylase inhibitor that is effective against T-cell malignancies. Although the clinical development of forodesine was discontinued in the US and Europe, a multicenter Phase I/II study of oral forodesine for relapsed PTCL was recently completed in Japan. The overall response rate was 24% (10 of 41 patients), which included four patients with complete response. In general, the toxicity of forodesine is manageable. As the study met the primary end point, forodesine was approved for the treatment of relapsed/refractory PTCL in Japan in March 2017, which was the first approval of forodesine in the world. As forodesine is an oral formulation, it is more convenient than other novel intravenous agents approved for PTCL. However, it is necessary to appropriately manage opportunistic infections and secondary lymphomas possibly associated with long-lasting lymphocytopenia caused by forodesine. In this manuscript, we have summarized the currently available evidence for forodesine and discussed the clinical implications for PTCL treatment.

Survival following salvage therapy for primary refractory peripheral T-cell lymphomas (PTCL)

Optimal salvage therapy for primary refractory peripheral T-cell lymphomas (PTCL) and the role of hematopoietic stem cell transplant (SCT) remain poorly defined. We conducted a retrospective review of clinical outcomes and prognostic factors in a single-center cohort of 93 patients with primary refractory PTCL, defined as progression during first-line therapy or relapse within 6 months of its completion. Clinical outcomes were poor in this population, with median event-free survival (EFS) of 3.5 months, median overall survival (OS) of 9.1 months, and 34% 3-year survival. Outcomes were comparable in patients who progressed through first-line therapy and patients who achieved CR/PR and subsequently relapsed within 6 months. A majority exhibited high-risk features and had intermediate to high risk IPI, which correlated with inferior outcomes. There was no difference in outcomes between patients who received single-agent salvage regimens and patients who underwent traditional, multi-agent salvage regimens. Thus, participation in well-designed clinical trials should be encouraged in this population. Additionally, there may be a trend toward improved EFS and OS in patients who underwent autologous or allogeneic SCT compared to patients who achieved CR or PR but were not transplanted.

Epimutational profile of hematologic malignancies as attractive target for new epigenetic therapies

In recent years, recurrent somatic mutations in epigenetic regulators have been identified in patients with hematological malignancies. Furthermore, chromosomal translocations in which the fusion protein partners are themselves epigenetic regulators or where epigenetic regulators are recruited/targeted by oncogenic fusion proteins have also been described. Evidence has accumulated showing that "epigenetic drugs" are likely to provide clinical benefits in several hematological malignancies, granting their approval for the treatment of myelodysplastic syndromes and cutaneous T-cell lymphomas. A large number of pre-clinical and clinical trials evaluating epigenetic drugs alone or in combination therapies are ongoing. The aim of this review is to provide a comprehensive summary of known epigenetic alterations and of the current use of epigenetic drugs for the treatment of hematological malignancies.

Activity of the PI3K-δ,γ inhibitor duvelisib in a phase 1 trial and preclinical models of T-cell lymphoma

Duvelisib (IPI-145) is an oral inhibitor of phosphatidylinositol 3-kinase (PI3K)-δ/γ isoforms currently in clinical development. PI3K-δ/γ inhibition may directly inhibit malignant T-cell growth, making duvelisib a promising candidate for patients with peripheral (PTCL) or cutaneous (CTCL) T-cell lymphoma. Inhibition of either isoform may also contribute to clinical responses by modulating nonmalignant immune cells. We investigated these dual effects in a TCL cohort from a phase 1, open-label study of duvelisib in patients with relapsed or refractory PTCL (n = 16) and CTCL (n = 19), along with in vitro and in vivo models of TCL. The overall response rates in patients with PTCL and CTCL were 50.0% and 31.6%, respectively (P = .32). There were 3 complete responses, all among patients with PTCL. Activity was seen across a wide spectrum of subtypes. The most frequently observed grade 3 and 4 adverse events were transaminase increases (40% alanine aminotransferase, 17% aspartate aminotransferase), maculopapular rash (17%), and neutropenia (17%). Responders and nonresponders had markedly different changes in serum cytokine profiles induced by duvelisib. In vitro, duvelisib potently killed 3 of 4 TCL lines with constitutive phospho-AKT (pAKT) vs 0 of 7 lines lacking pAKT (P = .024) and exceeded cell killing by the PI3K-δ-specific inhibitor idelalisib. Administration of duvelisib to mice engrafted with a PTCL patient-derived xenograft resulted in a shift among tumor-associated macrophages from the immunosuppressive M2-like phenotype to the inflammatory M1-like phenotype. In summary, duvelisib demonstrated promising clinical activity and an acceptable safety profile in relapsed/refractory TCL, as well as preclinical evidence of both tumor cell-autonomous and immune-mediated effects. This trial was registered at www.clinicaltrials.gov as #NCT01476657.

