Reduced-intensity conditioning compared with conventional allogeneic stem-cell transplantation in relapsed or refractory Hodgkin's lymphoma: an analysis from the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

Microenvironment-related biomarkers and novel targets in classical Hodgkin's lymphoma

Classical Hodgkin's lymphoma accounts for approximately 10% of all malignant lymphomas. Although most patients can be cured with modern treatment strategies, approximately 25% of them experience either primary or secondary chemorefractoriness or disease relapse, thus requiring novel treatments. Increasing preclinical and clinical evidences have demonstrated the role of microenvironment in the molecular pathogenesis of classical Hodgkin's lymphoma and elucidated the complex cross-talk between the malignant Hodgkin Reed–Sternberg cells and the nonmalignant, reactive cells of the microenvironment, strongly supporting novel therapeutic approaches aimed at targeting Hodgkin's Reed–Sternberg cells along with reactive cells in order to overcome chemorefractoriness. In the near future, these novel therapies will also be tested in chemosensitive patients to reduce long-term toxicities of chemo-radiotherapy.

Allogeneic hematopoietic cell transplantation after failed autologous transplant for lymphoma using TLI and anti-thymocyte globulin conditioning

We describe 47 patients with lymphoma and failed prior autologous hematopoietic cell transplantation (HCT) who received TLI-ATG conditioning followed by allogeneic HCT. Thirty-two patients had non-Hodgkin lymphoma (NHL; diffuse large B cell lymphoma [n=19], T-cell NHL [n=6], mantle cell lymphoma [n= 4], or other B-cell subtypes [n=3]), and 15 had Hodgkin lymphoma. The median follow-up was 4.9 (range, 2.1–11.9) years. The cumulative incidence of grade II–IV acute GVHD at day +100 was 12%, and the cumulative incidence of extensive chronic GVHD at 1 year was 36%. The 3-year cumulative incidences of overall survival, progression-free survival (PFS), and non-relapse mortality (NRM) were 81%, 44%, and 7%, respectively. Fifteen patients died (relapse, n=10; NRM, n=5). Among the 25 patients with relapse after allogeneic HCT, 11 (44%) achieved durable (>1 year) complete remissions following donor lymphocyte infusion or chemoradiotherapy. The majority of surviving patients (75%; n=24) were able to discontinue all immunosuppression. For patients with relapsed lymphoma after autologous HCT, allogeneic HCT using TLI-ATG conditioning is a well-tolerated, predominantly outpatient therapy with low NRM (7% at 3 years), a low incidence of GVHD, durable disease control, and excellent overall survival (81% at 3 years).

High Graft CD8 Cell Dose Predicts Improved Survival and Enables Better Donor Selection in Allogeneic Stem-Cell Transplantation With Reduced-Intensity Conditioning

PURPOSE

To characterize the impact of graft T-cell composition on outcomes of reduced-intensity conditioned (RIC) allogeneic hematopoietic stem-cell transplantation (alloHSCT) in adults with hematologic malignancies.

PATIENTS AND METHODS

We evaluated associations between graft T-cell doses and outcomes in 200 patients who underwent RIC alloHSCT with a peripheral blood stem-cell graft. We then studied 21 alloHSCT donors to identify predictors of optimal graft T-cell content.

RESULTS

Higher CD8 cell doses were associated with a lower risk for relapse (adjusted hazard ratio [aHR], 0.43; P = .009) and improved relapse-free survival (aHR, 0.50; P = .006) and overall survival (aHR, 0.57; P = .04) without a significant increase in graft-versus-host disease or nonrelapse mortality. A cutoff level of 0.72 × 10(8) CD8 cells per kilogram optimally segregated patients receiving CD8(hi) and CD8(lo) grafts with differing overall survival (P = .007). Donor age inversely correlated with graft CD8 dose. Consequently, older donors were unlikely to provide a CD8(hi) graft, whereas approximately half of younger donors provided CD8(hi) grafts. Compared with recipients of older sibling donor grafts (consistently containing CD8(lo) doses), survival was significantly better for recipients of younger unrelated donor grafts with CD8(hi) doses (P = .03), but not for recipients of younger unrelated donor CD8(lo) grafts (P = .28). In addition, graft CD8 content could be predicted by measuring the proportion of CD8 cells in a screening blood sample from stem-cell donors.

CONCLUSION

Higher graft CD8 dose, which was restricted to young donors, predicted better survival in patients undergoing RIC alloHSCT.

