Reduced-intensity conditioning compared with conventional allogeneic stem-cell transplantation in relapsed or refractory Hodgkin's lymphoma: an analysis from the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

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.

The optimal management of relapsed and refractory Hodgkin lymphoma: post-brentuximab and checkpoint inhibitor failure

The treatment landscape of classical Hodgkin lymphoma has changed dramatically over the past decade. Relapsed and refractory mainstay therapeutics such as brentuximab vedotin (BV) and checkpoint inhibitors (CPIs) are being moved to earlier lines of therapy. However, the treatment of patients who progress after BV and CPI remains a challenge. Allogeneic stem cell transplantation still plays an important role in this patient population as the only current treatment approach with curative potential. Unfortunately, not all patients are transplant candidates, and many will still relapse afterward. Cytotoxic chemotherapy and radiation may be used for symptom palliation or as a bridge to transplant. Targeted therapies, including the antibody drug conjugate, camidanlumab tesirine, and transcriptional agents such mammalian target of rapamycin and histone deacetylase inhibitors have shown some potential in patients with refractory disease. In addition, combination therapies with CPIs and novel agents may help overcome resistance to therapy. Clinical trials with cellular therapies, including chimeric antigen receptor T cells targeting CD30 and allogeneic natural killer cells combined with AFM13, a CD30/CD16a-bispecific antibody, have shown promising results. The availability of more therapeutic options for this patient population is eagerly awaited.

Hodgkin lymphoma: Focus on evolving treatment paradigms

Hodgkin lymphoma (HL) is a highly curable B-cell malignancy of germinal center origin. Biologically it is a hematologic malignancy that is highly dependent on the immune microenvironment and utilizes immune escape through upregulation of the programmed-death ligands on the neoplastic cells. Despite being highly curable, consensus is lacking nationally and internationally about the optimal approach to management, particularly in limited-stage disease. The addition of brentuximab vedotin and checkpoint inhibitors for the management of HL has led to a rapidly changing treatment landscape. Further studies should be done to include these novel agents at all stages of disease to determine improvements in frontline cure rates and long-term toxicity.

Safety and efficacy of immune checkpoint inhibitors after allogeneic hematopoietic cell transplantation

The immune system plays a major role in preventing infections and cancers. Impairment in immunity may facilitate the development of neoplasia owing to defective immune surveillance, among other mechanisms. Immune evasion plays a significant role in relapse after allogeneic hematopoietic cell transplantation (alloHCT); one purported mechanism is through immune checkpoint signaling pathways. Checkpoint inhibitors (CPIs) are FDA approved for relapsed classical Hodgkin's Lymphoma (cHL), primary mediastinal large B cell Lymphoma (PMBCL) and other solid tumors. Retrospective studies evaluating the outcomes of alloHCT after prior exposure to CPIs showed favorable survival outcomes but high rates of graft-versus-host disease (GVHD); the risk appears to be lower when using post-transplant cyclophosphamide as GVHD prophylaxis. CPIs have increasingly been used to prevent or treat post-alloHCT relapse. Available data, albeit limited, supports the clinical activity of CPIs in post-alloHCT relapse; however, serious and even fatal cases of GVHD have been reported. The optimal timing, schedule, dosing, and patients likely to benefit from this strategy are yet to be identified. In this review, we highlight the immune system's role in cancer surveillance and relapse prevention and discuss the current clinical evidence of CPIs use in post-alloHCT relapse.

Fludarabine-Melphalan-Campath, Followed by Unmanipulated Peripheral-Blood Haematopoietic Stem Cells, Can Still Cure Lymphoma

Background

The second decade of this millennium was characterized by a widespread availability of chimeric antigen receptor T-cell (CAR-T) therapies to treat relapsed and refractory lymphomas. As expected, the role and indication of allogeneic haematopoietic stem cell transplant (allo-HSCT) in the management of lymphoma changed. Currently, a non-neglectable proportion of patients will be considered candidate for an allo-HSCT, and the debate of which transplant platform should be offered is still active.

Objectives

to report the outcome of patients affected with relapsed/refractory lymphoma and transplanted following reduced intensity conditioning at King's College Hospital, London, between January 2009 and April 2021.

Methods

Conditioning was with 150mg/m2 of fludarabine and melphalan of 140mg/m2. The graft was unmanipulated G-CSF mobilized peripheral blood haematopoietic stem cells (PBSC). Graft-versus-host disease (GVHD) prophylaxis consisted of pre-transplant Campath at the total dose of 60 mg in unrelated donors and 30 mg in fully matched sibling donors and ciclosporin.

Results

One-year and five years OS were 87% and 79.9%, respectively, and median OS was not reached. The cumulative incidence of relapse was 16%. The incidence of acute GVHD was 48% (only grade I/II); no cases of grade III/IV were diagnosed. Chronic GVHD occurred in 39% of patients. TRM was 12%, with no cases developed within day 100 and 18 months after the procedure.

Conclusions

The outcomes of heavily pretreated lymphoma patients are favorable, with median OS and survival not reached after a median of 49 months. In conclusion, even if some lymphoma subgroups cannot be treated (yet) with advanced cellular therapies, this study confirms the role of allo-HSCT as a safe and curative strategy.

The role of transplantation in Hodgkin lymphoma

Despite the success of frontline anthracycline-based chemotherapy for classical Hodgkin Lymphoma (cHL), approximately 15% of patients do not achieve an adequate response and require further therapy. For transplant-eligible patients, additional treatment followed by high-dose chemotherapy and autologous hematopoietic stem cell transplantation (autoHCT) provides a durable response in 50% of patients. The most refractory patients, including those requiring multiple lines of therapy to achieve a response or those relapsing after an autoHCT, may achieve long-term survival with allogeneic hematopoietic stem cell transplant (alloHCT). Contemporary salvage regimens used as a bridge to transplant have expanded to include not only non-cross resistant chemotherapy, but also brentuximab vedotin (BV) and checkpoint inhibitors (CPI). As the management of relapsed/refractory (R/R) cHL evolves with the introduction of novel agents, so too does the role of transplantation. The paradigm of chemosensitivity as a predictor for autoHCT efficacy is being challenged by favorable post- autoHCT outcomes in heavily pre-treated CPI-exposed patients. Contemporary supportive care measures, validated comorbidity assessments, and an increased donor pool with haploidentical donors have broadened the application of transplantation to an increasingly older and diverse patient population. Despite the introduction of increasingly effective treatment options for R/R cHL, transplantation continues to play an important role in the management of these patients. In this review, we explore the impact of salvage therapy on autoHCT, conditioning regimens, maintenance therapy and the diminishing role of alloHCT for patients with cHL.

