Salvage Radiotherapy in Patients With Relapsed and Refractory Hodgkin’s Lymphoma: A Retrospective Analysis From the German Hodgkin Lymphoma Study Group

Patterns of progression after immune checkpoint inhibitors for Hodgkin lymphoma: implications for radiation therapy

ABSTRACT

Immune checkpoint inhibitors (ICIs) have demonstrated remarkable response rates in relapsed or refractory Hodgkin lymphoma (HL). Still, most patients eventually progress. Patterns of progression after ICIs are not well described and are essential to defining the role of local therapies in combination with ICIs. We identified patients who received ICIs for HL between 2013 and 2022. Fludeoxyglucose-18 positron emission tomography (FDG-PET) before initiating ICI and at progression on/after ICI were reviewed, and areas of active HL were recorded. An exploratory analysis of treatable progression included patients with ≤5 sites of disease on pre-ICI FDG-PET and progression only at pre-ICI sites. Ninety patients were identified; 69 had complete records, and of these, 32 (52%) had relapsed at ICI initiation, 17 (25%) were refractory, and 16 (23%) received ICI as first-line therapy. Forty-five of 69 patients had ≤5 sites of disease (limited) on pre-ICI FDG-PET. Patients with >5 sites of disease had a higher risk of progression, and every site of disease >5 sites conferred an additional 1.2x higher chance of progression. At a median follow-up of 4.0 years, 41 of 69 patients had progressed on/after ICIs (cumulative incidence 66.4%), and of these, 22 of 41 patients progressed only at pre-ICI sites (cumulative incidence 39.4%). In an exploratory analysis, the cumulative incidence of a treatable progression among 45 patients with limited disease was 34%. The cumulative incidence of any progression among this cohort was 58.9%. More than one-third of patients with limited disease before ICIs experienced progression only at pre-ICI sites of disease. These patients could be candidates for radiation during or after ICIs.

Optimizing Treatment for Relapsed/Refractory Classic Hodgkin Lymphoma in the Era of Immunotherapy

Most patients with classic Hodgkin lymphoma (cHL) are cured with combination chemotherapy, but approximately 10-20% will relapse, and another 5-10% will have primary refractory disease. The treatment landscape of relapsed/refractory (R/R) cHL has evolved significantly over the past decade following the approval of brentuximab vedotin (BV), an anti-CD30 antibody-drug conjugate, and the PD-1 inhibitors nivolumab and pembrolizumab. These agents have significantly expanded options for salvage therapy prior to autologous hematopoietic cell transplantation (AHCT), post-transplant maintenance, and treatment of relapse after AHCT, which have led to improved survival in the modern era. In this review, we highlight our approach to the management of R/R cHL in 2023 with a focus on choosing first salvage therapy, post-transplant maintenance, and treatment of relapse after AHCT. We also discuss the management of older adults and transplant-ineligible patients, who require a separate approach. Finally, we review novel immunotherapy approaches in clinical trials, including combinations of PD-1 inhibitors with other immune-activating agents as well as novel antibody-drug conjugates, bispecific antibodies, and cellular immunotherapies. Ongoing studies assessing biomarkers of response to immunotherapy and dynamic biomarkers such as circulating tumor DNA may further inform treatment decisions and enable a more personalized approach in the future.

Sequencing novel agents in the treatment of classical Hodgkin lymphoma

INTRODUCTION

Classical Hodgkin lymphoma (cHL) is a curable disease, with durable remission achieved in about 80% of patients following first-line treatment. Three new drugs were introduced to the daily use in cHL: brentuximab vedotin (BV), nivolumab, and pembrolizumab. All three drugs were initially approved for the treatment of relapsed/refractory cHL (RRHL) and with their promising outcomes, they are now incorporated in different stages of the treatment.

AREAS COVERED

We performed a literature search using PubMed on all cHL studies investigating BV and CPIs within the past 10 years. We analyzed literature to presume the sequencing of these novel agents.

EXPERT OPINION

Addition of BV or nivolumab to AVD backbone in the frontline setting showed promising activity in advanced stage cHL. BV and CPIs combined with chemotherapy in the second-line treatment of cHL are evaluated in phase 2 studies and comparable results are reported. The results of BrECADD, with good efficacy and toxicity profile, should be followed. Pembrolizumab was shown to be more effective in RRHL compared to BV in patients who have relapsed post-ASCT or ineligible for ASCT. BV is used in post-ASCT maintenance in high-risk cases, although its role will be questioned as it is increasingly used in the frontline treatment.

Do all patients with primary refractory/first relapse of HL need autologous stem cell transplant?

The standard approach to treatment of primary refractory/first relapse of classical Hodgkin lymphoma (cHL) is administration of second-line therapy (SLT) followed by consolidation with high-dose therapy and autologous hematopoietic cell transplantation (HDT/AHCT). Historically, this approach cured about 50% of patients. Due to improvements in supportive care, positron emission tomography-adaptive strategies, and incorporation of novel agents into SLT, contemporary studies show that about 75% of patients with primary refractory or first relapse of cHL can be cured. Recent studies evaluating incorporation of PD-1 blockade in SLT appear to show even further improvement in remission rates and bring into question whether an aggressive approach that includes HDT/AHCT is needed for everyone. To address this question, several ongoing studies are beginning to explore the possibility of avoiding or delaying HDT/AHCT for patients with primary refractory or first relapse of cHL.

Novel Salvage Therapy Options for Initial Treatment of Relapsed/Refractory Classical Hodgkin's Lymphoma: So Many Options, How to Choose?

