Unrelated donor reduced-intensity allogeneic hematopoietic stem cell transplantation for relapsed and refractory Hodgkin lymphoma

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.

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.

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.

Post-transplantation Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography in Patients with Lymphoblastic Lymphoma is an Independent Prognostic Factor with an Impact on Progression-Free Survival but not Overall Survival

Purpose: In the present study, we mainly aimed to evaluate the prognostic value of 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]F-FDG) positron emission tomography (PET)/computed tomography (CT) after allogeneic stem cell transplantation (allo-SCT) in lymphoblastic lymphoma (LBL) patients using Deauville Scores (DS). Materials and Methods: A total of 63 LBL patients who benefited from ¹⁸F-FDG PET-CT after allo-SCT in our institution between April 2010 and August 2020 were enrolled in this retrospective study. These above-mentioned patients were divided into two groups based on the Deauville criteria. Diagnostic efficiency of ¹⁸F-FDG PET/CT and integrated CT in detecting lymphoma were calculated. Consistencies were evaluated by comparing 18F-FDG PET/CT and integrated CT results through kappa coefficient. Kaplan-Meier method was used in survival analysis, and the log-rank method was adopted in comparisons. Prognostic factor analysis was performed by the Cox regression model. Results: The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of post-SCT ¹⁸F-FDG PET-CT were 100%(12/12), 92.2%(47/51), 75.0%(12/16), 100%(47/47) and 93.7%(59/63). The consistency of 18F-FDG PET-CT and integrated CT was moderate(Kappa = .702，P < .001). Positive post-SCT 18F-FDG PET-CT was associated with lower progression-free survival (PFS) but not overall survival (OS) (p = .000 and p = .056, respectively). The 3-year PFS of the PET-positive group and PET-negative group was 18.8% and 70.2%, respectively. Multivariate analysis showed that post-SCT PET-CT findings was an independent prognostic factor for PFS (p = .000; HR, 3.957; 95%CI, 1.839-8.514). Other factors independently affecting PFS were sex (p = .018; HR, 2.588; 95% CI, 1.181 − 5.670) and lactate dehydrogenase (LDH) (p = .005; HR, 3.246; 95% CI, 1.419 − 7.426). However, none of the above-mentioned factors were associated with OS. Conclusions: Collectively, we found that 18F-FDG PET-CT after allo-SCT was a strong indicator for PFS, but not OS, which might provide important evidence for the selection of subsequent treatment regimen for LBL patients. Trial registration number: ChiCTR2100046709.

Anti-CD30 CAR-T Cell Therapy in Relapsed and Refractory Hodgkin Lymphoma

PURPOSE

Chimeric antigen receptor (CAR) T-cell therapy of B-cell malignancies has proved to be effective. We show how the same approach of CAR T cells specific for CD30 (CD30.CAR-Ts) can be used to treat Hodgkin lymphoma (HL).

METHODS

We conducted 2 parallel phase I/II studies (ClinicalTrials.gov identifiers: NCT02690545 and NCT02917083) at 2 independent centers involving patients with relapsed or refractory HL and administered CD30.CAR-Ts after lymphodepletion with either bendamustine alone, bendamustine and fludarabine, or cyclophosphamide and fludarabine. The primary end point was safety.

RESULTS

Forty-one patients received CD30.CAR-Ts. Treated patients had a median of 7 prior lines of therapy (range, 2-23), including brentuximab vedotin, checkpoint inhibitors, and autologous or allogeneic stem cell transplantation. The most common toxicities were grade 3 or higher hematologic adverse events. Cytokine release syndrome was observed in 10 patients, all of which were grade 1. No neurologic toxicity was observed. The overall response rate in the 32 patients with active disease who received fludarabine-based lymphodepletion was 72%, including 19 patients (59%) with complete response. With a median follow-up of 533 days, the 1-year progression-free survival and overall survival for all evaluable patients were 36% (95% CI, 21% to 51%) and 94% (95% CI, 79% to 99%), respectively. CAR-T cell expansion in vivo was cell dose dependent.

CONCLUSION

Heavily pretreated patients with relapsed or refractory HL who received fludarabine-based lymphodepletion followed by CD30.CAR-Ts had a high rate of durable responses with an excellent safety profile, highlighting the feasibility of extending CAR-T cell therapies beyond canonical B-cell malignancies.

Salvage Therapy for Hodgkin's Lymphoma: A Review of Current Regimens and Outcomes

Relapse/refractory Hodgkin lymphoma patients are still a clinical concern. Indeed, despite more effective first-line chemotherapy regimens and better stratification of unresponsive patients by clinical factors and use of early PET, roughly one-third of such patients need salvage chemotherapy and consolidation with high-dose chemotherapy. In this paper, the authors review the different salvage treatments, with special emphasis on newer combinations with brentuximab vedotin or check point inhibitors. The overall response rate is constantly increasing, with a complete remission rate approaching 80%. Functional response evaluation by PET imaging is a strong predictive factor of longer survival, and more sophisticated tools, such as detection of circulating tumour DNA, are emerging to refine the disease-status assessment after treatment. Consolidation by high-dose chemotherapy is still considered the standard of care in chemosensitive patients, leading to a high fraction of patients towards long-term disease control. Maintenance therapy with BV is now approved, reducing disease relapse/progression. An increasing number of Hodgkin lymphoma patients will be cured after first- and second-line therapy, and long-term toxicity needs to be continuously assessed and avoided.

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.

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).

ESMO Consensus Conference on malignant lymphoma: management of 'ultra-high-risk' patients

The European Society for Medical Oncology (ESMO) consensus conference on malignant lymphoma was held on 20 June 2015 in Lugano, Switzerland, and included a multidisciplinary panel of 25 leading experts. The aim of the conference was to develop recommendations on critical subjects difficult to consider in detail in the ESMO Clinical Practice Guidelines. The following areas were identified: (1) the elderly patient, (2) prognostic factors suitable for clinical use and (3) the 'ultra-high-risk' group. Before the conference, the expert panel was divided into three working groups; each group focused on one of these areas in order to address clinically relevant questions relating to that topic. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, each working group developed recommendations to address each of the questions devised by their group. These recommendations were then presented to the entire multidisciplinary panel and a consensus was reached. This manuscript presents recommendations regarding the management of the following 'ultra-high-risk' situations: (1) early central nervous system relapse of diffuse large B-cell lymphoma, (2) primary refractory Hodgkin lymphoma and (3) plasmablastic lymphoma. Results, including a summary of evidence supporting each recommendation, are detailed in this manuscript. All expert panel members approved this final article.

