Comparable results of umbilical cord blood and HLA-matched sibling donor hematopoietic stem cell transplantation after reduced-intensity preparative regimen for advanced Hodgkin lymphoma

Impact of donor types on reduced-intensity conditioning allogeneic stem cell transplant for mature lymphoid malignancies

We retrospectively compared the outcomes of reduced-intensity conditioning (RIC) transplantation from matched related donors (MRD; n = 266), matched unrelated donors (MUD; n = 277), and umbilical cord blood (UCB; n = 513) for mature lymphoid malignancies. The 3-year overall survival rates for the MRD, MUD, and UCB groups were 54%, 59%, and 40%, respectively (P < 0.001). Multivariate analysis showed no differences in survival between the MRD group and the MUD or UCB group. However, survival was significantly affected by the conditioning regimen and graft-versus-host disease (GVHD) prophylaxis in the UCB group, but not in the MRD and MUD groups. Notably, multivariate analysis showed that the risk of overall mortality in the UCB recipients who received the optimal conditioning regimen and GVHD prophylaxis (n = 116) was lower than that in the MRD group (relative risk [RR], 0.69; P = 0.03) and tended to be lower than that in the MUD group (RR, 0.75; P = 0.09). Our results suggest that UCB transplantation performed with the optimal conditioning regimen and GVHD prophylaxis is highly effective. Moreover, UCB is readily available. Thus, UCB transplantation with the optimal conditioning regimen and GVHD prophylaxis is preferable to MUD transplantation when MRD are not available in the setting of RIC transplantation for mature lymphoid malignancies.

Relapse of Hodgkin lymphoma after autologous hematopoietic cell transplantation: A current management perspective

Hodgkin lymphoma (HL) is a highly responsive disease with nearly 70% of patients experiencing cure after front-line chemotherapy. Patients who experience disease relapse receive salvage chemotherapy followed by consolidation with autologous hematopoietic cell transplantation (auto-HCT). Nearly 50% of patients relapse after an auto-HCT and constitute a subgroup with poor prognosis. Novel treatments such as immune checkpoint inhibitors and an anti-CD30 monoclonal antibody are currently approved for patients relapsing after auto-HCT; however, the duration of remission with these therapies remains limited. Allogeneic HCT is currently the only potentially curative treatment modality for patients relapsing after a prior auto-HCT. Early clinical trials with chimeric antigen receptor T-cell therapy targeting CD30 are underway for patients with relapsed/refractory HL and are already demonstrating safety and promising efficacy.

Immune Reconstitution Disorders: Spotlight on Interferons

Three decades of research in hematopoietic stem cell transplantation and HIV/AIDS fields have shaped a picture of immune restoration disorders. This manuscript overviews the molecular biology of interferon networks, the molecular pathogenesis of immune reconstitution inflammatory syndrome, and post-hematopoietic stem cell transplantation immune restoration disorders (IRD). It also summarizes the effects of thymic involution on T cell diversity, and the results of the assessment of diagnostic biomarkers of IRD, and tested targeted immunomodulatory treatments.

Delayed immune reconstitution after allogeneic transplantation increases the risks of mortality and chronic GVHD

Slow immune reconstitution is a major obstacle to the successful use of allogeneic hematopoietic cell transplantation (allo-HCT). As matched sibling donor (MSD) allo-HCT is regarded as the gold standard, we evaluated the pace of immune reconstitution in 157 adult recipients of reduced-intensity conditioning followed by MSD peripheral blood HCT (n = 68) and compared these to recipients of umbilical cord blood (UCB; n = 89). At day 28, UCB recipients had fewer natural killer (NK) cells than MSD recipients, but thereafter, NK cell numbers (and their subsets) were higher in UCB recipients. During the first 6 months to 1 year after transplant, UCB recipients had slower T-cell subset recovery, with lower numbers of CD3⁺, CD8⁺, CD8⁺ naive, CD4⁺ naive, CD4⁺ effector memory T, regulatory T, and CD3⁺CD56⁺ T cells than MSD recipients. Notably, B-cell numbers were higher in UCB recipients from day 60 to 1 year. Bacterial and viral infections were more frequent in UCB recipients, yet donor type had no influence on treatment-related mortality or survival. Considering all patients at day 28, lower numbers of total CD4⁺ T cells and naive CD4⁺ T cells were significantly associated with increased infection risk, treatment-related mortality, and chronic graft-versus-host disease (GVHD). Patients with these characteristics may benefit from enhanced or prolonged infection surveillance and prophylaxis as well as immune reconstitution-accelerating strategies.