The treatment landscape for relapsed/refractory classical Hodgkin's lymphoma (cHL) has evolved with the introduction of several novel agents. Historically, the standard of care for relapsed cHL was salvage chemotherapy followed by autologous stem cell transplant (ASCT). However, many patients are ineligible for ASCT or will have poor responses to salvage chemotherapy and ASCT. Brentuximab vedotin (BV) and checkpoint inhibitors (nivolumab/pembrolizumab) were initially approved in the post-ASCT setting. However, as a result of excellent responses and durable outcomes in this setting, they are now being studied and explored in earlier lines of therapy. Additionally, these agents are also being studied for post-transplant consolidation and maintenance with promising results in improving progression-free survival. We will review current salvage therapy options involving these novel agents and provide comparisons between regimens to aid the clinician in selecting the appropriate salvage regimen for patients who progress after first-line therapy.

A systematic literature review of the epidemiology, quality of life, and economic burden, including disease pathways and treatment patterns of relapsed/refractory classical Hodgkin lymphoma

INTRODUCTION

A systematic literature review was conducted to understand disease burden in patients with relapsed/refractory classical Hodgkin lymphoma (R/R cHL).

AREAS COVERED

Embase®, PubMed®, and Cochrane were searched for records from 2001 to 2020 in accordance with PRISMA guidelines. A total of 13,257 abstracts and 1731 papers were screened; 144 studies were identified. cHL accounted for 0.5% of all cancers, with 4‒66.7% of cases progressing to R/R disease (studies with >500 patients); this range varied across countries. Quality of life (QoL) was assessed via EORTC-QLQ-C30 (n = 7), EQ-5D (n = 5), SF-36 (n = 3), FACIT-F (n = 1), and MFI (n = 1) questionnaires. In general, pembrolizumab and other programmed cell death protein-1 inhibitors improved QoL scores. Brentuximab vedotin showed mixed outcomes, and high-dose therapy (HDT) and autologous stem-cell rescue (ASCR) showed worsening functionality/symptoms. Economic burden studies (n = 21) reported increased costs and health care resource in R/R cHL. Across clinical guidelines (n = 13) and treatment pattern studies (n = 46), HDT followed by ASCR was recommended as initial R/R cHL treatment. Pembrolizumab and nivolumab were frequently recommended for patients relapsing following HDT/ASCR.

EXPERT OPINION

Despite recent treatment advances, patients with R/R cHL continue to report reduced quality of life. Unmet medical needs remain, particularly with respect to slowing disease progression and identifying the best treatment approaches for improving longer-term survival and quality of life. This systematic literature review provides an extensive overview of the current landscape in patients with R/R cHL, focusing on four key areas: epidemiology, QoL, economic burden, and disease management. These findings will be useful to those with an interest in managing patients with R/R cHL or in designing future studies.

Clinical outcomes of relapsed and refractory Hodgkin lymphoma patients after contemporary first-line treatment: a German Hodgkin Study Group analysis

To evaluate patterns of rrHL after contemporary first-line treatment we studied 409 patients with first rrHL (HD13: n = 87, HD14: n = 118, HD15: n = 188, HDR3i: n = 51) at a median age of 37.4 years (18.4-76.8) from the GHSG database. Time to first relapse was ≤12 months in 49% and stage III/IV rrHL present in 52% of patients. In total, 291 patients received high-dose chemotherapy and autologous stem-cell transplantation (ASCT) and intended ASCT failed in 38 patients. ASCT was primarily not intended in 80 patients largely due to low risk disease or age/comorbidities. Overall, 10-year progression-free (PFS) and overall survival (OS) rates after first relapse were 48.2% (95% CI 41.9-54.2%) and 59.4% (95% CI 53.0-65.2%), respectively, with significant differences between subgroups. Inferior survival was observed with no ASCT due to advanced age/comorbidities (five-year PFS 36.2%, 95% CI 17.7-55.0%) or failure of salvage therapy (five-year PFS 36.3%, 95% CI 19.7-53.2%). Similarly, presence of primary refractory disease or stage IV at rrHL conferred inferior survival. In patients with low-risk disease, however, survival appeared favorable even without ASCT (10 y PFS 72.6%, 95% CI 53.7-84.8%). We herein confirm the curative potential of current rrHL treatments providing a robust benchmark to evaluate novel therapeutic strategies in rrHL. Approximately 50% of rrHL patients experienced a consecutive relapse.

Current salvage therapies in Hodgkin lymphoma

Hodgkin lymphoma is a B-cell malignancy with approximately 85-95% complete remission rate following frontline therapy; however, relapsed/refractory disease occurs in roughly 10-30% of patients after treatment. Salvage therapy conventionally relies upon cytotoxic chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation. A considerable number of patients experience relapse after transplantation, and further salvage management has included the use of allogeneic transplantation and radiotherapy. In the past decade, novel therapies including, brentuximab vedotin, PD-1 inhibitors, and the incorporation of PET-imaging into management have changed the paradigm of relapsed/refractory disease care. Novel therapies have been investigated in both single and combination regimens with other novel therapies and traditional chemotherapies. There is promising early work into the utility of CD30.CAR-T cell therapy, AFM13, camidanlumab tesirine, novel PD-1 inhibitors, and JAK1/JAK2 inhibition in management. Herein, we will review current salvage therapies in Hodgkin lymphoma and future directions in relapsed/refractory disease management.

