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

Seven-year follow-up of allogeneic transplant using BCNU, etoposide, cytarabine and melphalan chemotherapy in patients with Hodgkin lymphoma after autograft failure: importance of minimal residual disease

Abstract Allogeneic transplant using reduced intensity conditioning is a therapeutic option for patients with Hodgkin lymphoma (HL) who relapse after an autograft. This was a prospective study of 31 consecutive eligible patients with HL who relapsed after an autograft and underwent an allograft using BEAM (BCNU, etoposide, cytarabine, melphalan) conditioning. At a median follow-up of 7 years the progression-free survival (PFS) was 36% (95% confidence interval [CI] 19-54%) and overall survival (OS) was 42% (95% CI 23-59%). In multivariate analysis only residual disease at the time of transplant predicted outcome, with a 4-year PFS and OS of 62% and 75% for patients with minimal residual disease versus 8% and 8% for patients with gross residual disease, respectively (p = 0.005 and p = 0.001, respectively). This benefit seemed to be irrespective of chemosensitivity, with an OS for patients with chemorefractory yet minimal disease of 71% at 4 years. BEAM allogeneic transplant is effective in producing long-term remissions after autograft failure. Regardless of chemosensitivity, minimizing tumor burden pre-transplant may improve long-term outcome.

Unrelated and alternative donor allogeneic stem cell transplant in patients with relapsed or refractory Hodgkin lymphoma: a systematic review

Abstract Allogeneic stem cell transplant (allo-SCT) is considered a clinical option for patients with Hodgkin lymphoma (HL) who have experienced at least two chemosensitive relapses. The aim of this systematic review was to determine the benefits and harms of allo-SCT with an unrelated donor (UD) versus related donor (RD) allo-SCT for adult patients with HL. Alternative donor sources such as haploidentical donor cells (Haplo) and umbilical cord blood (UCB) were also included. The available evidence was limited. Ten studies were included in this assessment. Four studies provided sufficient data to compare UD with RD allo-SCT. None of these studies was a randomized controlled trial. Additionally, three non-comparative studies, such as registry analyses, which considered patients with UD transplants were included. The risk of bias in the studies was high. Results on overall and progression-free survival (PFS) showed no consistent tendency in favor of a donor type. Results on therapy-associated mortality and acute (grade II-IV) and chronic graft-versus-host disease were also inconsistent. The study comparing UCB with RD transplants and two non-comparative studies with UCB transplants showed similar results. One of the studies comparing additionally Haplo with RD transplants indicated a benefit in PFS for the Haplo transplant group. In summary, our findings do not indicate a substantial outcome disadvantage of UD and alternative donor sources versus RD allo-SCT for adult patients with advanced HL.

Outcome of patients activating an unrelated donor search: the impact of transplant with reduced intensity conditioning in a large cohort of consecutive high-risk patients

An unrelated donor (UD) search was submitted to the Italian Bone Marrow Donor Registry between February 2002 and December 2004, for 326 consecutive patients with hematological malignancies, eligible for a reduced intensity conditioning (RIC) UD transplant. Only two regimens were allowed: melphalan, alemtuzumab, fludarabine and total body irradiation of 200 cGy (regimen A) and thiotepa, cyclophosphamide, anti-thymocyte globulin (regimen B). The outcome of patients receiving an UD transplant (n=121) was compared with patients who did not find a donor (n=205), in a time dependent analysis, correcting for time to transplant. The median follow up from activation of donor search was 6.1 years. UD transplant was associated with a significantly better survival in patients with acute leukemia and non-Hodgkin's lymphoma (NHL) whereas only a favorable trend was documented for Hodgkin's disease. No survival benefit was registered for chronic leukemias. The outcome of the two different conditioning regimens was comparable, in terms of survival, transplant-related mortality and graft versus host disease. In conclusion, finding an UD and undergoing a RIC transplant significantly improves survival of patients with acute leukemia and NHL. The advantage is less clear for HD and chronic leukemias. The role of different conditioning regimens remains to be elucidated by prospective clinical trials.

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.

