Abstract

PURPOSE Severe (grade 3-4) acute graft-versus-host disease (AGVHD) is a major cause of death after unrelated-donor (URD) hematopoietic cell transplant (HCT), resulting in particularly high mortality after HLA-mismatched transplantation. There are no approved agents for AGVHD prevention, underscoring the critical unmet need for novel therapeutics. ABA2 was a phase II trial to rigorously assess safety, efficacy, and immunologic effects of adding T-cell costimulation blockade with abatacept to calcineurin inhibitor (CNI)/methotrexate (MTX)-based GVHD prophylaxis, to test whether abatacept could decrease AGVHD. METHODS ABA2 enrolled adults and children with hematologic malignancies under two strata: a randomized, double-blind, placebo-controlled stratum (8/8-HLA-matched URD), comparing CNI/MTX plus abatacept with CNI/MTX plus placebo, and a single-arm stratum (7/8-HLA-mismatched URD) comparing CNI/MTX plus abatacept versus CNI/MTX CIBMTR controls. The primary end point was day +100 grade 3-4 AGVHD, with day +180 severe-AGVHD-free-survival (SGFS) a key secondary end point. Sample sizes were calculated using a higher type-1 error (0.2) as recommended for phase II trials, and were based on predicting that abatacept would reduce grade 3-4 AGVHD from 20% to 10% (8/8s) and 30% to 10% (7/8s). ABA2 enrolled 142 recipients (8/8s, median follow-up = 716 days) and 43 recipients (7/8s, median follow-up = 708 days). RESULTS In 8/8s, grade 3-4 AGVHD was 6.8% (abatacept) versus 14.8% (placebo) (P = .13, hazard ratio = 0.45). SGFS was 93.2% (CNI/MTX plus abatacept) versus 82% (CNI/MTX plus placebo, P = .05). In the smaller 7/8 cohort, grade 3-4 AGVHD was 2.3% (CNI/MTX plus abatacept, intention-to-treat population), which compared favorably with a nonrandomized matched cohort of CNI/MTX (30.2%, P < .001), and the SGFS was better (97.7% v 58.7%, P < .001). Immunologic analysis revealed control of T-cell activation in abatacept-treated patients. CONCLUSION Adding abatacept to URD HCT was safe, reduced AGVHD, and improved SGFS. These results suggest that abatacept may substantially improve AGVHD-related transplant outcomes, with a particularly beneficial impact on HLA-mismatched HCT.

Abstract

Graft-versus-host disease (GVHD) prophylaxis based on post-transplant cyclophosphamide (PTCy) or antithymocyte globulin (ATG) is widely used in allogeneic hematopoietic stem cell transplantations (allo-HCT). The differential impacts of PTCy and ATG on transplantation outcomes are not well characterized. Here we report a meta-analysis of PTCy versus ATG in allo-HCT. Ten studies were eligible, and a total of 1871 patients were included. The incidence of II-IV aGVHD, III-IV aGVHD, and NRM were significantly lower in PTCy arm (HR?=?0.63, 95% CI 0.45-0.89; HR?=?0.35, 95% CI 0.16-0.77; HR?=?0.59, 95% CI 0.48-0.73). PTCy was associated with a better OS and PFS (HR?=?0.62, 95% CI?=?0.53-0.73; HR?=?0.76, 95% CI 0.62-0.93). The relapse rate and cGVHD incidence were not significantly different between PTCy and ATG (HR?=?0.85, 95% CI 0.68-1.07; HR?=?0.65, 95% CI 0.38-1.12). Thus, compared with ATG, PTCy has a better aGVHD control and OS benefit, without increasing relapse risk, which needs further validation in prospective randomized trials.

Abstract

BACKGROUND Dipeptidyl peptidase 4 (DPP-4; also known as CD26), a transmembrane receptor expressed on T cells, has a costimulatory function in activating T cells. In a mouse model, down-regulation of CD26 prevented graft-versus-host disease (GVHD) but preserved graft-versus-tumor effects. Whether inhibition of DPP-4 with sitagliptin may prevent acute GVHD after allogeneic stem-cell transplantation is not known. METHODS We conducted a two-stage, phase 2 clinical trial to test whether sitagliptin plus tacrolimus and sirolimus would reduce the incidence of grade II to IV acute GVHD from 30% to no more than 15% by day 100. Patients received myeloablative conditioning followed by mobilized peripheral-blood stem-cell transplants. Sitagliptin was given orally at a dose of 600 mg every 12 hours starting the day before transplantation until day 14 after transplantation. RESULTS A total of 36 patients who could be evaluated, with a median age of 46 years (range, 20 to 59), received transplants from matched related or unrelated donors. Acute GVHD occurred in 2 of 36 patients by day 100; the incidence of grade II to IV GVHD was 5% (95% confidence interval [CI], 1 to 16), and the incidence of grade III or IV GVHD was 3% (95% CI, 0 to 12). Nonrelapse mortality was zero at 1 year. The 1-year cumulative incidences of relapse and chronic GVHD were 26% (95% CI, 13 to 41) and 37% (95% CI, 22 to 53), respectively. GVHD-free, relapse-free survival was 46% (95% CI, 29 to 62) at 1 year. Toxic effects were similar to those seen in patients undergoing allogeneic stem-cell transplantation. CONCLUSIONS In this nonrandomized trial, sitagliptin in combination with tacrolimus and sirolimus resulted in a low incidence of grade II to IV acute GVHD by day 100 after myeloablative allogeneic hematopoietic stem-cell transplantation. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02683525.).