Indications for allo- and auto-SCT for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2015

This is the sixth special report that the European Society for Blood and Marrow Transplantation regularly publishes on the current practice and indications for haematopoietic SCT for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred in the field of haematopoietic SCT over the last years. Cord blood units as well as haploidentical donors have been increasingly used as stem cell sources for allo-SCT, thus, augmenting the possibility of finding a suitable donor for a patient. Continuous refinement of conditioning strategies has also expanded not only the number of potential indications but also has permitted consideration of older patients or those with co-morbidity for a transplant. There is accumulating evidence of the role of haematopoietic SCT in non-haematological disorders such as autoimmune diseases. On the other hand, the advent of new drugs and very effective targeted therapy has challenged the role of SCT in some instances or at least, modified its position in the treatment armamentarium of a given patient. An updated report with revised tables and operating definitions is presented.

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.

Second allo-SCT in patients with lymphoma relapse after a first allogeneic transplantation. A retrospective study of the EBMT Lymphoma Working Party

The aim of this registry-based retrospective study was to analyze the outcome of second allogeneic hematopoietic SCT (alloHSCT_2) performed in patients with lymphoma who had relapsed after a first allogeneic transplant (alloHSCT_1). Patients ⩾18 years who had received an alloHSCT_2 for lymphoma relapse between 2000 and 2011 were eligible. One hundred and forty patients were identified. The diagnosis was Hodgkin lymphoma (HL) in 31%, diffuse large B-cell lymphoma in 14%, T-cell lymphoma in 12%, indolent lymphoma in 19%, mantle cell lymphoma in 16% and other lymphomas in 8% of the patients. The median interval from alloHSCT_1 to alloHSCT_2 was 19 (range 4-116) months. Disease status at alloHSCT_2 was chemosensitive in 46%, refractory in 43% and unknown in 11% of the patients. Three-year PFS, OS, relapse incidence and nonrelapse mortality were 19%, 29%, 58% and 23%, respectively. PFS and OS were significantly affected by refractory disease at alloHSCT_2 and a short interval between alloHSCT_1 and alloHSCT_2. Long-term PFS was observed across all lymphoma subsets except for aggressive B-cell lymphoma. In conclusion, alloHSCT_2 is feasible and can result in long-term disease control in patients with lymphoma recurrence after alloHSCT_1, in particular if relapse occurs late and is chemosensitive.

Current role of autologous and allogeneic stem cell transplantation for relapsed and refractory hodgkin lymphoma

Classical Hodgkin lymphoma (cHL) is a relatively rare disease, with approximately 9,200 estimated new cases and 1,200 estimated deaths per year in the United States. First-line chemo-radiotherapy leads to cure rates approaching 80% in patients with advanced-stage disease. However, 25 to 30% of these patients are not cured with chemotherapy alone (i.e., the ABVD regimen) and show either primary refractoriness to chemotherapy, early disease relapse or late disease relapse. Second-line salvage high-dose chemotherapy (HDC) and autologous stem cell transplantation (SCT) have an established role in the management of refractory/relapsed cHL, leading to durable responses in approximately 50% of relapsed patients and a minority of refractory patients. However, due to the poor responses to second-line salvage chemotherapy and dismal long-term disease control of primary refractory and early relapsed patients, their treatment represents an unmet medical need. Allogeneic SCT represents, by far, the only strategy with a curative potential for these patients; however, as discussed in this review, it’s role in cHL remains controversial. Despite a general consensus that early relapsed and primary refractory patients represent a clinical challenge requiring effective treatments to achieve long-term disease control, there has been no consensus on the optimal therapy that should be offered to these patients. This review will briefly discuss the clinical results and the main issues regarding autologous SCT as well as the current role of allogeneic SCT.

Brentuximab vedotin in patients with Hodgkin lymphoma and a failed allogeneic stem cell transplantation: results from a named patient program at four Italian centers

BACKGROUND

Brentuximab vedotin (BV) has demonstrated an extraordinary efficacy in heavily pretreated classical Hodgkin lymphoma (cHL) patients, targeting CD30-positive cells; however, limited data have been reported on the efficacy of BV in cHL patients failing allogeneic stem cell transplantation (allo-SCT). The aim of this study was to retrospectively evaluate the efficacy and safety of BV in a multicenter setting of cHL relapsing or progressing after allo-SCT.

METHODS

Sixteen BV-naïve patients with recurrent cHL after allo-SCT were included in a compassionate use program and treated with intravenous BV at the dose of 1.8 mg/kg of body weight every 3 weeks for a maximum of 16 cycles.

RESULTS

The objective response rate was 69%. Five patients (31%) had complete remission, and 6 (37%) had partial remission. Stable disease was observed in 4 patients (25%), and progressive disease was observed in 1 (6%). After median follow-up of 26 months (range: 5-30 months), median progression-free survival (PFS), overall survival (OS), and duration of response were 7, 25, and 5 months, respectively. The 2-year PFS and OS were 20% and 61%, respectively. Grade 3-4 hematological adverse events included anemia (15%), thrombocytopenia (12%), and neutropenia (18%). Grade 3 peripheral sensory neuropathy occurred in 2 patients (12%).