Outcomes associated with allogeneic hematopoietic stem cell transplantation for relapsed and refractory Hodgkin lymphoma in the era of novel agents

BACKGROUND

Relapsed or refractory Hodgkin lymphoma (R/R HL) is a challenging disease with limited treatment options beyond brentuximab vedotin and checkpoint inhibitors. Herein we present the time-trend analysis of R/R HL patients who received allogeneic hematopoietic cell transplantation (allo-HCT) at our center from 2001-2017.

METHODS

The patients were divided into two distinct treatment cohorts: era1 (2001-2010), and era2 (2011-2017). The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), non-relapse mortality (NRM), and cumulative incidence of acute and chronic graft versus host disease (GVHD).

RESULTS

Among the 51 patients included in the study, 29 were in era1, and 22 were in era2. There was decreased use of myeloablative conditioning in era2 (18% vs. 31%) compared to era1 and 95% of patients in era2 previously received brentuximab Vedotin (BV). Haploidentical donors were seen exclusively in era2 (0% vs. 14%) and more patients received alternative donor transplants (7% vs. 32%) in era2. The 4-year OS (34% vs. 83%, p < 0.001) and 4-year PFS (28% vs. 62%, p = 0.001) were significantly inferior in era1 compared to era2. The incidence of 1-year NRM was lower in era2 compared to era1 (5% vs. 34%, p = 0.06). The cumulative incidence of acute GVHD at day 100 was similar in both eras (p = 0.50), but the incidence of chronic GVHD at 1 year was higher in era2 compared to era1 (55% vs. 21%, p = 0.03).

CONCLUSIONS

Despite the advent of novel therapies, allo-HCT remains an important therapeutic option for patients with R/R HL.

Allogeneic hematopoietic stem cell transplantation in Hodgkin lymphoma in Switzerland, 20 years of experience: 2001-2020

Despite the high cure rate with initial therapy, approximately 10% of Hodgkin lymphoma (HL) patients are refractory to initial treatment, and up to 30% of patients will relapse after achieving initial complete remission. Despite promising initial results of treatment by immune checkpoint inhibitors, most patients will eventually progress. We analyzed 62 adult patients with relapsed or refractory HL (rrHL) treated by allogeneic hematopoietic stem cell transplantation (allo-HSCT) in one of three University Hospitals of Switzerland (Zurich, Basel, and Geneva) between May 2001 and January 2020. The primary endpoint was overall survival (OS). Secondary endpoints were relapse-free survival (RFS), non-relapse mortality (NRM), and relapse incidence, which were assessed in univariate analysis. The median follow-up was 61 months (interquartile range 59-139). The 2- and 5-year OS was 54% (standard error (SE) ±12) and 50.2% (SE ±13.3), respectively, and the 2- and 5-year RFS was 40.7% (SE ±16.3) and 34.4% (SE ±19.0), respectively. NRM was 23.1% (SE ±2.2) and 27.4% (SE ±2.5) at 2 and 5 years, respectively. The cumulative incidence of relapse was 36.1% (SE ±5.6) at 2 years and 38.2% (SE ±6.6) at 5 years. Our analysis of allo-HSCT outcomes in the context of rrHL shows encouraging OS and RFS rates, with the mortality rate reaching plateau at 50% at 2 years after allo-HSCT. This confirms that allo-HSCT still remains as a potentially curative option for half of patients with rrHL.

Filling the Gap: The Immune Therapeutic Armamentarium for Relapsed/Refractory Hodgkin Lymphoma

Despite years of clinical progress which made Hodgkin lymphoma (HL) one of the most curable malignancies with conventional chemotherapy, refractoriness and recurrence may still affect up to 20–30% of patients. The revolution brought by the advent of immunotherapy in all kinds of neoplastic disorders is more than evident in this disease because anti-CD30 antibodies and checkpoint inhibitors have been able to rescue patients previously remaining without therapeutic options. Autologous hematopoietic cell transplantation still represents a significant step in the treatment algorithm for chemosensitive HL; however, the possibility to induce complete responses after allogeneic transplant procedures in patients receiving reduced-intensity conditioning regimens informs on its sensitivity to immunological control. Furthermore, the investigational application of adoptive T cell transfer therapies paves the way for future indications in this setting. Here, we seek to provide a fresh and up-to-date overview of the new immunotherapeutic agents dominating the scene of relapsed/refractory HL. In this optic, we will also review all the potential molecular mechanisms of tumor resistance, theoretically responsible for treatment failures, and we will discuss the place of allogeneic stem cell transplantation in the era of novel therapies.

Checkpoint Inhibitors and the Changing Face of the Relapsed/Refractory Classical Hodgkin Lymphoma Pathway

PURPOSE OF REVIEW

Checkpoint inhibitors (CPIs) targeting PD1 are highly active in relapsed/refractory classical Hodgkin lymphoma. A plethora of recent studies, often small and non-randomised, have raised many questions about how to optimally integrate these into clinical practice. We aim to discuss the use of CPIs in different relapsed/refractory settings in an effort to better define their role and highlight areas of research.

RECENT FINDINGS

CPIs have shown efficacy at first relapse, as salvage pre- and post-autologous (ASCT) and allogeneic stem cell transplant (alloSCT) and as maintenance post-ASCT. Immune-related adverse events require careful attention, especially when used peri-alloSCT, where it is associated with hyperacute graft-versus-host disease. Newer PD1 inhibitors, as well as strategies to overcome CPI resistance, are being tested. CPIs are increasingly deployed at earlier points in the classical Hodgkin lymphoma pathway. Whilst progress is clearly being made, randomised studies are required to more clearly define the optimal positioning of these agents.

Favorable outcomes of allogeneic hematopoietic stem cell transplantation with fludarabine-bendamustine conditioning and posttransplantation cyclophosphamide in classical Hodgkin lymphoma

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with relapsed and refractory classic Hodgkin lymphoma (rrHL). However, the optimal conditioning regimen and GVHD prophylaxis for rrHL remain undetermined. The aim of this study was to investigate outcomes of allo-HSCT with a fludarabine plus bendamustine (FluBe) conditioning regimen and GVHD prophylaxis with posttransplantation cyclophosphamide (PTCY) in patients with rrHL.

METHODS

Allo-HSCT results in 58 adult patients with rrHL were analyzed retrospectively.