Abstract

BACKGROUND There have been concerns regarding increased peritransplantation complications, especially severe acute graft-versus-host disease (aGVHD), in patients with prior use of checkpoint inhibitors (CPI) before hematopoietic stem cell transplantation (HSCT). METHODS The authors performed a retrospective study of 43 patients with acute myeloid leukemia and/or myelodysplastic syndromes who were treated with an antiprogrammed cell death protein 1 (PD-1) (32 patients) or anticytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (9 patients) blockade or both (2 patients) prior to HSCT with the primary outcome of aGVHD by day 100 after HSCT. Outcome analyses were stratified by GVHD prophylaxis as use of post-HSCT cyclophosphamide (PTCy) (22 patients) or not (non-PTCy) (21 patients). RESULTS The PTCy group demonstrated a trend toward lower grade 3 to 4 aGVHD when compared with the non-PTCy group (5% vs 22%), although the rates of grade 2 to 4 aGVHD were comparable (49% vs 56%). The interval between CPI and HSCT did not appear to impact the incidence of aGVHD. However, a higher incidence of grade 3 to 4 aGVHD was observed in patients who received >4 treatments of CPI prior to HSCT if they were not given PTCy as GVHD prophylaxis (43% vs 12%). Matched control analyses using patients with no prior use of CPI confirmed the increase in grade 3 to 4 aGVHD with those agents. However, that increased risk was limited to patients who did not receive PTCy and was not observed in patients who received PTCy as GVHD prophylaxis. Despite persistent improvement in GVHD with the use of PTCy, disease control was not compromised and progression-free survival at 1 year was found to be superior for patients treated with PTCy compared with those not receiving PTCy among patients with prior use of CPI (55% vs 22%). CONCLUSIONS The results of the current study indicated that HSCT with prior use of CPI appears feasible in patients with acute myeloid leukemia and/or myelodysplastic syndromes and the use of PTCy as GVHD prophylaxis improves outcomes.

Abstract

Anti-thymocyte globulin (ATG) is used to reduce the incidence and severity of graft-versus-host disease (GVHD) with hematopoietic cell transplantation, yet optimum dosing has yet to be determined. We have previously demonstrated that 2.5 mg/kg of ATG in conditioning can reduce the incidence of GVHD in unrelated donor transplants. Recent literature has suggested that ATG dosing based on absolute lymphocyte count (ALC) could lead to more optimum exposure of the drug. We sought to determine if ALC at the time of transplant could impact clinical outcomes. We conducted a retrospective single centre study analyzing all consecutive patients at The Ottawa Hospital who received a matched unrelated donor stem cell transplant with ATG between 2009 and 2014. Patients received rabbit ATG (Thymoglobulin(R)) at 0.5 mg/kg on day -2 and 2.0 mg/kg on day -1. Univariate and multivariate analysis were used to determine if any patient or transplant related factors, including weight, ALC, and total ATG dose given, impacted GVHD, relapse, or mortality. One hundred and eleven patients met inclusion, with a median age of 50 years (range 19-70). The most common diagnoses were AML (43%), MDS/MPN (13%), and lymphoma (12%). The median weight at time of conditioning was 80.3 kg (range 45-216). The median ALC on the first day of ATG administration was 0.1 x 10(9)/L (range 0-190). The median total dose of ATG received was 201 mg (range 112-540). The incidence of acute and chronic GVHD was 35.1% and 21.6% respectively. In multivariate model, the actual dose of ATG given to patients was not associated with GVHD (HR=1.11, 95% CI 0.99-1.25, p=0.07), relapse (HR=1.13, 95% CI 0.98-1.30, p=0.1) or mortality (HR= 1.09, 95% CI 0.92-1.28, p=0.32). Similarly, the pre-transplant ALC was not associated with GVHD (HR=1, p=0.82), relapse (HR=1, p=0.90) or mortality (HR=1, p=0.39). If patients had received ALC based dosing according to previously published work (Admiraal et al., Lancet Haematol 2017), the mean total dose of ATG received would have been 1205 mg, more than five times the mean dose that was actually given based on weight. With GVHD outcomes being similar to that published by Admiraal et al. and ALC not independently associated with outcomes in our study, further studies are still needed to compare standard weight-based dosing to ALC-based dosing of ATG in matched unrelated donor stem cell transplant.

