Long-Term Follow-Up of the Response-Adjusted Therapy for Advanced Hodgkin Lymphoma Trial

2-deoxy-2-[18F]FDG PET Imaging for Therapy Assessment in Hodgkin's and Non-Hodgkin Lymphomas

The 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography combined with computed tomography (PET/CT) has contributed to outcome improvement of patients with lymphoma. The use of [18F]FDG PET/CT for staging and response assessment is successfully applied both in routine clinical practice and in clinical trials. The challenges lie in enhancing the outcomes of lymphoma patients, particularly those with advanced or refractory/relapsed disease, and to minimize the long-term toxicity associated with treatments, including radiation therapy. The objective of this review article is to present contemporary data on the use of [18F]FDG PET/CT for treatment assessment of aggressive lymphomas.

The role of autologous stem-cell transplantation in classical Hodgkin lymphoma in the modern era

Despite excellent cure rates with modern front-line regimens, up to 20% of patients with Hodgkin lymphoma will progress through front-line therapy or experience disease relapse. Worldwide, salvage chemotherapy followed by high-dose chemotherapy with autologous stem cell transplantation (HDT/ASCT) is considered the standard of care for these patients and can cure approximately 50% of relapsed or refractory (R/R) patients in the second line. Brentuximab vedotin (BV), an anti-CD30 antibody drug conjugate, and PD1 inhibitors like nivolumab and pembrolizumab, have high response rates in patients who recur after HDT/ASCT. When used prior to HDT/ASCT, BV and PD1 inhibitors appear to dramatically increase the effectiveness of salvage therapies with complete response rates often double those seen with historic chemotherapy-based regimens and durable progression free survival (PFS) post-HDT/ASCT. Emerging data in adults and from pediatric trials showing a durable PFS in a subset of relapsed patients raises the question of whether HDT/ASCT is essential for cure in R/R patients after PD1 based salvage. Future studies will help clarify if ASCT can omitted PD1 based salvage to avoid the potential toxicity of HDT/ASCT without compromising cure.

Optimizing salvage therapy for Hodgkin lymphoma: progress and future challenges

INTRODUCTION

Despite clear advancements in the management of classical Hodgkin lymphoma (cHL) over the past decade including better risk stratification, the usage of 18F-flurodeoxyglucose positron emission tomography (FDG-PET)-guided approaches and incorporation of novel agents, approximately one-third of the patients will relapse. Important themes have been recently explored in the first salvage setting including the recognition of the positive prognostic value of a negative pre-autologous stem cell transplantation (ASCT) FDG-PET response and the incorporation of novel agents such as brentuximab vedotin (BV) and immune checkpoint inhibitors (CPIs) as salvage regimens to improve patient outcomes.

AREAS COVERED

The evolving treatment paradigm in optimizing salvage therapy in relapsed refractory cHL (RR-cHL) is discussed, including a vision to the future. The methodology included a literature search on PubMed using keywords. Selected articles were screened and evaluated by the authors of this review.

EXPERT OPINION

Achieving a complete remission by FDG-PET pre-ASCT is the most important prognostic factor in obtaining disease control and subsequent cure, and therefore should be a key goal of any salvage regimen. Although data from randomized controlled trials are currently lacking, retrospective evidence demonstrate superior event free survival with CPI-based regimens compared to conventional chemotherapy or BV-based therapy.

Treatment approaches for older Hodgkin lymphoma patients

PURPOSE

Hodgkin lymphoma (HL) occurs at two age peaks around 25 and 60 years of age. Due to varying fitness and co-morbidities older patients are a heterogeneous group that has relatively poor treatment outcomes. The evolving therapeutic landscape for older HL is summarized herein.