RESULTS

Three-year overall survival and event-free survival were 81% (95% CI 65-91) and 55% (95% CI 38-72), respectively. The cumulative incidence of relapse (CIR) at 3 years was 33% (95% CI 13-51). The cumulative incidence of aGVHD grade II-IV and severe aGVHD grade III-IV was 36% (95% CI 22-48) and 22% (95% CI 9-33), respectively. The cumulative incidence of cGVHD was 32% (95% CI 17-45), including moderate or severe cGVHD in 17% (95% CI 4-28). Patients who developed aGVHD after allo-HSCT had significantly lower CIR (24% vs 49%, p = 0.004). The use of PBSC as a graft source also significantly reduced CIR (4% vs 61%, p = 0.002).

CONCLUSIONS

FluBe-PTCY allo-HSCT facilitates favorable outcomes, low toxicity, and mortality in rrHL.

Reappraising the Role of Allogeneic Hematopoietic Stem Cell Transplantation in Relapsed and Refractory Hodgkin’s Lymphoma: Recent Advances and Outcomes

Hodgkin’s lymphoma is a rare yet highly curable disease in the majority of patients treated with modern chemotherapy regimens. For patients who fail to respond to or relapse after initial systemic therapies, treatment with high-dose chemotherapy and autologous hematopoietic stem cell transplantation can provide a cure for many with chemotherapy-responsive lymphoma. Patients who relapse after autologous transplant or those with chemorefractory disease have poor prognosis and represent a high unmet need. Allogeneic hematopoietic stem cell transplantation provides a proven curative therapy for these patients and should be considered, especially in young and medically fit patients. The use of newer agents in this disease such as brentuximab vedotin and immune checkpoint inhibitors can help bring more patients to transplantation and should be considered as well.

Double-refractory Hodgkin lymphoma: tackling relapse after brentuximab vedotin and checkpoint inhibitors

The approval of brentuximab vedotin (BV) and checkpoint inhibitors (CPI) has revolutionized the management of relapsed/refractory classical Hodgkin lymphoma (cHL) patients. In recent years these agents have rapidly moved to earlier lines of therapy, including post-autologous hematopoietic cell transplant (auto-HCT) consolidation, pre-HCT salvage, and the frontline treatment setting. This shift in practice means that double-refractory (refractory to both BV and CPI) cHL is becoming an increasingly common clinical problem. In patients who are not eligible for clinical trials, conventional cytotoxic and targeted therapies (off label) may be a potential option. In patients who are transplant eligible, early referral to allogeneic HCT should be considered given the significant improvement in transplant outcomes in the contemporary era. Cellular therapy options including CD30.chimeric antigen receptor T cells, Epstein-Barr virus-directed cytotoxic T cells, and CD16A/30 bispecific natural killer cell engagers appear promising and are currently in clinical trials.

Long-term outcome of patients receiving haematopoietic allogeneic stem cell transplantation as first transplant for high-risk Hodgkin lymphoma: a retrospective analysis from the Lymphoma Working Party-EBMT

We analysed long-term outcome of patients receiving haematopoietic allogeneic stem cell transplantation (allo-HSCT) as a first transplant for high-risk Hodgkin lymphoma (HL). One hundred and ninety patients were included in this study, 63% of them had previously received brentuximab vedotin and/or checkpoint inhibitors. Seventy patients (37%) received an unrelated donor allo-HSCT, 99 (51%) had myeloablative conditioning (MAC) and 60% had in vivo T-cell/depleted grafts (TCD). The 100-day cumulative incidence (CI) of grade II-IV acute graft-versus-host disease (GVHD) was 25% and the 3-year CI of chronic GVHD was 38%. The 3-year CI of non-relapse mortality (NRM) and relapse rate were 21% and 38% respectively. After a median follow-up of 58 months, 3-year overall survival (OS) and progression-free survival (PFS) were 58% and 41% respectively. Multivariate analysis showed that, in comparison to reduced-intensity conditioning regimens with or without TCD, MAC using TCD had similar NRM and a lower risk of relapse leading to significantly better OS and PFS. MAC without TCD was associated with higher NRM and worse survival outcomes. These results suggest that in patients with high-risk HL and candidates of allo-HSCT, a MAC strategy with TCD might be the best option.

Classical Hodgkin lymphoma

Classical Hodgkin lymphoma is one of the more frequent lymphomas and is generally considered a highly curable disease with standard first-line chemotherapy and radiotherapy in some cases. Despite these outstanding results, major problems remain unresolved. First, there are still patients who will not be cured with front-line regimens and, second, many patients who are cured of classical Hodgkin lymphoma continue to die prematurely due to the late toxic effects of their therapy. Because the median age of patients with classical Hodgkin lymphoma is in the mid-30s, the disease's impact on the number of years lost from productive life is remarkable. In recent years, the gold standard of chemotherapy (often combined with radiotherapy) has changed, with the approval of immunotherapy mostly in relapse settings.

Stem-Cell Transplantation in Adult Patients with Relapsed/Refractory Hodgkin Lymphoma

Although the majority of patients with Hodgkin lymphoma (HL) are cured with initial therapy, in 85–90% of early stage and 70–80% of advanced-stage disease cases, relapse remains a major problem. Autologous stem-cell transplantation (auto-HCT) after salvage chemotherapy is currently considered to be the standard of care for patients who relapse after first-line chemotherapy or for whom first-line treatment fails. The curative capacity of auto-HCT has been improving with the introduction of new drug-based salvage strategies and consolidation strategies after auto-HCT. Allogeneic stem-cell transplantation (allo-HCT) represents a reasonable treatment option for young patients who relapse or progress after auto-HCT and have chemosensitive disease at the time of transplantation. Allo-HCT is a valid treatment strategy for patients with relapse/refractory HL (r/r HL) because the results have improved over time, mainly with the safe combination of allo-HCT and new drugs. Bearing in mind that outcomes after haploidentical stem-cell transplantation (haplo-HCT) are comparable with those for matched sibling donors and matched unrelated donors, haplo-HCT is now the preferred alternative donor source for patients with r/r HL without a donor or when there is urgency to find a donor if a matched related donor is not present. The development of new drugs such as anti-CD 30 monoclonal antibodies and checkpoint inhibitors (CPI) for relapsed or refractory HL has demonstrated high response rates and durable remissions, and challenged the role and timing of HCT. The treatment of patients with HL who develop disease recurrence or progression after allo-HCT remains a real challenge and an unmet need.

Allogeneic Stem Cell Transplantation for Relapsed and Refractory Hodgkin Lymphoma: Real World Experience of a Single Center

Introduction: Refractory and relapsed Hodgkin lymphoma (R/R HL) is associated with poor prognosis, and allogeneic stem cell transplantation (allo-SCT) remains the only potentially curative approach.

Aim: The aim of the study was to evaluate the feasibility of allotransplantation in R/R HL setting.