Outcomes of Advanced Hodgkin Lymphoma after Umbilical Cord Blood Transplantation: A Eurocord and EBMT Lymphoma and Cellular Therapy & Immunobiology Working Party Study

Allogeneic stem cell transplantation is an alternative for patients with relapsed or refractory Hodgkin lymphoma (HL), but only limited data on unrelated umbilical cord blood transplantation (UCBT) are available. We analyzed 131 adults with HL who underwent UCBT in European Society for Blood and Marrow Transplantation centers from 2003 to 2015. Disease status at UCBT was complete remission (CR) in 59 patients (47%), and almost all patients had received a previous autologous stem cell transplantation. The 4-year progression-free survival (PFS) and overall survival (OS) were 26% (95% confidence interval [CI], 19% to 34%) and 46% (95% CI, 37% to 55%), respectively. Relapse incidence was 44% (95% CI, 36% to 54%), and nonrelapse mortality (NRM) was 31% (95% CI, 23% to 40%) at 4 years. In multivariate analysis refractory/relapsed disease status at UCBT was associated with increased relapse incidence (hazard ratio [HR], 3.14 [95% CI, 1.41 to 7.00], P = .005) and NRM (HR, 3.61 [95% CI, 1.58 to 8.27], P = .002) and lower PFS (HR, 3.45 [95% CI, 1.95 to 6.10], P < .001) and OS (HR, 3.10 [95% CI, 1.60 to 5.99], P = .001). Conditioning regimen with cyclophosphamide + fludarabine + 2 Gy total body irradiation (Cy+Flu+2GyTBI) was associated with decreased risk of NRM (HR, .26 [95% CI, .10 to .64], P = .004). Moreover, Cy+Flu+2GyTBI conditioning regimen was associated with a better OS (HR, .25 [95% CI, .12 to .50], P < .001) and PFS (HR, .51 [95% CI, .27 to .96], P = .04). UCBT is feasible in heavily pretreated patients with HL. The reduced-intensity conditioning regimen with Cy+Flu+2GyTBI is associated with a better OS and NRM. However, outcomes are poor in patients not in CR at UCBT.

Transplant strategies in relapsed/refractory Hodgkin lymphoma

The majority of patients with Hodgkin lymphoma (HL) are cured with initial therapy. However, high-dose therapy with autologous hematopoietic cell transplant (AHCT) allows for the cure of an additional portion of patients with relapsed or primary refractory disease. Positron emission tomography-negative complete remission before AHCT is critical for long-term disease control. Several salvage options are available with comparable response rates, and the choice can be dependent of comorbidities and logistics. Radiation therapy can also improve the remission rate and is an important therapeutic option for selected patients. Brentuximab vedotin (BV) maintenance after AHCT is beneficial in patients at high risk for relapse, especially those with more than 1 risk factor, but can have the possibility of significant side effects, primarily neuropathy. Newer agents with novel mechanisms of action are under investigation to improve response rates for patients with subsequent relapse, although are not curative alone. BV and the checkpoint inhibitors nivolumab and pembrolizumab are very effective with limited side effects and can bridge patients to curative allogeneic transplants (allo-HCT). Consideration for immune-mediated toxicities, timing of allogeneic hematopoietic cell transplant based on response, and the potential for increased graft-versus-host disease remain important. Overall, prospective investigations continue to improve outcomes and minimize toxicity for relapsed or primary refractory HL patients.

