Front-line high-dose therapy with autologous stem cell transplantation for high risk Hodgkin's disease: comparison with combined-modality therapy

Advances in the pathophysiology and treatment of relapsed/refractory Hodgkin's lymphoma with an emphasis on targeted therapies and transplantation strategies

Hodgkin’s lymphoma (HL) is highly curable with first-line therapy. However, a minority of patients present with refractory disease or experience relapse after completion of frontline treatment. These patients are treated with salvage chemotherapy followed by autologous stem cell transplantation (ASCT), which remains the standard of care with curative potential for refractory or relapsed HL. Nevertheless, a significant percentage of such patients will progress after ASCT, and allogeneic hematopoietic stem cell transplantation remains the only curative approach in that setting. Recent advances in the pathophysiology of refractory or relapsed HL have provided the rationale for the development of novel targeted therapies with potent anti-HL activity and favorable toxicity profile, in contrast to cytotoxic chemotherapy. Brentuximab vedotin and programmed cell death-1-based immunotherapy have proven efficacy in the management of refractory or relapsed HL, whereas several other agents have shown promise in early clinical trials. Several of these agents are being incorporated with transplantation strategies in order to improve the outcomes of refractory or relapsed HL. In this review we summarize the current knowledge regarding the mechanisms responsible for the development of refractory/relapsed HL and the outcomes with current treatment strategies, with an emphasis on targeted therapies and hematopoietic stem cell transplantation.

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.

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.

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.

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.

The role of autologous and allogeneic hematopoietic stem cell transplantation for Hodgkin lymphoma

Patients with Hodgkin lymphoma are usually cured by primary therapy using chemotherapy alone or combined modality therapy with external beam radiation. Patients who do not experience a complete remission or those who experience relapse may by salvaged by high-dose therapy and autologous hematopoietic stem cell transplantation (ASCT). Success of this approach is largely dependent on the tumor being sensitive to salvage chemotherapy before transplant. More studies are showing the predictive value of functional imaging in this setting. Allogeneic hematopoietic stem cell transplantation has greater risk of nonrelapse mortality and is generally reserved for patients who experience relapse post-ASCT, but may provide long-term survival for some patients through graft-versus-tumor immune effects.