CONCLUSION

BV therapy is an effective and safe approach for achieving transient disease control in cHL patients with failed allo-SCT. To improve disease control, future studies should explore the combination of BV with targeted agents.

The role of hematopoietic stem cell transplantation for relapsed and refractory Hodgkin lymphoma

The optimal treatment strategy with the use of hematopoietic stem cell transplantation (HSCT) for relapsed and refractory Hodgkin lymphoma (HL) remains unclear. We performed a retrospective analysis using registry data from the Japanese Society for Hematopoietic Cell Transplantation. Adult patients with HL who underwent a first autologous or a first allogeneic HSCT between 2002 and 2009 were included. Patients who underwent HSCT in first complete remission (CR) were excluded. Autologous and allogeneic HSCT were performed in 298 and 122 patients, respectively. For autologous HSCT, overall survival at 3 years (3yOS) was 70%, and sex, age, disease status, and performance status (PS) at HSCT were prognostic factors. OS was favorable even in patients who underwent autologous HSCT in disease status other than CR. For allogeneic HSCT, 3yOS was 43%, and sex and PS at HSCT were prognostic factors. Disease status at HSCT, previous autologous HSCT, and conditioning intensity did not affect OS. Moreover, graft-versus-host disease did not affect progression-free survival or relapse/progression rate. A first allogeneic HSCT without a previous autologous HSCT was performed in 40 patients. 3yOS was 45%, and was significantly inferior to that in patients who underwent their first autologous HSCT. This result was retained after the correction by the different patient characteristics according to the type of HSCT. In conclusion, autologous HSCT is effective in prolonging survival in patients with relapsed and refractory HL. Allogeneic HSCT might be beneficial even to relapsed HL after autologous HSCT, although establishing the role of allogeneic HSCT remains a challenge.

The role of allogeneic stem cell transplantation in Hodgkin's lymphoma

OPINION STATEMENT

The treatment of patients with classical Hodgkin's lymphoma relapsing after autologous stem cell transplantation represents a clear unmet need. Overall long-term outcome is not the same in these patients and therapeutic options in this setting are very heterogeneous and include salvage CT and/or RT followed or not by a second stem cell transplantation, palliative care, new drugs, or biological agents. Despite the absence of prospective, randomized, clinical trials, allogeneic stem cell transplantation either from a HLA identical sibling or a matched, unrelated donor represents an attractive option for those young patients with chemosensitive disease after being treated with a salvage protocol. The use of reduced intensity conditioning regimens has been able to drastically decrease nonrelapse mortality, although relapse rate remains a significant issue in this setting. More intense conditioning protocols could eventually decrease the relapse rate after the allogeneic procedure and, as indicated by a recent retrospective analysis of the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation, nonrelapse mortality does not represent a major problem nowadays for patients with multiply relapsed Hodgkin's lymphoma. Brentuximab vedotin is an antibody-drug conjugate that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. Its use has been approved recently for patients with Hodgkin's lymphoma relapsing after autologous stem cell transplantation. As a single dose, brentuximab vedotin is able to achieve an objective response rate of 75 % with 34 % of the patients achieving a complete remission. Its widespread use will most certainly change the treatment paradigm of this subgroup of patients, either avoiding the allogeneic procedure in some patients or by increasing the group of potential candidates to an allogeneic transplant being used as a "bridge to allo." Additional information on long-term outcome of patients being treated with this drug or the development of prospective clinical trials in this setting will most probably give some light to this question we have nowadays.

Allogeneic transplant following brentuximab vedotin in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma

Brentuximab vedotin is an antibody drug conjugate that induces durable objective responses in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma. Fifteen of 160 patients who participated in two pivotal phase 2 studies received a consolidative allogeneic stem cell transplant (allo-SCT) following brentuximab vedotin treatment. This case series describes their experience. The studies were approved by Institutional Review Boards prior to patient enrollment. Patients received 1.8 mg/kg brentuximab vedotin every 3 weeks for up to 16 cycles. The estimated 2-year progression-free survival (PFS) rate was 66%, and the median PFS has not yet been reached. Eleven of the 15 patients were alive and the estimated 2-year survival rate was 80%. The safety of brentuximab vedotin treatment in this series was consistent with the known safety profile in this setting. Brentuximab vedotin is a compelling option for reducing tumor burden to facilitate a consolidative allo-SCT.

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.