Material: Overall, 24 patients (17 men and 7 women) at a median age of 27 years (range 18–44) underwent allo-SCT between 2002 and 2020.

Results: Nineteen patients received prior autologous stem cell transplantation (ASCT1) whereas eight patients received second ASCT (ASCT2) after failure of ASCT1. Six patients received only brentuximab vedotin (BV; n = 4) or BV followed by checkpoint inhibitors (CPI; n = 2) before entering allo-SCT. Median time from ASCT1 to allo-SCT was 17.1 months. Fifteen patients received grafts from unrelated donors. Peripheral blood was a source of stem cells for 16 patients. Reduced-intensity conditioning was used for all patients. Disease status at transplant entry was as follows: complete remission (CR; n = 4), partial response (PR; n = 10), and stable disease (SD; n = 10). Acute and chronic graft-versus-host disease (GVHD) developed in 13 (54%) and 4 (16%) patients, respectively. Median follow-up for the entire cohort was 13.3 months. At the last follow-up, 17 (71%) patients died. The main causes of death were disease progression (n = 10), infectious complications (n = 6), and steroid-resistant GVHD (n = 1). Non-relapse mortality at 12 months was 25%. At the last follow-up, seven patients were alive; six patients were in CR, and one had PR. The 2-year overall survival (OS) was 40%.

Conclusion: Chemosensitive disease at transplant was associated with better outcome. Allo-SCT allows for long-term survival in refractory and relapsed HL.

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

Long-Term Remission After Matched Sibling Donor Hematopoietic Cell Transplantation in a Patient With Primary Cutaneous CD8+ Aggressive Epidermotropic Cytotoxic T-Cell Lymphoma

Primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (CD8+ PCAECTL) is an extremely rare neoplasm with a poor prognosis. Chemotherapy typically does not result in a sustained response, and hematopoietic stem cell transplant (HSCT) is the only therapy that has been shown to produce a durable response of any kind. Here, we report a case of a 25-year-old previously healthy male who presented with a painful ulcerative lesion on the bottom of his right great toe and local lymphadenopathy. The biopsy of the lesion was consistent with CD8+ PCAECTL. He received immediate chemotherapy followed by matched related donor HSCT (MRD-HSCT) and remained in complete remission (CR) for eight years post-transplant, longer than any CR reported in the literature. In conclusion, our report provides clinical evidence that early transplant consult and donor search is one of the key factors in the management of CD8+ PCAECTL.

Trends in postrelapse survival in classic Hodgkin lymphoma patients after experiencing therapy failure following auto-HCT

Patients with classic Hodgkin lymphoma (cHL) who relapse after autologous hematopoietic cell transplantation (auto-HCT) historically have had poor outcomes. We hypothesized that, post-auto-HCT relapse, overall survival (PR-OS) has improved in recent years as a result of more widespread use of novel therapies and allogeneic HCT (allo-HCT). We conducted a retrospective study in 4 US academic centers, evaluating 215 patients who underwent auto-HCT from 2005 to 2016 and relapsed thereafter. Patients were divided into 2 cohorts based on timing of auto-HCT, 2005 through 2010 (cohort 1; n = 118) and 2011 to 2016 (cohort 2; n = 97), to compare differences in clinical outcomes. The median age and disease status at auto-HCT were similar in cohorts 1 and 2. The proportions of patients who received brentuximab vedotin (Bv; 55% vs 69%; P = .07), checkpoint inhibitors (CPIs; 3% vs 36%; P ≤ .001), and allogeneic-HCT (22% vs 35%, P = .03) were significantly different between cohorts 1 and 2, respectively. At the 5-year follow-up after auto relapse, 32% and 50% of patients were alive in cohorts 1 and 2, respectively (P = .01). In multivariate analysis for PR-OS, cohort 1 vs 2 (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.14-4.60; P = .01), age at auto-HCT (HR, 1.48; 95% CI, 1.18-1.87; P ≤ .001), and time to relapse from auto-HCT (HR, 0.59; 95% CI, 0.47-74; P ≤ .0001), retained independent prognostic significance for PR-OS. Our study supports the hypothesis that survival of cHL patients after auto-HCT failure has significantly improved in recent years, most likely because of incorporation of novel therapies and more widespread use of allo-HCT.

Checkpoint inhibition before haploidentical transplantation with posttransplant cyclophosphamide in Hodgkin lymphoma

We report on 59 Hodgkin lymphoma patients undergoing haploidentical stem cell transplantation (SCT; haplo-SCT) with posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, comparing outcomes based on pretransplant exposure to checkpoint inhibitors (CPIs). Considering pretransplant characteristics, the 2 cohorts (CPI = 29 patients vs no-CPI = 30 patients) were similar, except for the number of prior lines of therapy (6 vs 4; P < .001). With a median follow-up of 26 months (range, 7.5-55 months), by univariate analysis, the 100-day cumulative incidence of grade 2-4 acute GVHD was 41% in the CPI group vs 33% in the no-CPI group (P = .456), whereas the 1-year cumulative incidence of moderate to severe chronic GVHD was 7% vs 8%, respectively (P = .673). In the CPI cohort, the 2-year cumulative incidence of relapse appeared lower compared with the no-CPI cohort (0 vs 20%; P = .054). No differences were observed in terms of overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) (at 2 years, 77% vs 71% [P = .599], 78% vs 53% [P = .066], and 15% vs 21% [P = .578], respectively). By multivariable analysis, CPI before SCT was an independent protective factor for PFS (hazard ratio [HR], 0.32; P = .037). Stable disease (SD)/progressive disease (PD) was an independent negative prognostic factor for both OS and PFS (HR, 14.3; P < .001 and HR, 14.1; P < .001, respectively) . In conclusion, CPI as a bridge to haplo-SCT seems to improve PFS, with no impact on toxicity profile.

Haploidentical Stem Cell Transplantation in Lymphomas-Expectations and Pitfalls

T-cell replete Haploidentical stem cell transplantation (Haplo-SCT) with Post-transplant cyclophosphamide (PT-Cy) is an emerging therapeutic option for patients with advanced relapsed or refractory lymphoma. The feasibility of this platform is supported by several retrospective studies showing a toxicity profile that is improved relative to umbilical cord blood and mismatched unrelated donor (UD) transplant and comparable to matched unrelated donor transplant. In particular, cumulative incidence of chronic graft-versus-host disease (GVHD) is reduced after Haplo-SCT relative to UD and matched related donor (MRD) transplant thanks to PT-Cy employed as GVHD prophylaxis. This achievement, together with a similar incidence of acute GVHD and disease relapse, results in a promising advantage of Haplo-SCT in terms of relapse-free/GVHD free survival. Unmet needs of the Haplo-SCT platform are represented by the persistence of a not negligible rate of non-relapse mortality, especially due to infections and disease relapse. Future efforts are warranted in order to reduce life-threatening infections and to employ Halo-SCT with PT-Cy as a platform to build new immunotherapeutic strategies.

