Permanent Impairment-Free, Relapse-Free Survival: A Novel Composite Endpoint to Evaluate Long-Term Success in Allogeneic Transplantation.

Permanent impairment (PI) of vital organs is one of the transplantation-related health problems affecting the quality of life and morbidity even in patients who do not develop graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HCT), but no data are available on PI of multiple organs. This retrospective study aimed to estimate a novel composite endpoint of PI-free, relapse-free survival (PIRFS) in 164 allo-HCT recipients. We defined PI as >26% to 30% impairment of the whole person in 6 vital organs using the whole person impairment rating. Conventional GVHD-free/relapse-free survival (GRFS) and PIRFS at 5 years were 33.8% (95% confidence interval [CI], 26.5% to 41.3%) and 40.6% (95% CI, 32.6% to 48.4%), respectively. In the whole cohort, PIRFS was higher than GRFS at any time after allo-HCT. However, PIRFS was lower than GRFS after day 397 post-transplantation in patients who underwent umbilical cord blood transplantation (UCBT). In UCBT recipients, 5-year GRFS and PIRFS were 47.6% (95% CI, 34.3% to 59.7%) and 39.2% (95% CI, 26.6% to 51.5%), respectively. The cumulative incidence of PI after 5 years was 20.9% (95% CI, 13.7% to 29.0%) in patients surviving for ≥6 months without relapse. The multivariate analysis revealed that high disease risk (hazard ratio [HR], 1.91; 95% CI, 1.26 to 2.88; P < .01) and Karnofsky Performance Status score ≤90% at transplantation (HR, 1.73; 95% CI, 1.14 to 2.63; P = .01) were correlated with the lower PIRFS, whereas UCBT (HR, 2.35; 95% CI, 1.11 to 4.99; P = .03), grade III-IV acute GVHD by day 180 (HR, 3.59; 95% CI, 1.04 to 12.4; P = .04), and thrombotic microangiopathy by day 180 (HR, 2.74; 95% CI, 1.10 to 6.87; P = .03) were significantly correlated with a higher incidence of PI. More than 20% of long-term survivors had PI. Our data suggest that PIRFS is a useful endpoint for assessing long-term transplantation success from a different perspective than has been established previously.

High Graft-versus-Host Disease-Free, Relapse/Rejection-Free Survival and Similar Outcome of Related and Unrelated Allogeneic Stem Cell Transplantation for Aplastic Anemia: A Nationwide Swedish Cohort Study.

Allogeneic stem cell transplantation (SCT) as primary treatment for aplastic anemia (AA) is being increasingly used. Yet, age, stem cell source, and donor type are important outcome factors. We have recently performed a nationwide cohort study of all patients with AA in Sweden diagnosed from 2000 to 2011 and now present outcome data on SCT patients. In total, 68 patients underwent SCT, and 63% of them had failed immunosuppressive therapy. We found that, with a median follow-up of 109 months (range, 35 to 192 months), 5-year overall survival (OS) for all patients was 86.8%, whereas graft-versus-host disease-free, relapse/rejection-free survival (GRFS) at 5 years was 69.1%. There was no survival impact regarding the donor type or stem cell source. Patients aged ≥40 years had a higher transplant-related mortality (29.4% versus 7.8%; P = .023), which translated into a lower 5-year OS: 70.6% versus 92.2% (P = .022) and a trend of lower GRFS (52.9% versus 74.5%; P = .069). In conclusion, we found in this real-world setting that both OS and GRFS were high, but SCT for patients with AA aged ≥40 years is problematic, and clinical trials addressing this issue are warranted.

Allogeneic Stem Cell Transplantation for Relapsed/Refractory B Cell Lymphomas: Results of a Multicenter Phase II Prospective Trial including Rituximab in the Reduced-Intensity Conditioning Regimen.

