Fludarabine-melphalan as a preparative regimen for reduced-intensity conditioning allogeneic stem cell transplantation in relapsed and refractory Hodgkin's lymphoma: the updated M.D. Anderson Cancer Center experience

Relapsed Hodgkin lymphoma: management strategies

Although Hodgkin lymphoma (HL) is largely curable with first-line therapy, approximately one-third of patients will not have a complete response to frontline treatment or will subsequently relapse. Only 50% of these patients will be effectively salvaged with conventional therapies. The prognosis is particularly poor for those patients with chemotherapy refractory disease, who are unable to obtain even transient disease control, and for patients who relapse following high dose chemotherapy and autologous stem cell transplant. In this review, we summarize the most recent updates on the management of patients with relapsed HL, the role of novel therapies such as brentuximab vedotin, and an overview of promising new agents currently under investigation. We also discuss the role of consolidation strategies such as high-dose chemotherapy and autologous stem cell transplant, and reduced-intensity allogeneic hematopoietic stem cell transplant, and the need for new strategies in the elderly patient population.

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.

Update on salvage options in relapsed/refractory hodgkin lymphoma after autotransplant

Despite a high clinical success, relapse in Hodgkin lymphoma occurs in 10–30% of cases and 5–10% patients are nonresponsive to initial chemotherapy. The standard management of these patients includes high-dose chemotherapy followed by autologous stem cell transplant. However, 50% of patients ultimately relapse after autotransplant which poses a big challenge. Allogeneic stem cell transplantation offers the only chance of cure in these patients. For patients who are not candidates for allogeneic stem cell transplantation, achieving cure with other possible options is highly unlikely, and thus the treatment plan becomes noncurative. Various novel agents have shown promising results but the duration of response is short lived. A standard approach to deliver the most effective treatment for these patients is still lacking. This review focuses on the treatment options currently available for relapsed and refractory disease after autotransplant.

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.

Outcomes of adults with active or progressive hematological malignancies at the time of allo-SCT: a survey from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

Previous data suggested that allo-SCT might be an effective therapy in the setting of chemo-refractory/relapsed diseases because of the potent long-term immune-mediated tumor control. This retrospective study aimed to analyze the outcome of adult patients who received allo-SCT in a chemo-refractory/relapsed status. The series included 840 patients with active or progressive disease at the time of transplant. Median age was 50 years. With a median follow-up of 40 months, 3-year OS, disease-free survival (DFS), and non-relapse mortality rates were 29±2, 23±2, and 30±2%, respectively. At the last follow-up, 252 patients (30%) were still alive (of whom 201 were in CR (24%). In a Cox multivariate analysis, the use of a reduced-intensity conditioning (RIC) before allo-SCT and use of an HLA-identical sibling donor remained independently associated with a better OS (hazard ratio (HR)=0.82; 95% confidence interval (CI), 0.69-0.98, P=0.03; and HR=0.79; 95% CI, 0.66-0.93, P=0.006, respectively). Also, a diagnosis of myelodysplastic syndrome/myeloproliferative disorder, Hodgkin lymphoma and non-Hodgkin lymphoma compared with acute leukemia had a favorable impact on OS (HR=0.55; 95% CI, 0.45-0.68, P<0.0001; HR=0.49; 95% CI, 0.31-0.75, P=0.001; and HR=0.47; 95% CI, 0.35-0.63, P<0.0001, respectively). In conclusion, this study suggests that allo-SCT may be of benefit in some subgroups of patients with active or progressive hematological malignancies at the time of allo-SCT.

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.

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.

