A Prospective, Longitudinal Observation of the Incidence, Treatment, and Survival of Late Acute and Chronic Graft-versus-Host Disease by National Institutes of Health Criteria in a Japanese Cohort.

To prospectively validate the incidence, manifestations, and outcomes of graft-versus-host disease (GVHD) by National Institutes of Health criteria, we recruited 406 hematopoietic stem cell transplantation recipients at 16 transplant centers in Japan from May 2012 to June 2014. The 2-year cumulative incidence of late acute and chronic GVHD was 3.2% (n = 13) and 35.4% (n = 145), with a median onset of 3.6 and 4.7 months after transplant, respectively. The global severity at onset was mild in 30.3%, moderate in 43.5%, and severe in 26.2%. Eighty-two patients were followed up for 2 years, with 79.3% still manifesting GVHD symptoms, and 80.6% (n = 117) of the patients received systemic immunosuppressive treatment (IST), with a 2-year cumulative incidence of IST termination of 33.1%. Severe patients showed a significantly lower rate of IST termination than those with mild and moderate severities (mild, 38.5%; moderate, 40.9%; and severe, 17.2%). The 2-year incidence of nonrelapse mortality (NRM) and relapse was not significantly different according to the severity at onset (NRM: mild [16.6%] versus moderate [8.7%] versus severe [16.1%]; relapse: mild [14.9%] versus moderate [14.7%] versus severe [5.3%]). As a result, 2-year overall survival (OS) and GVHD-specific survival (GSS) were equivalent according to the severity at onset (mild: OS = 81.0%, GSS = 85.7%; moderate: OS = 84.2%, GSS = 92.5%; severe: OS = 83.9%, GSS = 89.2%). Our study helped identify the characteristics of late acute and chronic GVHD in Japanese patients. Further investigation is needed to identify an optimal endpoint for survival prediction.

Assessment of Individual versus Composite Endpoints of Acute Graft-versus-Host Disease in Determining Long-Term Survival after Allogeneic Transplantation.

The overall composite of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS), defined as survival free of grade III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD) requiring systemic immunosuppressive therapy (IST), or relapse, has emerged as a useful composite in clinical trials and to capture clinically meaningful events that impact quantity and quality of survival after allogeneic hematopoietic cell transplantation (HCT). We reviewed 565 consecutive patients aged ≥18 years undergoing HCT for hematologic malignancy to analyze how baseline incidence, specifics of clinical definitions, and proposed reductions in any one individual event may dynamically alter the overall performance of the composite To determine the relative impact of each GRFS event (excluding death), we accounted for competing risks using Fine and Gray methods, and correlated each event with overall survival (OS) using Kaplan-Meier methods. The consequences of modulating individual or composite endpoints on OS, such as hypothesized reductions of events of an HCT interventional trial, were examined using Monte Carlo simulations. The median age of the cohort was 54 years (range, 18 to 73 years). The majority of patients received HLA-matched unrelated donor HCT (53%), consisting of peripheral blood stem cell grafts (90%) after myeloablative conditioning (68%). Relapse conferred the greatest risk for death (hazard ratio [HR], 7.89; 95% confidence interval [CI], 5.83 to 10.69), followed by grade III-IV aGVHD (HR, 6.16; 95% CI, 4.42 to 8.56) and cGVHD requiring IST (HR, 1.69; 95% CI, 1.16 to 2.46). The overall GRFS composite correlated with an HR of 4.81 (95% CI, 3.61 to 6.41), which was lower compared with either relapse or grade III-IV aGVHD. Statistical simulations found that modulating the combined risk of both relapse and grade III-IV aGVHD predicted the greatest change in 5-year OS. These simulations suggest that GRFS as currently defined may be less optimal for correlating with OS, and further refinement of composite endpoints is needed. Nonetheless, composite endpoints may be particularly helpful in mitigating potential difficulties in interpretation when competing risks are present, most commonly seen in HCT studies.

Hematogones Predict Better Outcome in Allogeneic Hematopoietic Stem Cell Transplantation Irrespective of Graft Sources.