The treatment of patients with refractory/relapsed B cell non-Hodgkin lymphoma (NHL) is evolving because of the availability of novel drugs. Allogeneic stem cell transplantation (alloSCT) can be curative, but its morbidity and mortality remain a matter of concern. We conducted a multicenter prospective phase II trial to evaluate the benefit of including only 1 dose of rituximab in the conditioning regimen before alloSCT. The primary endpoint was progression-free survival. The study enrolled 121 patients with relapsed/refractory B cell lymphomas. The conditioning regimen consisted of thiotepa, cyclophosphamide, fludarabine, and rituximab (500 mg/m2). Rabbit antithymocyte globulin was administered only in case of unrelated donors. Sixty-seven (55%) and 54 (45%) patients received grafts from related and unrelated donors, respectively. The crude cumulative incidence (CCI) of nonrelapse mortality (NRM) was 21% at 3 years. The CCIs of chronic graft-verus-host disease (GVHD) at 3 years were 54% and 31% in recipients of matched sibling and unrelated grafts, respectively. At a median follow-up of 41 months, the estimated 3-year progression-free and overall survival were 50% and 61%, respectively. Long-term outcome was also evaluated with the composite endpoint of GVHD-free and relapse-free survival (GRFS). This is the first work evaluating the GRFS in a prospective trial of lymphoma patients: the 1-year and 3-year GRFS were 40% and 34%, respectively. AlloSCT can cure a fraction of patients with rather low NRM and an encouraging PFS and GRFS.

Beneficial Role of Low-Dose Antithymocyte Globulin in Unrelated Stem Cell Transplantation for Adult Patients with Acquired Severe Aplastic Anemia: Reduction of Graft-versus-Host Disease and Improvement of Graft-versus-Host Disease-Free, Failure-Free Survival Rate.

Stem cell transplantation (SCT) from an unrelated donor (URD) is often considered in patients with severe aplastic anemia (SAA) whom immunosuppressive therapy failed and matched sibling donor is not available. To reduce the incidence of graft-versus-host disease (GVHD) in URD SCT, introducting antithymocyte globulin (ATG) into the conditioning regimen has been proposed. Although ATG was shown to play a role in reducing GVHD in a cohort with diverse hematologic diseases, its role in SAA remains uncertain. The aim of this study was to determine the efficacy and toxicity of ATG in URD SCT for adult patients with SAA. We investigated 83 adult patients with SAA who underwent URD SCT between 2003 and 2014. The transplantation strategy consisted of total body irradiation (total 800 cGy) and cyclophosphamide (total 100 mg/kg to 120 mg/kg), followed by tacrolimus and a short-term methotrexate. We divided patients into 2 groups: group 1 (n = 25), which received HLA-matched (8/8) bone marrow (BM) without ATG, and group 2 (n = 58), which received SCT from either an HLA-mismatched donor or peripheral blood (PB). Thereafter, group 2 was subdivided according to ATG use into group 2A (without ATG, n = 26), which served as a historical cohort, and group 2B (with ATG, n = 32). Rabbit ATG (Thymoglobulin; Genzyme-Sanofi, Lyon, France) was used in group 2B at a dose of 2.5 mg/kg. The median age of all patients was 30 years (range, 17 to 59 years). The incidence of GVHD was significantly lower in group 2B than group 2A, as demonstrated by the rate of grade II to IV acute GVHD at day 100 (31.2% versus 61.5%, P = .003) and the rate of chronic GVHD at 3 years (21.9% versus 65.4%, P = .002). The overall survival rates of the 3 groups were similar. However, GVHD-free, failure-free survival (GFFS) was significantly higher in group 2B than group 2A (P = .034). A multivariable model identified use of ATG as an independent factor affecting grades II to IV acute GVHD (hazard ratio [HR], 2.902; 95% confidence interval [CI], 1.417 to 5.942; P = .004), chronic GVHD (HR , 3.005; 95% CI, 1.279 to 7.059; P = .012), and GFFS (HR, 2.363; 95% CI, 1.162 to 4.805; P = .014). Toxicities, including infectious complications, were not different among the 3 groups. In conclusion, low-dose ATG (2.5 mg/kg) can reduce the incidence of acute and chronic GVHD and improve the quality of life in patients with SAA who receive stem cells from either an HLA-mismatched donor or PB; importantly, these benefits are achieved without increased toxicity. Furthermore, ATG can be considered in URD SCT from HLA-matched BM cells.

