Current and future immunotherapeutic approaches in Hodgkin lymphoma

[Checkpoint inhibitors in Hodgkin lymphoma]

BACKGROUND

Checkpoint blockade contributes to the immunosuppressive microenvironment in classical Hodgkin lymphoma (cHL) and in particular the interaction of Hodgkin cells and macrophages with T‑cells and natural killer cells via programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1).

OBJECTIVES

The aim of this article is the evaluation the role and potential of checkpoint blockade in cHL as compared with the results of standard chemo- and radiotherapy.

METHODS

We analyzed preclinical and clinical data from phase I and phase II studies with checkpoint blockade in cHL.

RESULTS AND DISCUSSION

In 60-70% of patients with chemotherapy-refractory cHL, PD‑1 blockade results in responses. Overall survival is excellent and a small number of patients achieve persistent response. Thus, the use of anti-PD‑1 monoclonal antibodies has become an important treatment approach in relapsed cHL in line with the label. The results of first-line therapy are still preliminary; initial phase II studies using nivolumab in combination with doxorubicin (=adriamycin), vinblastin and dacarbazin (AVD) in early unfavorable or advanced stages showed response rates of up to 90%. Thus, implementing immunomodulatory approaches using PD 1‑blockade have resulted in a significant reduction of chemotherapy. This might represent a paradigm shift in the therapy of cHL.

Autologous hematopoietic cell transplantation for the treatment of relapsed/refractory pediatric, adolescent, and young adult Hodgkin lymphoma: a single institutional experience

Pediatric, adolescent, and young adult patients with relapsed or refractory Hodgkin lymphoma receive multimodal therapy, including autologous hematopoietic cell transplantation (AutoHCT). Despite aggressive therapy, historical outcomes for this patient population have been poor. This paper describes a single institutional experience utilizing AutoHCT in 74 patients treated from 1988-2015. Our results demonstrate significantly improved outcomes over time. Compared with patients treated in the earlier era (1988-2001), 5-year overall survival improved from 62.5 ± 9.6% to 91.8 ± 4.4% (p < 0.001) and event free survival improved from 41.7 ± 9.6% to 87.7 ± 5.3% (I < 0.001) for patients treated in a later era (2002-2015). Improvements in survival are multifactorial, including reductions in both relapse and nonrelapse mortality. Further investigation is needed to determine the role of AutoHCT in a modern treatment cohort that includes frequent use of targeted immunotherapies. In addition, as the use and availability of effective novel therapeutics increases for this patient population there may be an opportunity for the reduction of standard cytotoxic therapies, including in AutoHCT preparative regimens, thereby mitigating late effects.

Current targeted therapies in lymphomas

Purpose

This article summarizes current targeted therapies that have received regulatory approval for the treatment of B- and T-cell lymphomas.

Summary

Over the last 20 years, new drug therapies for lymphomas of B cells and T cells have expanded considerably. Targeted therapies for B-cell lymphomas include: (1) monoclonal antibodies directed at the CD20 lymphocyte antigen, examples of which are rituximab, ofatumumab, and obinutuzumab; (2) gene transfer therapy, an example of which is chimeric antigen receptor–modified T-cell (CAR-T) therapy directed at the CD19 antigen expressed on the cell surface of both immature and mature B cells; and (3) small-molecule inhibitors (ibrutinib, acalabrutinib, copanlisib, duvelisib, and idelalisib) that target the B-cell receptor signaling pathway. Of note, brentuximab vedotin is an antibody–drug conjugate that targets CD30, another lymphocyte antigen expressed on the cell surface of both Hodgkin lymphoma (a variant of B-cell lymphoma) and some T-cell lymphomas. Although aberrant epigenetic signaling pathways are present in both B- and T-cell lymphomas, epigenetic inhibitors (examples include belinostat, vorinostat, and romidepsin) are currently approved by the Food and Drug Administration for T-cell lymphomas only. In addition, therapies that target the tumor microenvironment have been developed. Examples include mogamulizumab, bortezomib, lenalidomide, nivolumab, and pembrolizumab. In summary, the efficacy of these agents has led to the development of supportive care to mitigate adverse effects, due to the presence of on- or off-target toxicities.

Conclusion

The therapeutic landscape of lymphomas has continued to evolve. In turn, the efficacy of these agents has led to the development of supportive care to mitigate adverse effects, due to the presence of on- or off-target toxicities. Further opportunities are warranted to identify patients who are most likely to achieve durable response and reduce the risk of disease progression. Ongoing trials with current and investigational agents may further elucidate their place in therapy and therapeutic benefits.

Time for radioimmunotherapy: an overview to bring improvements in clinical practice

Harnessing the patient's own immune system against an established cancer has proven to be a successful strategy. Within the last years, several antibodies blocking critical "checkpoints" that control the activation of T cells, the immune cells able to kill cancer cells, have been approved for the use in patients with different tumours. Unfortunately, these cases remain a minority. Over the last years, radiotherapy has been reported as a means to turn a patient's own tumour into an in situ vaccine and generate anti-tumour T cells in patients who lack sufficient anti-tumour immunity. Indeed, review data show that the strategy of blocking multiple selected immune inhibitory targets in combination with radiotherapy has the potential to unleash powerful anti-tumour responses and improve the outcome of metastatic solid tumours. Here, we review the principal tumours where research in this field has led to new knowledge and where radioimmunotherapy becomes a reality.