Durable remissions in a pivotal phase 2 study of brentuximab vedotin in relapsed or refractory Hodgkin lymphoma

We present response and survival outcomes of a pivotal phase 2 trial of the antibody-drug conjugate brentuximab vedotin in patients with relapsed/refractory Hodgkin lymphoma following autologous stem cell transplant (N = 102) after a median observation period of approximately 3 years. Median overall survival and progression-free survival were estimated at 40.5 months and 9.3 months, respectively. Improved outcomes were observed in patients who achieved a complete remission (CR) on brentuximab vedotin, with estimated 3-year overall survival and progression-free survival rates of 73% (95% confidence interval [CI]: 57%, 88%) and 58% (95% CI: 41%, 76%), respectively, in this group (medians not reached). Of the 34 patients who obtained CR, 16 (47%) remain progression-free after a median of 53.3 months (range, 29.0 to 56.2 months) of observation; 12 patients remain progression-free without a consolidative allogeneic stem cell transplant. Younger age, good performance status, and lower disease burden at baseline were characteristic of patients who achieved a CR and were favorable prognostic factors for overall survival. These results suggest that a significant proportion of patients who respond to brentuximab vedotin can achieve prolonged disease control. The trial was registered at www.clinicaltrials.gov as #NCT00848926.

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.

Brentuximab vedotin is associated with improved progression-free survival after allogeneic transplantation for Hodgkin lymphoma

We previously reported that brentuximab vedotin (BV) enabled successful reduced-intensity allogeneic hematopoietic cell transplantation (RIC-alloHCT) in patients with relapsed Hodgkin lymphoma, after a median follow-up of 14.4 months. We now provide an updated report on 21 patients who were treated from 2009 to 2012 with BV before RIC-alloHCT with a uniform fludarabine/melphalan conditioning regimen and donor source after a median follow-up of 29.9 months. We have also retrospectively compared the patient characteristics and outcomes of these BV-pretreated patients to 23 patients who received fludarabine/melphalan RIC-alloHCT without prior BV, in the time period before the drug was available (2003 to 2009). Patients who were treated with BV before RIC-alloHCT had a lower median hematopoietic cell transplantation-specific comorbidity index and a reduced number of peri-transplantation toxicities. There were also improvements in 2-year progression-free survival (59.3% versus 26.1%) and cumulative incidence of relapse/progression (23.8% versus 56.5%).

Reduced-toxicity conditioning with fludarabine, once-daily intravenous busulfan, and antithymocyte globulins prior to allogeneic stem cell transplantation: results of a multicenter prospective phase 2 trial

BACKGROUND

The optimal intensity of myeloablation delivered as part of a reduced-intensity/toxicity conditioning (RIC/RTC) regimen to decrease the recurrence rate, without increasing nonrecurrence mortality (NRM), remains to be established.

METHODS

The current phase 2, prospective, multicenter trial aimed to assess the efficacy and safety of an RIC/RTC regimen based on busulfan at a dose of 130 mg/m(2) /day intravenously for 3 days, fludarabine at a dose of 30 mg/m(2) /day for 5 days, and antithymocyte globulins at a dose of 2.5 mg/kg/day for 2 days. A total of 80 patients (median age, 53 years; range, 25-64 years) with hematological malignancies were included.

RESULTS

With a median follow-up of 21 months (range, 12-36.5 months), the Kaplan-Meier estimates of overall and disease-free survival at 2 years were 62% (95% confidence interval [95% CI], 51%-73%) and 50% (95% CI, 33%-57%), respectively. The cumulative incidences of grade 2 to 4 acute graft-versus-host disease (GVHD) and chronic GVHD (all grades) were 29% (95% CI, 19%-39%) and 35% (95% CI, 24%-46%), respectively. At 2 years, the cumulative incidence of recurrence/disease progression and NRM were 44% (95% CI, 31%-56%) and 11% (95% CI, 6%-19%), respectively. Patient age, diagnosis, donor type, sex, presence of comorbidities, and the Hematopoietic cell transplantation-specific comorbidities index did not appear to have any statistically significant impact on NRM, recurrence/disease progression, disease-free survival, or overall survival.

CONCLUSIONS

The RIC/RTC regimen used in the current study appeared to be safe, with a low NRM rate at 2 years noted among high-risk patients, and efficient disease control, warranting prospective phase 3 trials.

Stem cell transplantation in Hodgkin lymphoma

Patients with Hodgkin lymphoma (HL) who relapse following effective front-line therapy are offered salvage second-line chemotherapy regimens followed by high-dose therapy and autologous stem cell transplantation (HDT/ASCT). Randomized studies comparing HDT/ASCT with conventional chemotherapy in patients with relapsed refractory HL have shown significant improvement in progression-free survival and freedom from treatment failure but were not powered to show improvements in overall survival. For patients who relapse after salvage HDT/ASCT, novel therapies exist as a bridge to allogeneic SCT. In this article, we review indications and results of autologous and allogeneic SCT in HL.

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.