Recent advances in understanding and managing T-cell lymphoma

Owing to the rarity of peripheral T-cell lymphoma (PTCL) and the heterogeneity of subtypes, there are no compelling data to guide the therapeutic approaches for such patients. Over the years, there have been remarkable advances in molecular subtyping and treatment of PTCL, although there are still many areas to be explored. In this review, we summarize recent updates on the evolution of understanding and treatment for PTCL.

A single center phase II study of ixazomib in patients with relapsed or refractory cutaneous or peripheral T-cell lymphomas

The transcription factor GATA-3, highly expressed in many cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphomas (PTCL), confers resistance to chemotherapy in a cell-autonomous manner. As GATA-3 is transcriptionally regulated by NF-κB, we sought to determine the extent to which proteasomal inhibition impairs NF-κB activation and GATA-3 expression and cell viability in malignant T cells. Proteasome inhibition, NF-κB activity, GATA-3 expression, and cell viability were examined in patient-derived cell lines and primary T-cell lymphoma specimens ex vivo treated with the oral proteasome inhibitor ixazomib. Significant reductions in cell viability, NF-κB activation, and GATA-3 expression were observed preclinically in ixazomib-treated cells. Therefore, an investigator-initiated, single-center, phase II study with this agent in patients with relapsed/refractory CTCL/PTCL was conducted. Concordant with our preclinical observations, a significant reduction in NF-κB activation and GATA-3 expression was observed in an exceptional responder following one month of treatment with ixazomib. While ixazomib had limited activity in this small and heterogeneous cohort of patients, inhibition of the NF-κB/GATA-3 axis in a single exceptional responder suggests that ixazomib may have utility in appropriately selected patients or in combination with other agents.

A phase 1 study of romidepsin and pralatrexate reveals marked activity in relapsed and refractory T-cell lymphoma

Peripheral T-cell lymphomas (PTCL) are a group of rare malignancies characterized by chemotherapy resistance and poor prognosis. Romidepsin and pralatrexate were approved by the US Food and Drug Administration for patients with relapsed/refractory PTCL, exhibiting response rates of 25% and 29% respectively. Based on synergy in preclinical models of PTCL, we initiated a phase 1 study of pralatrexate plus romidepsin in patients with relapsed/refractory lymphoma. This was a single institution dose-escalation study of pralatrexate plus romidepsin designed to determine the dose-limiting toxicities (DLTs), maximum tolerated dose, pharmacokinetic profile, and response rates. Patients were treated with pralatrexate (10 to 25 mg/m²) and romidepsin (12 to 14 mg/m²) on 1 of 3 schedules: every week × 3 every 28 days, every week × 2 every 21 days, and every other week every 28 days. Treatment continued until progression, withdrawal of consent, or medical necessity. Twenty-nine patients were enrolled and evaluable for toxicity. Coadministration of pralatrexate and romidepsin was safe, well tolerated, with 3 DLTs across all schedules (grade 3 oral mucositis × 2; grade 4 sepsis × 1). The recommended phase 2 dose was defined as pralatrexate 25 mg/m² and romidepsin 12 mg/m² every other week. Twenty-three patients were evaluable for response. The overall response rate was 57% (13/23) across all patients and 71% (10/14) in PTCL. The phase 1 study of pralatrexate plus romidepsin resulted in a high response rate in patients with previously treated PTCL. A phase 2 study in PTCL will determine the efficacy of the combination. This trial was registered at www.clinicaltrials.gov as #NCT01947140.

[Lymphomas: A therapeutic update]

Emergence of new molecules has considerably reshaped the management of patients in onco-hematology. Cytotoxic chemotherapy has not been altered, and CHOP remains the reference treatment for lymphomas. However, the development of targeted therapies has allowed for a broader spectrum of treatments. Immunotherapy with monoclonal antibodies entered the market with rituximab in diffuse large B-cell lymphomas, in the 1990s and it is now developing as new-generation anti-CD20 antibodies (obinotuzumab and ofatumumab). Anti-CD30 antibodies have been proposed in the treatment of T lymphomas and Hodgkin lymphomas. More recently, anti-PD1 antibodies have brought new perspectives in several cancers and more specifically in Hodgkin's lymphoma. Finally the BTK inhibitor, ibrutinib developed in the LLC has established itself in the management of mantle cell lymphoma and Waldenström macroglobulinemia. How can we deal with all these new molecules? Should they be offered as monotherapy or in association? In first line or relapse? The objective of this review is to trace history of the latest advances, and to highlight the validated strategies representing the new standards of treatment of lymphomas in 2017.