Promising role of reduced-toxicity hematopoietic stem cell transplantation (PART-I)

Allogeneic hematopoietic stem cell transplantation (HSCT) remains a potential curative option for many patients with hematological malignancies (HM). However, the high rate of transplantation-related mortality (TRM) restricted the use of standard myeloablative HSCT to a minority of young and fit patients. Over the past few years, it has become evident that the alloreactivity of the immunocompetent donor cells mediated anti-malignancy effects independent of the action of high dose chemoradiotherapy. The use of reduced intensity conditioning (RIC) regimens has allowed a graft-versus-malignancy (GvM) effect to be exploited in patients who were previously ineligible for HSCT on the grounds of age and comorbidity. Retrospective analysis showed that RIC has been associated with lower TRM but a higher relapse rate leading to similar intermediate term overall and progression-free survivals when compared to standard myeloablative HSCT. However, the long term antitumor effect of this approach is less well established. Prospective studies are ongoing to define which patients might most benefit from reduced toxicity stem cell transplant (RT-SCT) and which transplant protocols are suitable for the different types of HM. The advent of RT-SCT permits the delivery of a potentially curative GvM effect to the majority of patients with HM whose outcome with conventional chemotherapy would be dismal. Remaining challenges include development of effective strategies to reduce relapse rates by augmenting GvM effects without increasing toxicity.

Hematopoietic progenitor cells transplantation for recurrent or refractory Hodgkin's lymphoma

INTRODUCTION

Advanced-stage Hodgkin's lymphoma (HL) has become a curable disease in the majority of patients. Despite this, about 20% of these patients relapsed or are primary refractory to the first-line treatment and high-dose chemotherapy (HDC) and autologous (Auto) hematopoietic progenitor cells transplantation (HPCT) are considered a therapeutic option.

AREAS COVERED

The authors reviewed HDC and HPCT treatment strategies in recurrent or refractory HL patients, with the goal of providing an overview of this approach.

EXPERT OPINION

Patients younger than 60-65 years with relapsed disease or refractory to first-line therapy should receive a second-line chemotherapy, followed by HDC and Auto-HPCT. Progression-free and overall survival results are significantly better when a second remission or a minimal disease status is achieved before Auto-HPCT, and demonstrate that this strategy is able to cure more than half of the advanced HL patients. Myeloablative allogeneic HPCT (Allo-HPCT) has been employed in advanced phases of the disease, but there have been significant concerns due to treatment-related mortality (TRM). The safety of allogeneic transplantation has improved with the use of reduced-intensity allogeneic (RIC-Allo) HPCT strategies. Despite early favorable results, mature results of RIC-Allo available in the literature are consistent in demonstrating a lack of long-term disease control.

Impact of disease status and stem cell source on the results of reduced intensity conditioning transplant for Hodgkin's lymphoma: a retrospective study from the French Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)

The role of reduced intensity allogeneic stem cell transplantation for the treatment of relapsed/refractory Hodgkin's lymphoma remains controversial. We retrospectively analyzed 191 patients who underwent reduced intensity allogeneic stem cell transplantation between 1998 and 2008 for relapsed or refractory Hodgkin's lymphoma and whose data were reported to the French registry. The median follow-up was 36 months. The estimated 3-year overall survival rate, progression-free survival rate, cumulative incidence of relapse and cumulative incidence of non-relapse mortality were 63%, 39%, 46%, and 16%, respectively. There was no difference in outcome between patients in complete response and in partial response at the time of transplantation with regards to overall survival (70% versus 74%, no significant difference) and progression-free survival (51% versus 42%, no significant difference). Patients with chemoresistant disease had a shorter overall survival (39% at 3 years; P=0.0003) and progression-free survival (18% at 3 years; P=0.001) than patients in complete remission. The use of umbilical cord blood as the source of stem cells was associated with a poor outcome with an increased risk of death with a hazard ratio of 3.49 (95% confidence interval: 1.26 to 9.63; P=0.016). The use of peripheral blood was associated with a better outcome for patients who where alive 1 year after transplantation with a hazard ratio of 0.38 (95% confidence interval: 0.17 to 0.83; P=0.016). Disease status at transplantation remains the most important risk factor for outcome. Our data suggest that the use of peripheral blood should be preferred whereas umbilical cord blood should be used with caution.