Donor lymphocyte infusion is an effective therapy for relapsed Hodgkin lymphoma after reduced-intensity allogeneic hematopoietic stem cell transplantation

A 3-year-old boy with Hodgkin lymphoma relapsed only 2 months after completion of first-line therapy. He received reduced-intensity conditioning and allogeneic hematopoietic stem cell transplantation (RIC allo-HSCT), but relapsed again. To treat the second relapse, donor lymphocyte infusions were performed four times. He showed no evidence of disease and his quality of life was maintained for 500 days after stem cell transplant. However, his condition worsened and he died 3 years and 3 months after onset. In high-risk patients fully intolerant to myeloablative regimens, RIC allo-HSCT followed by subsequent donor lymphocyte infusions must be considered an effective therapeutic approach.

Cardiopulmonary exercise testing prior to myeloablative allo-SCT: a feasibility study

The feasibility of symptom-limited cardiopulmonary exercise testing (CPET) prior to allo-SCT was assessed in addition to the prognostic value of CPET-derived measures. CPET was performed prospectively on 21 patients with hematologic malignancies, with assessments of peak (for example, peak oxygen consumption, VO2peak) and submaximal (for example, ventilatory threshold (VT)) measures of cardiopulmonary function. No serious adverse events were observed during CPET procedures, with 95% of patients achieving criteria for a peak test. Mean VO2peak was 24.7±6.4 mL kg(-1 )min(-1) (range: 10.9-35.5), equivalent to 29%±17% below that of age-matched healthy controls. All patients proceeded with the conditioning regimen followed by allo-SCT. Median follow-up was 25 months. During this period, 11 (52.4%) patients died (n=6, relapsed disease; n=5, non-relapse mortality (NRM)); 9 patients (43%) developed pulmonary toxicity. In univariate analyses, both peak and submaximal markers of cardiopulmonary function were predictors of OS, pulmonary toxicity and NRM. For OS, the HR for VO2peak and VT were 0.89 (95% CI, 0.8-0.99, P=0.04) and 0.84 (95% CI, 0.71-0.98, P=0.03), respectively. In conclusion, CPET is safe and feasible prior to allo-SCT. Patients have marked impairments in cardiopulmonary function prior to allo-SCT. CPET-derived metrics may complement conventional measures to improve risk stratification.

Classical Hodgkin's lymphoma: the Lymphoma Study Association guidelines for relapsed and refractory adult patients eligible for transplant

The Hodgkin's Lymphoma Committee of the Lymphoma Study Association (LYSA) gathered in 2012 to prepare guidelines on the management of transplant-eligible patients with relapsing or refractory Hodgkin's lymphoma. The working group is made up of a multidisciplinary panel of experts with a significant background in Hodgkin's lymphoma. Each member of the panel of experts provided an interpretation of the evidence and a systematic approach to obtain consensus was used. Grades of recommendation were not required since levels of evidence are mainly based on phase II trials or standard practice. Data arising from randomized trials are emphasized. The final version was endorsed by the scientific council of the LYSA. The expert panel recommends a risk-adapted strategy (conventional treatment, or single/double transplantation and/or radiotherapy) based on three risk factors at progression (primary refractory disease, remission duration < 1 year, stage III/IV), and an early evaluation of salvage chemosensitivity, including (18)fluorodeoxy glucose-positron emission tomography interpreted according to the Deauville scoring system. Most relapsed or refractory Hodgkin's lymphoma patients chemosensitive to salvage should receive high-dose therapy and autologous stem-cell transplantation as standard. Efforts should be made to increase the proportion of chemosensitive patients by alternating non-cross-resistant chemotherapy lines or exploring the role of novel drugs.

Early donor chimerism levels predict relapse and survival after allogeneic stem cell transplantation with reduced-intensity conditioning

The success of hematopoietic stem cell transplantation (HSCT) with reduced-intensity conditioning (RIC) is limited by a high rate of disease relapse. Early risk assessment could potentially improve outcomes by identifying appropriate patients for preemptive strategies that may ameliorate this high risk. Using a series of landmark analyses, we investigated the predictive value of early (day-30) donor chimerism measurements on disease relapse, graft-versus-host disease, and survival in a cohort of 121 patients allografted with a uniform RIC regimen. Chimerism levels were analyzed as continuous variables. In multivariate analysis, day-30 whole blood chimerism levels were significantly associated with relapse (hazard ratio [HR] = .90, P < .001), relapse-free survival (HR = .89, P < .001), and overall survival (HR = .94, P = .01). Day-30 T cell chimerism levels were also significantly associated with relapse (HR = .97, P = .002), relapse-free survival (HR = .97, P < .001), and overall survival (HR = .99, P = .05). Multivariate models that included T cell chimerism provided a better prediction for these outcomes compared with whole blood chimerism. Day-30 chimerism levels were not associated with acute or chronic graft-versus-host disease. We found that high donor chimerism levels were significantly associated with a low lymphocyte count in the recipient before transplant, highlighting the impact of pretransplant lymphopenia on the kinetics of engraftment after RIC HSCT. In summary, low donor chimerism levels are associated with relapse and mortality and can potentially be used as an early predictive and prognostic marker. These findings can be used to design novel approaches to prevent relapse and to improve survival after RIC HSCT.