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.

Haploidentical Stem Cell Transplantation With Post-Transplantation Cyclophosphamide for Aggressive Lymphomas: How Far Have We Come and Where Are We Going?

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplant cyclophosphamide (PTCy) offers universal donor availability and can potentially cure relapsed or primary refractory Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). However, a conditioning regimen intensity that balances the graft-versus-lymphoma (GvL) effect with regimen-related toxicities (RRTs) has not yet been optimized. Limited data exist on the management of relapse, which is common post-transplant. Few prospective or randomized control trials have been conducted on lymphoma patients undergoing haplo-HSCT. Therefore, the current review aims to summarize published retrospective data in the field to help guide clinical decision making for high-risk patients. Retrospective studies in the field are characterized by variability in patient population and sample sizes, eligibility criteria, number of prior treatments (e.g., chemotherapy, radiation therapy, and autologous transplant), graft source (bone marrow or peripheral blood), as well as choice and intensity of the conditioning regimen (non-myeloablative, reduced intensity, or myeloablative). Nonetheless, common themes that emerge from the literature include: 1) Enhanced donor availability and selection with haplo-HSCT with success in heterogeneous patient populations; 2) Outcomes that are comparable if not superior to matched related (MRD) or unrelated (MUD) donor transplants; 3) The benefit of PTCy for reducing incidence of relapse and chronic graft-versus-host disease (GvHD); 4) Presence of co-morbidities leading to poorer transplant-related outcomes; and 5) The need for novel approaches to address disease relapse, particularly for patients with active disease at the time of transplant. Excellent transplant-related outcomes with haplo-HSCT with PTCy have been seen for HL and NHL based on retrospective data. Further studies are needed to determine integration with advanced cellular therapy techniques, such as chimeric antigen receptor (CAR) T-cell, antibody drug conjugates, and checkpoint inhibitors. Graft manipulation may be another avenue for future research.

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.

Allogeneic transplantation for relapsed and refractory Hodgkin lymphoma: long-term outcomes and graft-versus-host disease-free/relapse-free survival

This monocentric retrospective study included 70 consecutive relapsed/refractory Hodgkin lymphoma (RR-HL) patients receiving reduced-intensity allogeneic stem cell transplantation (alloSCT). We evaluated overall and progression-free survival (OS, PFS), graft-versus host disease/relapse-free survival (GFRS), and chronic GVHD-free OS (cGVHD-free OS) defined as OS without moderate-to-severe cGVHD. Patients had a median age of 33 years (range, 18-60 years), 23% had refractory disease (SD/PD). Donors were HLA identical (39%), unrelated (30%), or haploidentical (31%). Median follow-up was 6.2 years. Five-year OS was 59% and PFS was 49%. NRM was 16% at 1 year. 44% of patients had cGVHD, and 14% moderate-to-severe cGVHD at last follow-up. GFRS and cGVHD-free OS were 26 and 48% at 5 years. In multivariate analysis, resistant disease at alloSCT impacted survival and GFRS. In conclusion, disease response before alloSCT impacts survival and GFRS. GVHD outcomes may help comparing the long-term effects of the new salvage treatments that bridge patients to alloSCT.

Nivolumab for Relapsed/Refractory Classic Hodgkin Lymphoma After Failure of Autologous Hematopoietic Cell Transplantation: Extended Follow-Up of the Multicohort Single-Arm Phase II CheckMate 205 Trial

Purpose

Genetic alterations causing overexpression of programmed death-1 ligands are near universal in classic Hodgkin lymphoma (cHL). Nivolumab, a programmed death-1 checkpoint inhibitor, demonstrated efficacy in relapsed/refractory cHL after autologous hematopoietic cell transplantation (auto-HCT) in initial analyses of one of three cohorts from the CheckMate 205 study of nivolumab for cHL. Here, we assess safety and efficacy after extended follow-up of all three cohorts.

Methods

This multicenter, single-arm, phase II study enrolled patients with relapsed/refractory cHL after auto-HCT treatment failure into cohorts by treatment history: brentuximab vedotin (BV)–naïve (cohort A), BV received after auto-HCT (cohort B), and BV received before and/or after auto-HCT (cohort C). All patients received nivolumab 3 mg/kg every 2 weeks until disease progression/unacceptable toxicity. The primary end point was objective response rate per independent radiology review committee.

Results

Overall, 243 patients were treated; 63 in cohort A, 80 in cohort B, and 100 in cohort C. After a median follow-up of 18 months, 40% continued to receive treatment. The objective response rate was 69% (95% CI, 63% to 75%) overall and 65% to 73% in each cohort. Overall, the median duration of response was 16.6 months (95% CI, 13.2 to 20.3 months), and median progression-free survival was 14.7 months (95% CI, 11.3 to 18.5 months). Of 70 patients treated past conventional disease progression, 61% of those evaluable had stable or further reduced target tumor burdens. The most common grade 3 to 4 drug-related adverse events were lipase increases (5%), neutropenia (3%), and ALT increases (3%). Twenty-nine deaths occurred; none were considered treatment related.

Conclusion

With extended follow-up, responses to nivolumab were frequent and durable. Nivolumab seems to be associated with a favorable safety profile and long-term benefits across a broad spectrum of patients with relapsed/refractory cHL.

Allogeneic hematopoietic stem cell transplantation for relapsed follicular lymphoma: A combined analysis on behalf of the Lymphoma Working Party of the EBMT and the Lymphoma Committee of the CIBMTR

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HCT) remains the only potentially curative treatment option for relapsed follicular lymphoma (FL), yet questions remain about the optimal timing. This study analyzed long-term outcomes and associated factors among recipients of allo-HCT with FL.