Hodgkin lymphoma: A review and update on recent progress

Hodgkin lymphoma (HL) is a unique hematopoietic neoplasm characterized by cancerous Reed-Sternberg cells in an inflammatory background. Patients are commonly diagnosed with HL in their 20s and 30s, and they present with supradiaphragmatic lymphadenopathy, often with systemic B symptoms. Even in advanced-stage disease, HL is highly curable with combination chemotherapy, radiation, or combined-modality treatment. Although the same doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapeutic regimen has been the mainstay of therapy over the last 30 years, risk-adapted approaches have helped de-escalate therapy in low-risk patients while intensifying treatment for higher risk patients. Even patients who are not cured with initial therapy can often be salvaged with alternate chemotherapy combinations, the novel antibody-drug conjugate brentuximab, or high-dose autologous or allogeneic hematopoietic stem cell transplantation. The programmed death-1 inhibitors nivolumab and pembrolizumab have both demonstrated high response rates and durable remissions in patients with relapsed/refractory HL. Alternate donor sources and reduced-intensity conditioning have made allogeneic hematopoietic stem cell transplantation a viable option for more patients. Future research will look to integrate novel strategies into earlier lines of therapy to improve the HL cure rate and minimize long-term treatment toxicities. CA Cancer J Clin 2018;68:116-132. © 2017 American Cancer Society.

Umbilical Cord Blood Research: Current and Future Perspectives

Umbilical cord blood (UCB) banking has become a new obstetrical trend. It offers expectant parents a biological insurance policy that can be used in the event of a child or family member's life-threatening illness and puts patients in a position of control over their own treatment options. However, its graduation to conventional therapy in the clinical realm relies on breakthrough research that will prove its efficacy for a range of ailments. Expanding the multipotent cells found within the mononuclear fraction of UCB so that adequate dosing can be achieved, effectively expanding desired cells ex vivo, establishing its safety and limitations in HLA-mismatched recipients, defining its mechanisms of action, and proving its utility in a wide variety of both rare and common illnesses and diseases are a few of the challenges left to tackle. Nevertheless, the field is moving fast and new UCB-based therapies are on the horizon.

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

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

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

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

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

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

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

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

Alternative donors: cord blood for adults

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for patients with hematological diseases. The probability of finding a human leukocyte antigen (HLA)- identical donor among family members is around 25% and 30% that of having a full matched unrelated donor in the registry. Patients in need may also benefit of a HLA-mismatched HSCT either from an haploidentical donors or from umbilical cord blood (UCB). Much has been learned about UCB transplant (UCBT) since the first human UCBT was performed back in 1988. Cord blood banks have been established worldwide for the collection, cryopreservation, and distribution of UCB for HSCT. Today, a global network of cord blood banks and transplant centers has been established with a large common inventory of more than 650,000 UCB units available, allowing for more than 40,000 UCBT worldwide in children and adults with severe hematological diseases. Several studies have been published on UCBT, assessing risk factors such as cell dose and HLA mismatch. Outcomes of several retrospective comparative studies showed similar results using other stem cell sources both in pediatric and adult setting. New strategies are ongoing to facilitate engraftment and reduce transplant-related mortality. In this issue, we review the current results of UCBT in adults with hematological malignancies and the clinical studies comparing UCBT with other transplant strategies. We provide guidelines for donor algorithm selection in UCBT setting.

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

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

Double umbilical cord blood transplant is effective therapy for relapsed or refractory Hodgkin lymphoma