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.

[News in hodgkin lymphoma therapy]

Hodgkin lymphoma is a well-known clinico-pathological entity with a stable incidence among time accounting for 1200 new cases each year in France. The disease is one of the most curable cancer and occurs often in young patients with a median age at 33 years, the major clinical symptoms are lymph nodes mostly above the diaphragm (mediastinal and supra-clavicular). The diagnosis should be suggested with non-specific symptoms such as fever, night sweats, pruritus, weight-loss, lymph node, cough.. leading to prescribe routine exams like blood test with leucocyte count, erythrocyte sedimentation rate and chest Xray. Treatments always include chemotherapy and radiotherapy in localized disease and at a low dose only in involved fields. The usually good prognostic of Hodgkin lymphoma may not let us forget that there are still deaths in patients with refractory or early relapse of the disease. There is still an unmet need is these patients and the search for new drugs is essential.

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.

Twin pregnancy and childbirth after reduced-intensity conditioning allogeneic haematopoietic stem cell transplantation combined with imatinib mesylate for chronic myeloid leukaemia: case report and literature review

The successful outcome of a pregnancy in a woman who had received reduced-intensity conditioning (RIC) allogeneic haematopoietic stem cell transplantation (allo-HSCT) for chronic myeloid leukaemia is reported; publications on recovery of ovarian function and pregnancy following myeloablative conditioning (MAC) or RIC allo-HSCT for haematological disorders are reviewed. Research suggests that RIC allo-HSCT may facilitate ovarian recovery. Indeed, in the case study presented, the patient had a successful twin pregnancy and delivery, subsequent to treatment. After a 5-year follow-up, the patient survives disease-free with a sustained molecular response; her children are both healthy, with no physical defects. These findings suggest that RIC allo-HSCT combined with short-term imatinib mesylate does not necessarily have profound effects on female fertility.

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.

Reduced-intensity conditioning followed by allogeneic transplantation in pediatric malignancies: a report from the Société Française des Cancers de l'Enfant and the Société Française de Greffe de Moelle et de Thérapie Cellulaire

We report French prospective experience with reduced-intensity conditioning-allo-SCT in 46 patients (median age: 15.5 years, 4.8-20.2) presenting high-risk AL (n=11), Hodgkin's lymphoma (n=15) or solid tumors (n=20). Graft sources were BM (n=21), PBSC (n=20) and cord blood (CB; n=5) from related (n=20) or unrelated (n=26) donors. For CB grafts, only one patient out of five achieved sustained engraftment. For PBSC/BM grafts, engraftment rate was 95%, hematopoietic recovery times were not significantly different between BM, PBSC, sibling or unrelated grafts, day+100. Full donor chimerism was achieved in 94% of patients, and incidences of primary acute GVHD and chronic GVHD were 49% and 14%, respectively. Underlying disease was fatal in 39% of patients. TRM was 6.9%. Three-year OS was 49.15%. OS and EFS were not significantly different between patients transplanted with different grafts and with or without primary GVHD. Patients with solid tumor or measurable disease at transplant had poorer outcomes. Three-year EFS: 33.3% for ALL, 75.0% for AML, 51.8% for Hodgkin's lymphoma, 28.6% for neuroblastoma and 22.2% for sarcoma patients. This multicentre study concluded that Bu/fludarabine/anti-thymocyte globulin conditioning with PB or BM, related or unrelated grafts in patients with various malignancies at high-risk for transplantation toxicity results in high engraftment rates, low TRM and acceptable survival.

Identification of prognostic factors predicting outcome in Hodgkin's lymphoma patients relapsing after autologous stem cell transplantation

BACKGROUND

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard of care for patients with relapsed Hodgkin's lymphoma (HL). However, there is currently little information on the predictors of outcome for patients whose disease recurs after ASCT.

METHODS

Five hundred and eleven adult patients with relapsed HL after ASCT from EBMT-GITMO databases were reviewed.

RESULTS

Treatments administered following ASCT failure included conventional chemotherapy and/or radiotherapy in 294 (64%) patients, second ASCT in 35 (8%), and alloSCT in 133 (29%). After a median follow-up of 49 months, overall survival (OS) was 32% at 5 years. Independent risk factors for OS were early relapse (<6 months) after ASCT, stage IV, bulky disease, poor performance status (PS), and age ≥50 years at relapse. For patients with no risk factors OS at 5 years was 62% compared with 37% and 12% for those having 1 and ≥2 factors, respectively. This score was also predictive for outcome in each group of rescue treatment after ASCT failure.