Extracellular Vesicles: New Players in Lymphomas

Lymphomas are heterogeneous diseases, and the term includes a number of histological subtypes that are characterized by different clinical behavior and molecular phenotypes. Valuable information on the presence of lymphoma cell-derived extracellular vesicles (LCEVs) in the bloodstream of patients suffering from this hematological cancer has recently been provided. In particular, it has been reported that the number and phenotype of LCEVs can both change as the disease progresses, as well as after treatment. Moreover, the role that LCEVs play in driving tumor immune escape has been reported. This makes LCEVs potential novel clinical tools for diagnosis, disease progression, and chemoresistance. LCEVs express surface markers and convey specific molecules in accordance with their cell of origin, which can be used as targets and thus lead to the development of specific therapeutics. This may be particularly relevant since circulating LCEVs are known to save lymphoma cells from anti-cluster of differentiation (CD)20-induced complement-dependent cytotoxicity. Therefore, effort should be directed toward investigating the feasibility of using LCEVs as predictive biomarkers of disease progression and/or response to treatment that can be translated to clinical use. The use of liquid biopsies in combination with serum EV quantification and cargo analysis have been also considered as potential approaches that can be pursued in the future. Upcoming research will also focus on the identification of specific molecular targets in order to generate vaccines and/or antibodies against LCEVs. Finally, the removal of circulating LCEVs has been proposed as a simple and non-invasive treatment approach. We herein provide an overview of the role of LCEVs in lymphoma diagnosis, immune tolerance, and drug resistance. In addition, alternative protocols that utilize LCEVs as therapeutic targets are discussed.

[18F]FDG-PET/CT in Hodgkin Lymphoma: Current Usefulness and Perspectives

Functional imaging using 18-fluorodeoxyglycose ([¹⁸F]FDG) positron emission tomography combined with computed tomography (PET/CT) has become a major imaging modality in Hodgkin lymphoma. This imaging modality allows for a significant improvement in staging, increased sensitivity, which involves differentiating residual tumors from fibrosis during assessment, and highly impacts treatment decisions into new PET-driven strategies. This review presents the main scientific data concerning the current applications of [¹⁸F]FDG-PET/CT in Hodgkin lymphoma at baseline, interim, and the end of treatment evaluation along with the main PET-driven trials for therapeutic decisions. The emergence of total metabolic tumor volume as a new functional prognostic factor will also be discussed.

Toxicity Management: Development of a Novel and Immune-Mediated Adverse Events Algorithm

BACKGROUND

Novel immunotherapy and biologic agents are being developed with the potential to improve outcomes and reduce long-term toxicities among individuals with hematologic malignancies. These emerging drugs affect neoplastic cells and the surrounding microenvironment, causing unique immune-mediated toxicities.
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OBJECTIVES

The aim was to develop an algorithm for clinical staff to manage unique toxicities associated with next-generation immunotherapies indicated in the hematologic population, using a system-focused approach.
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METHODS

Data were collected using specific toxicities based on the four major novel biologic classes. Immune-mediated adverse events were reported across studies. Based on published literature, institutional experience, and group consensus, a novel algorithm for managing immune-mediated toxicities was created.
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FINDINGS

The development of this treatment algorithm provides a more streamlined approach for managing common but unique toxicities and improves safety, compliance, patient outcome, and quality of life with novel immuno-oncologic agents.

The evolving role of targeted drugs in the treatment of Hodgkin lymphoma

INTRODUCTION

Hodgkin lymphoma (HL) is a B-cell-derived malignancy mostly affecting young adults. More than 80% of patients are cured after stage-adapted first-line treatment with chemotherapy and/or radiotherapy. About 50% of patients with disease recurrence achieve long-term remission with second-line treatment consisting of high-dose chemotherapy and autologous stem cell transplantation. However, HL treatment is often associated with acute toxicity and in part life-threatening late effects. Implementing targeted drugs may reduce toxicity and potentially further optimize efficacy. In recent years, the CD30-directed antibody-drug conjugate brentuximab vedotin (BV) and anti-PD-1 antibodies, nivolumab and pembrolizumab, underwent extensive evaluation in HL. They have exhibited encouraging single agent activity and a favorable toxicity profile in patients with multiple relapses. Therefore, they are currently under investigation in different additional indications. Areas covered: This article gives an overview over clinical trials evaluating targeted drugs either as single agent or as part of combination therapies in HL patients. Expert commentary: A multitude of targeted drugs are investigated in HL. Promising data have particularly emerged from studies with BV and anti-PD-1 antibodies. However, mature data needed for final conclusions are still pending.