Allogeneic stem cell transplantation after reduced intensity conditioning in patients with relapsed or refractory Hodgkin's lymphoma. Results of the HDR-ALLO study - a prospective clinical trial by the Grupo Español de Linfomas/Trasplante de Médula Osea (GEL/TAMO) and the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

BACKGROUND

Although Hodgkin's lymphoma is a highly curable disease with modern chemotherapy protocols, some patients are primary refractory or relapse after first-line chemotherapy or even after high-dose therapy and autologous stem cell transplantation. We investigated the potential role of allogeneic stem cell transplantation in this setting.

DESIGN AND METHODS

In this phase II study 92 patients with relapsed Hodgkin's lymphoma and an HLA-identical sibling, a matched unrelated donor or a one antigen mismatched, unrelated donor were treated with salvage chemotherapy followed by reduced intensity allogeneic transplantation. Fourteen patients showed refractory disease and died from progressive lymphoma with a median overall survival after trial entry of 10 months (range, 6-17). Seventy-eight patients proceeded to allograft (unrelated donors, n=23). Fifty were allografted in complete or partial remission and 28 in stable disease. Fludarabine (150 mg/m(2) iv) and melphalan (140 mg/m(2) iv) were used as the conditioning regimen. Anti-thymocyte globulin was additionally used as graft-versus-host-disease prophylaxis for recipients of grafts from unrelated donors.

RESULTS

The non-relapse mortality rate was 8% at 100 days and 15% at 1 year. Relapse was the major cause of failure. The progression-free survival rate was 47% at 1 year and 18% at 4 years from trial entry. For the allografted population, the progression-free survival rate was 48% at 1 year and 24% at 4 years. Chronic graft-versus-host disease was associated with a lower incidence of relapse. Patients allografted in complete remission had a significantly better outcome. The overall survival rate was 71% at 1 year and 43% at 4 years.

CONCLUSIONS

Allogeneic stem cell transplantation can result in long-term progression-free survival in heavily pre-treated patients with Hodgkin's lymphoma. The reduced intensity conditioning approach significantly reduced non-relapse mortality; the high relapse rate represents the major remaining challenge in this setting. The HDR-Allo trial was registered in the European Clinical Trials Database (EUDRACT, https://eudract.ema.europa.eu/) with number 02-0036.

Hematopoietic Cell Transplantation for Lymphomas

Background

The heterogeneity of lymphomas results in numerous treatment options, including both autologous and allogeneic hematopoietic cell transplantation. However, the type of transplantation, the timing the procedure, and the selection of suitable patients for transplant continue to evolve.

Methods

We reviewed the current medical literature to provide a succinct synthesis for the most common types of lymphoma and the indications for transplantation.

Results

This review discusses the outcomes of autologous and allogeneic transplantation for patients with diffuse large B-cell lymphoma, follicular lymphoma, HIV-associated lymphomas, mantle cell lymphoma, T-cell lymphoma, and Hodgkin lymphoma.

Conclusions

Each of these histologies differs in the indications and timing for transplantation. However, ongoing clinical trials support the continuing role of both autologous and allogeneic transplantation for lymphoma management.

Allogeneic transplantation for lymphoma

Historically, high levels of treatment-related mortality restricted the use of standard myeloablative allogeneic stem-cell transplantation to a minority of young and fit patients with lymphoma. Over the last decade, increasing numbers of patients with lymphoma have undergone allogeneic stem-cell transplantation using reduced-intensity protocols that are associated with lower toxicity and reduced transplantation-related mortality. Graft-versus-lymphoma effects contribute to the therapeutic effect in patients with indolent or Hodgkin's lymphoma. However, definitive evidence for efficacy of this strategy is lacking because most patients undergoing transplantation do so after failure of several lines of treatment, leaving no obvious comparator arm for randomized controlled studies. Nevertheless, encouraging results have been reported for selected patients for most lymphoma subtypes, with pretransplantation disease status emerging as the most important predictor of outcome. The major long-term toxicity is chronic graft-versus-host disease that contributes to ill health in a significant minority of survivors. In the future, risk-adapted trials that evaluate reduced-intensity allogeneic transplantation in patients with predicted poor outcomes with immunochemotherapy or autologous transplantation will be important in determining the role of this treatment.