Abstract

BACKGROUND Previous trials testing prevention strategies for chronic graft versus host disease (GVHD) have measured its cumulative incidence. In this trial of anti-thymocyte globulin, we measured treatment-independence at a long-term timepoint as the primary endpoint. METHODS This was a randomised, open-label, multicentre, phase 3 trial done at ten centres in Canada and one in Australia. Eligible patients had a haematological malignancy (leukaemia, myelodysplastic syndrome, or lymphoma), were between 16 and 70 years of age, eligible for transplantation with a Karnofsky score of at least 60, and received an unrelated donor (fully matched or one-locus mismatched at HLA-A, HLA-B, HLA-C, or DRB1 loci) graft following myeloablative or non-myeloablative-reduced intensity conditioning. Patients were randomly assigned to receive anti-thymocyte globulin 4.5 mg/kg plus standard GVHD prophylaxis (cyclosporine or tacrolimus plus methotrexate or mycophenolate) or standard GVHD prophylaxis alone. The primary endpoint, freedom from immunosuppressive therapy without resumption at 12 months, was previously reported. Here we report on the prespecified 24-month analysis. Analyses were per-protocol, excluding those patients who did not proceed to transplantation. This trial is registered as ISRCTN 29899028 and NCT01217723, status completed. FINDINGS Between June 9, 2010, and July 8, 2013, we recruited and randomly assigned 203 eligible patients to receive anti-thymocyte globulin (n=101) or no additional treatment (n=102) along with standard GVHD prophylaxis. 7 (3%) patients did not receive a transplant and were excluded from the analysis. 38 (38%) of 99 evaluable patients in the anti-thymocyte globulin plus GVHD prophylaxis group were free from immunosuppressive therapy at 24 months compared with 18 (19%) of 97 patients in the standard GVHD prophylaxis group (adjusted odds ratio [OR] 3.49 [95% CI 1.60-7.60]; p=0.0016. At 24 months, the cumulative incidence of relapse was 16.3% (95% CI 8.9-23.7) in the anti-thymocyte globulin plus GVHD prophylaxis group compared with 17.5 (9.9-25.1) in the standard GVHD prophylaxis group (p=0.73) and non-relapse mortality was 21.2% (95% CI 13.2-29.2) versus 31.3% (21.9-40.7; p=0.15). The cumulative incidence of chronic GVHD at 24 months was 26.3% (95% CI 17.5-35.1) in the anti-thymocyte globulin group and 41.3% (31.3-51.3) in the standard GVHD prophylaxis group (p=0.032). Overall survival at 24 months was 53.3% (95% CI 42.8-62.7) in the anti-thymocyte globulin plus GVHD prophylaxis group compared with 70.6% (95% CI 60.6-78.6) in the standard GVHD prophylaxis group (adjusted hazard ratio [HR] 0.56, 95% CI [0.35-0.90]; p=0.017. Symptoms of chronic GVHD by the Lee Scale were more prevalent in the standard GVHD prophylaxis group, with scores of 13.27 (SD 10.94) in the anti-thymocyte globulin plus GVHD prophylaxis group and 20.38 (SD 14.68) in the standard GVHD prophylaxis group (p=0.040). Depressive symptoms were more prominent in the standard GVHD prophylaxis group, the mean Center for Epidemiological Studies Depression scale (CES-D) scores were 10.40 (SD 9.88) in the anti-thymocyte globulin group and 14.62 (SD 12.26) in the standard GVHD prophylaxis group (p=0.034). Serious adverse events (CTCAE grade 4 or 5) occurred in 38 (38%) patients in the anti-thymocyte globulin group and in 49 (51%) in the standard GVHD prophylaxis group, the most common being infection and GVHD. One patient died of Epstein-Barr virus hepatitis. INTERPRETATION The results of this prespecified 24-month analysis suggest that pretreatment with anti-thymocyte globulin provides clinically meaningful benefits when added to standard GVHD prophylaxis in patients undergoing unrelated donor transplantation, including a decrease in use of immunosuppressive therapy, chronic GVHD and its symptoms, depressive symptoms, and improved overall survival. Anti-thymocyte globulin could be included in the preparative regimens of patients with haematological malignancies selected for unrelated donor transplantation. FUNDING Canadian Institutes of Health Research and Sanofi.