Fifty years of melphalan use in hematopoietic stem cell transplantation

Melphalan remains the most widely used agent in preparative regimens for hematopoietic stem cell transplantation (SCT). From its initial discovery more than 50 years ago, it has been gradually incorporated in the conditioning regimens for both autologous and allogeneic transplantations because of its myeloablative properties and broad antitumor effects as a DNA alkylating agent. Melphalan remains the mainstay conditioning for multiple myeloma and lymphomas, and it has been used successfully in preparative regimens of a variety of other hematological and nonhematological malignancies. The addition of newer agents to conditioning, such as bortezomib or lenalidomide for myeloma or clofarabine for myeloid malignancies, may improve antitumor effects for transplantation, whereas melphalan in combination with alemtuzumab may represent a backbone for future cellular therapy because of reliable engraftment and low toxicity profile. This review summarizes the development and the current use of this remarkable drug in hematopoietic SCT.

Brentuximab vedotin enables successful reduced-intensity allogeneic hematopoietic cell transplantation in patients with relapsed or refractory Hodgkin lymphoma

Brentuximab vedotin induces an overall response rate of 75% in patients with relapsed/refractory Hodgkin lymphoma, but its impact on future allogeneic transplantation (allo-HCT) is not known. We retrospectively examined the records of 18 patients with relapsed/refractory Hodgkin lymphoma who were treated on brentuximab vedotin clinical trials to evaluate the efficacy and safety of subsequent reduced-intensity allo-HCT. Seventeen patients had previous autologous transplant; 6 were in complete remission, and 8 were in partial remission before allo-HCT with 12 grafts from unrelated or mismatched donors. The 1-year overall survival was 100%, progression-free survival was 92.3%, and nonrelapse mortality was 0% (median follow-up, 14 months). The incidence of acute GVHD was 27.8% and chronic GVHD was 56.3%. Brentuximab vedotin before reduced-intensity allo-HCT does not appear to adversely affect engraftment, GVHD, or survival and may provide sufficient disease control to enable reduced-intensity allo-HCT.

Treatment strategies for Hodgkin lymphoma recurring following autologous hematopoietic stem cell transplantation

Hodgkin lymphoma (HL) represents one of the great success stories in hematology going from a uniformly fatal disease, to one that is curable in the vast majority of cases. Despite this success, some patients experience relapse. To address this unmet need a variety of agents, classes of drugs, and strategies have demonstrated activity in HL recurring after autologous hematopoietic stem cell transplantation. These include chemotherapeutics (gemcitabine-based combinations, bendamustine), histone deacetylase (HDAC) inhibitors (panobinostat), immunomodulatory agents (lenalidomide), mTOR inhiobitors (everolimus), monoclonal antibodies (rituximab), and antibody-drug conjugates (brentuximab vedotin) as well the potential of long-term disease control via allogeneic transplantation. Such advances reflect our increased understanding of the biology of HL and hold promise for continued improved outcomes for those suffering with this condition.

Results of a pivotal phase II study of brentuximab vedotin for patients with relapsed or refractory Hodgkin's lymphoma

PURPOSE

Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. In phase I studies, brentuximab vedotin demonstrated significant activity with a favorable safety profile in patients with relapsed or refractory CD30-positive lymphomas.

PATIENTS AND METHODS

In this multinational, open-label, phase II study, the efficacy and safety of brentuximab vedotin were evaluated in patients with relapsed or refractory Hodgkin's lymphoma (HL) after autologous stem-cell transplantation (auto-SCT). Patients had histologically documented CD30-positive HL by central pathology review. A total of 102 patients were treated with brentuximab vedotin 1.8 mg/kg by intravenous infusion every 3 weeks. In the absence of disease progression or prohibitive toxicity, patients received a maximum of 16 cycles. The primary end point was the overall objective response rate (ORR) determined by an independent radiology review facility.

RESULTS

The ORR was 75% with complete remission (CR) in 34% of patients. The median progression-free survival time for all patients was 5.6 months, and the median duration of response for those in CR was 20.5 months. After a median observation time of more than 1.5 years, 31 patients were alive and free of documented progressive disease. The most common treatment-related adverse events were peripheral sensory neuropathy, nausea, fatigue, neutropenia, and diarrhea.

CONCLUSION

The ADC brentuximab vedotin was associated with manageable toxicity and induced objective responses in 75% of patients with relapsed or refractory HL after auto-SCT. Durable CRs approaching 2 years were observed, supporting study in earlier lines of therapy.

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.