Hodgkin's lymphoma therapy: past, present, and future

IMPORTANCE OF THE FIELD

The treatment of Hodgkin's lymphoma (HL) with the use of radiotherapy and systemic chemotherapy has been one of the success stories of modern oncology. HL therapy has been the paradigm for the systematic evaluation of different curative modalities, resulting in cure for the majority of patients. The current focus is on designing initial therapeutic strategies that retain efficacy and minimize long-term toxicity. Appropriate use of pathologic, clinical, biologic and radiologic prognostic factors in identification of aggressive HL is paramount in designing a successful therapeutic strategy.

AREAS COVERED IN THIS REVIEW

This review addresses the current and future use of prognostic tools, including PET scanning and other biomarkers, in identifying patients with aggressive HL, with reference to publications from the last two decades. The current standard approaches with the use of combined modality therapy and systemic chemotherapy as well as the promising role of future response-adapted strategies is reviewed.

WHAT THE READER WILL GAIN

The reader will obtain a comprehensive review of risk assessment strategies as well as current and investigational therapeutic approaches in the management of HL.

TAKE HOME MESSAGE

In HL, appropriate utilization of risk assessment strategies is required to maximize therapeutic outcomes while minimizing toxicity, especially long-term toxicity. Response-adapted therapy utilizing PET has the potential to profoundly improve the therapeutic landscape in HL.

Allogeneic transplantation for lymphoma: long-term outcome

PURPOSE OF REVIEW

In the last 20 years, allogeneic stem cell transplantation (alloSCT) has been increasingly applied in lymphoma patients, due to the shift towards reduced intensity and nonmyeloablative conditioning. This review reports on the most significant long-term results of allografted lymphoma patients coming from both prospective studies and retrospective analyses.

RECENT FINDINGS

AlloSCT can cure 40-60% of aggressive B-cell lymphomas, but an unfavourable outcome has been observed in case of chemorefractory and active disease at the time of allografting. Indolent lymphoma displays the best outcome, and reduced-intensity alloSCT should be always considered in patients relapsing after an autologous SCT and in cases of chemorefractory disease. Most recent findings in Hodgkin's and T-cell lymphoma are also encouraging.

SUMMARY

Although the nonrelapse mortality has been reduced and survival curves show a plateau, the analysis of the long-term outcome reveals that a significant proportion of patients still experiences disease relapse and delayed morbidity and mortality. At the best of our knowledge, the process of decision-making should be based on lymphoma subtype, chemosensitivity, disease status and patient comorbidities at the time of allografting. To answer some of the still open questions, physicians should try to improve the enrolment of patients in multicentre prospective clinical trials.

High-dose cyclophosphamide for graft-versus-host disease prevention

PURPOSE OF REVIEW

Administration of high-dose cyclophosphamide after transplantation inhibits both graft rejection and graft-versus-host disease (GvHD) in mouse models of allogeneic blood or marrow transplantation (alloBMT). This strategy has recently been adapted to human transplantation.

RECENT FINDINGS

The safety and efficacy of high-dose posttransplantation cyclophosphamide, when given in combination with tacrolimus and mycophenolate mofetil, was first demonstrated after nonmyeloablative conditioning and allografting using human leukocyte antigen (HLA)-mismatched related donors. Further analysis shows that increasing HLA disparity does not worsen overall outcome. High-dose posttransplantation cyclophosphamide was also found to be effective as sole prophylaxis of acute and chronic GvHD after HLA-matched alloBMT.

SUMMARY

Taking advantage of the differential susceptibility of proliferating, alloreactive T cells over nonproliferating, nonalloreactive T cells to high-dose cyclophosphamide, and owing to the drug's stem cell sparing effects, this novel strategy provides a unique opportunity to optimize GvHD prophylaxis after HLA-matched alloBMT and increase the use of HLA-mismatched related donors. Well tolerated and effective mismatched related alloBMT provides access to essentially everyone, such as patients with sickle cell anemia, in need of the procedure.