METHODS

Patients with relapsed FL who underwent allo-HCT from 2001 to 2011 with a human leukocyte antigen (HLA)-matched donor were included. Outcome analyses for overall survival (OS), progression-free survival (PFS), transplant-related mortality (TRM), and disease relapse/progression were calculated. A multivariate analysis was performed to determine factors associated with outcomes, and a prognostic score for treatment failure was developed in a subset analysis of patients.

RESULTS

In all, 1567 patients with relapsed FL were included; the median follow-up was 55 months. The 5-year probabilities of OS and PFS were 61% and 52%, respectively. The 5-year cumulative incidences of disease progression/relapse and TRM were 29% and 19%, respectively. Chemoresistant disease, older age, heavy pretreatment, poor performance status (PS), and myeloablative protocols were predictors for worse survival. The prognostic score, using age, lines of prior therapy, disease status, and PS, stratified patients into 3 groups-low, intermediate, and high risk-with 5-year PFS rates of 68%, 53%, and 46%, respectively, and 5-year OS rates of 80%, 62%, and 50%, respectively.

CONCLUSIONS

Allo-HCT should be considered for patients with relapsed FL and available HLA-matched donors. Outcomes are better in earlier phases of the disease, and reduced-intensity conditioning should be preferred. The prognostic score presented here can assist in counseling patients and determining the time to proceed to transplantation. Cancer 2018;124:1733-42. © 2018 American Cancer Society.

Post-Transplantation Cyclophosphamide-Based Haploidentical Transplantation as Alternative to Matched Sibling or Unrelated Donor Transplantation for Hodgkin Lymphoma: A Registry Study of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation

Purpose

To compare the outcome of patients with Hodgkin lymphoma who received post-transplantation cyclophosphamide–based haploidentical (HAPLO) allogeneic hematopoietic cell transplantation with the outcome of patients who received conventional HLA-matched sibling donor (SIB) and HLA-matched unrelated donor (MUD).

Patients and Methods

We retrospectively evaluated 709 adult patients with Hodgkin lymphoma who were registered in the European Society for Blood and Marrow Transplantation database who received HAPLO (n = 98), SIB (n = 338), or MUD (n = 273) transplantation.

Results

Median follow-up of survivors was 29 months. No differences were observed between groups in the incidence of acute graft-versus-host disease (GVHD). HAPLO was associated with a lower risk of chronic GVHD (26%) compared with MUD (41%; P = .04). Cumulative incidence of nonrelapse mortality at 1 year was 17%, 13%, and 21% in HAPLO, SIB, and MUD, respectively, and corresponding 2-year cumulative incidence of relapse or progression was 39%, 49%, and 32%, respectively. On multivariable analysis, relative to SIB, nonrelapse mortality was similar in HAPLO ( P = .26) and higher in MUD ( P = .003), and risk of relapse was lower in both HAPLO ( P = .047) and MUD ( P < .001). Two-year overall survival and progression-free survival were 67% and 43% for HAPLO, 71% and 38% for SIB, and 62% and 45% for MUD, respectively. There were no significant differences in overall survival or progression-free survival between HAPLO and SIB or MUD. The rate of the composite end point of extensive chronic GVHD and relapse-free survival was significantly better for HAPLO (40%) compared with SIB (28%; P = .049) and similar to MUD (38%; P = .59).

Conclusion

Post-transplantation cyclophosphamide–based HAPLO transplantation results in similar survival outcomes compared with SIB and MUD, which confirms its suitability when no conventional donor is available. Our results also suggest that HAPLO results in a lower risk of chronic GVHD than MUD transplantation.

Relapse of Hodgkin lymphoma after autologous transplantation: Time to rethink treatment?

Relapse of Hodgkin lymphoma after autologous hematopoietic cell transplantation (autologous HCT) is a major therapeutic challenge. Its management, at least in younger patients, traditionally involves salvage chemotherapy aiming to achieve disease remission followed by consolidation with allogeneic hematopoietic cell transplantation (allogeneic HCT) in eligible patients. The efficacy of salvage therapy is variable and newer combination chemotherapy regimens have improved the outcomes. Factors such as shorter time to relapse after autologous HCT and poor performance status have been identified as predictors of poor outcome. Newer agents such as immunoconjugate brentuximab vedotin, checkpoint inhibitors (e.g., pembrolizumab, nivolumab), lenalidomide, and everolimus are available for the treatment of patients relapsing after autologous HCT. With the availability of reduced intensity conditioning allogeneic HCT, more patients are eligible for this therapy with lesser toxicity and better efficacy due to graft versus lymphoma effects. Alternative donor sources such as haploidentical stem cell transplantation and umbilical cord blood transplantation are expanding this procedure to patients without HLA-matched donors. However, strategies aimed at reduction of disease relapse after reduced intensity conditioning allogeneic HCT are needed to improve the outcomes of this treatment. This review summarizes the current data on salvage chemotherapy and HCT strategies used to treat patients with relapsed Hodgkin lymphoma after prior autologous HCT.

Improving outcomes after allogeneic hematopoietic cell transplantation for Hodgkin lymphoma in the brentuximab vedotin era

Allogeneic hematopoietic cell transplantation (allo HCT) remains a valuable alternative for relapsed/refractory (R/R) Hodgkin lymphoma (HL). Data on allo HCT outcomes in the era of new HL therapies are needed. We evaluated 72 R/R HL patients who received reduced intensity conditioning (RIC) allo HCT and compared the time periods 2009-2013 (n=20) to 2000-2008 (n=52). Grafts included HLA-matched sibling (35%), unrelated donor (8%) and umbilical cord blood (UCB, 56%). In recent period, patients more often received brentuximab vedotin (BV, 60% vs 2%), had fewer comorbidities (Sorror index 0: 60% vs 12%) and were in complete remission (50% vs 23%). Median follow-up was 4.4 years. Three-year progression-free survival (PFS) improved for patients treated between 2009-2013 (49%, 95% CI 26-68%) as compared to the earlier era (23%, 95% CI 13-35%, p=0.02). Overall survival (OS) at 3-years was 84% (95% CI 57-94%) vs 50% (95% CI 36-62%, p=0.01), reflecting lower non-relapse mortality and relapse rates. In multivariate analysis mortality was higher among those with chemoresistance (HR 3.83, 95% CI 1.38-10.57), while treatment during the recent era was associated with better OS (HR for period 2009-2013: 0.24, 95% CI 0.07-0.79) and PFS (HR 0.46, 95% CI 0.23-0.92). Allo HCT in patients with R/R HL is now a more effective treatment.