Benign precursors of B lymphocytes, termed hematogones, are observed in the regenerative state of hematopoiesis following chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous studies have demonstrated that expansion of hematogones correlates with better clinical outcomes after allo-HSCT. We retrospectively analyzed the association between hematogones and clinical outcomes in 309 consecutive patients who underwent allo-HSCT, which is the largest population-based cohort reported so far. The incidence of hematogones was significantly higher in complete remission (CR) patients at the time of transplantation than in non-CR patients, after myeloablative conditioning than after reduced-intensity conditioning, with tacrolimus-based graft-versus-host disease (GVHD) prophylaxis than with cyclosporine-based prophylaxis, and with disease other than malignant lymphoma (all P < .05). Patients with hematogones developed less acute GVHD and infections than did those without them (P < .05). Emergence of hematogones was associated with superior GVHD-free relapse-free survival and lower nonrelapse mortality, and was an independent prognostic factor for overall survival, irrespective of donor sources.

Chronic kidney disease, survival and graft-versus-host-disease-free/relapse-free survival in recipients of allogeneic hematopoietic stem cell transplant.

Background: Advances in allogeneic hematopoietic stem cell transplant (HSCT) have increased patient survival, although substantial treatment-related toxicity remains, including chronic kidney disease (CKD). We assessed the association between CKD and survival and transplant-specific outcomes in HSCT recipients. Methods: We conducted a retrospective study of all 408 adult patients with allogenic HSCT at Princess Margaret Cancer Centre (Toronto, Canada, 2015-18). We used logistic regression to identify risk factors for CKD at 1 year post-transplant. Associations between CKD at 1 year and overall survival, relapse-free survival, graft-versus-host-disease (GVHD)-free/relapse-free survival, relapse and transplant-related mortality were examined using extended time-varying Cox models. In a sensitivity analysis, we restricted the cohort to survivors at 1 year, using standard Cox proportional hazard models to examine associations between CKD and overall survival, relapse-free survival and GVHD-free/relapse-free survival, and Fine and Gray's competing risk models to determine associations between CKD and relapse/transplant-related mortality. Results: The prevalence of CKD at 1 year was 19% (46 patients) with median follow-up of 23 months. Multivariable regression identified age at transplant [adjusted OR (aOR) 1.09, 95% confidence interval (95% CI) = 1.05-1.14; P < 0.0001), female gender (aOR 2.83, 95% CI = 1.34-5.97; P = 0.006) and acute kidney injury during the first 100 days (aOR 3.86, 95% CI = 1.70-8.73; P = 0.001) as risk factors for CKD at 1 year. Patients with CKD at 1 year had significantly poorer overall survival than those without CKD, when adjusted for relevant covariates [adjusted HR (aHR) 1.93, 95% CI = 1.02-3.66; P = 0.04 in the time-varying Cox model, and aHR 2.06, 95% CI = 1.04-4.07; P = 0.04 using the standard Cox model]. CKD at 1 year was also associated with worse GVHD-free/relapse-free survival (aHR 1.65, 95% CI = 1.04-2.61; P = 0.03). Conclusions: CKD adversely affects the long-term prognosis for allogeneic HSCT recipients, with increased mortality risk and worse GVHD-free/relapse-free survival.

Optimizing antithymocyte globulin dosing in haploidentical hematopoietic cell transplantation: long-term follow-up of a multicenter, randomized controlled trial.

Given that randomized studies testing the long-term impact of antithymocyte globulin (ATG) dosing are scarce, we report the results of an extended follow-up from the original trial. In our prospective, multicenter, randomized trial, 408 leukemia patients 14-65 years of age who underwent haploidentical hematopoietic cell transplantation (haplo-HCT) under our original "Beijing Protocol" were randomly assigned one-to-one to ATG doses of 7.5 mg/kg (n = 203, ATG-7.5) or 10 mg/kg (n = 205, ATG-10.0) at four sites. Extended follow-up (median 1968 d (range: 1300-2710 d) indicated comparable 5-year probabilities of moderate-to-severe chronic graft-versus-host disease (GVHD) (hazard ratio (HR): 1.384, 95% confidence interval (CI): 0.876-2.189, P = 0.164), nonrelapse mortality (HR: 0.814, 95% CI: 0.526-1.261, P = 0.357), relapse (HR: 1.521, 95% CI: 0.919-2.518, P = 0.103), disease-free survival (HR: 1.074, 95% CI: 0.783-1.473, P = 0.658), and GVHD-free/relapse-free survival (HR: 1.186, 95% CI: 0.904-1.555, P = 0.219) between groups (ATG-7.5 vs. ATG-10.0). The 5-year rate of late effects did not differ significantly. However, the cytomegalovirus/Epstein-Barr virus-related death rate was much higher in the ATG-10.0 cohort than in the ATG-7.5 cohort (9.8% vs. 1.5%; P = 0.003). In summary, patients undergoing haplo-HCT benefit from 7.5 mg/kg ATG compared to 10.0 mg/kg ATG based on a balance between GVHD and infection control. ATG (7.5 mg/kg) is potentially regarded as the standard regimen in the platform. These results support the optimization of ATG use in the "Beijing Protocol", especially considering the potential economic advantage in developing countries.