Therapeutic Updates for Relapsed and Refractory Classical Hodgkin Lymphoma

Hodgkin lymphoma (HL) is a B-cell malignancy representing approximately one in ten lymphomas diagnosed in the United States annually. The majority of patients with HL can be cured with chemotherapy; however, 5-10% will have refractory disease to front-line therapy and 10-30% will relapse. For those with relapsed or refractory (r/r) HL, salvage chemotherapy followed by autologous stem cell transplant (ASCT) is standard of care, but half of patients will subsequently have disease progression. Relapse following ASCT has been associated with exceedingly poor prognosis with a median survival of only 26 months. However, in recent years, novel agents including brentuximab vedotin (BV) and programmed cell death protein 1 monoclonal antibodies (anti-PD-1, nivolumab and pembrolizumab) have been shown to extend overall survival in r/r HL. With the success of novel agents in relapsed disease after ASCT, these therapies are beginning to show clinically meaningful response rates prior to ASCT. Finally, a new investigation in r/r HL continues to produce promising treatment options even after ASCT including CD30 directed chimeric antigen receptor T-cell therapy. In this review, we will discuss the recent advances of BV and anti-PD-1 therapy prior to ASCT, novel approaches in r/r HL after ASCT, and review active clinical trials.

BEAM-Campath Allogeneic Stem Cell Transplant for Patients with Relapsed/Refractory Lymphoma: High Incidence of Long-Term Mixed Donor-Recipient Chimerism and the Response to Donor Lymphocyte Infusions

BiCNU (carmustine), etoposide, Ara-C, melphalan (BEAM) and Campath conditioning was developed to reduce the high transplant-related mortality in patients with lymphoma while delivering intensive antilymphoma immunotherapy, as well as to some extent a platform for allogeneic stem cell engraftment. Significant numbers of patients appeared to have persistent recipient-derived hematopoiesis, and therefore we retrospectively analyzed patients with lymphoma undergoing BEAM-Campath conditioned allogeneic stem cell transplantation at our center (2003 to 2017) to characterize the patterns of chimerism and patient outcomes. Chimerism was analyzed with short tandem repeat PCR. Mixed donor-recipient chimerism (MDRC) was defined as 5% to 94.9% donor. Fifty-two patients (n = 30 male), with a median age of 45 years, were identified with histologic diagnoses of Hodgkin lymphoma (n = 13), diffuse large B cell lymphoma (n = 7), low-grade non-Hodgkin lymphoma (n = 16), mantle cell lymphoma (n = 10), and T cell lymphoma (n = 6). Pretransplant, 93% achieved complete response (52%) or partial response (41%) with a median of 3 prior therapies (n = 3 prior autologous stem cell transplantation). Donors were Matched sibling donors (MSD) (n = 21), matched unrelated donors (MUD) (n = 24), miss-matched unrelated donors (MMUD) (n = 6), and syngeneic (n = 1). Acute graft-versus host disease (GVHD) developed in 52% (81% grade I to II) and chronic GVHD (83% extensive) in 12%. MDRC of T cells (MDRCt) developed in 62% (n = 32), and 29% (n = 15) developed MDRC of myeloid cells (MDRCm) at a median onset of 100 days. Donor lymphocyte infusion (DLI) was given to 17 patients, with a median starting dose of 1 × 10⁶/kg. The first DLI was given at a median of 225 days post-transplant (range, 99 days to 5.3 years). Of these, 9 developed acute post-DLI GVHD and 2 limited chronic GVHD. Conversion to full donor occurred in 47% MDRCt and 50% MDRCm. Multivariate analysis identified sibling donor type as associated with increased MDRCt (P = .035; hazard ratio [HR], 0.17) and reduced total nucleated cell dose with increased MDRCm (P = .021; HR, 0.76). The median follow-up was 6 years, and 2-year NRM cumulative incidence was 16% (95% confidence interval [CI], 7% to 27%). Ten-year progression and extensive GVHD-free survival was 45% (95% CI, 28% to 61%), and overall survival was 66% (95% CI, 50% to 78%). One-year landmark analysis identified no increased GVHD or relapse risk with MDRCt or MDRCm but reduced nonrelapse mortality (NRM) risk with MDRCt (P = .001). BEAM-Campath allografts for high-risk lymphoma achieve long-term disease-free survival with low rates of GVHD and transplant-related mortality. The frequent development of myeloid MDRC demonstrates that BEAM-Campath is a nonmyeloablative conditioning regimen in almost a third of patients. MDRCt is associated with reduced NRM, but neither MDRCt or MDRCm is associated with increased GVHD or relapse.

Second autologous stem cell transplantation for relapsed/refractory Hodgkin lymphoma after a previous autograft: a study of the lymphoma working party of the EBMT

The purpose of this study was to analyze the results of second autologous hematopoietic stem cell transplantation (ASCT2) for patients with relapsed/refractory Hodgkin lymphoma (HL) after a first transplantation (ASCT1). Outcomes for 56 patients receiving an ASCT2 registered in the EBMT database were analyzed. The 4-year cumulative incidences of non-relapse mortality and disease relapse/progression were 5% and 67%, respectively. The 4-year overall survival (OS) and progression-free survival (PFS) were 62% and 28%. In univariate analysis, relapse of HL within 12 months of ASCT1 was associated with a worse OS (35% versus 76%, p = 0.01) and PFS (19% versus 29%, p = 0.059). Chemosensitivity at ASCT2 predicted better outcomes (4-year OS 72% versus 29%, p = 0.002; PFS 31% versus 12%, p = 0.015). This series shows that ASCT2 is a safe procedure and a relatively effective option for patients with late relapses after ASCT1 and with chemosensitive disease who are not eligible for an allogeneic transplant.

Relapse of Hodgkin lymphoma after autologous hematopoietic cell transplantation: A current management perspective

Hodgkin lymphoma (HL) is a highly responsive disease with nearly 70% of patients experiencing cure after front-line chemotherapy. Patients who experience disease relapse receive salvage chemotherapy followed by consolidation with autologous hematopoietic cell transplantation (auto-HCT). Nearly 50% of patients relapse after an auto-HCT and constitute a subgroup with poor prognosis. Novel treatments such as immune checkpoint inhibitors and an anti-CD30 monoclonal antibody are currently approved for patients relapsing after auto-HCT; however, the duration of remission with these therapies remains limited. Allogeneic HCT is currently the only potentially curative treatment modality for patients relapsing after a prior auto-HCT. Early clinical trials with chimeric antigen receptor T-cell therapy targeting CD30 are underway for patients with relapsed/refractory HL and are already demonstrating safety and promising efficacy.