Reduced-intensity and non-myeloablative allogeneic stem cell transplantation from alternative HLA-mismatched donors for Hodgkin lymphoma: a study by the French Society of Bone Marrow Transplantation and Cellular Therapy

Allogeneic stem cell transplantation (allo-SCT) following a non-myeloablative (NMA) or reduced-intensity conditioning (RIC) is considered a valid approach to treat patients with refractory/relapsed Hodgkin lymphoma (HL). When an HLA-matched donor is lacking a graft from a familial haploidentical (HAPLO) donor, a mismatched unrelated donor (MMUD) or cord blood (CB) might be considered. In this retrospective study, we compared the outcome of patients with HL undergoing a RIC or NMA allo-SCT from HAPLO, MMUD or CB. Ninety-eight patients were included. Median follow-up was 31 months for the whole cohort. All patients in the HAPLO group (N=34) received a T-cell replete allo-SCT after a NMA (FLU-CY-TBI, N=31, 91%) or a RIC (N=3, 9%) followed by post-transplant cyclophosphamide. After adjustment for significant covariates, MMUD and CB were associated with significantly lower GvHD-free relapse-free survival (GRFS; hazard ratio (HR)=2.02, P=0.03 and HR=2.43, P=0.009, respectively) compared with HAPLO donors. In conclusion, higher GRFS was observed in Hodgkin lymphoma patients receiving a RIC or NMA allo-SCT with post-transplant cyclophosphamide from HAPLO donors. Our findings suggest they should be favoured over MMUD and CB in this setting.

Outcomes of allogeneic hematopoietic stem cell transplantation for lymphomas: a single-institution experience

Introduction

Allogeneic hematopoietic stem cell transplantation offers the opportunity for extended survival in patients with Hodgkin's and non-Hodgkin lymphomas who relapsed after, or were deemed ineligible for, autologous transplantation. This study reports the cumulative experience of a single center over the past 14 years aiming to define the impact of patient, disease, and transplant-related characteristics on outcomes.

Methods

All patients with histologically confirmed diagnosis of Hodgkin's or non-Hodgkin lymphomas who received allogeneic transplantation from 2000 to 2014 were retrospectively studied.

Results

Forty-one patients were reviewed: 10 (24%) had Hodgkin's and 31 (76%) had non-Hodgkin lymphomas. The median age was 50 years and 23 (56%) were male. The majority of patients (68%) had had a prior autologous transplantation. At the time of allogeneic transplantation, 18 (43%) patients were in complete and seven (17%) were in partial remission. Most (95%) patients received reduced-intensity conditioning, 49% received matched sibling donor grafts, 24% matched-unrelated donor grafts, and 27% received double umbilical cord blood grafts. The 100-day treatment-related mortality rate was 12%. After a median duration of follow up of 17.1 months, the median progression-free and overall survival was 40.5 and 95.8 months, respectively. On multivariate analysis, patients who had active disease at the time of transplant had inferior survival.

Conclusions

Allogeneic transplantation results extend survival in selected patients with relapsed/refractory Hodgkin's and non-Hodgkin lymphomas with low treatment-related mortality. Patients who have active disease at the time of allogeneic transplantation have poor outcomes.

Next-generation sequencing-based detection of circulating tumour DNA After allogeneic stem cell transplantation for lymphoma

Next-generation sequencing (NGS)-based circulating tumour DNA (ctDNA) detection is a promising monitoring tool for lymphoid malignancies. We evaluated whether the presence of ctDNA was associated with outcome after allogeneic haematopoietic stem cell transplantation (HSCT) in lymphoma patients. We studied 88 patients drawn from a phase 3 clinical trial of reduced-intensity conditioning HSCT in lymphoma. Conventional restaging and collection of peripheral blood samples occurred at pre-specified time points before and after HSCT and were assayed for ctDNA by sequencing of the immunoglobulin or T-cell receptor genes. Tumour clonotypes were identified in 87% of patients with adequate tumour samples. Sixteen of 19 (84%) patients with disease progression after HSCT had detectable ctDNA prior to progression at a median of 3·7 months prior to relapse/progression. Patients with detectable ctDNA 3 months after HSCT had inferior progression-free survival (PFS) (2-year PFS 58% vs. 84% in ctDNA-negative patients, P = 0·033). In multivariate models, detectable ctDNA was associated with increased risk of progression/death (Hazard ratio 3·9, P = 0·003) and increased risk of relapse/progression (Hazard ratio 10·8, P = 0·0006). Detectable ctDNA is associated with an increased risk of relapse/progression, but further validation studies are necessary to confirm these findings and determine the clinical utility of NGS-based minimal residual disease monitoring in lymphoma patients after HSCT.