A sub-group of patients with Hodgkin Lymphoma (HL) who relapse after autologous stem cell transplant can achieve long-term disease-free-survival after allogeneic stem cell transplant (alloSCT). There is limited information regarding the tolerability and efficacy of double umbilical cord blood transplant (dUCBT) for relapsed/refractory HL. We analyzed 27 consecutive, heavily pre-treated patients receiving dUCBT for relapsed/refractory HL at two centers from 2003-2014. The majority of patients relapsed <6 months after autologous stem cell transplant. A total of 15 patients received myeloablative (most commonly melphalan, fludarabine, thiotepa and anti-thymocyte globulin [ATG]) and 12 non-myeloablative conditioning regimens (fludarabine, cyclophosphamide, 200cGy total body irradiation +/- ATG). All patients engrafted; median time to neutrophil and platelet engraftment was 17 and 37 days, respectively. Overall response rate was 68%; 58% achieved complete remission. Median progression-free survival (PFS) was 12.2 months; median overall survival was 27 months. Cumulative incidences of relapse and of non-relapse mortality at 5 years were 30% and 37.9%, respectively; 5-year PFS was 31.3% (95%CI 10.1-52.5). There was a trend toward inferior PFS in patients with lymph node size ≥2 cm at the time of alloSCT (p = 0.07) and toward inferior survival in patients with chemorefractory disease pre-alloSCT (p = 0.12). dUCBT is feasible in patients with heavily pre-treated HL and can achieve long-term disease-free survival in approximately 30% of patients.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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

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

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

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

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Umbilical cord blood banking: from personal donation to international public registries to global bioeconomy

The procedures for collecting voluntarily and freely donated umbilical cord blood (UCB) units and processing them for use in transplants are extremely costly, and the capital flows thus generated form part of an increasingly pervasive global bioeconomy. To place the issue in perspective, this article first examines the different types of UCB biobank, the organization of international registries of public UCB biobanks, the optimal size of national inventories, and the possibility of obtaining commercial products from donated units. The fees generally applied for the acquisition of UCB units for transplantation are then discussed, and some considerations are proposed regarding the social and ethical implications raised by the international network for the importation and exportation of UCB, with a particular emphasis on the globalized bioeconomy of UCB and its commerciality or lack thereof.

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.

Alternative donor hematopoietic stem cell transplantation for mature lymphoid malignancies after reduced-intensity conditioning regimen: similar outcomes with umbilical cord blood and unrelated donor peripheral blood

We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97%, respectively; P<0.0001) and chronic graft-versus-host disease (26% vs. 52%; P=0.0005) were less frequent after unrelated cord blood than after matched unrelated donor, whereas no differences were observed in grade II-IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28%), and relapse or progression (28% vs. 35%) at 36 months. There were also no significant differences in 2-year progression-free survival (43% vs. 58%, respectively) and overall survival (36% vs. 51%) at 36 months. In a multivariate analysis, no differences were observed in the outcomes between the two stem cell sources except for a higher risk of neutrophil engraftment (hazard ratio=2.12; P<0.0001) and chronic graft-versus-host disease (hazard ratio 2.10; P=0.0002) after matched unrelated donor transplant. In conclusion, there was no difference in final outcomes after transplantation between umbilical cord blood and matched unrelated donor transplant. Umbilical cord blood is a valuable alternative for patients with lymphoid malignancies lacking an HLA-matched donor, being associated with lower risk of chronic graft-versus-host disease.

Double umbilical cord blood transplantation for hematological malignancies: a long-term analysis from the SFGM-TC registry

Allogeneic hematopoietic stem cell (HSC) transplantation is a curative treatment for many hematologic malignancies for which umbilical cord blood (UCB) represents an alternative source of HSCs. To overcome the low cellularity of one UCB unit, double UCB transplantation (dUCBT) has been developed in adults. We have analyzed the outcome of 136 patients who underwent dUCBT reported to the SFGM-TC registry between 2005 and 2007. Forty-six patients received myeloablative regimens, and 90 patients received reduced-intensity conditioning regimens. There were 84 cases of leukemia, 17 cases of non-Hodgkin lymphoma, 11 cases of myeloma, and 24 other hematologic malignancies. At transplantation, 40 (29%) patients were in complete remission. At day 60 after transplantation, the cumulative incidence of neutrophil recovery was 91%. We observed one UCB unit domination in 88% of cases. The cumulative incidence of day 100 acute graft-versus-host disease, chronic graft-versus-host disease, transplant-related mortality, and relapse at 2 years were 36%, 23%, 27%, and 28% respectively. After a median follow-up of 49.5 months, the 3-year probabilities of overall and progression-free survival were 41% and 35%, respectively, with a significant overall survival advantage when male cord engrafted male recipients. We obtained a long-term plateau among patients in complete remission, which makes dUCBT a promising treatment strategy for these patients.