Acute Lymphoblastic Leukemia in Children: Better Transplant Outcomes After Total Body Irradiation-based Conditioning.

BACKGROUND/AIM: Comparison of transplant outcomes in long-term follow-up of children after total body irradiation (TBI)- or chemotherapy-based conditioning allogeneic hematopoietic cell transplantation (allo-HCT). PATIENTS AND METHODS: Patients undergoing allo-HCT for Acute lymphoblastic leukemia (ALL) conditioned either with TBI (n=55) or chemotherapy (n=84) were compared. The following transplant outcomes were analyzed: overall survival (OS), event-free survival (EFS), relapse incidence (RI), and graft-versus-host-disease (GVHD)-free-relapse-free survival (GRFS). RESULTS: All analyzed long-term transplant outcomes were significantly better for patients conditioned with TBI at 2 years after transplant. OS at 2 years was 84% after TBI and 60.5% after chemotherapy-conditioning (p=0.005). Risk factor analysis showed that two factors, TBI-based conditioning and transplant in first remission of ALL, significantly improved OS, EFS, GRFS, and decreased RI. CONCLUSION: TBI-based conditioning before allogeneic HCT in children with acute lymphoblastic leukemia provides significantly better transplant outcomes, when compared to chemotherapy-based conditioning.

Superior GVHD-free, relapse-free survival for G-BM to G-PBSC grafts is associated with higher MDSCs content in allografting for patients with acute leukemia.

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (G-PBSC) has largely replaced unstimulated bone marrow (un-BM) for allografting because of accelerated engraftment, but with a higher morbidity and mortality of graft-versus-host-disease (GVHD). Recent studies suggested that G-CSF-primed BM (G-BM) had similar engraftment but lower morbidity and mortality of GVHD comparing to G-PBSC. A prospective, randomized, multicenter study was conducted to compare G-BM with G-PBSC as the grafts in allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute leukemia in first complete remission (CR1). METHODS: Totally 101 adult leukemia in CR1 undergoing HLA-identical sibling transplants were randomized into G-BM or G-PBSC group. The primary study endpoint was GVHD-free/relapse-free survival (GRFS). RESULTS: Both the engraftment of neutrophil and platelet were 2 days later in G-BM than in G-PBSC group (P = 0.412, P = 0.39). G-BM group showed significantly lower II-IV acute GVHD (aGVHD) and similar III-IV aGVHD compared with G-PBSC group (12.2% vs 28.8% for II-IV, P = 0.048; 4.1% vs 9.6% for III-IV aGVHD, P = 0.267, respectively). The overall cumulative incidence of chronic GVHD (cGVHD) at 3 years were 22.3% ± 6.3% and 44.8% ± 7.6% (P = 0.026), respectively, and extensive cGHVD were 4.5% ± 3.1% and 15% ± 5.3% (P = 0.08), respectively, in G-BM and G-PBSC groups. Two groups had similar 3-year relapse, transplant-related mortality (TRM), overall survival (OS), and disease-free survival (DFS) (all P > 0.05). G-BM group showed significantly higher probability of GRFS than G-PBSC group (73.5% ± 6.3% vs 55.8% ± 6.9% at 1 year, P = 0.049; 69.0% ± 6.7% vs 49.7% ± 7.0% at 2 and 3 years, P = 0.03, respectively). Graft content analysis revealed statistically higher frequency of myeloid-derived suppressor cells (MDSCs) in the G-BM than in G-PBSC grafts (P < 0.01), and recipients received statistically higher numbers of MDSCs in G-BM than in G-PBSC group (P = 0.045). Numbers of MDSCs infused to patients were negatively correlated with the severity of aGVHD (P = 0.032, r = -0.214). Multivariate analysis showed that MDSC cell dose below the median (HR = 3.49, P < 0.001), recipient age (HR = 2.02, P = 0.039), and high risk of disease (HR = 2.14, P = 0.018) were independent risk factors for GRFS. CONCLUSIONS: G-BM grafts lead a better GRFS and less GVHD associated with a higher MDSCs content compared with G-PBSC grafts.