Impact of Pretransplantation (18)F-Fluorodeoxyglucose-Positron Emission Tomography on Survival Outcomes after T Cell-Depleted Allogeneic Transplantation for Hodgkin Lymphoma

Pretransplant (18)F-fluorodeoxyglucose (FDG) positron emission tomography status is an important prognostic factor for outcomes after autologous stem cell transplantation (SCT) in Hodgkin lymphoma (HL), but its impact on outcomes after allogeneic SCT remains unclear. We retrospectively evaluated outcomes after T cell-depleted allogeneic SCT of 116 patients with nonprogressive HL according to pretransplant Deauville scores. Endpoints were overall survival (OS), progression-free survival (PFS), relapse rate (RR), and nonrelapse-related mortality (NRM). OS, PFS, and RR did not differ significantly between the Deauville 1 to 2 and Deauville 3 to 5 cohorts (OS: 77.5% versus 67.3%, P = .49; PFS: 59.4% versus 55.7%, P = .43; RR: 20.9% versus 22.6%, P = .28 at 4 years). Differences in PFS remained statistically nonsignificant when comparisons were made between Deauville 1 to 3 and Deauville 4 to 5 cohorts (60.9% versus 51.4%, P = .10), and RR remained very similar (21.5% versus 23.8%, P = .42). Multivariate analyses demonstrated trends toward significance for an effect of Deauville score on PFS (hazard ratio 1.82 for Deauville 4 to 5, P = .06) and for number of lines of prior therapy on OS (hazard ratio 2.34 for >5 lines, P = .10). The latter effect appeared to be driven by higher NRM rather than increased RR. Our findings suggest that Deauville score before allogeneic SCT in patients with nonprogressive HL has a relatively modest impact on survival outcomes in comparison with the impact in autologous SCT and that predictive values for the individual patient remain low, indicating that residual FDG-avid disease should not preclude allogeneic SCT. Furthermore, our findings bring into question the importance of attainment of metabolic complete response in this setting if it is at the expense of increasing NRM risk.

Allogeneic hematopoietic stem cell transplantation in Hodgkin lymphoma: a systematic review and meta-analysis

Allogeneic stem cell transplantation (allo-SCT) outcomes in patients with Hodgkin lymphoma (HL) remain poorly defined. We performed a meta-analysis of allo-SCT studies in HL patients. The primary endpoints were 6-month, 1-year, 2-year and 3-year relapse-free survival (RFS) and overall survival (OS). A total of 42 reports (1850 patients) was included. The pooled estimates (95% confidence interval) for 6-month, 1-year, 2-year and 3-year RFS were 77 (59-91)%, 50 (42-57)%, 37 (31-43)% and 31 (25-37)%, respectively. The corresponding numbers for OS were 83 (75-91)%, 68 (62-74)%, 58 (52-64)% and 50 (41-58)%, respectively. There was statistical heterogeneity among studies in all outcomes. In meta-regression, accrual initiation year in 2000 or later was associated with higher 6-month (P=0.012) and 1-year OS (P=0.046), and pre-SCT remission with higher 2-year OS (P=0.047) and 1-year RFS (P=0.016). In conclusion, outcomes of allo-SCT in HL have improved over time, with 5-10% lower non-relapse mortality and relapse rates, and 15-20% higher RFS and OS in studies that initiated accrual in 2000 or later compared with earlier studies. However, there is no apparent survival plateau, demonstrating the need to improve on current allo-SCT strategies in relapsed/refractory HL.

Salvage treatment for relapsed/refractory Hodgkin lymphoma: role of allografting, brentuximab vedotin and newer agents

INTRODUCTION

Second-line, salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (AUTO-SCT) is the standard of care for patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL). Approximately 50% of patients relapse after AUTO-SCT and their prognosis is generally poor. Brentuximab Vedotin (BV) has demonstrated efficacy in this setting and allogeneic (ALLO)-SCT represents an option with curative potential in this subgroup of patients.

AREAS COVERED

A systematic review has been conducted to explore the actual knowledge on ALLO-SCT, BV and newer agents in R/R HL.

EXPERT OPINION

The introduction of BV in clinical practice has significantly improved the management of post-AUTO-SCT relapses and the drug can induce durable remissions in a subset of R/R HL. Allografting select patients has been used to improve clinical outcomes and recent case series have begun to explore BV as a potential 'bridge' to allo-SCT, even though the optimal timing of ALLO-SCT after BV response remains undetermined. However, reduced tumor burden at the time of ALLO-SCT is a key factor to decrease relapse risk. Based on the unique composition of the tumor, more recently new agents such as PD-1 inhibitors have been developed. The potential role of PD-1 inhibitors with ALLO-SCT remains to be explored.

Outcomes of Haploidentical Stem Cell Transplantation for Lymphoma with Melphalan-Based Conditioning

Haploidentical transplantation (Haplo-SCT) with post-transplantation cyclophosphamide (PTCy) is increasingly utilized for the treatment of lymphoma and almost exclusively with the nonmyeloablative fludarabine (Flu)/cyclophosphamide/total body irradiation (TBI) conditioning regimen. We present early results of a reduced-intensity (RIC) regimen utilizing fludarabine and melphalan (FM) for the treatment of advanced lymphoma. All patients with a diagnosis of lymphoma or chronic lymphocytic leukemia (CLL) who received Haplo-SCT at the University of Texas MD Anderson Cancer Center between 2009 and 2014 were reviewed (N = 22). Patients received Flu 160 mg/m(2) and melphalan 100 mg/m(2) to 140 mg/m(2) with thiotepa 5 mg/kg or 2 Gy TBI. Because of concerns of increased treatment-related mortality (TRM) with the melphalan 140 mg/m(2) regimen (FM140), a RIC regimen with melphalan 100 mg/m(2) (FM100) was devised. Rituximab was included for CD20(+) disease. Graft-versus-host disease prophylaxis consisted of PTCy 50 mg/kg on days +3 and + 4, tacrolimus, and mycophenolate mofetil. Sixty-eight percent of all patients were not in complete remission at the time of transplantation. The 2-year progression-free survival (PFS) and overall survival (OS) for the entire cohort were 54%, 1-year TRM was 19%, and the cumulative incidence of relapse at 2 years was 27%. Two-year PFS for Hodgkin lymphoma, non-Hodgkin lymphoma, and CLL/small lymphocytic lymphoma were 57%, 51%, and 75%. Patients treated with FM100 compared to FM140 had equivalent PFS (71% versus 37%, P = .246) and OS (71% versus 58%, P = .32). These early results establish Flu and melphalan 100 mg/m(2) with 2 Gy TBI or thiotepa 5 mg/kg as a very promising conditioning regimen for the treatment of advanced lymphoma with Haplo-SCT and PTCy.