CONCLUSION(S)

Early relapse, stage IV, bulky disease, poor PS, and age ≥50 years at ASCT failure are relevant factors for outcome that may help to understand the results of different therapeutic approaches.

Reduced-intensity conditioning allogeneic stem cell transplantation in malignant lymphoma: current status

Allogeneic stem cell transplantation (allo-SCT) is a potential cure for patients with malignant lymphoma that is based on the graft-versus-lymphoma (GVL) effect. Myeloablative conditioning allo-SCT is associated with high mortality and morbidity, particularly in patients older than 45 years, heavily pretreated patients (prior hematopoietic stem cell transplantation or more than two lines of conventional chemotherapy) or patients affected by other comorbidities. Therefore, conventional allo-SCT is restricted to younger patients (<50 to 55 years) in good physical condition. Over the last decade, allo-SCT with reduced-intensity conditioning (RIC-allo-SCT) has been increasingly used to treat patients with lymphoma. This treatment is associated with lower toxicity and substantial decrease in the incidence of transplant-related mortality, and has the potential to lead to long-term remissions. Therefore, patients who are not suitable to undergo conventional allo-SCT can benefit from the potentially curative GVL effects of allo-SCT. Although RIC-allo-SCT has improved the survival of lymphoma patients, high post-transplant relapse rates or disease progression mainly results in treatment failure. Thus, further improvement is clearly needed. The role and timing of RIC-allo-SCT in the treatment of lymphoma remains unclear. Therefore, more prospective studies should clarify the effectiveness of this method. In this article, we review the recent literature on RIC-allo-SCT as a treatment for major lymphoma subtypes. Areas that require further investigation in the context of clinical trials are also highlighted.

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.

Indications and outcomes of reduced-toxicity hematopoietic stem cell transplantation in adult patients with hematological malignancies

Hematopoietic stem cell transplantation (HCT) utilizing non-myeloablative (NMA) and reduced-intensity conditioning (RIC) regimens (collectively referred to as reduced-toxicity HCT, RT-HCT) has become a viable therapeutic option for patients with hematological malignancies who are ineligible for standard myeloablative conditioning transplantation (MA-HCT). RT-HCT has been shown to induce stable engraftment with low toxicity, and to produce similar overall and progression-free survival (PFS) when compared to MA-HCT in acute myeloid leukemia and myelodysplastic syndrome. The best results for RT-HCT have been reported for patients with disease that is in remission, indolent and chemosensitive, and with a strong graft-versus-malignancy effect. Chronic graft-versus-host disease seems to correlate with a lower relapse rate and better PFS. RT-HCT is inferior when performed in poor risk or advanced disease, due to high relapse rates. A search for novel strategies that includes the most appropriate conditioning regimens and post-transplant immunomodulation protocols with more intensive anti-malignancy activity but limited toxicity is in progress. This review provides an update on the results of clinical studies of RT-HCT, and discusses possible indications and investigative strategies for improving the clinical outcomes of RT-HCT for the major hematological malignancies.

The role of hematopoietic stem cell transplantation in the treatment of relapsed/refractory Hodgkin's lymphoma

PURPOSE OF REVIEW

Autologous stem cell transplantation (ASCT) represents the treatment of choice for primary refractory or relapsed Hodgkin's lymphoma patients. Nevertheless, the results of ASCT are not universally uniform in all groups of patients. Allogeneic stem cell transplantation (allo-SCT) has increasingly been used to rescue failures after an ASCT. Its use is going to be potentially challenged by the advent of targeted therapy.

RECENT FINDINGS

Comprehensive information regarding prognostic factors in the ASCT setting that can allow to discriminate specific groups potentially candidates for other therapies is presented as well as an updated summary of the potential role of reduced intensity allo-SCT in relapsed patients including the largest phase II prospective clinical trial. Outcome of multiply relapsed Hodgkin's lymphoma patients treated with single-dose brentuximab vedotin, a new anti-CD30 monoclonal antibody, is discussed.

SUMMARY

ASCT results might well be implemented by improving the quality of the remission of patients undergoing the procedure with more effective salvage protocols or by selecting those patients who might better benefit from the procedure. Results of allo-SCT as well as the percentage of patients potentially candidates for the procedure will also be able to be modified with a better selection of the patients and the use of targeted and less toxic therapy to render patients into an adequate response.

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.