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.

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.

Comparison of outcomes after two standards-of-care reduced-intensity conditioning regimens and two different graft sources for allogeneic stem cell transplantation in adults with hematologic diseases: a single-center analysis

Recent advances in allogeneic stem cell transplantation (allo-HSCT) have included the advent of reduced-intensity conditioning (RIC) regimens to decrease the toxicity of myeloablative allo-SCT and the use of double umbilical cord blood (dUCB) units as a graft source in adults lacking a suitable donor. The FB2A2 regimen (fludarabine 30 mg/kg/day for 5-6 days + i.v. busulfan 3.6 mg/kg/day for 2 days + rabbit antithymocyte globulin 2.5 mg/kg/day for 2 days) supported by peripheral blood stem cells (PBSCs) and the TCF regimen (fludarabine 200 mg/m² for 5 days + cyclophosphamide 50 mg/kg for 1 day + low-dose [2 Gy] total body irradiation) supported by dUCB units are currently the most widely used RIC regimens in many centers and could be considered standard of care in adults eligible for an RIC allo-SCT. Here we compared, retrospectively, the outcomes of adults patients who received the FB2A2-PBSC RIC regimen (n = 52; median age, 59 years; median follow-up, 19 months) and those who received the dUCB-TCF RIC regimen (n = 39; median age, 56 years; median follow-up, 20 months) for allo-SCT between January 2007 and November 2010. There were no significant between-group differences in patient and disease characteristics. Cumulative incidences of engraftment, acute grade II-IV and chronic graft-versus-host disease were similar in the 2 groups. The median time to platelet recovery, incidence of early death (before day +100), and 2-year nonrelapse mortality were significantly higher in the dUCB-TCF group (38 days versus 0 days [P <.0001]; 20.5% versus 4% [P = .05], and 26.5% versus 6% [P = .02], respectively). The groups did not differ in terms of 2-year overall survival (62% for FB2A2-PBSC versus 61% for dUCB-TCF), disease-free survival (59% versus 50.5%), or relapse incidence (35.5% versus 23%). In multivariate analysis, the presence of a lymphoid disorder was associated with a significantly higher 2-year overall survival (hazard ratio, 0.42; 95% confidence interval, 0.20-0.87; P = .02), whereas patients receiving a FB2A2-PBSC allo-SCT had a significantly lower 2-year nonrelapse mortality (hazard ratio, 0.24; 95% confidence interval, 0.1-0.7; P = .01). There were no factors associated with higher 2-year disease-free survival or lower relapse incidence. This study suggests that the dUCB-TCF regimen provides a valid alternative in adults lacking a suitable donor and eligible for RIC allo-SCT. Prospective and randomized studies are warranted to establish the definitive role of dUCB RIC allo-SCT in adults. In addition, strategies for decreasing nonrelapse mortality after dUCB RIC allo-SCT are urgently needed.

Population pharmacokinetics of unbound mycophenolic acid in adult allogeneic haematopoietic cell transplantation: effect of pharmacogenetic factors

AIM

To evaluate pharmacogenetic factors as contributors to the variability of unbound mycophenolic acid (MPA) exposure in adult allogeneic haematopoietic cell transplantation (alloHCT) recipients.

METHODS

A population-based pharmacokinetic (PK) model of unbound MPA was developed using non-linear mixed-effects modelling (nonmem). Previously collected intensive unbound MPA PK data from 132 adult alloHCT recipients after oral and intravenous dosing of the prodrug mycophenolate mofetil (MMF) were used. In addition to clinical covariates, genetic polymorphisms in UGT1A8, UGT1A9, UGT2B7 and MRP2 were evaluated for their impact on unbound MPA PK.