Relapsing/refractory HL after autotransplantation: which treatment?

For advanced-stage Hodgkin lymphoma (HL), front-line chemotherapy, alone or in combination with radiotherapy, leads to 5-year progression-free survival (PFS) rates and freedom-from-treatment failure (FFTF) rates of 70-85%, regardless of the chemotherapy regimen applied. Patients with HL experiencing disease progression during or within 3 months of front-line therapy (primary refractory) and patients whose disease relapses after a complete response have a second chance of treatment. The standard of care for relapsed or refractory HL is second-line chemotherapy followed by autologous stem cell transplantation (ASCT), which can induce long-term remission in approximately 40-50% of patients. However, HL recurrence occurs in about 50% of patients after ASCT, usually within the first year, and represents a significant therapeutic challenge. Allogeneic transplantation from HLA-matched donors represents the standard of care for patients with HL relapsing after- or refractory to ASCT.

Changes in patients population and characteristics of hematopoietic stem cell transplantation for relapsed/refractory Hodgkin lymphoma: an analysis of the Lymphoma Working Party of the EBMT

Indications for autologous (auto-HCT) and allogeneic transplantation (allo-HCT) in relapsed/refractory Hodgkin lymphoma (rrHL) have been long established. The expectation is that long-term outcomes have significantly improved over time with increased experience in these procedures. The objective of this study was to assess whether this is the case and to identify further areas of improvement. A total of 13,639 adult patients receiving an auto-HCT or allo-HCT for rrHL were reported to the European Society for Blood and Marrow Transplantation (EBMT) over a 25-year period. Regarding auto-HCT, recipients are younger, interval between diagnosis and transplant shorter, peripheral blood has become the universal stem cell source and the use of total body irradiation is almost non-existent in recent years. Allo-HCT is currently mostly used as a second transplant; recipients are younger, fitter and less frequently, chemorefractory. Reduced intensity conditioning protocols have vastly replaced myeloablative protocols. Increasing numbers of haplo-HCT have been reported. Both in auto-HCT and allo-HCT, NRM, PFS and OS have significantly improved but relapse remains the main cause of treatment failure. A better selection of patients and improvements in the supportive care has resulted in a reduction in the NRM. Relapse after HCT remains unchanged and further research is needed.

Impact of type of reduced-intensity conditioning regimen on the outcomes of allogeneic haematopoietic cell transplantation in classical Hodgkin lymphoma

Reduced-intensity conditioning (RIC) allogeneic haematopoietic cell transplantation (allo-HCT) is a curative option for select relapsed/refractory Hodgkin lymphoma (HL) patients; however, there are sparse data to support superiority of any particular conditioning regimen. We analyzed 492 adult patients undergoing human leucocyte antigen (HLA)-matched sibling or unrelated donor allo-HCT for HL between 2008 and 2016, utilizing RIC with either fludarabine/busulfan (Flu/Bu), fludarabine/melphalan (Flu/Mel140) or fludarabine/cyclophosphamide (Flu/Cy). Multivariable regression analysis was performed using a significance level of <0·01. There were no significant differences between regimens in risk for non-relapse mortality (NRM) (P = 0·54), relapse/progression (P = 0·02) or progression-free survival (PFS) (P = 0·14). Flu/Cy conditioning was associated with decreased risk of mortality in the first 11 months after allo-HCT (HR = 0·28; 95% CI = 0·10-0·73; P = 0·009), but beyond 11 months post allo-HCT it was associated with a significantly higher risk of mortality, (HR = 2·46; 95% CI = 0·1.32-4·61; P = 0·005). Four-year adjusted overall survival (OS) was similar across regimens at 62% for Flu/Bu, 59% for Flu/Mel140 and 55% for Flu/Cy (P = 0·64), respectively. These data confirm the choice of RIC for allo-HCT in HL does not influence risk of relapse, NRM or PFS. Although no OS benefit was seen between Flu/Bu and Flu/Mel 140; Flu/Cy was associated with a significantly higher risk of mortality beyond 11 months from allo-HCT (possibly due to late NRM events).

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.

Lower Graft-versus-Host Disease and Relapse Risk in Post-Transplant Cyclophosphamide-Based Haploidentical versus Matched Sibling Donor Reduced-Intensity Conditioning Transplant for Hodgkin Lymphoma

Classic Hodgkin lymphoma (cHL) patients with relapsed or refractory disease may benefit from allogeneic hematopoietic cell transplantation (allo-HCT), but many lack a matched sibling donor (MSD). Herein, we compare outcomes of 2 reduced-intensity conditioning (RIC) HCT platforms in cHL: T cell-replete related donor haploidentical (haplo) HCT with a post-transplant cyclophosphamide (PTCy)-based approach versus an MSD/calcineurin inhibitor (CNI)-based approach. The study included 596 adult patients who underwent a first RIC allo-HCT for cHL between 2008 and 2016 using either a haplo-PTCy (n = 139) or MSD/CNI-based (n = 457) approach. Overall survival (OS) was the primary endpoint. Secondary endpoints included acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), nonrelapse mortality (NRM), relapse/progression, and progression-free survival (PFS). On multivariate analysis, there was no significant difference between haplo/PTCy and MDS/CNI-based approaches in terms of OS (hazard ratio [HR], 1.07; 95% confidence interval [CI], .79 to 1.45; P = .66) or PFS (HR, .86; 95% CI, .68 to 1.10; P = .22). Haplo/PTCy was associated with a significantly higher risk of grades II to IV aGVHD (odds ratio [OR], 1.73, 95% CI, 1.16 to 2.59; P = .007), but the risk of grades III to IV aGVHD was not significantly different between the 2 cohorts (OR, .61; 95% CI, .29 to 1.27; P = .19). The haplo/PTCy platform provided a significant reduction in cGVHD risk (HR, .45; 95% CI, .32 to .64; P < .001), and a significant reduction in relapse risk (HR, .74; 95% CI, .56 to .97; P = .03). There was a statistically nonsignificant trend toward higher NRM with a haplo/PTCy approach (HR, 1.65; 95% CI, .99 to 2.77; P = .06). Haplo/PTCy-based approaches are associated with lower incidences of cGVHD and relapse, with PFS and OS outcomes comparable with MSD/CNI-based approaches. There was a leaning toward higher NRM with a haplo/PTCy-based platform. These data show that haplo/PTCy allo-HCT in cHL results in survival comparable with MSD/CNI-based allo-HCT.