Clinico-Epidemiological Profile, Prognostic Factors and Treatment Outcome of Refractory Hodgkin Lymphoma

Approximately 5-10% of patients with Hodgkin lymphoma are refractory to initial treatment. The aim of our study was to assess the clinico-epidemiological profile, prognostic factors and treatment outcome. A retrospective study was conducted over a period of 12 years between June 2006 and January 2018 at the oncology department of Salah Azaïz Institute. Thirty-one patients were included. The median age was 27 years with a female predominance (sex ratio = 0.93).The majority had an advanced stage (61%). IGEV regimen was the most commonly used salvage chemotherapy (n = 14). Age above 30 years was predictive of treatment failure after salvage therapy (p = 0.003). IGEV regimen showed better results than ICE protocol in terms of response to salvage therapy (p = 0.048). Seven patients had salvage radiotherapy. Four patients had autologous stem cell transplant. Progressive disease (n = 12) was the main cause of non-eligibility of autologous stem cell tansplant. Overall survival and progression free survival at 3 years were 50% and 5% respectively. The prognostic factors influencing the overall survival were age above 30 years (p = 0.001), advanced Ann Arbor stage before progression (p = 0.02), advanced Ann Arbor stage of refractory Hodgkin lymphoma (p = 0.001), histological subtype (p = 0.001), CD20 expression (p = 0.027) and non-response to salvage therapy (p = 0.004). The prognostic factor influencing progression free survival was the non-response to salvage therapy (p = 0.045). The prognosis of refractory Hodgkin lymphoma remains poor. The current standard secondary treatment consists of combination therapy, usually followed by autologous stem cell transplantat. Innovative therapies are needed to improve the prognosis of refractory Hodgkin lymphoma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-021-01463-4.

Immune checkpoint inhibitors in combination with radiotherapy as salvage treatment for relapsed/refractory classical Hodgkin lymphoma: A retrospective analysis in 12 patients

The rate of complete remission (CR) with the anti-PD1 immune checkpoint inhibitors (ICI) nivolumab (N) and pembrolizumab (P) in patients with relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) is low (20-30%), and the majority of patients eventually relapse. One strategy to improve their outcome is to combine ICI with radiotherapy (ICI-RT), taking advantage of a supposed synergistic effect. We retrospectively collected data of 12 adult patients with R/R cHL treated with ICI-RT delivered during or within 8 weeks from the start or after the end of ICI. Median age at ICI-RT was 37 years, 50% had previously received an autologous stem cell transplantation (SCT) and 92% brentuximab vedotin. RT was given concurrently, before or after ICI in 4, 1 and 7 patients. Median RT dose was 30Gy, for a median duration of 22 days. Median number of ICI administrations was 15. Overall response and CR rate were 100% and 58%. Nine patients received subsequent SCT consolidation (7 allogeneic and 2 autologous). After a median follow-up of 18 months, 92% of patients were in CR. No major concerns about safety were reported. ICI-RT combination appears to be a feasible and highly active bridge treatment to transplant consolidation.

Checkpoint Inhibition Therapy in Transplant-Ineligible Relapsed or Refractory Classic Hodgkin Lymphoma

The checkpoint inhibitors nivolumab and pembrolizumab are principal treatment options for relapsed or refractory classic Hodgkin lymphoma. In patients who decline autologous stem-cell transplantation or who are unsuited for high-dose chemotherapy and subsequent autologous stem-cell transplantation because of comorbidities, the use of checkpoint inhibitors may improve overall survival and have a manageable side effect profile. This clinical review provides an evidence-based summary to guide practicing oncologists in the use of checkpoint inhibitors in relapsed or refractory classic Hodgkin lymphoma and includes checkpoint inhibitor efficacy and adverse effect profiles. We highlight the use of checkpoint inhibitors in the management of relapsed or refractory classic Hodgkin lymphoma in patients who are ineligible for an autologous stem-cell transplant with the goal of improving disease control while limiting adverse events.

Relapse After Early-Stage, Favorable Hodgkin Lymphoma: Disease Characteristics and Outcomes With Conventional or High-Dose Chemotherapy

PURPOSE

We evaluated disease and treatment characteristics of patients with relapse after risk-adapted first-line treatment of early-stage, favorable, classic Hodgkin lymphoma (ES-HL). We compared second-line therapy with high-dose chemotherapy and autologous stem cell transplantation (ASCT) or conventional chemotherapy (CTx).

METHODS

We analyzed patients with relapse after ES-HL treated within the German Hodgkin Study Group HD10+HD13 trials. We compared, by Cox proportional hazards regression, progression-free survival (PFS) after relapse (second PFS) treated with either ASCT or CTx and performed sensitivity analyses with overall survival (OS) from relapse and Kaplan-Meier statistics.

RESULTS

A total of 174 patients' disease relapsed after treatment in the HD10 (n = 53) and HD13 (n = 121) trials. Relapse mostly occurred > 12 months after first diagnosis, predominantly with stage I-II disease. Of 172 patients with known second-line therapy, 85 received CTx (49%); 70, ASCT (41%); 11, radiotherapy only (6%); and 4, palliative single agent therapies (2%). CTx was predominantly bleomycin, etoposide, doxorubicin cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP [68%]), followed by the combination regimen of doxorubicin, bleomycin, vinblastine, and dacarbazine (19%), or other regimens (13%). Patients aged > 60 years at relapse had shorter second PFS (hazard ratio [HR], 3.0; P = .0029) and were mostly treated with CTx (n = 33 of 49; 67%) and rarely with ASCT (n = 8; 16%). After adjustment for age and a disadvantage of ASCT after the more historic HD10 trial, we did not observe a significant difference in the efficacy of CTx versus ASCT for second PFS (HR, 0.7; 95% CI, 0.3 to 1.6; P = .39). In patients in the HD13 trial who were aged ≤ 60 years, the 2-year, second PFS rate was 94.0% with CTx (95% CI, 85.7% to 100%) versus 83.3% with ASCT (95% CI, 71.8% to 94.8%). Additional sensitivity analyses including OS confirmed these observations.

CONCLUSION

After contemporary treatment of ES-HL, relapse mostly occurred > 12 months after first diagnosis. Polychemotherapy regimens such as BEACOPP are frequently administered and may constitute a reasonable treatment option for selected patients with relapse after ES-HL.

