Allogeneic transplantation for Hodgkin lymphoma

Hematopoietic Stem Cell Transplantation and Brentuximab Vedotin for Patients with Relapsed or Refractory Hodgkin Lymphoma and Systemic Anaplastic Large-Cell Lymphoma

Brentuximab vedotin (BV) is an antibody-drug conjugate that has demonstrated effectiveness as a monotherapy for patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large-cell lymphoma via several clinical trials. Salvage chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplantation (HSCT) has been performed as a second- or later-line regimen for improving the survival of patients with lymphoma. In particular, the effectiveness of autologous HSCT and the importance of achieving a complete response prior to autologous HSCT are established in Hodgkin lymphoma. Several clinical trials have reported that salvage chemotherapy followed by autologous HSCT showed high response rates, although significant treatment-related hematological toxicity was observed. In the present article, we review clinical reports for assessing the efficacy and safety of relatively less toxic BV as a bridging therapy before HSCT or as a consolidation therapy post-HSCT in patients with relapsed or refractory Hodgkin lymphoma or systemic anaplastic large-cell lymphoma. Generally, the reported BV regimens seem to be effective and well tolerated in such patients, and no significant influence of BV treatment is noted on hematopoietic stem cell harvest before HSCT. Large-scale clinical studies and long-term follow-up are expected to establish the safety and efficacy of these regimens.Funding: Takeda Pharmaceutical Co., Ltd., Tokyo, Japan.

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.

Immunological barriers to stem cell therapy in the central nervous system

The central nervous system is vulnerable to many neurodegenerative disorders such as Alzheimer's disease that result in the extensive loss of neuronal cells. Stem cells have the ability to differentiate into many types of cells, which make them ideal for treating such disorders. Although stem cell therapy has shown some promising results in animal models for many brain disorders it has yet to translate into the clinic. A major hurdle to the translation of stem cell therapy into the clinic is the immune response faced by stem cell transplants. Here, we focus on immunological and related hurdles to stem cell therapies for central nervous system disorders.

Advances in the treatment of relapsed or refractory Hodgkin's lymphoma

Hodgkin's lymphoma (HL) is diagnosed in 20,000 men and women annually in North America and Europe. Despite treatment advancements for HL resulting in an overall survival rate of 80%, patients with advanced stage disease continue to have suboptimal outcomes, with relapse rates of 30%-40%. An additional 10%-15% of patients present with primary refractory disease. For patients who relapse after initial treatment, salvage chemotherapy followed by autologous stem cell transplant in those with chemotherapy-sensitive disease is the standard of care. Patients who relapse after second-line therapy have a median survival time in the range of 6-36 months, and the optimal management of these patients remains unclear. Unfortunately, there have been no new agents approved for relapsed HL treatment since the 1970s. Consequently, clinical decision making in this population is difficult. Recently however, several agents have emerged that have shown clinical promise in this poor-risk population. This review discusses the management of these patients and also discusses several newer agents showing clinical promise in the treatment of HL.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: Report from the Committee on Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation

Relapse is a major cause of treatment failure after allogeneic hematopoietic stem cell transplantation (alloHSCT). Treatment options for relapse have been inadequate, and the majority of patients ultimately die of their disease. There is no standard approach to treating relapse after alloHSCT. Withdrawal of immune suppression and donor lymphocyte infusions are commonly used for all diseases; although these interventions are remarkably effective for relapsed chronic myelogenous leukemia, they have limited efficacy in other hematologic malignancies. Conventional and novel chemotherapy, monoclonal antibody therapy, targeted therapies, and second transplants have been utilized in a variety of relapsed diseases, but reports on these therapies are generally anecdotal and retrospective. As such, there is an immediate need for well-designed, disease-specific trials for treatment of relapse after alloHSCT. This report summarizes current treatment options under investigation for relapse after alloHSCT in a disease-specific manner. In addition, recommendations are provided for specific areas of research necessary in the treatment of relapse after alloHSCT.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.