Umbilical cord blood transplantation in adults with advanced hodgkin's disease: high incidence of post-transplant lymphoproliferative disease

We report the outcome of 30 consecutive patients with Hodgkin disease (HD) who underwent single-unit UCBT. Most (90%) patients had failed previous autologous hematopoietic stem cell transplantation. The conditioning regimens were based on combinations of thiotepa, busulfan, cyclophosphamide or fludarabine, and antithymocyte globulin. The cumulative incidence (CI) of myeloid engraftment was 90% [95% confidence interval (C.I.), 74-98%] with a median of 18 d (range, 10-48). CI of acute graft-versus-host disease (GvHD) grades II-IV was 30% (95% C.I., 17-44%), while the incidence of chronic GVHD was 42% (95% C.I., 23-77%). The non-relapse mortality (NRM) at 100 d and 4 yr was 30% (95% C.I., 13-46%) and 47% (95% C.I., 29-65%), respectively. EBV-related post-transplant lymphoproliferative disease (EBV-PTLD) accounted for more than one-third of transplant-related death, with an estimate incidence of 26% (95% C.I., 9-44). The incidence of relapse at 4 yr was 25% (95% C.I., 9-42%). Four-year event-free survival (EFS) and overall survival (OS) were 28% and 30%, respectively. Despite a high NRM and an unexpected high incidence of EBV-PTLD, UCBT in heavily pretreated HD patients is an option for patients lacking a suitable adult donor, provided the disease is not in refractory relapse.

Role of cytotoxic therapy with hematopoietic cell transplantation in the treatment of Hodgkin lymphoma: guidelines from the American Society for Blood and Marrow Transplantation

The role of hematopoietic cell transplantation (HCT) in the therapy of Hodgkin lymphoma (HL) in pediatric and adult patients is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are included and were reached unanimously by a panel of HL experts. Both autologous and allogeneic HCT offer a survival benefit in selected patients with advanced or relapsed HL and are currently part of standard clinical care. Relapse remains a significant cause of failure after both transplant approaches, and strategies to decrease the risk of relapse remain an important area of investigation.

Current role of autologous and allogeneic stem cell transplantation for relapsed and refractory hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is a relatively rare disease, with approximately 9,200 estimated new cases and 1,200 estimated deaths per year in the United States. First-line chemo-radiotherapy leads to cure rates approaching 80% in patients with advanced-stage disease. However, 25 to 30% of these patients are not cured with chemotherapy alone (i.e., the ABVD regimen) and show either primary refractoriness to chemotherapy, early disease relapse or late disease relapse. Second-line salvage high-dose chemotherapy (HDC) and autologous stem cell transplantation (SCT) have an established role in the management of refractory/relapsed cHL, leading to durable responses in approximately 50% of relapsed patients and a minority of refractory patients. However, due to the poor responses to second-line salvage chemotherapy and dismal long-term disease control of primary refractory and early relapsed patients, their treatment represents an unmet medical need. Allogeneic SCT represents, by far, the only strategy with a curative potential for these patients; however, as discussed in this review, it’s role in cHL remains controversial. Despite a general consensus that early relapsed and primary refractory patients represent a clinical challenge requiring effective treatments to achieve long-term disease control, there has been no consensus on the optimal therapy that should be offered to these patients. This review will briefly discuss the clinical results and the main issues regarding autologous SCT as well as the current role of allogeneic SCT.

The role of hematopoietic stem cell transplantation for relapsed and refractory Hodgkin lymphoma

The optimal treatment strategy with the use of hematopoietic stem cell transplantation (HSCT) for relapsed and refractory Hodgkin lymphoma (HL) remains unclear. We performed a retrospective analysis using registry data from the Japanese Society for Hematopoietic Cell Transplantation. Adult patients with HL who underwent a first autologous or a first allogeneic HSCT between 2002 and 2009 were included. Patients who underwent HSCT in first complete remission (CR) were excluded. Autologous and allogeneic HSCT were performed in 298 and 122 patients, respectively. For autologous HSCT, overall survival at 3 years (3yOS) was 70%, and sex, age, disease status, and performance status (PS) at HSCT were prognostic factors. OS was favorable even in patients who underwent autologous HSCT in disease status other than CR. For allogeneic HSCT, 3yOS was 43%, and sex and PS at HSCT were prognostic factors. Disease status at HSCT, previous autologous HSCT, and conditioning intensity did not affect OS. Moreover, graft-versus-host disease did not affect progression-free survival or relapse/progression rate. A first allogeneic HSCT without a previous autologous HSCT was performed in 40 patients. 3yOS was 45%, and was significantly inferior to that in patients who underwent their first autologous HSCT. This result was retained after the correction by the different patient characteristics according to the type of HSCT. In conclusion, autologous HSCT is effective in prolonging survival in patients with relapsed and refractory HL. Allogeneic HSCT might be beneficial even to relapsed HL after autologous HSCT, although establishing the role of allogeneic HSCT remains a challenge.

Brentuximab vedotin compared with other therapies in relapsed/refractory Hodgkin lymphoma post autologous stem cell transplant: median overall survival meta-analysis

OBJECTIVE

This meta-analysis compared the median overall survival (mOS) of brentuximab vedotin reported in the pivotal phase 2 study with published results of other therapies for the treatment of relapsed/refractory (R/R) Hodgkin lymphoma (HL) post autologous stem cell transplant (ASCT).

RESEARCH DESIGN AND METHODS

A systematic literature review identified studies that reported survival outcomes following conventional/experimental therapies in R/R HL patients, with ≥50% having failed ≥1 ASCT. Kaplan-Meier curves were used to reconstruct individual patient level survival data. Patients were grouped by treatment type and reconstructed data were used to estimate the mOS. Censored median regression modeling was used to compare mOS in each group with the mOS in the pivotal brentuximab vedotin trial. All patients in the pivotal trial had undergone ASCT, therefore a sensitivity analysis was conducted among studies with a 100% post-ASCT patient population.