Relapsed, Refractory, or Advanced Hodgkin Lymphoma: A Single-Center Experience

PURPOSE

To assess the treatment and outcomes of patients with relapsed, refractory, or advanced Hodgkin lymphoma treated with consolidation or salvage radiotherapy.

PATIENTS AND METHODS

We studied all patients diagnosed with this profile treated by radiotherapy in our center between 2006 and 2019.

RESULTS

A total of 33 patients who received external-beam radiotherapy for advanced (21%), relapsed (52%), or refractory (24%) Hodgkin lymphoma were studied. Median [interquartile range] age was 25 [22-38] years, with 11 women (33%). The follow-up after first-line treatment was 28 [10-53] months. Number of chemotherapy lines received before radiotherapy was 3 [1-4]. Fourteen patients (42%) had undergone autologous stem-cell transplantation before radiotherapy, and 2 patients were treated by radiotherapy alone. Nine patients (27%) were treated by involved-field radiotherapy, 17 (52%) by involved-site radiotherapy, 5 (17%) by involved-node radiotherapy, and 2 by other volumes. The acute toxicity profile was favorable, with grade 1 radiodermatitis (33%) or dysphagia (30%). Overall, 21 patients (64%) experienced prolonged complete response and 12 experienced relapse (36%) after radiotherapy. Median disease-free survival was 68.8 months.

CONCLUSIONS

External-beam radiotherapy should be considered an effective treatment modality for advanced, relapsed, or refractory Hodgkin lymphoma as part of a multimodal approach.

Hodgkin lymphoma

Hodgkin lymphoma (HL) is a B cell lymphoma characterized by few malignant cells and numerous immune effector cells in the tumour microenvironment. The incidence of HL is highest in adolescents and young adults, although HL can affect elderly individuals. Diagnosis is based on histological and immunohistochemical analyses of tissue from a lymph node biopsy; the tissue morphology and antigen expression profile enable classification into one of the four types of classic HL (nodular sclerosis, mixed cellularity, lymphocyte-depleted or lymphocyte-rich HL), which account for the majority of cases, or nodular lymphocyte-predominant HL. Although uncommon, HL remains a crucial test case for progress in cancer treatment. HL was among the first systemic neoplasms shown to be curable with radiation therapy and multiagent chemotherapy. The goal of multimodality therapy is to minimize lifelong residual treatment-associated toxicity while maintaining high levels of effectiveness. Recurrent or refractory disease can be effectively treated or cured with high-dose chemotherapy followed by autologous haematopoietic stem cell transplantation, and prospective trials have demonstrated the potency of immunotherapeutic approaches with antibody-drug conjugates and immune checkpoint inhibitors. This Primer explores the wealth of information that has been assembled to understand HL; these updated observations verify that HL investigation and treatment remain at the leading edge of oncological research.

Hodgkin Lymphoma, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology for Hodgkin Lymphoma (HL) provide recommendations for the management of adult patients with HL. The NCCN panel meets at least annually to review comments from reviewers within their institutions, examine relevant data, and reevaluate and update their recommendations. Current management of classic HL involves initial treatment with chemotherapy alone or combined modality therapy followed by restaging with PET/CT to assess treatment response. Overall, the introduction of less toxic and more effective regimens has significantly advanced HL cure rates. This portion of the NCCN Guidelines focuses on the management of classic HL.

Treatment of Hodgkin Lymphoma Relapsed after Autologous Stem Cell Transplantation

Although autologous stem cell transplantation (auto-HCT) is the standard of care for patients with refractory/relapsed (R/R) classical Hodgkin’s lymphoma (cHL), there is still a significant proportion of patients that relapse after the procedure. This review contemplates different treatment strategies for patients with cHL that relapse or progress after auto-HCT. Allogeneic stem cell transplantation (allo-HCT) has, for many years, been the only curative option for this group of patients. Although the advent of haploidentical donors has allowed for the possibility to allograft almost all patients that are in need of it and to eventually improve historical results, allo-HCT is still associated with substantial morbidity and mortality. Brentuximab vedotin (BV) is an antibody drug conjugate that binds to CD30 antigen; BV is able to give up to 34% metabolic complete remissions (mCR) in HL patients that fail auto-HCT. Unleashing the immune system with PD-1 inhibitors has resulted in remarkable responses in a number of malignancies, including HL. Nivolumab and pembrolizumab offer a 20%–25% mCR and 40%–50% partial remissions, with an acceptable safety profile. R/R cHL do have several options nowadays that, without any doubt, have significantly improved the long-term outcome of this hard-to-treat population.

Resources-Stratified Guidelines for Classical Hodgkin Lymphoma

Hodgkin lymphoma is a haematological malignancy predominantly affecting young adults. Hodgkin lymphoma is a highly curable disease by current treatment standards. Latest treatment guidelines for Hodgkin lymphoma however imply access to diagnostic and treatment modalities that may not be available in settings with restricted healthcare resources. Considerable discrepancies in Hodgkin lymphoma patient survival exist, with poorer outcomes reported in resources-constrained settings. Resources-stratified guidelines for diagnosis, staging and treatment of Hodgkin lymphoma were derived in an effort to optimize patient outcome provided a given setting of available resources. These guidelines were derived based on the framework of the Breast Health Global Initiative stratifying resource levels in basic, core, advanced and maximal categories.