Relapse of lymphoma after allogeneic hematopoietic cell transplantation: management strategies and outcome

The outcome and management of relapsed lymphoma after allogeneic hematopoietic cell transplantation (HCT) is difficult. Therapeutic options may include donor lymphocyte infusion (DLI), reduction of immunosuppression (RIS), chemotherapy, radiation, immunotherapy, second HCT, and experimental treatments, but reported data contrasting the response and efficacy of these salvage treatments are limited. We describe the treatments, response, prognosis, and long-term survival of 72 patients with relapse of lymphoma after allogeneic HCT. Between 1991 and 2007, 227 lymphoma patients underwent allogeneic HCT. Of these, 72 (32%) developed relapse/progression after their HCT at a median of 99 days (0-1898 days); 37 had early (<100 days) post-HCT relapse. Forty-four had non-Hodgkin lymphoma (7 mantle cell, 5 indolent, 15 diffuse large B cell, 4 Burkitt's, and 13 T/Natural Killer cell), and 28 patients had Hodgkin lymphoma. At the time of HCT, 62 patients were in remission (22 in complete [CR] and 40 in partial [PR]), 1 had stable whereas 9 had progressive disease. Seventeen cases received myeloablative and 55 received a reduced-intensity conditioning regimen. At relapse, most patients had generalized lymphadenopathy, extranodal organ involvement, and advanced disease. Five patients received no intervention for the post-HCT relapse. Immunosuppressive treatment was reduced or withdrawn as the first-line therapy in 58 patients (80.5%); 47 were treated using combinations of conventional chemotherapy (n = 22), rituximab (n = 27), interferon (IFN) (n = 1), DLI (n = 7), second HCT (n = 2), local radiation (n = 23), and other therapy (n = 6). Thirty-eight patients had an objective response (CR in 30, PR in 8), and 2 had stable disease (SD). At the post-HCT relapse, favorable prognostic factors for survival after HCT included good ECOG performance status (0-2), normal lactate dehydrogenase (LDH), early stage disease (stage I-III), isolated extranodal organ involvement, and later relapse (>100 days) post-HCT. Three-year survival after HCT was significantly better in late than early relapse (53%; 95% confidence interval [CI] [34%-69%] versus 36%, [20%-52%], P = .02). Of 72 relapsed patients, 29 (40%) survived at a median of 34 (3-148) months posttransplant. The most common cause of death was underlying lymphoma (79%). The overall prognosis of relapsed/progressive lymphoma after allogeneic HCT is disappointing, yet half of patients respond to withdrawal of immunosuppression and additional therapies. Novel treatments can control lymphoma with acceptable morbidity. Particularly for patients with later relapse, ongoing treatment after relapse can yield meaningful benefit and prolonged survival.

How I treat relapsed and refractory Hodgkin lymphoma

Relapsed or refractory Hodgkin lymphoma is a challenging problem for clinicians who treat hematologic malignancies. The standard management of these patients should include the use of salvage chemotherapy followed by autologous stem cell transplant (ASCT) in patients who are chemotherapy sensitive. Open issues in this area include the role of functional imaging, the specific chemotherapy regimen to be used before ASCT, and the role of consolidative radiotherapy. Some patients will not be eligible for ASCT, and alternative approaches with conventional chemotherapy alone or with salvage radiotherapy should be considered. Prognostic factors for relapsed/refractory disease have been identified but generally are not used as a part of risk-adapted therapy. Allogeneic transplantation may offer the potential of a graft-versus-lymphoma effect, but this therapy has significant toxicity and results in few long-term disease-free survivors; hence, it should only be offered in the context of disease-specific clinical trials. An expanding list of novel drugs has exhibited promising single-agent activity. Patients have effective options beyond primary therapy, and continued progress through controlled trials remains a tangible goal in the treatment of relapsed and refractory disease.

Allogeneic hematopoietic stem cell transplantation: does it have a place in treating Hodgkin lymphoma?