Hodgkin lymphoma: highlights from the 2012 European School of Hematology International Conference

The ESH International Conference on Lymphomas gathered clinicians and scientists involved in all aspects of clinical treatment and biology of lymphomas. The 2012 International Conference was held in Marseille, France, and presented an appealing program. Of particular interest was the session dedicated to Hodgkin lymphoma. Our knowledge on the pathology of Hodgkin lymphoma and on the new therapeutic possibilities has changed greatly during the last three decades. During the session, the speakers focused on the results of conventional chemotherapy and on the new drugs for resistant/relapsed patients.

Autologous hematopoietic stem cell transplantation in classical Hodgkin's lymphoma

Background

Hodgkin's lymphoma has high rates of cure, but in 15% to 20% of general patients and between 35% and 40% of those in advanced stages, the disease will progress or will relapse after initial treatment. For this group, hematopoietic stem cell transplantation is considered one option of salvage therapy.

Objectives

To evaluate a group of 106 patients with Hodgkin's lymphoma, who suffered relapse or who were refractory to treatment, submitted to autologous hematopoietic stem cell transplantation in a single transplant center.

Methods

A retrospective study was performed with data collected from patient charts. The analysis involved 106 classical Hodgkin's lymphoma patients who were consecutively submitted to high-dose chemotherapy followed by autologous transplants in a single institution from April 1993 to December 2006.

Results

The overall survival rates of this population at five and ten years were 86% and 70%, respectively. The disease-free survival was approximately 60% at five years. Four patients died of procedure-related causes but relapse of classical Hodgkin's lymphoma after transplant was the most frequent cause of death. Univariate analysis shows that sensitivity to pre-transplant treatment and hemoglobin < 10 g/dL at diagnosis had an impact on patient survival. Unlike other studies, B-type symptoms did not seem to affect overall survival. Lactic dehydrogenase and serum albumin concentrations analyzed at diagnosis did not influence patient survival either.

Conclusion

Autologous hematopoietic stem cell transplantation is an effective treatment strategy for early and late relapse in classical Hodgkin's lymphoma for cases that were responsive to pre-transplant chemotherapy. Refractory to treatment is a sign of worse prognosis. Additionally, a hemoglobin concentration below 10 g/dL at diagnosis of Hodgkin's lymphoma has a negative impact on the survival of patients after transplant. As far as we know this relationship has not been previously reported.

Reduced-intensity hematopoietic stem cell transplants for malignancies: harnessing the graft-versus-tumor effect

Allogeneic hematopoietic cell transplantation combines the power of cytotoxic chemo/radiotherapy with the ability of the new immune system to seek out and destroy tumor cells. However, administration of such myeloablative transplants is fraught with risks, some of which are related to the intensive conditioning regimens. Reductions in the intensity of the administered cytotoxic therapy have demonstrated that under some circumstances, the burden of fighting tumor and enhancing stem cell engraftment can be shouldered mostly by the transplanted immune system. Reduced intensity has allowed a potentially curative therapy for hematologic malignancies to be offered to an expanded patient population. Ongoing research seeks to enhance the safety and power of this form of allogeneic immunotherapy.

Two days of antithymocyte globulin are associated with a reduced incidence of acute and chronic graft-versus-host disease in reduced-intensity conditioning transplantation for hematologic diseases

BACKGROUND

The optimal combination of fludarabine, busulfan, and antithymocyte globulin (ATG) for reduced-intensity conditioning (RIC) transplantation has not been established. ATG plays a pivotal role in the prevention of graft-versus-host disease (GvHD), but it is associated with a higher relapse rate and an elevated incidence of infections when high doses are used.

METHODS

The authors retrospectively compared 2 different doses of ATG combined with fludarabine and busulfan in 229 adult patients who underwent transplantation at their institution. ATG was administered over 1 day (FBA1) or over 2 days (FBA2) at a daily dose of 2.5 mg/kg.

RESULTS

There were 124 patients in the FBA2 cohort and 105 patients in the FBA2 cohorts. Patients in the FBA2 cohort were older and more frequently underwent transplantation from an unrelated donor; 93% of patients in the FBA2 cohort received intravenous busulfan versus only 5% in the FBA1 cohort. The incidence of grade 2 through 4 acute GvHD was 23% in the FBA2 cohort versus 42% in the FBA1 cohort (P = .002); the incidence of grade 3 through 4 acute GvHD was 10% versus 23%, respectively (P = .006); and the incidence of chronic GvHD was 35% versus 69%, respectively (P < .0001). The 2-year rates of overall survival, nonrelapse mortality, and relapse/progression for the FBA1 and FBA2 cohorts were 65% versus 67%, respectively (P = .99), 20% versus 19%, respectively (P = .61), and 30% versus 19%, respectively (P = .09). The results were confirmed in multivariate analysis.

CONCLUSIONS

The use of ATG at a dose of 5 mg/kg was correlated significantly with reduced incidence and severity of GvHD without impairing disease control. Taken together, the current results suggest that this conditioning represents a step forward in the optimization of RIC.