Optimizing outcomes in relapsed/refractory Hodgkin lymphoma: a review of current and forthcoming therapeutic strategies

The outcome of patients with relapsed/refractory classical Hodgkin lymphoma (rr-cHL) has improved considerably in recent years owing to the approval of highly active novel agents such as brentuximab vedotin and Programmed Death-1 (PD-1) inhibitors. Although no randomized trials have been conducted to provide formal proof, it is almost undisputable that the survival of these patients has been prolonged. As autologous stem-cell transplantation (SCT) remains the standard of care for second-line therapy of most patients with rr-cHL, optimization of second-line regimens with the use of brentuximab vedotin, or, in the future, checkpoint inhibitors, is promising to increase both the eligibility rate for transplant and the final outcome. The need for subsequent therapy, and especially allogeneic SCT, can be reduced with brentuximab vedotin consolidation for 1 year, while pembrolizumab is also being tested in this setting. Several other drug categories appear to be active in rr-cHL, but their development has been delayed by the appearance of brentuximab vedotin, nivolumab and pembrolizumab, which have dominated the field of rr-cHL treatment in the last 5 years. Combinations of active drugs in chemo-free approaches may further increase efficacy and hopefully reduce toxicity in rr-cHL, but are still under development.

Risk and Response Adapted Treatment Guidelines for Managing First Relapsed and Refractory Classical Hodgkin Lymphoma in Children and Young People. Recommendations from the EuroNet Pediatric Hodgkin Lymphoma Group

The objective of this guideline is to aid clinicians in making individual salvage treatment plans for pediatric and adolescent patients with first relapse or refractory (R/R) classical Hodgkin lymphoma (cHL). While salvage with standard dose chemotherapy followed by high dose chemotherapy and autologous stem cell transplant is often considered the standard of care in adult practice, pediatric practice adopts a more individualized risk stratified and response adapted approach to salvage treatment with greater use of non-transplant salvage. Here, we present on behalf of the EuroNet Pediatric Hodgkin Lymphoma group, evidence and consensus-based guidelines for standardized diagnostic, prognostic and response procedures to allocate children and adolescents with R/R cHL to stratified salvage treatments.

Radiotherapy in combination with nivolumab for relapsed/refractory classical Hodgkin lymphoma: About two cases

Hodgkin lymphoma is a highly curable malignancy involving lymph nodes and the lymphatic system. Even at late stage disease, about 70% of patients will be cured with standard first line therapy. For patients who experience relapse or refractory classical Hodgkin lymphoma, the standard treatment option is high-dose chemotherapy followed by autologous stem cell rescue or transplant. However about 50% of patients will have recurrence after high-dose chemotherapy followed by autologous stem cell rescue or transplantation and have worse prognosis with median overall survival of 32% at 5 years. The anti-PD1 checkpoints inhibitors pembrolizumab and nivolumab have remarkably improved outcomes of patients with relapse of refractory classical Hodgkin lymphoma after high-dose chemotherapy followed by autologous stem cell rescue or transplantation. On the other hand, radiotherapy is an entire component of salvage therapy and its efficacy is now well established in term of local disease control in sites of relapsed or refractory Hodkin lymphoma. Defining the optimal modality and timing of radiotherapy as these new agents arrive is a challenge. An interesting approach is the combination of radiotherapy with checkpoint inhibitor and the possibility of stopping the treatment when complete response is achieved. We add to the literature two new cases of combination of radiotherapy with immunotherapy in patients who relapsed after high-dose chemotherapy followed by autologous stem cell rescue or transplantation and consolidation with brentuximab vedotin, resulting in excellent outcomes.

Treatment-Resistant Hodgkin Lymphoma: Defining the Role of Autologous Transplantation

Autologous hematopoietic stem cell transplant (AHCT) remains the current standard of care for patients with relapsed or refractory Hodgkin lymphoma (HL) after frontline chemotherapy. However, treatment paradigms for HL are rapidly changing with positron emission tomography-adapted therapy, as well as the incorporation of brentuximab vedotin and checkpoint inhibitors into frontline, salvage, and maintenance therapy for HL. Patients who relapse or are refractory to these novel agents are likely to have different responses and outcomes with AHCT than the 3-year event-free survivals of 50% historically reported with AHCT for patients failing conventional combination chemotherapy. This article reviews the current data on the efficacy of AHCT, pretransplant prognostic markers, pretransplant salvage regimens, peritransplant radiation therapy, and posttransplant maintenance therapy in classic HL. Future research should reexamine the efficacy, timing, risk factors, pretransplant salvage regimens, and maintenance approaches posttransplant in the era of brentuximab vedotin and checkpoint inhibitors for HL.

The Role of Radiation Therapy in Patients With Relapsed or Refractory Hodgkin Lymphoma: Guidelines From the International Lymphoma Radiation Oncology Group

Relapsed and refractory Hodgkin lymphoma (HL) challenges clinicians to devise treatment strategies that are effective and safe. This problem is particularly prominent in an era when de-escalation trials are designed to minimize therapeutic toxicities in both early- and advanced-stage disease. Radiation therapy is the single most effective treatment modality for HL, and its integration into salvage regimens, or its independent use in select patients, must be understood to maximize our success in treating these patients. The complexity of treating relapsed or refractory HL derives from the spectrum of primary treatment approaches currently in use that creates heterogeneity in both treatment exposure and the potential toxicities of salvage therapy. Patients can have relapsed or refractory disease after limited or aggressive primary therapy (with or without radiation therapy), at early or delayed time points, with limited or extensive disease volumes, and with varying degrees of residual morbidity from primary therapy. Their response to salvage systemic therapy can be partial or complete, and the use of consolidative stem cell transplantation is variably applied. New biologics and immunotherapeutic approaches have broadened but also complicated salvage treatment approaches. Through all of this, radiation therapy remains an integral component of treatment for many patients, but it must be used effectively and judiciously. The purpose of this review is to describe the different treatment scenarios and provide guidance for radiation dose, volume, and timing in patients with relapsed or refractory HL.