Although the majority of patients with Hodgkin lymphoma achieve sustained remission with frontline treatment, there is still a subset of patients with much less favorable prognosis. The current standard of care for Hodgkin lymphoma patients with relapsed or refractory disease is autologous stem cell transplantation. However, no randomized trial has compared autologous stem cell transplantation with allogeneic stem cell transplantation prospectively, and most studies comparing allogeneic stem cell transplantation with historical controls of autologous stem cell transplantation use a myeloablative conditioning reference group. With the more frequent use of reduced-intensity conditioning transplantation in recent studies, the role for allogeneic stem cell transplantation in Hodgkin lymphoma patients is being redefined. In contrast to other types of lymphomas, Hodgkin lymphoma patients are younger at diagnosis, which makes a curative strategy such as allogeneic stem cell transplantation particularly appealing. This review examines the role of allogeneic stem cell transplantation in Hodgkin lymphoma by looking at both retrospective and prospective analyses in the era of reduced-intensity conditioning transplantation, donor lymphocyte infusions, and biologically based treatments.

The Role of Allogeneic Stem Cell Transplantation in Relapsed/Refractory Hodgkin's Lymphoma Patients

Despite the favorable prognosis of most patients with Hodgkin's Lymphoma (HL), 15-20% of patients remain refractory to chemoradiotherapy, and 20-40% experience relapses following autologous stem cell transplantation (SCT) being used as salvage approach in this situation. Long-term survival of only 20% was reported for patients who failed this option. As some authors suggested the presence of a graft versus HL effect, allogeneic SCT was introduced as a further option. Myeloablative strategies were reported to be able to achieve cure in some younger patients, but high nonrelapse mortality remains a problem. Reduced intensity conditioning, in turn, was found to be associated with high posttransplant relapse rates. As there is currently no standard in the management of HL patients who failed autologous SCT, we here review the literature on allogeneic stem cell transplantation in HL patients with a special focus on the outcomes and risk factors being reported in the largest studies.

Allogeneic haematopoietic stem-cell transplantation with reduced intensity conditioning for advanced stage Hodgkin's lymphoma in Sweden: high incidence of post transplant lymphoproliferative disorder

Allogeneic transplantation after reduced intensity conditioning (allo-RIC) is a treatment option for patients with Hodgkin's lymphoma (HL) relapsing after autologous transplantation. In all, 23 adult patients with HL underwent allo-RIC in Sweden between 2000 and 2007. The median number of previous treatment lines was five and 20 patients (87%) were previously autografted. TRM at 100 days and at 1 year was 13 and 22% respectively. Acute GVHD grades II-IV developed in 7 out of 23 patients (30%) and chronic GVHD in 10 out of 20 patients at risk (50%). The OS and EFS at three years was 59 and 27%, respectively. Four patients (17%) developed post transplant lymphoproliferative disease (PTLD) after a median time of 55 days (range 38-95); two of these patients later died. The study confirmed that allo-RIC is feasible, but associated with a substantial relapse rate: only 20% of the patients were still alive 7 years after the transplant. A finding of high incidence of PTLD needs to be confirmed in a larger trial that includes patients with non-HL and CLL.

High-dose, post-transplantation cyclophosphamide to promote graft-host tolerance after allogeneic hematopoietic stem cell transplantation

Graft-versus-host disease, or GVHD, is a major complication of allogeneic hematopoietic stem cell transplantation (alloHSCT) for the treatment of hematologic malignancies. Here, we describe a novel method for preventing GVHD after alloHSCT using high-dose, post-transplantation cyclophosphamide (Cy). Post-transplantation Cy promotes tolerance in alloreactive host and donor T cells, leading to suppression of both graft rejection and GVHD after alloHSCT. High-dose, post-transplantation Cy facilitates partially HLA-mismatched HSCT without severe GVHD and is effective as sole prophylaxis of GVHD after HLA-matched alloHSCT. By reducing the morbidity and mortality of alloHSCT, post-transplantation Cy may expand the applications of this therapy to the treatment of autoimmune diseases and non-malignant hematologic disorders such as sickle cell disease.