Significant oral graft-versus-host disease after allogeneic stem cell transplantation with the FLU/MEL conditioning regimen

Background

Oral graft-versus-host disease (GVHD) is a significant complication after allogeneic stem cell transplantation (SCT) and there is no consistent information about its characteristics in patients after reduced-intensity conditioning regimen FLU/MEL (fludarabine 120 mg/m² and melphalan 140mg/m²).

Material/Methods

This was a single-centre prospective observational study of patients after allogeneic SCT with FLU/MEL conditioning performed during the period 1/2005-12/2007. Characteristics of oral GVHD were observed in 71 patients. The observation was discontinued due to death, donor lymphocyte infusion (DLI) or new chemotherapy administration.

Results

In 10/2010, the median duration of the observation of the cohort of the patients was 13 (0.2–69) months, and 42 (35–69) months in the still-ongoing 20/71 (28%) patients. Oral acute GVHD had sporadic 7% incidence, whereas oral chronic GVHD was observed in 33% of patients and persisted with median duration of 188 (11–665) days. Clinical and histopathological features were similar in both acute and chronic oral GVHD and included mucosal lichenoid changes, erythema, ulcerations and pseudomembranes, satellite necrosis, apoptotic bodies and lichenoid interface inflammation.

Conclusions

It is necessary to consider complex clinical symptomatology and pathological correlations when classifying the oral GVHD, because local oral symptoms and histopathological features in both acute and chronic oral GVHD forms can be similar. Even though the oral chronic GVHD was mild in the majority of patients, it can be considered as clinically significant due to its incidence, duration and symptomatology. The FLU/MEL conditioning regimen should not be considered as low-risk protocol in this context.

A phase I weekly dosing study of brentuximab vedotin in patients with relapsed/refractory CD30-positive hematologic malignancies

PURPOSE

The antibody-drug conjugate (ADC) brentuximab vedotin comprises a CD30-directed antibody covalently attached to the potent antimicrotubule agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. This study explored the safety, maximum-tolerated dose (MTD), and activity of weekly dosing of brentuximab vedotin in patients with relapsed or refractory CD30-positive hematologic malignancies.

EXPERIMENTAL DESIGN

In this phase I dose-escalation study, brentuximab vedotin was administered intravenously on Days 1, 8, and 15, of each 28-day cycle at doses ranging from 0.4 to 1.4 mg/kg. Forty-four patients were enrolled: 38 with Hodgkin lymphoma, five with systemic anaplastic large cell lymphoma, and one with peripheral T-cell lymphoma not otherwise specified. Doses were escalated in increments of 0.2 mg/kg until dose-limiting toxicity (DLT) was observed. Patients were monitored for antitherapeutic antibodies and pharmacokinetic parameters. Antitumor assessments were carried out every two cycles.

RESULTS

The MTD was 1.2 mg/kg. The most common adverse events were peripheral sensory neuropathy, fatigue, nausea, diarrhea, arthralgia, and pyrexia; and the majority of events were mild to moderate in severity. Tumor regression occurred in 85% of patients and the overall objective response rate was 59% (n = 24), with 34% (n = 14) complete remissions. The median duration of response was not reached at a median follow-up of 45 weeks on study.

CONCLUSIONS

Weekly administration of brentuximab vedotin resulted in tumor regression and durable remissions in patients with CD30-positive malignancies. This ADC was associated with manageable toxicity, including peripheral neuropathy. Further study in CD30-positive malignancies is warranted.

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.

Hodgkin's lymphoma: current treatment strategies and novel approaches

Approximately 80% of Hodgkin's lymphoma (HL) patients achieve long-term remission after primary chemotherapy or chemo/radiotherapy. Despite these excellent results, further treatment improvement is necessary. HL therapy is associated with severe acute and long-term toxicities. Thus, a major aim of clinical HL research is to evaluate novel schemes that are less toxic than current standard regimens without being less effective. Another focus is the treatment of patients with multiple relapses. Standard treatment for these patients has not yet been defined, and their prognosis is still poor. Reduced-intensity conditioning allogeneic stem cell transplantation was recently shown to be effective in carefully selected young chemosensitive patients. Furthermore, new strategies such as antibody- and small-molecule-based therapy have demonstrated encouraging results in preclinical studies and the first clinical trials.