Novel treatment concepts in Hodgkin lymphoma

Treatment of classical Hodgkin's lymphoma (HL) has been a success story, with cure of localized disease with radiotherapy in the 1930s, cure of advanced stages with combination chemotherapy with/without radiotherapy in the mid-1960s and continuous improvements since then. Nonetheless, at present approximately 2% of patients with classical HL are primarily refractory to conventional therapy with only 50% becoming long-term survivors. Another 13% of patients relapse, with only 60% being alive 10 years postrecurrence (as exemplified in this review in a Swedish cohort of 18- to 65-year-old patients diagnosed during the period 1992-2009). Recently, novel targeted drugs were approved for refractory/relapsed HL and here we review results of trials that form the basis for these approvals as well as new trials. In summary, brentuximab vedotin can be used in refractory patients (i) as a complement to high-dose chemotherapy with autologous stem cell transplantation (SCT) improving the chances of being able to proceed to an allogenic SCT and cure, (ii) as consolidation after autologous SCT and (iii) as palliative life-prolonging treatment. However, we have yet to determine whether this drug provides the greatest benefit in first- or second-line treatment, as consolidation or in refractory disease or relapse. Trials of immune checkpoint inhibitors, such as those targeting programmed death 1 (nivolumab and pembrolizumab), and thus not primarily the tumour cells, have shown overall response rates of >65%. Long-term results and data from Phase III trials are still lacking, but nivolumab recently gained approval in refractory patients already treated with brentuximab vedotin and autologous SCT. Other novel treatments of interest include T cells with a chimeric antigen receptor and combination therapies with histone deacetylase inhibitors.

Personalisierte Medizin in der Hämatologie am Beispiel der akuten myeloischen Leukämie

Fortschritte in der genetischen Charakterisierung von Leukämien und Lymphomen haben in den letzten Jahren zielgerichtete Therapieansätze ermöglicht. So haben zum Beispiel BCR-ABL1-inhibierende Tyrosinkinaseinhibitoren (TKI) die Behandlung der chronischen myeloischen Leukämie (CML) revolutioniert. Im Gegensatz dazu hat sich die Behandlung der akuten myeloischen Leukämie (AML) in den letzten 40 Jahren nicht wesentlich verändert, wobei neueste Erkenntnisse beginnen, auch zielgerichtete Therapien in der AML zu ermöglichen. Als sehr heterogene Erkrankung mit unterschiedlichem Ausgang, je nach AML-Subtyp, haben jüngste Fortschritte im Verständnis der AML-Biologie und der Identifizierung von Treibermutationen eine neue Ära der molekularen Therapie ermöglicht. Eine Reihe von prognostischen und prädiktiven molekularen Markern und Signalwegen wurden als neue therapeutische Ziele entdeckt, wie z. B. die Aktivierung der Fms-like-tyrosinkinase-3(FLT3)-Rezeptortyrosinkinase oder aberrante DNA-Methylierungsmuster, denen eine Vielzahl unterschiedlicher Mutationen in epigenetischen Treibern zugrunde liegt. Aber auch zielgerichtete Therapien mit monoklonalen Antikörpern und weiteren Kinaseinhibitoren sind vielversprechende Therapieoptionen, die dazu beitragen könnten, die Heilungsrate der AML weiter verbessern zu können. In diesem Übersichtsartikel werden wir die aktuellen Ansätze zielgerichteter Therapien bei der AML beleuchten und einen Ausblick auf neuartige und bevorstehende therapeutische Optionen sowie einen kurzen Überblick zu den aktuellen Optionen bei weiteren hämatologischen Neoplasien geben.

The emerging role of immune checkpoint inhibition in malignant lymphoma

To evade elimination by the host immune system, tumor cells commonly exploit physiological immune checkpoint pathways, restraining efficient anti-tumor immune cell function. Growing understanding of the complex dialog between tumor cells and their microenvironment contributed to the development of immune checkpoint inhibitors. This innovative strategy has demonstrated paradigm-shifting clinical activity in various malignancies. Antibodies targeting programmed death 1 and cytotoxic T-lymphocyte-associated protein-4 are also being investigated in lymphoid malignancies with varying levels of activity and a favorable toxicity profile. To date, evaluated only in the setting of relapsed or refractory disease, anti-programmed death 1 antibodies such as nivolumab and pembrolizumab show encouraging response rates particularly in classical Hodgkin lymphoma but also in follicular lymphoma and diffuse-large B-cell lymphoma. As the first immune checkpoint inhibitor in lymphoma, nivolumab was approved for the treatment of relapsed or refractory classical Hodgkin lymphoma by the Food and Drug Administration in May 2016. In this review, we assess the role of the pathways involved and potential rationale of checkpoint inhibition in various lymphoid malignancies. In addition to data from current clinical trials, immune-related side effects, potential limitations and future perspectives including promising combinatory approaches with immune checkpoint inhibition are discussed.

Hodgkin Lymphoma Cells Have a Specific Long Noncoding RNA Expression Pattern

This commentary highlights the article by Tayari et al that suggests studying clinical implications of long noncoding RNAs as possible diagnostic and predictive biomarkers of Hodgkin lymphoma.