Allogeneic hematopoietic cell transplantation: the state of the art

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative procedure for a variety of hematologic malignancies. The field has evolved substantially over the past decade, with advances in patient and donor selection, stem cell sources, supportive care, prevention of complications and reduced-toxicity preparative regimens. As a result, the indications for HCT and the pool of eligible patients have expanded significantly. In this article, we provide an overview of the major aspects of allogeneic HCT, and focus specifically on areas of active research and on novel approaches to challenges in the field. Specifically, we will discuss approaches to reduce the toxicity of the preparative regimen, with the goal of increasing the safety and applicability of HCT. The availability of suitable donors may be an obstacle to wider application of HCT. We review three major approaches to broadening the donor pool: the use of HLA-mismatched unrelated donors, umbilical cord blood and HLA-haploidentical family donors. Graft-versus-host disease remains a major cause of morbidity and mortality after HCT. We review recent advances in the understanding of this phenomenon, and novel prophylactic and therapeutic approaches that hold the promise of further improving the safety of the procedure. We conclude with a speculative outline of the next 5 years of research in the field of HCT.

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.

Allogeneic transplantation improves the overall and progression-free survival of Hodgkin lymphoma patients relapsing after autologous transplantation: a retrospective study based on the time of HLA typing and donor availability

Hodgkin lymphoma relapsing after autologous transplantation (autoSCT) has a dismal outcome. Allogeneic transplantation (alloSCT) using reduced intensity conditioning (RIC) is a salvage option, but its effectiveness is still unclear. To evaluate the role of RIC alloSCT, we designed a retrospective study based on the commitment of attending physicians to perform a salvage alloSCT; thus, only Hodgkin lymphoma patients having human leukocyte antigen-typing immediately after the failed autoSCT were included. Of 185 patients, 122 found an identical sibling (55%), a matched unrelated (32%) or a haploidentical sibling (13%) donor; 63 patients did not find any donor. Clinical features of both groups did not differ. Two-year progression-free (PFS) and overall survival (OS) were better in the donor group (39.3% vs 14.2%, and 66% vs 42%, respectively, P < .001) with a median follow-up of 48 months. In multivariable analysis, having a donor was significant for better PFS and OS (P < .001). Patients allografted in complete remission showed a better PFS and OS. This is the largest study comparing RIC alloSCT versus conventional treatment after a failed autoSCT, indicating a survival benefit for patients having a donor.

HLA-haploidentical stem cell transplantation for hematologic malignancies

Partially HLA-mismatched related, or HLA-haploidentical, donor stem cell transplantation (SCT) is a feasible therapeutic option for advanced hematologic malignancies patients who lack an HLA-matched related or unrelated donor. Advances in conditioning regimens, graft manipulation, and pharmacologic prophylaxis of graft-versus-host disease (GVHD) have reduced the risk of fatal graft failure and severe GVHD, two of the most serious complications of traversing the HLA barrier. Clinical observations reveal a potential role for natural killer (NK) cell alloreactivity in reducing the risk of relapse of acute myeloid leukemia after HLA-haploidentical SCT. NK cell infusions attempt to harness the graft-versus-leukemia effect without producing GVHD. The availability of multiple potential HLA-haploidentical related donors for most patients opens the possibility of optimizing transplantation outcome through intelligent donor selection.

Optimal treatment for relapsing patients with Hodgkin lymphoma

Relapsed or refractory classical Hodgkin lymphoma (HL) remains a therapeutic challenge. Patients with relapsed HL should be identified according to their prognostic factors at relapse (duration of remission and extranodal disease or stage). Patients with refractory disease, defined as progression during induction treatment or within 90 days after the end of treatment, have the worst prognosis. Following non-crossresistant salvage chemotherapy to achieve cytoreduction, high-dose therapy (HDT) and autologous stem cell transplantation has been shown to be better than conventional-dose chemotherapy for first-relapse/refractory HL. For patients with very unfavorable relapse or primary refractory HL, outcome remains poor with HDT. For these patients, the role of tandem HDT or allogeneic stem cell transplantation will be discussed. In this setting, novel investigational treatments will be presented.