Current strategies for salvage treatment for relapsed classical Hodgkin lymphoma

Hodgkin lymphoma (HL) is curable in 70-80% of patients with first-line therapy. However, relapses occur in a minority of patients with favorable early stage disease and are more frequent in patients with advanced HL. Salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplant (ASCT) for patients with chemotherapy-sensitive disease is a standard treatment sequence for relapsed or refractory (rel/ref) HL. Patients who achieve complete response prior to ASCT have better survival outcomes. The choice of salvage chemotherapy therapy is becoming increasingly difficult in the era of novel agents, as there are no randomized studies to guide the choice of a second-line regimen. In this article, we will review current salvage therapy options, including combination chemotherapy and novel-agent-based salvage regimens for rel/ref HL.

Accelerated Total Lymphoid Irradiation-containing Salvage Regimen for Patients With Refractory and Relapsed Hodgkin Lymphoma: 20 Years of Experience

PURPOSE

We report the long-term results of integrated accelerated involved field radiation therapy (IFRT) followed by total lymphoid irradiation (TLI) as part of the high-dose salvage regimen followed by autologous bone marrow transplantation or autologous stem cell transplantation in patients with relapsed or refractory Hodgkin lymphoma (HL).

METHODS AND MATERIALS

From November 1985 to July 2008, 186 previously unirradiated patients with relapsed or refractory HL underwent salvage therapy on 4 consecutive institutional review board-approved protocols. All patients had biopsy-proven primary refractory or relapsed HL. After standard-dose salvage chemotherapy (SC), accelerated IFRT (18-20 Gy) was given to relapsed or refractory sites, followed by TLI (15-18 Gy) and high-dose chemotherapy. Overall survival (OS) and event-free survival (EFS) were analyzed by Cox analysis and disease-specific survival (DSS) by competing-risk regression.

RESULTS

With a median follow-up period of 57 months among survivors, 5- and 10-year OS rates were 68% and 56%, respectively; 5- and 10-year EFS rates were 62% and 56%, respectively; and 5- and 10-year cumulative incidences of HL-related deaths were 21% and 29%, respectively. On multivariate analysis, complete response to SC was independently associated with improved OS and EFS. Primary refractory disease and extranodal disease were independently associated with poor DSS. Eight patients had grade 3 or higher cardiac toxicity, with 3 deaths. Second malignancies developed in 10 patients, 5 of whom died.

CONCLUSIONS

Accelerated IFRT followed by TLI and high-dose chemotherapy is an effective, feasible, and safe salvage strategy for patients with relapsed or refractory HL with excellent long-term OS, EFS, and DSS. Complete response to SC is the most important prognostic factor.

Targeting the programmed cell death 1 pathway in Hodgkin lymphoma: the place of nivolumab

Nivolumab is a humanized immunoglobulin gamma-4 kappa anti-programmed cell death 1 monoclonal antibody that is currently approved in the treatment of several solid tumors and recently gained accelerated approval in classical Hodgkin lymphoma (cHL) that has relapsed or progressed following autologous hematopoietic stem-cell transplantation and post-transplantation brentuximab vedotin. The purpose of this article is to review the immunophysiologic basis, clinical efficacy, and toxicity of nivolumab in the treatment of cHL. In addition, we will review ongoing clinical trials and potential future directions of checkpoint inhibition in the treatment of cHL.

A multi-institutional analysis of peritransplantation radiotherapy in patients with relapsed/refractory Hodgkin lymphoma undergoing autologous stem cell transplantation

BACKGROUND

No consensus exists regarding the use of radiotherapy (RT) in conjunction with high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with relapsed/refractory classical Hodgkin lymphoma (HL). The objectives of the current study were to characterize practice patterns and assess the efficacy and toxicity of RT at 2 major transplantation centers.

METHODS

Eligible patients underwent HDC/ASCT from 2006 through 2015 using the combination of either carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) or cyclophosphamide, BCNU, and etoposide (CBV).

RESULTS

For the cohort of 189 patients, the 4-year overall survival rate was 80%, the progression-free survival rate was 67%, and the local control (LC) rate was 68%. RT was used within 4 months of ASCT for 22 patients (12%) and was given more often for disease that was early stage, primary refractory, or [¹⁸ F]fluorodeoxyglucose (FDG)-avid at the time of HDC/ASCT. Disease recurrence occurring after HDC/ASCT was associated with primary refractory disease and FDG-avidity at the time of HDC/ASCT. RT was not found to be associated with LC, progression-free survival, or overall survival on univariate analysis. In a model incorporating primary refractory HL and FDG-avid disease at the time of HDC/ASCT, RT was found to be associated with a decreased risk of local disease recurrence (hazard ratio, 0.3; P = .02). In patients with primary refractory HL and/or FDG-avid disease at the time of HDC/ASCT, the 4-year LC rate was 81% with RT versus 49% without RT (P = .03). There was one case of Common Terminology Criteria for Adverse Events grade ≥ 3 RT-related toxicity (acute grade 3 pancytopenia).

CONCLUSIONS

In patients undergoing ASCT for relapsed/refractory HL, peritransplantation RT was used more often for disease that was early stage, primary refractory, or FDG-avid after salvage conventional-dose chemotherapy. RT was associated with improved LC of high-risk localized disease and was well tolerated with modern techniques. Cancer 2017;123:1363-1371. © 2016 American Cancer Society.

Novel agents and strategies in transplant-eligible patients with relapsed and refractory Hodgkin lymphoma

The majority of patients with Hodgkin lymphoma are cured with frontline therapy; however, 10% to 15% with early-stage disease and 20% to 30% with advanced stage require second-line therapy that includes a potentially curative transplant, of which an additional 50% to 55% are cured. Those with multiply relapsed disease traditionally would receive novel agents on a clinical trial or combination chemotherapy as a potential bridge to an allogeneic stem cell transplant. This treatment paradigm has changed with the availability of brentuximab vedotin, an antibody drug conjugate used pre- and post-ASCT, as well as for palliation. With the availability of the checkpoint inhibitors, nivolumab and pembrolizumab, there will be another shift in treatment, with these agents being used for palliation and potentially replacing allogeneic stem cell transplantation in certain patient populations. Finally, up-front management is also changing and this will have an impact on how patients in the relapsed and refractory setting will be treated.