Histology and time to progression predict survival for lymphoma recurring after reduced-intensity conditioning and allogeneic hematopoietic cell transplantation

Reduced-intensity conditioning (RIC) before allogeneic hematopoietic cell transplantation (HCT) is increasingly used as a potentially curative option for patients with advanced lymphoma; however, relapse remains a major challenge. Unfortunately, little data are available on outcomes, predictors of survival, and results of specific management strategies in these patients. In the present study, a total of 101 consecutive relapses occurred and were evaluated in 280 patients with lymphoma who underwent RIC HCT. Diseases included aggressive non-Hodgkin lymphoma (NHL) (n = 42), indolent NHL (n = 33), and Hodgkin lymphoma (HL) (n = 26). Median time to relapse was 90 days (range, 3-1275 days), and graft-versus-host disease at relapse was present in 56 patients (55%). Interventions after relapse included no therapy (n = 14), withdrawal of immunosuppression alone (n = 11), chemoradiotherapy (n = 60), and donor lymphocyte infusion/second HCT (n = 16). Overall survival (OS) was 33% (95% confidence interval [CI], 23%-44%) at 3 years after relapse and 23% (95% CI, 13%-34%) at 5 years after relapse. Both aggressive NHL (vs indolent disease; hazard ratio, 2.29; P = .008) and relapse within 1 month post-HCT (vs >6 months; hazard ratio, 3.17; P = .004) were associated with increased mortality. Estimated 3-year OS was 16% (95% CI, 5%-32%) after relapse for aggressive NHL, 40% (95% CI, 19%-61%) after relapse for indolent NHL, and 47% (95% CI, 29%-64%) after relapse for HL. The 1-year survival was 24% for patients relapsing within 1 month post-HCT, compared with 52% for those relapsing at 1-3 months, 74% for those relapsing at 3-6 months, and 77% for those relapsing at more than 6 months. We conclude that despite relapse of lymphoma after RIC HCT, some patients may experience prolonged survival, with better postrelapse outcomes occurring in patients with indolent NHL, HL, or late relapse.

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.

The Management of Classical Hodgkin's Lymphoma: Past, Present, and Future

The management of classical Hodgkin's lymphoma (CHL) is a success story of modern multi-agent haemato-oncology. Prior to the middle of the twentieth century CHL was fatal in the majority of cases. Introduction of single agent radiotherapy (RT) demonstrated for the first time that these patients could be cured. Developments in chemotherapy including the mechlorethamine, vincristine, procarbazine and prednisolone (MOPP) and Adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) regimens have resulted in cure rates of over 80%. Even in relapse, CHL patients can be salvaged with high dose chemotherapy and autologous haematopoietic stem cell transplantation (ASCT). Challenges remain, however, in finding new strategies to manage the small number of patients who continue to relapse or progress. In addition, the young age of many Hodgkin's patients forces difficult decisions in balancing the benefit of early disease control against the survival disadvantage of late toxicity. In this article we aim to summarise past trials, define the current standard of care and appraise future developments in the management of CHL.

Donor Lymphocyte Infusions Modulate Relapse Risk in Mixed Chimeras and Induce Durable Salvage in Relapsed Patients After T-Cell–Depleted Allogeneic Transplantation for Hodgkin's Lymphoma

Purpose

Reduced-intensity conditioning has minimized nonrelapse-related mortality rates after allogeneic transplantation in patients with Hodgkin's lymphoma, and relapse has now become the major cause for treatment failure. We aimed to assess the impact of donor lymphocyte infusions (DLIs) on relapse incidence when administered for mixed chimerism and their utility as salvage therapy when given for relapse.

Patients and Methods

This study reports the outcomes of 76 consecutive patients with multiply relapsed or refractory Hodgkin's lymphoma who underwent allogeneic transplantation that incorporated in vivo T-cell depletion. Forty-two patients had related donors and 34 had unrelated donors. DLIs were administered in a dose-escalating fashion to 22 patients for mixed chimerism (median time of first dose, 9 months post-transplantation) and to 24 patients for relapse.