RESULTS

The mOS reported for brentuximab vedotin was 40.5 (95% CI 30.8-NA) compared with 26.4 months (95% CI 23.5-28.5) across all 40 studies identified (n = 2518 excluding the brentuximab vedotin trial) (p < 0.0001). The difference in mOS between brentuximab vedotin and chemotherapy, allogeneic stem cell transplant (allo-SCT), and other therapies, was 17.7 (95% CI 10.6-24.7; p < 0.0001), 12.5 (95% CI 8.2-16.9; p < 0.0001), and 15.2 months (95% CI 4.9-25.5; p = 0.0037), respectively. For the 11 studies reporting a 100% prior-ASCT rate (n = 662 excluding the brentuximab vedotin trial), the mOS was 28.1 months (95% CI 23.9-34.5), and the difference in mOS between brentuximab vedotin, chemotherapy, allo-SCT, and other therapies was 19.0 (95% CI 12.9-25.1; p < 0.0001), 9.4 (p > 0.05), and 6.8 months (95% CI 1.2-12.5; p = 0.0018), respectively.

CONCLUSIONS

While some selection bias may occur when comparing trials with heterogeneous eligibility criteria, in the absence of randomized controlled trial data these results suggest brentuximab vedotin improves long-term survival and is associated with longer mOS in R/R HL post-ASCT compared with other therapies.

Durable remissions in a pivotal phase 2 study of brentuximab vedotin in relapsed or refractory Hodgkin lymphoma

We present response and survival outcomes of a pivotal phase 2 trial of the antibody-drug conjugate brentuximab vedotin in patients with relapsed/refractory Hodgkin lymphoma following autologous stem cell transplant (N = 102) after a median observation period of approximately 3 years. Median overall survival and progression-free survival were estimated at 40.5 months and 9.3 months, respectively. Improved outcomes were observed in patients who achieved a complete remission (CR) on brentuximab vedotin, with estimated 3-year overall survival and progression-free survival rates of 73% (95% confidence interval [CI]: 57%, 88%) and 58% (95% CI: 41%, 76%), respectively, in this group (medians not reached). Of the 34 patients who obtained CR, 16 (47%) remain progression-free after a median of 53.3 months (range, 29.0 to 56.2 months) of observation; 12 patients remain progression-free without a consolidative allogeneic stem cell transplant. Younger age, good performance status, and lower disease burden at baseline were characteristic of patients who achieved a CR and were favorable prognostic factors for overall survival. These results suggest that a significant proportion of patients who respond to brentuximab vedotin can achieve prolonged disease control. The trial was registered at www.clinicaltrials.gov as #NCT00848926.

Alternative donors extend transplantation for patients with lymphoma who lack an HLA matched donor

Alternative donor transplantation is increasingly used for high risk lymphoma patients. We analyzed 1593 transplant recipients (2000 to 2010) and compared transplant outcomes in recipients of 8/8 allele human leukocyte antigen (HLA)-A, -B, -C, and DRB1 matched unrelated donors (MUD; n=1176), 7/8 allele HLA-matched unrelated donors (MMUD; n=275) and umbilical cord blood donors (1 or 2 units UCB; n=142). Adjusted 3-year non-relapse mortality of MMUD (44%) was higher as compared to MUD (35%; p=0.004), but similar to UCB recipients (37%; p=0.19), although UCB had lower rates of neutrophil and platelet recovery compared to unrelated donor groups. With a median follow-up of 55 months, 3-year adjusted cumulative incidence of relapse was lower after MMUD compared with MUD (25% vs 33%, p=0.003) but similar between UCB and MUD (30% vs 33%; p=0.48). In multivariate analysis UCB recipients had lower risks of acute and chronic graft versus host disease compared with adult donor groups (UCB vs MUD: HR=0.68, p=0.05; HR=0.35; p<0.001). Adjusted 3-year overall survival was comparable (43% MUD, 37% MMUD and 41% UCB). Data highlight that patients with lymphoma have acceptable survival after alternative donor transplantation. MMUD and UCB can expand the curative potential of allotransplant to patients who lack suitable HLA-matched sibling or MUD.

Stem cell transplantation in Hodgkin lymphoma

Patients with Hodgkin lymphoma (HL) who relapse following effective front-line therapy are offered salvage second-line chemotherapy regimens followed by high-dose therapy and autologous stem cell transplantation (HDT/ASCT). Randomized studies comparing HDT/ASCT with conventional chemotherapy in patients with relapsed refractory HL have shown significant improvement in progression-free survival and freedom from treatment failure but were not powered to show improvements in overall survival. For patients who relapse after salvage HDT/ASCT, novel therapies exist as a bridge to allogeneic SCT. In this article, we review indications and results of autologous and allogeneic SCT in HL.

Nonmyeloablative conditioning, unmanipulated haploidentical SCT and post-infusion CY for advanced lymphomas

Allo-SCT is regularly performed in advanced lymphoma. Haploidentical family donors are a valuable source of hematopoietic stem cells and transplants from these donors, using T-repleted grafts, has recently been successfully reported. We report on 49 patients with refractory lymphoma who received T-repleted haploidentical SCT with a non-myeloablative regimen and post-transplant CY. The median time to recover ANC >0.5 × 10e9/L and transfusion independent plt count >20 × 10e9/L was 20 days (range 14-38) and 26 days (range 14-395). The probability to reach ANC >0.5 × 10e9/L at 30 days was 87% and transfusion independent plt count >20 × 10e9/L at 100 days was 87%. The cumulative incidence of grade 2-4 acute GVHD (aGVHD) was 25.6% (95% confidence interval (CI): 12.9-38.3%) and the cumulative incidence of chronic GVHD (cGVHD) was 5.2% (95% CI: 0-12.4%). The median follow-up is 20.6 months (range 12-54), and the projected 2-year OS and PFS were 71 and 63%. The relapse rate was 18.7% (95% CI: 7.6-29.8%) and the median time to relapse was 4.4 months (range 1.1-8.3). At 2 years, cumulative incidence of NRM was 16.3% (95% CI: 5.9-26.8%). T-repleted Haploidentical transplantation with post-infusion CY is a feasible and effective therapy in the poor prognosis of advanced lymphoma patients.