RESULTS

Unbound MPA concentration-time data were well described by a two compartment model with first order absorption and linear elimination. For the typical patient (52 years of age, creatinine clearance 86 ml min(-1)), the median estimated values [coefficient of variation, %, (CV)] of systemic clearance, intercompartmental clearance, central and peripheral volumes of MPA were 1610 l h(-1) (37.4%), 541 l h(-1) (75.6%), 1230 l (37.5%), and 6140 l (120%), respectively. After oral dosing, bioavailability was low (0.56) and highly variable (CV 46%). No genetic polymorphisms tested significantly explained the variability among individuals. Creatinine clearance was a small but significant predictor of unbound MPA CL. No other clinical covariates impacted unbound MPA PK.

CONCLUSIONS

In adult alloHCT recipients, variability in unbound MPA AUC was large and remained largely unexplained even with the inclusion of pharmacogenetic information. Targeting unbound MPA AUC in a patient will require therapeutic drug monitoring.

Reduced-intensity conditioning transplantation in acute leukemia: the effect of source of unrelated donor stem cells on outcomes

We report the relative efficacy of co-infusing 2 umbilical cord blood units (dUCB) compared with peripheral blood progenitor cells (PBPCs) from 8 of 8 or 7 of 8 HLA-matched unrelated donors. All patients received reduced-intensity conditioning (RIC) regimens. Four treatment groups were evaluated: 4-6 of 6 matched dUCB-TCF (n = 120; TCF = total body irradiation [TBI] 200 cGy + cyclophosphamide + fludarabine), 4-6 of 6 matched dUCB-other (n = 40; alkylating agent + fludarabine ± TBI), and 8 of 8 (n = 313) and 7 of 8 HLA-matched PBPCs (n = 111). Compared with matched 8 of 8 PBPC transplantations, transplantation-related mortality (TRM), and overall mortality were similar after dUCB-TCF (relative risk [RR] 0.72, P = .72; RR 0.93, P = .60) but higher after dUCB-other RIC (hazard ratio [HR] 2.70, P = .0001; 1.79 P = .004). Compared with 7 of 8 PBPC transplantations, TRM (but not overall mortality) was lower after dUCB-TCF (RR 0.57, P = .04; RR 0.87 P = .41). The probabilities of survival after dUCB-TCF, dUCB-other RIC, and 8 of 8 PBPC and 7 of 8 PBPC transplantations were 38%, 19%, 44%, and 37%, respectively. With similar survival after 8 of 8, 7 of 8 matched PBPCs, and dUCB-TCF, these data support use of dUCB-TCF transplantation in adults with acute leukemia who may benefit from RIC transplantation urgently or lack a 7-8 of 8 unrelated donor.

Selection of optimal alternative graft source: mismatched unrelated donor, umbilical cord blood, or haploidentical transplant

Only 30% of patients who require an allogeneic hematopoietic cell transplant will have an HLA-matched sibling donor. A search for an unrelated donor will be undertaken for patients without a matched family donor. However, many patients, particularly patients of diverse racial and ethnic backgrounds, may not be able to rapidly identify a suitably matched unrelated donor. Three alternative graft sources, umbilical cord blood (UCB), haploidentical (haplo)-related donor, and mismatched unrelated donor (MMUD) are available. UCB is associated with decreased GVHD, but hematologic recovery and immune reconstitution are slow. Haplo-HCT is characterized by donor availability for transplantation and after transplantation adoptive cellular immunotherapy but may be complicated by a high risk of graft failure and relapse. A MMUD transplant may also be an option, but GVHD may be of greater concern. Phase 2 studies have documented advances in HLA typing, GVHD prophylaxis, and infection prevention, which have improved survival. The same patient evaluated in different transplant centers may be offered MMUD, UCB, or haplo-HCT depending on center preference. In this review, we discuss the rationale for donor choice and the need of phase 3 studies to help answer this important question.

Umbilical Cord Blood Transplantation for the Treatment of Hematologic Malignancies

Background

The use of unrelated umbilical cord blood (UCB) has grown as an allogeneic source of hematopoietic cells for transplantation of patients with hematologic malignancies. As the number of UCB transplantation procedures has grown, an increasing number of publications have focused on disease-specific outcomes.