Non-Hodgkin lymphoma

Lymphomas can affect any organ in the body, present with a wide range of symptoms, and be seen by primary care physicians and physicians from most specialties. They are traditionally divided into Hodgkin's lymphoma (which accounts for about 10% of all lymphomas) and non-Hodgkin lymphoma, which is the topic of this Seminar. Non-Hodgkin lymphoma represents a wide spectrum of illnesses that vary from the most indolent to the most aggressive malignancies. They arise from lymphocytes that are at various stages of development, and the characteristics of the specific lymphoma subtype reflect those of the cell from which they originated. Since this topic was last reviewed in The Lancet in 2012, advances in understanding the biology and genetics of non-Hodgkin lymphoma and the availability of new diagnostic methods and therapies have improved our ability to manage patients with this disorder.

Romidepsin in Japanese patients with relapsed or refractory peripheral T-cell lymphoma: a phase I/II and pharmacokinetics study

This phase I/II multicenter study evaluated romidepsin treatment in Japanese patients with relapsed/refractory peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma (CTCL). Patients aged ≥20 years received romidepsin via a 4-h intravenous infusion on days 1, 8, and 15 of each 28-day cycle. Phase I used a 3 + 3 design to identify any dose-limiting toxicity (DLT) for regimens of romidepsin 9 and 14 mg/m². The primary endpoints for phase I and II were DLT and overall response rate (ORR), respectively. Intent-to-treat patients were those who received ≥1 romidepsin dose (PTCL, n = 48; CTCL, n = 2). In phase I, none of the patients (n = 3, 9 mg/m²; n = 6, 14 mg/m²) exhibited DLT. In phase II, 40 patients with PTCL were treated with 14 mg/m² romidepsin. The most common treatment-emergent grade ≥3 adverse events were lymphopenia (74%), neutropenia (54%), leukopenia (46%), and thrombocytopenia (38%). Patients in phase II showed a 43% ORR, including 25% complete responses. Median progression-free survival was 5.6 months and median duration of response was 11.1 months. This phase I/II study identified a well-tolerated dose of romidepsin, with an acceptable toxicity profile and clinically meaningful efficacy in Japanese patients with relapsed/refractory PTCL. ClinicalTrials.gov Identifier NCT01456039.

Complete remission with romidepsin in a patient with T-cell acute lymphoblastic leukemia refractory to induction hyper-CVAD

T‐cell acute lymphoblastic leukemia (T‐ALL) and T‐cell lymphoblastic lymphoma (T‐LBL) are neoplasms that originate from T‐cell precursors. Outcomes in adult patients with T‐ALL/LBL remain unsatisfactory; early relapse following intensive induction chemotherapy is a concern, and patients with relapsed or refractory disease have a poor prognosis. Romidepsin is a potent, class 1 selective histone deacetylase inhibitor approved for the treatment of patients with peripheral T‐cell lymphoma who have had ≥1 prior therapy and patients with cutaneous T‐cell lymphoma who have had ≥1 prior systemic therapy. Here, we report the case of an adult patient with T‐ALL refractory to induction hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper‐CVAD). Treatment with romidepsin was initiated, and romidepsin in combination with hyper‐CVAD resulted in complete remission, with mild tumor lysis syndrome as the only detectable additional toxicity. The patient eventually underwent allogeneic stem cell transplant while in first complete remission. Prior studies have shown that romidepsin is capable of inducing durable responses with manageable toxicities in patients with mature T‐cell lymphomas. This case study describes the successful use of romidepsin in combination with hyper‐CVAD in an adult patient with refractory T‐ALL and highlights the activity of romidepsin in the T‐cell lineage. The potential of romidepsin‐containing regimens in patients with T‐ALL/LBL deserves further study.

Romidepsin is effective and well tolerated in older patients with peripheral T-cell lymphoma: analysis of two phase II trials

Peripheral T-cell lymphomas (PTCLs) are a rare group of lymphoid neoplasms with high relapse rates after initial therapy and poor prognosis. Most patients are aged ≥60 years and are often not candidates for aggressive salvage therapies. Romidepsin, a potent class I histone deacetylase inhibitor, has shown significant single-agent activity in relapsed/refractory PTCL. We evaluated the efficacy and tolerability of romidepsin in elderly patients in this setting. Ninety-five patients aged ≥60 years were identified from 2 prospective phase 2 registration trials of romidepsin, and comparative analyses were performed with younger patients from these trials. Response rates, progression-free survival, and overall survival were not statistically different for younger vs older patients. The toxicity profile in older and younger patients was similar in both trials. Romidepsin demonstrated similar efficacy and tolerability in younger and older patients and presents an attractive treatment option for relapsed/refractory PTCL regardless of age.