Abstract

Although a combination of calcineurin inhibitor and methotrexate (MTX) is used for graft-versus-host disease (GVHD) prophylaxis in umbilical cord blood transplantation (CBT), optimal dose of MTX for CBT remains to be determined.We conducted a retrospective study to evaluate the safety and efficacy of standard-dose MTX (St-MTX, 15 mg/m(2) on day 1 and 10 mg/m(2) on days 3 and 6) and mini-dose MTX (Mini-MTX, 5 mg/m(2) on days 1, 3 and 6) for GVHD prophylaxis in patients who underwent single unit CBT against hematological malignancies.Thirty-two and 26 patients received St-MTX and Mini-MTX, respectively. Cumulative incidence of neutrophil engraftment was significantly higher in the Mini-MTX group than in the St-MTX group (88.5% vs 65.6%, P = 0.00448). Cumulative incidences of grade II to IV and grade III to IV of acute graft-versus-host disease (GVHD) were 34.4% and 6.2% in the St-MTX group, and 34.6% and 7.7% in the Mini-MTX group with no statistical significance. One-year non-relapse mortality (NRM) was significantly lower in the Mini-MTX group compared to the St-MTX group (31.2% vs 3.8%, P = 0.00938), whereas relapse rate was not different between the groups. Multivariate analysis also indicated that Mini-MTX significantly improved engraftment (HR, 0.5359; 95% CI, 0.3082 to 0.9318; P = 0.0270) and reduced NRM (HR, 0.117; 95% CI, 0.0151 to 0.9067; P = 0.040).Our study suggests that GVHD prophylaxis using Mini-MTX in CBT is feasible and associated with improvement of engraftment and reduction in NRM.

Abstract

Graft-versus-host disease (GVHD) is a major factor contributing to mortality and morbidity after allogeneic stem-cell transplantation. Because of the small number of results from well designed, large-scale, clinical studies there is considerable variability in the prevention and treatment of GVHD worldwide. In 2014, to standardise treatment approaches the European Society of Blood and Marrow Transplantation published recommendations on the management of GVHD in the setting of HLA-identical sibling or unrelated donor transplantation in adult patients with haematological malignancies. Here we update these recommendations including the results of study published after 2014. Evidence was searched in three steps: first, a widespread scan of published trials, meta-analyses, and systematic reviews; second, expert opinion was added for specific issues following several rounds of debate; and third, a refined search to target debated or rapidly updating issues. On the basis of this evidence and the 2014 recommendations, five members of the EBMT Transplant Complications Working Party created 38 statements on GVHD prophylaxis, drug management, and treatment of acute and chronic GVHD. Subsequently, they created the EBMT GVHD management recommendation expert panel by recruiting 20 experts with expertise in GVHD management. An email-based, two-round Delphi panel approach was used to manage the consensus. Modified National Comprehensive Cancer Network categories for evidence and consensus were applied to the approved statements. We reached 100% consensus for 29 recommendations and 95% consensus for nine recommendations. Key updates to these recommendations include a broader use of rabbit anti-T-cell globulin; lower steroid doses for the management of grade 2 acute GVHD with isolated skin or upper gastrointestinal tract manifestations; fluticasone, azithromycin, and montelukast should be used for bronchiolitis obliterans syndrome; and the addition of newer treatment options for resteroid-refractory acute and chronic GVHD. In addition, we discuss specific aspects of GVHD prophylaxis and management in the setting of haploidentical transplantation and in paediatric patients, but no formal recommendations on those procedures have been provided in this Review. The European Society of Blood and Marrow Transplantation proposes to use these recommendations as a basis for the routine management of GVHD during stem-cell transplantation.

Abstract

We analyzed data relative to cell content in 88 consecutive patients receiving HLA haploidentical bone marrow (BM) transplants with post-transplantation cyclophosphamide (PT-CY). Median age was 54.5 (range, 17-72); diagnoses were acute leukemia (n = 46), lymphoproliferative disorders (n = 24), myelofibrosis (n = 11) and myelodysplastic syndromes (n = 5). Total nucleated cell (TNC) and CD34+, CD3+, CD4+ and CD8+ cell doses were stratified as higher than first, second and third quartile and the dose effect on various clinical outcomes was assessed. Median time to engraftment was 17 days for neutrophils and 24 days for platelets. To receive a dose of TNC ≥3.2 x 10(6)/kg or CD34+ cells ≥2.7 x 10(6)/kg significantly shortened the time to neutrophil and platelet engraftment and reduced the blood product requirements in the 30-day period after transplantation. Overall, TNC and CD34+ cell doses had no effect on acute graft-versus-host disease (GVHD) incidence, whereas patients receiving higher CD3+ and CD8+ cell doses seemed to have less chronic GVHD. No effect on non-relapse mortality, progression-free survival and overall survival was observed at different cell dose thresholds. These data suggest that in HLA haploidentical BM transplant with PT-CY, appropriate cell doses are relevant to the engraftment. The association between low CD3+/CD8+ cells and chronic GVHD deserves further investigation.