First Successful Haploidentical Stem Cell Transplantation in Romania

Hematopoietic stem cell transplantation is an established treatment for many malignant and non-malignant haematological disorders. In the current case report, we describe the first haploidentical stem cell transplantation, used for the first time in Romania, the case of a 33 year-old young woman diagnosed with Hodgkin's lymphoma that has underwent a haploSCT after she relapsed from several chemotherapy regimens, as well as after an autologous stem cell transplantation. This success represents a prèmiere in Romanian clinical hematology, being the first case of a haploSCT in Romania, as well as in South-Eastern Europe.

Pembrolizumab in classical Hodgkin's lymphoma

Pembrolizumab is a humanized monoclonal antibody directed against programmed cell death protein 1 (PD-1), a key immune-inhibitory molecule expressed on T cells and implicated in CD4+ T-cell exhaustion and tumor immune-escape mechanisms. Classical Hodgkin's lymphoma (cHL) is a unique B-cell malignancy in the sense that malignant Reed-Sternberg (RS) cells represent a small percentage of cells within an extensive immune cell infiltrate. PD-1 ligands are upregulated on RS cells as a consequence of both chromosome 9p24.1 amplification and Epstein-Barr virus infection and by interacting with PD-1 promote an immune-suppressive effect. By augmenting antitumor immune response, pembrolizumab and nivolumab, another monoclonal antibody against PD-1, have shown significant activity in patients with relapsed/refractory cHL as well as an acceptable toxicity profile with immune-related adverse events that are generally manageable. In this review, we explore the rationale for targeting PD-1 in cHL, review the clinical trial results supporting the use of checkpoint inhibitors in this disease, and present future directions for investigation in which this approach may be used.

Treatment of relapsed and refractory Hodgkin Lymphoma

Despite the high first-line cure rates in patients with Hodgkin Lymphoma (HL) still 10%-20% of patients suffer from relapsed or refractory disease. High-dose chemotherapy (HDCT) followed by autologous stem cell transplant (ASCT) is standard of care for suitable patients with relapsed or refractory HL and allows for cure in approximately 50%. Due to the poor prognosis of high-risk patients even with HDCT and ASCT, consolidation strategies have been evaluated to improve the cure rates. For patients with recurrence after HDCT and ASCT, treatment is palliative in most cases. The anti-CD30 antibody-drug conjugate brentuximab vedotin (BV) has been shown to induce high response rates in these patients; however, durable responses were reported in a small percentage of patients only. For carefully selected patients with multiple relapses, dose-reduced allogeneic transplant (RICallo) is a potentially curative option. The role of RICallo will have to be re-evaluated in the era of anti-programmed death-1 (PD1) antibodies.

No survival benefit associated with routine surveillance imaging for Hodgkin lymphoma in first remission: a Danish-Swedish population-based observational study

The use of routine imaging for patients with classical Hodgkin lymphoma (HL) in complete remission (CR) is controversial. In a population-based study, we examined the post-remission survival of Danish and Swedish HL patients for whom follow-up practices were different. Follow-up in Denmark included routine imaging, usually for a minimum of 2 years, whereas clinical follow-up without routine imaging was standard in Sweden. A total of 317 Danish and 454 Swedish comparable HL patients aged 18-65 years, diagnosed in the period 2007-2012 and having achieved CR following ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine)/BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisone) therapy, were included in the study. The cumulative progression rates in the first 2 years were 4% (95% confidence interval [CI] 1-7) for patients with stage I-II disease vs. 12% (95% CI 6-18) for patients with stage III-IV disease. An imaging-based follow-up practice was not associated with a better post-remission survival in general (P = 0·2) or in stage-specific subgroups (P = 0·5 for I-II and P = 0·4 for III-IV). Age ≥45 years was the only independent adverse prognostic factor for survival. In conclusion, relapse of HL patients with CR is infrequent and systematic use of routine imaging in these patients does not improve post-remission survival. The present study supports clinical follow-up without routine imaging, as encouraged by the recent Lugano classification.

How I treat relapsed classical Hodgkin lymphoma after autologous stem cell transplant

Despite the success of standard front-line chemotherapy for classical Hodgkin lymphoma (cHL), a subset of these patients, particularly those with poor prognostic factors at diagnosis (including the presence of B symptoms, bulky disease, advanced stage, or extranodal disease), relapse. For those patients who relapse following autologous stem cell transplant (SCT), multiple treatment options are available, including single-agent chemotherapy, combination chemotherapy strategies, radiotherapy, the immunoconjugate brentuximab, checkpoint inhibitors nivolumab and pembrolizumab, lenalidomide, everolimus, or observation in selected patients. In patients with an available donor, allogeneic SCT may also be considered. With numerous treatment options available, we advocate for a tailored therapeutic approach for patients with relapsed cHL guided by patient-specific characteristics including age, comorbidities, sites of disease (nodal or organ), previous chemosensitivity, and goals of treatment (long-term disease control vs allogeneic SCT).