Optimal dose of rabbit thymoglobulin in conditioning regimens for unmanipulated, haploidentical, hematopoietic stem cell transplantation: Long-term outcomes of a prospective randomized trial.

BACKGROUND: Antithymocyte globulin (ATG) is an important component of conditioning regimens to prevent severe graft-versus-host disease (GVHD) in patients undergoing unmanipulated, haploidentical stem cell transplantation (haplo-SCT). However, to the authors' knowledge, the optimal dose of ATG is unknown. METHODS: In this prospective, randomized trial, the authors compared the long-term outcomes of 2 ATG doses (rabbit thymoglobulin) used in myeloablative conditioning before unmanipulated haplo-HSCT. Patients were randomly assigned (1:1) to received 10 mg/kg (ATG-10) or 6 mg/kg (ATG-6) of ATG. Analysis of disease-free survival, GVHD-free/recurrence-free survival (GRFS), disease recurrence, nonrecurrence mortality, and chronic GVHD (cGVHD) included the entire population. Late effects were assessed in disease-free patients who had survived for at least 6 months and had received regular follow-up evaluations. RESULTS: A total of 224 patients were recruited. The median follow-up period was 1614 days (range, 28-1929 days). The rate of infection-related deaths in ATG-10 arm was double that of the ATG-6 arm (14.3% vs 7.1%; P = .084). The 5-year cumulative incidence was comparable between the ATG-6 and ATG-10 groups for disease recurrence (12.8% vs 13.4%; P = .832) and nonrecurrence mortality (11.6% vs 17.0%; P = .263). The 5-year probability of disease-free survival was comparable between the groups (75.6% vs 69.6%; P = .283). The 5-year cumulative incidence of cGVHD was found to be higher with ATG-6 (75.0% vs 56.3% [P = .007] and moderate-to-severe cGVHD: 56.3% vs 30.4% [P<.0001]) as well as that for late effects (71.2% vs 56.9%; P = .043). The 5-year probability of GRFS was higher in the ATG-10 group (41.0% vs 26.8%; P = .008). In the multivariate analysis, ATG-10 was found to be associated with a lower risk of cGVHD and improved GRFS. CONCLUSIONS: ATG-10 was found to be associated with better GVHD prevention and superior GRFS, but an increase in infection-related deaths. Cancer 2017;123:2881-92. © 2017 American Cancer Society.

Early Cardiac Toxicity Associated With Post-Transplant Cyclophosphamide in Allogeneic Stem Cell Transplantation.

BACKGROUND: Post-transplant cyclophosphamide (PT-Cy) has become a standard of care in haploidentical hematopoietic stem cell transplantation (HSCT) to reduce the risk of graft-versus-host disease. However, data on cardiac events associated with PT-Cy are scarce. OBJECTIVES: This study sought to assess the incidence and clinical features of cardiac events associated with PT-Cy. METHODS: The study compared clinical outcomes between patients who received PT-Cy (n = 136) and patients who did not (n = 195), with a focus on early cardiac events (ECE) occurring within the first 100 days after HSCT. All patients had the same systematic cardiac monitoring. RESULTS: The cumulative incidence of ECE was 19% in the PT-Cy group and 6% in the no-PT-Cy group (p < 0.001). The main ECE occurring after PT-Cy were left ventricular systolic dysfunction (13%), acute pulmonary edema (7%), pericarditis (4%), arrhythmia (3%), and acute coronary syndrome (2%). Cardiovascular risk factors were not associated with ECE. In multivariable analysis, the use of PT-Cy was associated with ECE (hazard ratio: 2.7; 95% confidence interval: 1.4 to 4.9; p = 0.002]. Older age, sequential conditioning regimen, and Cy exposure before HSCT were also associated with a higher incidence of ECE. Finally, a history of cardiac events before HSCT and ECE had a detrimental impact on overall survival. CONCLUSIONS: PT-Cy is associated with a higher incidence of ECE occurring within the first 100 days after HSCT. Patients who have a cardiac event after HSCT have lower overall survival. These results may help to improve the selection of patients who are eligible to undergo HSCT with PT-Cy, especially older adult patients and patients with previous exposure to Cy.