Allogeneic stem cell transplantation improves survival in relapsed Hodgkin lymphoma patients achieving complete remission after salvage treatment

Allogeneic stem cell transplant (alloSCT) is a current treatment option for patients with refractory/relapsed classic Hodgkin lymphoma (CHL), including those who have failed an autologous transplantation. We performed a retrospective multicenter analysis of 113 patients (median age 28 years; range 14-56; 54% males) with refractory/relapsed (R/R) CHL who had undergone alloSCT in Argentina. Kaplan-Meier was used to estimate overall (OS) and progression-free survival (PFS). Relapse rate (RR) and non-relapse mortality (NRM) were estimated with cumulative incidence analysis. Disease status at transplant was complete remission (CR) in 39%, partial remission (PR) in 44%, and stable/progressed disease (S/PD) in 17% of the patients. Donor type was matched related (MRD) in 60%, unrelated (URD) in 19%, and haploidentical (HID) in 21% of the patients. OS and PFS at 2 years were 43% and 27%, respectively, for all the cohort. In the univariate analysis, patients in CR showed better OS (p ≤ 0.001) and PFS (p ≤ 0.001), and lower NRM (p = 0.04). HID had better PFS (p = 0.04) and lower RR (p = 0.02). In the multivariate analysis, CR showed a significant impact on OS and PFS, and HID on PFS. AlloSCT is a feasible procedure in patients with CHL. Those in CR at the time of the transplant had better outcomes. Haploidentical transplantation is associated with better PFS in these patients with poor prognosis.

Is It Time to Revisit the Role of Allogeneic Transplantation in Lymphoma?

PURPOSE OF REVIEW

A multitude of new drug and cell therapy approvals for lymphoma has prompted questions about the role of allogeneic blood or marrow transplantation (allo-BMT). We sought to review the latest evidence examining the role of allo-BMT for lymphoma in this evolving landscape.

RECENT FINDINGS

Despite several new drug classes, there remains a large unmet need, particularly in hard to treat subtypes of lymphoma and for patients with relapsed/refractory disease. Allo-BMT can provide an opportunity for cure due to a potent graft vs lymphoma effect in high-risk relapse/refractory follicular lymphoma, mantle cell lymphoma, and aggressive T cell lymphomas. Chimeric antigen receptor T cell therapy and checkpoint blockers have improved outcomes for patients with relapsed /aggressive B cell lymphomas and Hodgkin lymphoma respectively; the role of allo-BMT consolidation in the treatment algorithm for responders to these therapies is an evolving topic. Expanded donor availability including haploidentical relatives has improved access to allo-BMT. Non-myeloablative conditioning regimens and post-transplant cyclophosphamide prophylaxis have improved early transplant-related morbidity and rates of graft versus host disease and translated into long-term survival for patients with lymphoid malignancies. Patient selection remains key, but allo-BMT remains the only modality able to deliver durable long-term remissions across different types of lymphoma.

Long-term efficacy of anti-PD1 therapy in Hodgkin lymphoma with and without allogenic stem cell transplantation

INTRODUCTION

Long-term efficacy of anti-PD1 therapy and the need for a consolidation with allogenic haematopoietic stem cell transplantation (allo-HSCT) remain unclear in patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL).

METHODS

We retrospectively analysed 78 patients with R/R HL treated with nivolumab in the French Early Access Program and compared their outcomes according to subsequent allo-HSCT.

RESULTS

After a median follow-up of 34.3 months, the best overall response rate was 65.8%, including 38.2% complete responses (CRs). The median progression-free survival (PFS) was 12.1 months. Patients reaching a CR upon nivolumab had a significantly longer PFS than those reaching a partial response (PR) (median = not reached vs 9.3 months, p < 0.001). In our cohort, 13 patients who responded (i.e. in CR or PR) to nivolumab monotherapy underwent consolidation with allo-HSCT. Among responding patients, none of those who underwent subsequent allo-HSCT (N = 13) relapsed, whereas 62.2% of those who were not consolidated with allo-HSCT (N = 37) relapsed (p < 0.001). There was no difference in overall survival (OS) between the two groups. Five of 6 patients who were not in CR at the time of transplantation (4 PRs and 1 progressive disease) converted into a CR after allo-HSCT.

CONCLUSION

Most patients with R/R HL treated with anti-PD1 monotherapy eventually progressed, notably those who did not achieve a CR. Patients undergoing consolidation with allo-HSCT after anti-PD1 therapy experienced prolonged disease-free survival compared with non-transplanted patients, but this difference did not translate into a benefit in OS. This information should be considered when evaluating the risk/benefit ratio of allo-HSCT after anti-PD1 therapy.

EBV/LMP-specific T cells maintain remissions of T- and B-cell EBV lymphomas after allogeneic bone marrow transplantation

Autologous T cells targeting Epstein-Barr virus (EBV) latent membrane proteins (LMPs) have shown safety and efficacy in the treatment of patients with type 2 latency EBV-associated lymphomas for whom standard therapies have failed, including high-dose chemotherapy followed by autologous stem-cell rescue. However, the safety and efficacy of allogeneic donor-derived LMP-specific T cells (LMP-Ts) have not been established for patients who have undergone allogeneic hematopoietic stem-cell transplantation (HSCT). Therefore, we evaluated the safety and efficacy of donor-derived LMP-Ts in 26 patients who had undergone allogeneic HSCT for EBV-associated natural killer/T-cell or B-cell lymphomas. Seven patients received LMP-Ts as therapy for active disease, and 19 were treated with adjuvant therapy for high-risk disease. There were no immediate infusion-related toxicities, and only 1 dose-limiting toxicity potentially related to T-cell infusion was seen. The 2-year overall survival (OS) was 68%. Additionally, patients who received T-cell therapy while in complete remission after allogeneic HSCT had a 78% OS at 2 years. Patients treated for B-cell disease (n = 10) had a 2-year OS of 80%. Patients with T-cell disease had a 2-year OS of 60%, which suggests an improvement compared with published posttransplantation 2-year OS rates of 30% to 50%. Hence, this study shows that donor-derived LMP-Ts are a safe and effective therapy to prevent relapse after transplantation in patients with B cell- or T cell-derived EBV-associated lymphoma or lymphoproliferative disorder and supports the infusion of LMP-Ts as adjuvant therapy to improve outcomes in the posttransplantation setting. These trials were registered at www.clinicaltrials.gov as #NCT00062868 and #NCT01956084.