RECENT FINDINGS

Due to lack of data from larger trials and approval of novel drugs, first-line treatment of limited-stage HL (i.e. early-stage favourable and unfavourable) remains largely A(B)VD and radiotherapy based. For patients with advanced-stage HL, the anti-CD30 antibody-drug conjugate brentuximab vedotin is approved in combination with AVD chemotherapy (BV-AVD). Due to toxicities such as febrile neutropenia or polyneuropathy and lack of improvement in progression-free and overall survival in the older subgroup, fully concomitant BV-AVD is however not used widely. More recently, promising early data was reported with the combination of nivolumab and AVD (N-AVD) in patients >60 years with advanced-stage HL. Second-line treatment depends on fitness and might include high-dose chemotherapy and autologous stem-cell transplantation for selected patients. For unfit or multiply relapsed patients, anti-PD1 antibodies are the preferred treatment option.

SUMMARY

The increasing number of older HL patients constitutes a therapeutic challenge despite recent advances and the increased usage of targeted agents.

The role of response adapted therapy in the era of novel agents

The optimal treatment of classic Hodgkin Lymphoma (cHL) requires an individualized approach, with therapy guided by pretreatment clinical risk stratification and interim response assessment with positron emission tomography (PET). The overall goal is to achieve high cure rates while minimizing acute toxicity and late therapy-related effects. Interim PET-adapted strategies (iPET) were initially developed with traditional chemotherapy, reducing intensity after interim complete response and escalating treatment for patients with iPET+ disease. Recently, novel agents including brentuximab vedotin and the checkpoint inhibitor immunotherapies (CPIs) pembrolizumab and nivolumab have been adopted into the front-line treatment of cHL, and PET-adapted approaches may be relevant for these drugs as well. In this review we discuss response-adapted strategies utilizing novel agents, consider challenges including indeterminate radiographic findings with CPIs, and address emerging techniques for response assessment including new PET-based imaging metrics and the role of circulating tumor DNA.

Paradigm Shifts in Hodgkin Lymphoma Treatment: From Frontline Therapies to Relapsed Disease

Combination chemotherapy with or without radiation has served as the primary therapeutic option for classic Hodgkin lymphoma (cHL), leading to durable remission in a majority of patients with early- and advanced-stage cHL. Patients with relapsed/refractory (RR) cHL could still be cured with salvage chemotherapy and autologous stem-cell transplantation. Brentuximab vedotin (BV) and the anti-PD-1-blocking antibodies, nivolumab and pembrolizumab, are highly effective treatments for cHL and have revolutionized the management of the disease. Recent studies incorporating BV and PD-1 blockade into salvage therapy for RR cHL and into frontline treatment regimens have changed the cHL treatment paradigm. The novel agents are also useful in the treatment of older patients who have poor outcomes with traditional therapy. This manuscript will review current strategies for approaching the management of previously untreated, RR, and challenging populations with cHL, including how to incorporate the novel agents.

Harnessing multi-source data for individualized care in Hodgkin Lymphoma

Hodgkin lymphoma is a rare, but highly curative form of cancer, primarily afflicting adolescents and young adults. Despite multiple seminal trials over the past twenty years, there is no single consensus-based treatment approach beyond use of multi-agency chemotherapy with curative intent. The use of radiation continues to be debated in early-stage disease, as part of combined modality treatment, as well as in salvage, as an important form of consolidation. While short-term disease outcomes have varied little across these different approaches across both early and advanced stage disease, the potential risk of severe, longer-term risk has varied considerably. Over the past decade novel therapeutics have been employed in the retrieval setting in preparation to and as consolidation after autologous stem cell transplant. More recently, these novel therapeutics have moved to the frontline setting, initially compared to standard-of-care treatment and later in a direct head-to-head comparison combined with multi-agent chemotherapy. In 2018, we established the HoLISTIC Consortium, bringing together disease and methods experts to develop clinical decision models based on individual patient data to guide providers, patients, and caregivers in decision-making. In this review, we detail the steps we followed to create the master database of individual patient data from patients treated over the past 20 years, using principles of data science. We then describe different methodological approaches we are taking to clinical decision making, beginning with clinical prediction tools at the time of diagnosis, to multi-state models, incorporating treatments and their response. Finally, we describe how simulation modeling can be used to estimate risks of late effects, based on cumulative exposure from frontline and salvage treatment. The resultant database and tools employed are dynamic with the expectation that they will be updated as better and more complete information becomes available.