Results

Three-year donor lymphocyte–related mortality was 7%, relating mainly to the induction of graft-versus-host disease. Nineteen (86%) of 22 patients receiving donor lymphocytes for mixed chimerism converted to full donor status. Four-year relapse incidence was 5% in these 22 patients compared with 43% in patients who remained relapse free but full donor chimeras at 9 months post-transplantation (P = .0071). Nineteen (79%) of 24 patients receiving donor lymphocytes for relapse responded (14 complete responses, five partial responses). Four-year overall survival from relapse was 59% in recipients of donor lymphocytes, contributing to a 4-year overall survival from transplantation of 64% and a 4-year current progression-free survival of 59% in all 76 patients.

Conclusion

These data demonstrate the potential for allogeneic immunotherapy with donor lymphocytes both to reduce relapse risk and to induce durable antitumor responses in patients with Hodgkin's lymphoma after hematopoietic stem-cell transplantation that incorporates in vivo T-cell depletion.

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.

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.

Reduced intensity allogeneic hematopoietic cell transplantation can induce durable remission in heavily pretreated relapsed Hodgkin lymphoma

Hodgkin lymphoma (HL) can be aggressive and intractable in some cases. Patients who relapse after autologous HCT (auto-HCT) have limited treatment options. City of Hope reports our experience in the use of reduced intensity allogeneic hematopoietic cell transplantation (allo-HCT) in 24 heavily pretreated patients with relapsed HL, between January 2003 and December 2008. The median number of prior therapies was 5; 20/24 patients had prior auto-HCT. The conditioning regimen for all patients was fludarabine and melphalan. With a median follow-up for living patients of 39.0 months, at 2 years the overall survival (OS) was 60% (95% CI 42, 72) and the progression-free survival was 27% (95% CI 22, 32). Non-relapse mortality was 13.1% (95% CI 5.1, 31.4) at 2 years. The incidence of grade II-IV aGVHD was 45.8% and 8.3% for grade III-IV. Allo-HCT in heavily pretreated relapsed Hodgkin lymphoma is feasible, tolerable, and can induce durable clinical remissions.

Pretransplantation [18-F]fluorodeoxyglucose positron emission tomography scan predicts outcome in patients with recurrent Hodgkin lymphoma or aggressive non-Hodgkin lymphoma undergoing reduced-intensity conditioning followed by allogeneic stem cell transplantation

BACKGROUND

The use of positron emission tomography (PET) scanning in Hodgkin lymphoma (HL) and aggressive non-Hodgkin lymphoma (HG-NHL) has recognized prognostic value in patients who are receiving chemotherapy or undergoing autologous stem cell transplantation (SCT). In contrast, the role of PET before reduced-intensity conditioning (RIC) and followed by allogeneic SCT has not been investigated to date.

METHODS

PET was used to assess 80 patients who had chemosensitive disease (34 patients with HG-NHL and 46 patients with HL) before they underwent allogeneic SCT: 42 patients had negative PET studies, and 38 patients had positive PET studies. Patients underwent allograft from matched related siblings (n=41) or alternative donors (n=39).

RESULTS

At the time of the last follow-up, 48 patients were alive (60%), and 32 had died. The 3-year cumulative incidence of nonrecurrence mortality and disease recurrence was 17% and 40%, respectively. The cumulative incidence of disease recurrence was significantly lower in the PET-negative patients (25% vs 56%; P=.007), but there was no significant difference between the patients with or without chronic graft-versus-host disease (P=.400). The patients who had negative PET studies before undergoing allogenic SCT also had significantly better outcomes in terms of 3-year overall survival (76% vs 33%; P=.001) and 3-year progression-free survival (73% vs 31%; P=.001). On multivariate analysis, overall survival was influenced by PET status (hazard ratio [HR], 3.35), performance status (HR, 5.15), and type of donor (HR, 6.26 for haploidentical vs sibling; HR, 1.94 for matched unrelated donor vs sibling).

CONCLUSIONS

The current results indicated that PET scanning appears to be an accurate tool for assessing prognosis in patients who are eligible for RIC allografting.