Methods

This review focuses on the outcome data following UCB transplantation in subsets of hematologic malignancies in which experience with this graft source is greater.

Results

Registry and single-institution reports regarding the outcomes of children and adults with acute leukemias after UCB transplantation include many patients, while data on the clinical outcomes of other leukemias are limited due in part to the small number of patients with these diseases. UCB is now routinely used as a source of hematopoietic stem cells (HSCs) in pediatric allogeneic transplantation when a suitable sibling donor is not available. Data also support the use of UCB as an alternative source of HSC for transplantation of patients with hematologic malignancies who lack a more conventional donor. Current data also support UCB for patients who require an allograft in the setting of prospective clinical trials.

Conclusions

Along with safety and feasibility in UCB transplantation, continued study is needed that focuses on issues such as accelerating engraftment, extending access, ensuring quality, and examining outcomes in specific subgroups of patients.

A comparison of immune reconstitution and graft-versus-host disease following myeloablative conditioning versus reduced toxicity conditioning and umbilical cord blood transplantation in paediatric recipients

Immune reconstitution appears to be delayed following myeloablative conditioning (MAC) and umbilical cord blood transplantation (UCBT) in paediatric recipients. Although reduced toxicity conditioning (RTC) versus MAC prior to allogeneic stem cell transplantation is associated with decreased transplant-related mortality, the effects of RTC versus MAC prior to UCBT on immune reconstitution and risk of graft-versus-host disease (GVHD) are unknown. In 88 consecutive paediatric recipients of UCBT, we assessed immune cell recovery and immunoglobulin reconstitution at days +100, 180 and 365 and analysed risk factors associated with acute and chronic GVHD. Immune cell subset recovery, immunoglobulin reconstitution, and the incidence of opportunistic infections did not differ significantly between MAC versus RTC groups. In a Cox model, MAC versus RTC recipients had significantly higher risk of grade II-IV acute GVHD [Hazard Ratio (HR) 6·1, P = 0·002] as did recipients of 4/6 vs. 5-6/6 HLA-matched UCBT (HR 3·1, P = 0·03), who also had significantly increased risk of chronic GVHD (HR 18·5, P = 0·04). In multivariate analyses, MAC versus RTC was furthermore associated with significantly increased transplant-related (Odds Ratio 26·8, P = 0·008) and overall mortality (HR = 4·1, P = 0·0001). The use of adoptive cellular immunotherapy to accelerate immune reconstitution and prevent and treat opportunistic infections and malignant relapse following UCBT warrants further investigation.

Reduced-intensity hematopoietic cell transplantation in older patients with AML/MDS: umbilical cord blood is a feasible option for patients without HLA-matched sibling donors

Umbilical cord blood (UCB) has increased access to hematopoietic cell transplantation (HCT) for patients without HLA-matched sibling donors (MSD). We compared outcomes of HCT using MSD (N=38) or UCB (N=60) among older patients (age ≥ 55 years) with AML or myelodysplastic syndromes (MDS). All patients received a reduced intensity regimen consisting of CY, fludarabine and 200 cGy TBI. Median age at HCT was 63 years for MSD and 61 years for UCB recipients. Among UCB recipients, 95% received two UCB units and 88% received 1-2 locus HLA-mismatched units to optimize cell dose. OS at 3-years was 37% for MSD and 31% for UCB recipients (P=0.21). On multivariate analysis, donor source (MSD vs UCB) did not impact risks of OS, leukemia-free survival and relapse or treatment-related mortality. UCB is feasible as an alternative donor source for reduced-intensity conditioning HCT among older patients with AML and MDS who do not have a suitable MSD.

Umbilical cord blood: current status and future directions

Once considered biological waste, umbilical cord blood (UCB) has become an accepted source of haematopoietic stem cells (HSCs). With initial success in the pediatric setting, UCB transplantation continues to gain favor in the adult patient population. Novel approaches to UCB transplantation include use of two units and a variety of graft manipulations. Additional uses for UCB are currently being explored and include applications in regenerative medicine and immunotherapy.

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.