Allogeneic Stem Cell Transplantation with CD34+ Cell Selection.

The success of allogeneic stem cell transplant is hampered by the development of acute and chronic graft-versus-host disease (GvHD) which has direct impact on treatment-related mortality and morbidity. As a result, T cell depletion through positive selection of CD34+ cells has emerged as a promising strategy to reduce acute and chronic GvHD in these patients. In this review, we summarize the main characteristics of allogeneic stem cell transplant with CD34+ cell selection including risks of graft failure, GvHD, infection, organ toxicity, and long-term survival. Moreover, we highlight future strategies to improve the results of this platform and to consolidate its use in clinical practice.

A single-center analysis of chronic graft-versus-host disease-free, relapse-free survival after alternative donor stem cell transplantation in children with hematological malignancies.

We assessed the clinical outcomes of allogeneic hematopoietic stem cell transplantation (SCT) from alternative donors for pediatric patients with hematological malignancies, defining graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) as a composite endpoint. We also defined chronic GVHD-free, relapse-free survival (cGRFS) as survival without severe chronic GVHD, relapse, or death. The probabilities of 2-year disease-free survival from a human leukocyte antigen (HLA) matched unrelated donor (n = 57), related donor with HLA-1 antigen mismatch in the graft-versus-host direction (1Ag-GvH-MMRD, n = 28), and unrelated umbilical cord blood (n = 35) were 52.2, 38.5, and 40.4%, respectively (P = 0.14), and for 2-year GRFS were 26.2, 13.4, and 30.4%, respectively (P = 0.089), and for 2-year cGRFS were 36.2, 16.7, and 40.4%, respectively (P = 0.015). Of the three groups, the 1Ag-GvH-MMRD group showed a significantly higher cumulative incidence of severe cGVHD, and was identified as a significant risk factor for worse cGRFS. These results suggest that intensification of GVHD prophylaxis may be needed for SCT from 1Ag-GvH-MMRD. As with GRFS, cGRFS should be used as an endpoint of the clinical study to predict long-term morbidity and mortality for patients who need longer follow-up such as pediatric SCT recipients.

Prognostic factors on graft-versus-host disease-free and relapse-free survival after allogeneic hematopoietic stem cell transplantation for adults with acute leukemia.

The cure of acute leukemia by allogeneic hematopoietic stem cell transplantation (allo-HSCT) is closely linked to major complications leading to adverse outcomes, including graft-versus-host disease (GVHD), disease relapse and death. This study retrospectively investigated a consecutive series of 312 adult patients with acute leukemia receiving allo-HSCT by using a novel concept of GVHD-free/relapse-free survival (GRFS), and further evaluated the impact of clinical factors on GRFS. Results indicated that the 1- and 2-year GRFS were 54.8% and 51.5%, respectively. In multivariable analysis, recipient age >35years (HR 1.676; p=0.006), diagnosis of acute lymphoblastic leukemia (HR 1.653; p=0.027) and acute biphenotypic leukemia (HR 2.175; p=0.010), advanced disease (HR 2.702; p<0.001), and donor age >35 years (HR 1.622; p=0.008) were significantly associated with inferior GRFS post-HSCT. GRFS of haploidentical-related donor transplant was comparable to that of matched sibling donor or matched unrelated donor transplant. Furthermore, prophylactic donor lymphocyte infusion (DLI) had an overall beneficial effect on GRFS (HR 0.645, p=0.044). Collectively, with a better understanding of these significant prognostic factors which impacted on GRFS, we can effectively evaluate the risk and probability of real recovery after allo-HSCT, further optimizing the therapeutic avenues for acute leukemia.