Classical Hodgkin's lymphoma: the Lymphoma Study Association guidelines for relapsed and refractory adult patients eligible for transplant

The Hodgkin's Lymphoma Committee of the Lymphoma Study Association (LYSA) gathered in 2012 to prepare guidelines on the management of transplant-eligible patients with relapsing or refractory Hodgkin's lymphoma. The working group is made up of a multidisciplinary panel of experts with a significant background in Hodgkin's lymphoma. Each member of the panel of experts provided an interpretation of the evidence and a systematic approach to obtain consensus was used. Grades of recommendation were not required since levels of evidence are mainly based on phase II trials or standard practice. Data arising from randomized trials are emphasized. The final version was endorsed by the scientific council of the LYSA. The expert panel recommends a risk-adapted strategy (conventional treatment, or single/double transplantation and/or radiotherapy) based on three risk factors at progression (primary refractory disease, remission duration < 1 year, stage III/IV), and an early evaluation of salvage chemosensitivity, including (18)fluorodeoxy glucose-positron emission tomography interpreted according to the Deauville scoring system. Most relapsed or refractory Hodgkin's lymphoma patients chemosensitive to salvage should receive high-dose therapy and autologous stem-cell transplantation as standard. Efforts should be made to increase the proportion of chemosensitive patients by alternating non-cross-resistant chemotherapy lines or exploring the role of novel drugs.

High-dose therapy followed by stem cell transplantation in Hodgkin's lymphoma: past and future

Hodgkin's lymphoma (HL) has been a fascinating challenge for physicians and investigators since its recognition during the 19th century. However, many questions still remain unanswered. One issue regards high-dose therapy followed by autologous stem cell transplantation (ASCT), which has yet to find its place among several guidelines. Other topics are still controversial with respect to transplantation for HL, including its role for newly diagnosed patients with advanced stage disease, the optimal timing of transplantation, the best conditioning regimen and the role of allogeneic/haploidentical SCT. Moreover, the potential use of localized radiotherapy or immunologic methods to decrease post-transplant recurrence, the role of novel agents such as brentuximab vedotin and their positioning in the treatment algorithm of resistant/relapsed HL patients, either before transplant to boost salvage therapy or after transplant as consolidation/maintenance, are burning questions without an answer. In this review, the authors try to give an answer to some of these dilemmas.

Update on salvage options in relapsed/refractory hodgkin lymphoma after autotransplant

Despite a high clinical success, relapse in Hodgkin lymphoma occurs in 10–30% of cases and 5–10% patients are nonresponsive to initial chemotherapy. The standard management of these patients includes high-dose chemotherapy followed by autologous stem cell transplant. However, 50% of patients ultimately relapse after autotransplant which poses a big challenge. Allogeneic stem cell transplantation offers the only chance of cure in these patients. For patients who are not candidates for allogeneic stem cell transplantation, achieving cure with other possible options is highly unlikely, and thus the treatment plan becomes noncurative. Various novel agents have shown promising results but the duration of response is short lived. A standard approach to deliver the most effective treatment for these patients is still lacking. This review focuses on the treatment options currently available for relapsed and refractory disease after autotransplant.

Brentuximab vedotin treatment for primary refractory hodgkin lymphoma

Up to 40% of patients with advanced Hodgkin lymphoma (HL) become refractory or relapsed after current standard chemotherapy, among which primary refractory HL confers a particularly poor outcome. With intensive salvage chemotherapy and autologous stem cell transplantation, the long-term remission rate for these patients was only 30%, but more selective treatments with higher therapeutic index are needed. We report the experience of using a new anti-CD30 immunotoxin, brentuximab vedotin, in salvage treatment of a 30-year-old woman with primary refractory Hodgkin lymphoma. The patient presented with SVC syndrome due to the bulky mediastinal tumor and was confirmed to have classical Hodgkin lymphoma, nodular sclerosis type, stage IIIA. The tumor responded to induction chemotherapy transiently, but local progression was noted during subsequent cycles of treatment. Salvage radiotherapy to the mediastinal tumor, obtained no remission but was followed by rapid in-field progression and then lung metastasis. She declined stem cell transplantation and received salvage brentuximab vedotin (BV) therapy, which induced dramatic shrinkage of tumor without significant side effects. Serial followup of PET/CT imaging confirmed a rapid and continuous complete remission for 12 months. Although durability of the remission needs further observation, this case illustrates the excellent efficacy of brentuximab vedotin in primary refractory Hodgkin lymphoma.

Hodgkin's lymphoma in adults

Management of Hodgkin's lymphoma continues to develop. Outcomes for patients with favourable-risk, early-stage disease are excellent, and serial reductions in intensity of treatment have been made to retain the excellent prognosis while reducing the late effects of treatment. Prognosis is also very good in advanced-stage disease but the rate of relapse is higher than in early-stage disease, and the optimum first-line treatment is unclear. Workers are investigating the role of functional imaging to assess whether treatment can be tailored according to response, with the most intensive therapies reserved for patients predicted to have poor outcomes. In this Seminar we critically appraise the management of Hodgkin's lymphoma in early-stage disease, advanced-stage disease, and at relapse, with a focus on late effects of treatment.

Role of immune escape mechanisms in Hodgkin's lymphoma development and progression: a whole new world with therapeutic implications

Hodgkin's lymphoma represents one of the most frequent lymphoproliferative syndromes, especially in young population. Although HL is considered one of the most curable tumors, a sizeable fraction of patients recur after successful upfront treatment or, less commonly, are primarily resistant. This work tries to summarize the data on clinical, histological, pathological, and biological factors in HL, with special emphasis on the improvement of prognosis and their impact on therapeutical strategies. The recent advances in our understanding of HL biology and immunology show that infiltrated immune cells and cytokines in the tumoral microenvironment may play different functions that seem tightly related with clinical outcomes. Strategies aimed at interfering with the crosstalk between tumoral Reed-Sternberg cells and their cellular partners have been taken into account in the development of new immunotherapies that target different cell components of HL microenvironment. This new knowledge will probably translate into a change in the antineoplastic treatments in HL in the next future and hopefully will increase the curability rates of this disease.