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.

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 fludarabine exposure and relationship with treatment-related mortality after nonmyeloablative hematopoietic cell transplantation

Despite its common use in nonmyeloablative preparative regimens, the pharmacokinetics of fludarabine are poorly characterized in hematopoietic cell transplantation (HCT) recipients and exposure-response relationships remain undefined. Our objective of this study was to evaluate the association between plasma F-ara-A exposure, the systemically circulating moiety of fludarabine, and engraftment, acute graft vs host disease (GVHD), treatment-related mortality (TRM) and survival after HCT. The preparative regimen consisted of cyclophosphamide 50 mg/kg/day i.v. day −6; plus fludarabine 30-40 mg/m²/day i.v. on days −6 to −2 and TBI 200 cGy on day −1. F-ara-A pharmacokinetics were performed with the first dose of fludarabine in 87 adult patients. Median (range) F-ara-A AUC _(0-∞) was 5.0 ug*hr/mL (2.0-11.0), clearance 15.3 L/hour (6.2-36.6), C_min 55 ng/mL (17-166), and concentration on day_zero 16.0 ng/mL (0.1-144.1). Despite dose reductions, patients with renal insufficiency had higher F-ara-A exposures. There was strong association between high plasma concentrations of F-ara-A and increased risk of TRM and reduced overall survival. Patients with an AUC_(0-∞) greater than 6.5 ug*hr/mL had 4.56 greater risk of TRM and significantly lower survival. These data suggest that clinical strategies are needed to optimize dosing of fludarabine to prevent overexposure and toxicity in HCT.

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.

CD34+ cell dose and establishment of full donor chimerism at day +100 are important factors for survival with reduced-intensity conditioning with fludarabine and melphalan before allogeneic hematopoietic SCT for hematologic malignancies

The combination of fludarabine and melphalan as a reduced-intensity conditioning (RIC) regimen extends allogeneic hematopoietic SCT (HSCT) as a therapeutic option for elderly or frail patients with relapsed, refractory or other high-risk hematologic malignancies. Whether any modifiable factors exist that could improve survival before or immediately after HSCT is unknown. We reviewed the medical records of the first 50 patients at our institution to undergo fludarabine/melphalan RIC from September 2000 to September 2007 to determine factors associated with survival. A total of 25 (50%) patients had undergone prior HSCT and as such was a high-risk group of patients. On multivariate analysis, CD34(+) cell dose greater than 5.5 × 10(6) per kg (risk ratio (RR) 0.44, 95% CI 0.19-0.98, P=0.02) and full donor chimerism at day +100 (RR 0.17, 95% CI 0.06-0.64, P=0.002) remained independent prognostic factors. In our series, achievement of full donor chimerism at day +100 was associated with an approximately 70% 2-year survival, a favorable outcome in this high-risk group of patients. Although the infused CD34(+) cell dose is a modifiable variable, whether donor lymphocyte infusions or other immunologic interventions should be performed to promote the establishment of full chimerism early post transplant remains unknown.

Evidence of a clinical response at one yr after reduced-intensity allogeneic hematopoietic stem cell transplantation in heavily pretreated adolescents with aggressive refractory Hodgkin's lymphoma

We report results of RIC AHSCT in four adolescents with aggressive refractory HL. They all received three or four lines of therapy prior to RIC-AHSCT including autografts. At the time of RIC, they were in partial response except for one patient who had progressive chemoresistant disease. The conditioning regimen consisted of fludarabin, busulfan and ATG. They all had a matched related donor. The median follow-up was 12-16-month post-allograft. All patient transplants engrafted rapidly. The median time of hospitalization was 35 days. The median time to neutrophil recovery (>or=500/muL) was 19 days. All the patients were in complete donor chimerism at day 60. Four patients developed skin (grade <or= II) acute GvHD. All responded and all are alive. Two patients are in CR, one in PR and one relapsed six months after grafting after a PR. Each of the patients in PR received two DLI. These observations, together with the responses after DLI, suggest the presence of a graft vs. lymphoma effect in patients with advanced active HL. Prospective studies are needed to identify the patients likely to benefit most from this treatment approach.

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.