TRIAL REGISTRATION

Clinicaltrials.gov identifiers: NCT00426764, NCT00007345.

THZ1 targeting CDK7 suppresses STAT transcriptional activity and sensitizes T-cell lymphomas to BCL2 inhibitors

Peripheral T-cell lymphomas (PTCL) are aggressive diseases with poor response to chemotherapy and dismal survival. Identification of effective strategies to target PTCL biology represents an urgent need. Here we report that PTCL are sensitive to transcription-targeting drugs, and, in particular, to THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7). The STAT-signalling pathway is highly vulnerable to THZ1 even in PTCL cells that carry the activating STAT3 mutation Y640F. In mutant cells, CDK7 inhibition decreases STAT3 chromatin binding and expression of highly transcribed target genes like MYC, PIM1, MCL1, CD30, IL2RA, CDC25A and IL4R. In surviving cells, THZ1 decreases the expression of STAT-regulated anti-apoptotic BH3 family members MCL1 and BCL-XL sensitizing PTCL cells to BH3 mimetic drugs. Accordingly, the combination of THZ1 and the BH3 mimetic obatoclax improves lymphoma growth control in a primary PTCL ex vivo culture and in two STAT3-mutant PTCL xenografts, delineating a potential targeted agent-based therapeutic option for these patients.

T-cell lymphomas are aggressive diseases associated with poor outcome. Here, the authors show that the THZ1, a CDK7 inhibitor, suppresses STAT transcriptional activity leading to apoptosis and sensitization to BCL2 inhibitors in T-cell lymphomas.

Safety and efficacy of abexinostat, a pan-histone deacetylase inhibitor, in non-Hodgkin lymphoma and chronic lymphocytic leukemia: results of a phase II study

Histone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in B-cell lymphomas. Abexinostat is an orally available hydroxamate-containing histone deacetylase inhibitor that differs from approved inhibitors; its unique pharmacokinetic profile and oral dosing schedule, twice daily four hours apart, allows for continuous exposure at concentrations required to efficiently kill tumor cells. In this phase II study, patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia received oral abexinostat at 80 mg BID for 14 days of a 21-day cycle and continued until progressive disease or unacceptable toxicity. A total of 100 patients with B-cell malignancies and T-cell lymphomas were enrolled between October 2011 and July 2014. All patients received at least one dose of study drug. Primary reasons for discontinuation included progressive disease (56%) and adverse events (25%). Grade 3 or over adverse events and any serious adverse events were reported in 88% and 73% of patients, respectively. The most frequently reported grade 3 or over treatment-emergent related adverse events were thrombocytopenia (80%), neutropenia (27%), and anemia (12%). Among the 87 patients evaluable for efficacy, overall response rate was 28% (complete response 5%), with highest responses observed in patients with follicular lymphoma (overall response rate 56%), T-cell lymphoma (overall response rate 40%), and diffuse large B-cell lymphoma (overall response rate 31%). Further investigation of the safety and efficacy of abexinostat in follicular lymphoma, T-cell lymphoma, and diffuse large B-cell lymphoma implementing a less dose-intense week-on-week-off schedule is warranted. (Trial registered at: EudraCT-2009-013691-47)

Autologous stem cell transplantation as frontline strategy for peripheral T-cell lymphoma: A single-centre experience

Objective To determine the efficacy and prognosis of autologous hematopoietic stem cell transplantation (ASCT) as frontline treatment for peripheral T cell lymphoma (PTCL). Methods Clinical data from 46 PTCL patients who achieved complete (CR) or partial remission (PR) after ASCT from October 1996 to July 2014 were analysed retrospectively. Results Median patient age was 32 (range: 15-68) years. Disease types included PTCL, unspecified type, in 23 patients, anaplastic large cell lymphoma in eight, angioimmunoblastic lymphoma in eight, extranodal NK/T-cell lymphoma in five, and hepatosplenic T-cell lymphoma and enteropathy associated T-cell lymphoma in one each. Of these patients, 80% had Prognostic Index for Peripheral T-cell Lymphoma scores ≥1. Thirty-four patients had pre-transplantation CR and 12 had PR. Median follow up was 37 (6-176) months. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 77.1% and 61.9%, respectively. Multivariate analysis showed that pre-transplantation CR was an independent risk factor for survival, and CR was more common than PR (OS 81% vs 59.3%; PFS 71.8% vs 17.8%). Conclusion Frontline consolidation treatment with ASCT was associated with favourable outcomes in patients with PTCL. Pre-transplantation CR was a prognostic factor for survival, suggesting that ASCT may be favoured as front-line consolidation therapy after first complete remission.