Effect of dose rate on pulmonary toxicity in patients with hematolymphoid malignancies undergoing total body irradiation

BACKGROUND

This study evaluated the effect of radiation dose rate in patients with hematolymphoid malignancies undergoing myeloablative conditioning with total body irradiation (TBI), for hematopoietic stem cell transplantation.

METHODS

The incidence of pulmonary toxicity (PT) and treatment efficacy were compared between the conventional (≥ 6 cGy/min) and reduced dose rate (< 6 cGy/min). Seventy-seven patients receiving once-daily TBI between 2000 and 2016 were reviewed. We compared the cumulative rate of PT, overall survival (OS), relapse, and transplantation-related mortality (TRM) between conventional (n = 54) and reduced (n = 23) groups. Factors associated with PT were assessed in the presence of competing risks.

RESULTS

The median follow-up time was 40.7 months, and PT occurred in 50 patients (64.9%). On multivariate analyses, the groups classified by the dose rate (P = 0.010), total dose (P = 0.025), and conditioning regimen (P = 0.029) were significant factors for the development of PT. OS was significantly reduced when PT occurred (P < 0.001). However, the OS, relapse, and TRM were not different between the two groups.

CONCLUSIONS

In summary, about two-thirds of the patients undergoing daily TBI experienced PT, which affected OS. Therefore, reducing the dose rate (less than 6 cGy/min) of TBI can decrease the risk of PT, without compromising the treatment efficacy.

Comprehensive Genomic Profiling of Hodgkin Lymphoma Reveals Recurrently Mutated Genes and Increased Mutation Burden

A better understanding of the underlying disease biology that leads to improvement in treatment outcomes is needed. Investigation of the genomic landscape of Hodgkin lymphoma has been difficult because of the low tumor content in these inflammatory cell‐ and stroma‐rich tissue samples. A comprehensive genomic profiling with targeted next‐generation sequencing panel was performed to test for genomic aberrations in archival tumor samples from patients with Hodgkin lymphoma to identify potentially actionable molecular targets.

Background.

The genomic landscape of Hodgkin lymphoma (HL) has been difficult to characterize due to the paucity of neoplastic cells and an abundant microenvironment. Such characterization is needed in order to improve treatment strategies.

Materials and Methods.

We performed comprehensive genomic profiling (CGP) using targeted next‐generation sequencing on archival formalin‐fixed paraffin embedded tumor samples from 63 patients to analyze the landscape of HL.

Results.

CGP was successful for 49/63 archival specimens (78%), and revealed aberrations impacting genes including B2M, TP53, and XPO1 (E571). Of the 34 patients for whom total mutation burden (TMB; mutations/megabase [Mb]) was assessed, 5 (15%) had high TMB (≥20 mutations/Mb), 18 (53%) had intermediate TMB (6–19 mutations/Mb), and 11 (32%) had low TMB (≤5 mutations/Mb). We next tested 13 patients' plasma cell‐free DNA with droplet digital polymerase chain reaction for the presence of XPO1 E571 mutation, which was confirmed in the plasma of 31% of patients. In three patients with serially collected plasma samples, XPO1 E571K allelic frequency changes corresponded with changes in tumor size on conventional radiographic imaging.

Conclusion.

The study demonstrates that comprehensive genomic profiling of archival Hodgkin lymphoma tumor samples is feasible and leads to the identification of genes that are recurrently mutated and that Hodgkin lymphoma has increased mutation burden in the majority of samples analyzed. Furthermore, tracking of XPO1 E571 mutant allele frequency in a subset of patients may also represent a potential disease‐monitoring strategy and warrants further investigation.

Implications for Practice.

This study provides the first evidence that comprehensive genomic profiling can be performed to map the genomic landscape of Hodgkin lymphoma and that a subpopulation of patients has mutations in TP53, B2M, XPO1, and other genes. It was found that 15% of patients have high mutation burden, which, in cancers such as melanoma, may indicate sensitivity to immune checkpoint inhibitors, and may thus be explored for Hodgkin lymphoma. Lastly, this work demonstrates that changes in the mutant allele frequency of XPO1 in serially collected plasma cell‐free DNA samples correspond with treatment outcomes measured with conventional radiographic imaging.

Strategies for Recognizing and Managing Immune-Mediated Adverse Events in the Treatment of Hodgkin Lymphoma with Checkpoint Inhibitors

The programmed death-1 (PD-1) receptor checkpoint inhibitors nivolumab and pembrolizumab represent an important therapeutic advance in the treatment of relapsed or refractory classical Hodgkin lymphoma (cHL). Clinical trials have shown substantial therapeutic activity and an acceptable safety profile in heavily pretreated patients, resulting in U.S. Food and Drug Administration approval of nivolumab for the treatment of cHL that has relapsed or progressed after either autologous hematopoietic cell transplantation (auto-HCT) and brentuximab vedotin treatment or three or more lines of systemic therapy (including auto-HCT), and of pembrolizumab for adult or pediatric patients with refractory cHL or cHL that has relapsed after three or more prior therapies. Mechanistically, anti-PD-1 therapy prevents inhibitory signaling through PD-1 receptors on T cells, thereby releasing a 'block' to antitumor T-cell responses. However, this disinhibition can also lead to inappropriate T-cell activation and responses against healthy tissues, resulting in immune-mediated adverse events (IMAEs) that affect a number of organ systems. The skin, gastrointestinal, hepatic, and endocrine systems are most commonly involved, typically resulting in rash, colitis, abnormal liver enzyme levels, and thyroiditis, respectively. Notably, pneumonitis is a potentially fatal complication of checkpoint inhibitor immunotherapy. Hematologic oncologists who treat cHL with PD-1 immune checkpoint inhibitors should monitor patients for IMAEs, as early recognition and treatment can rapidly reduce morbidity and mortality. This review focuses on IMAEs during the treatment of relapsed or refractory cHL with nivolumab and pembrolizumab. IMPLICATIONS FOR PRACTICE: This article highlights the importance of monitoring for immune-mediated adverse events (IMAEs) in patients with Hodgkin lymphoma (HL) who receive anti-programmed death-1 (anti-PD-1) therapy, with particular attention given to the recognition and management of such events. The risk of individual IMAEs differs between patients with HL and those with solid tumors, as prior treatments may predispose certain organ systems to specific IMAEs. Accurate and prompt diagnosis of IMAEs is essential for optimal management, allowing PD-1 inhibitor therapy to be restarted in order to maintain disease control. Potential difficulties, such as distinguishing disease progression from pneumonitis, or colitis from diarrhea, are highlighted to raise clinical awareness.