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.

Functional mesenchymal stem cells remain present in bone marrow microenvironment of patients with leukemia post-allogeneic hematopoietic stem cell transplant

Mesenchymal stem cells (MSCs) and their progenies are important supporting cells in the bone marrow (BM) microenvironment. However, the function and kinetics of MSCs post-hematopoietic stem cell transplant (HSCT) remain unknown. In the present study, MSCs were cultured from a total of 76 BM samples from 15 patients receiving HSCT. Colony-forming unit fibroblasts in BM before pre-conditioning and 1, 3, 6 and 9 months post-HSCT were cultured and counted to quantify MSCs. Hematopoiesis-supporting activity of MSCs was observed with long-term culture of hematopoietic progenitors. An inhibitory effect of MSCs on in vitro lymphocyte proliferation was also observed. Results showed that post-HSCT MSCs supported in vitro hematopoiesis and inhibited lymphocyte growth. Moreover, the quantity of MSCs was reduced at an early stage and restored to baseline level 9 months post-transplant. The results indicate that functional MSCs remain present in the BM microenvironment, and these findings shed light on the understanding of BM microenvironment reconstitution post-HSCT.

Managing Hodgkin lymphoma relapsing after autologous hematopoietic cell transplantation: a not-so-good cancer after all!

Hodgkin lymphoma (HL) relapsing after an autologous hematopoietic cell transplant (HCT) poses a therapeutic challenge. In this setting, salvage chemotherapy (for example, gemcitabine-based, ifosfamide-containing and others) or immunotherapy (for example, brentuximab vedotin) is essential as a bridging-cytoreduction strategy to an allogeneic HCT. Myeloablative allogeneic hematopoietic cell transplantation in relapsed HL is associated with high rates of non-relapse mortality. In carefully selected patients with chemosensitive disease, allografting following lower-intensity conditioning regimens can provide durable disease control rates of about 25-35%. Promising early results with haploidentical and umbilical cord transplantation are noteworthy and are expanding this procedure to patients for whom HLA-matched related or unrelated donors are not available. Unfortunately, a significant number of HL patients relapsing after an autologous HCT are not candidates for allografting because of the presence of resistant disease, donor unavailability or comorbidities. Brentuximab vedotin is approved for HL relapsing after a prior autograft. Rituximab and bendamustine are also active in this setting, albeit with short durations of remission. Histone deacetylase inhibitors (for example, panobinostat, mocetinostat), mTOR inhibitors (for example, everolimus) and immunomodulatory agents (lenalidomide) have shown activity in phase II trials, but currently are not approved for this indication. Second autologous HCT are rarely performed but this approach should not be considered standard practice at this time. The need for effective agents for post autograft failures of HL largely remains unmet. Continuous efforts to ensure early referral of such patients for allogeneic HCT or investigational therapies are the key to improving outcomes of this not-so-good lymphoma.

Simplified validated prognostic model for progression-free survival after autologous transplantation for hodgkin lymphoma

Hodgkin lymphoma (HL) prognostic models based on factors measured at time of autologous hematopoietic cell transplantation (AHCT) are limited by small sample sizes. Models based on information at diagnosis are often not uniformly collected or available at transplantation. We propose an easily implementable prognostic model for progression-free survival (PFS) post-AHCT based on factors available at transplantation in a large international cohort of HL patients. The outcomes of 728 AHCT recipients for relapsed/refractory HL were studied. Patients were randomly selected for model development (n = 337) and validation (n = 391). The multivariate model identified 4 major adverse risk factors at the time of AHCT with the following relative weights: Karnofsky performance score <90 and chemotherapy resistance at AHCT were each assigned 1 point, whereas at least 3 chemotherapy regimens pre-AHCT and extranodal disease at AHCT were each assigned 2 points. Based on the total score summed for the 4 adverse risk factors, 3 risk groups were identified: low (score = 0), intermediate (score = 1 to 3), or high (score = 4 to 6). The 4-year PFS for the low- (n = 176), intermediate- (n = 261), and high- (n = 283) risk groups were 71% (95% confidence interval [CI], 63% to 78%), 60% (95% CI, 53% to 66%), and 42% (95% CI, 36% to 49%), respectively. The prognostic model was validated in an independent cohort. The Center for International Blood and Marrow Transplant Research model is based on factors easily available at the time of AHCT and discriminates patients with favorable post-AHCT outcomes as well as an intermediate-risk group. This model should assist in the prospective evaluation of alternative treatment strategies.

Unmanipulated haploidentical BMT following non-myeloablative conditioning and post-transplantation CY for advanced Hodgkin's lymphoma

Twenty-six patients with advanced Hodgkin's disease received a related HLA haploidentical unmanipulated BMT, following a non-myeloablative conditioning with low-dose TBI, proposed by the Baltimore group; GvHD prophylaxis consisted of high-dose post-transplantation CY (PT-CY), mycophenolate and a calcineurin inhibitor. All patients had received a previous autograft, and 65% had active disease at the time of BMT. Sustained engraftment of donor cells occurred in 25 patients (96%), with a median time to neutrophil recovery (>0.5 × 10(9)/L) and platelet recovery (>20 × 10(9)/L) of +18 and +23 days from BMT. The incidence of grade II-IV acute GVHD and of chronic GVHD was 24% and 8%, respectively. With a median follow-up of 24 months (range 18-44) 21 patients are alive, 20 disease free. The cumulative incidence of TRM and relapse was 4% and 31%, respectively. The actuarial 3-year survival is 77%, the actuarial 3-year PFS is 63%. In conclusion, we confirm that high-dose PT-CY is effective as prophylaxis of GVHD after HLA haploidentical BMT, can prevent rejection and does not appear to eliminate the allogeneic graft versus lymphoma effect.