Umbilical cord blood: biology and transplantation

Umbilical cord blood transplantation is becoming an acceptable alternative source of hematopoietic stem cells for patients with malignant diseases. Cord blood differs from bone marrow and peripheral blood progenitors in its immune tolerance and kinetics of engraftment. In this article, we will review the biology of cord blood stem cells and clinical studies of cord blood transplants in pediatric and adult populations. We will also discuss potential uses of cord blood stem cells in regenerative medicine and novel methods for ex vivo expansion of hematopoietic stem cells. As we learn more about cord blood transplants, there is the potential to overcome the limitations of cord blood transplants so that they can become more widely available.

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.

Cord blood transplantation and stem cell regenerative potential

The past 20 years of experience with umbilical cord blood transplantation have demonstrated that cord blood is effective in the treatment of a spectrum of diseases, including hematological malignancies, bone marrow failure, hemoglobinopathies, and inborn errors of metabolism. Cord blood can be obtained with ease and then safely cryopreserved for either public or private use without loss of viability. As compared to other unrelated donor cell sources, cord blood transplantation allows for greater human leukocyte antigen disparity without a corresponding increase in graft-vs.-host disease. Moreover, cord blood has a lower risk of transmitting infections by latent viruses and is less likely to carry somatic mutations than other adult cells. Recently, multiple populations of stem cells with primitive stem cell properties have been identified from cord blood. Meanwhile, there is an increasing interest in applying cord blood mononuclear cells or enriched stem cell populations to regenerative therapies. Accumulating evidence has suggested functional improvements after cord blood transplantation in various animal models for treatments of cardiac infarction, diabetes, neurological diseases, etc. In this review, we will summarize the most recent updates on clinical applications of cord blood transplantation and the promises and limitations of cell-based therapies for tissue repair and regeneration.

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.

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.

Overcoming the barriers to umbilical cord blood transplantation

Umbilical cord blood (UCB) transplantation (UCBT) has seen a marked increase in utilization in recent years, especially in the pediatric population; however, graft failure, delayed engraftment and profound delay in immune reconstitution leads to significant morbidity and mortality in adults. The lack of cells available for post-transplant therapies, such as donor lymphocyte infusions, has also been considered a disadvantage. To overcome the cell-dose barrier, the combination of two UCB units is becoming commonplace in adolescent and adult populations, and is currently being studied in pediatrics as well. In some studies, the use of two UCB units appears to have a positive impact on outcomes; however, engraftment is still suboptimal. A possible additional way to improve outcome and extend applicability of UCBT is via ex vivo expansion. Studies to develop optimal expansion conditions are still in the exploratory phase; however, recent studies suggest expanded UCB is safe and can improve outcomes. The ability to transplant across HLA disparities, rapid procurement time and decreased graft-versus-host disease (GvHD) seen with UCBT makes it a promising stem cell source and, while barriers exist, consistent progress is being made to overcome them.

Unrelated umbilical cord blood transplantation and immune reconstitution

This review highlights the unique features of immune reconstitution following unrelated cord blood transplantation (UCBT) that lead to heightened risk of infection-related mortality in the early post-UCBT period. There is no evidence that innate immunity is uniquely compromised after UCBT, but the development of antigen-specific cellular immunity is affected by numerical and qualitative deficits, primarily within the first 100 days. Nevertheless, beyond the first few months after UCBT there is no evidence for reduced graft-versus-leukemia (GVL) or anti-viral immunity compared to other hematopoietic cell therapy (HCT) modalities. Novel cellular therapies that are about to enter the clinical setting in the form of natural killer (NK) cell and T-cell therapies in the form of donor lymphocyte infusion (DLI) are also discussed.

Cord blood transplantation for haematological malignancies: conditioning regimens, double cord transplant and infectious complications

Growing evidence supports the efficacy of cord blood transplantation (CBT) to treat patients with haematological malignancies, and the number of CBTs is rapidly increasing. Herein, we review considerations regarding conditioning regimens for CBT, the impact of double unit transplantation on CBT outcomes, and data regarding infectious complications following CBT.