Incidence Of cGVHD Research Articles

Post-transplant cyclophosphamide as graft-versus-host disease prophylaxis in HLA matched sibling donor stem cell transplantation for patients with acute leukemia.

e19523 Background: Graft-versus-host disease (GVHD) is a life-threatening complication of Allogeneic Hematopoietic Stem Cell Transplantation (HSCT). Calcineurin inhibitor (CNI) and methotrexate (MTX) have been used as the standard GVHD prophylaxis in HLA-matched HSCT. Promising clinical trial data using high dose post-transplant Cyclophosphamide (PT-Cy) with or without additional immunosuppressive agents (IS) have shown that it’s an effective, well tolerated alternative. However, experiences are limited with controversial results. Methods: We analyzed 62 patients with Acute Leukemia (39 males, 23 females) with age ranges from 18 to 60 years underwent allogeneic HSCT from matched sibling donors (MSD) using reduced intensity chemotherapy at Maadi Armed Forces Medical Hospital after informed consent. They were randomized into 2 groups according to GVHD prophylaxis regimen. The 1st group (40 patients) received MTX in the following doses; day+2 (15mg), day +4 (10 mg), day +6 (10 mg) with Cyclosporine (5mg/kg) from day -3 till day +90 and Mycophenolate (MMF) (2 -3gm/day) from day +1 till day +30. The 2nd group(22 patients) received PT-Cy (45 mg/kg/day) on days +3 and +4 with Cyclosporine (5mg/kg) from day +5 till day +30 & MMF:(2-3gm /day) from day +5 till +30. Results: At median 1 year Post Allo, PT-Cy was associated with statistically significant lowering of chronic GVHD (cGVHD) incidence compared to MTX group (22.7%, 56.4%) respectively (P = 0.011). Incidence of acute GVHD (aGVHD) at day +100 was (40%, 22.7%) in group 1, 2 respectively (P = 0.169). 92% of patients in group 1 and 86.4 % of patients in group 2 were engrafted with full donor chimerism on day +30 (P = 0.659). The cumulative incidence of relapse at 4 years after transplantation was 17.9 % for group 1 and 36.4 % for group 2 (P > 0.05). Relapse related mortality were 16.2% among MTX group while 27.3% in PT-Cy group (P = 0.10). Transplant related mortality (TRM) in MTX group were; Severe aGVHD (8%), cGVHD (10%), Hepatic Toxicity (8%), Nephrotoxicity (2.7%) & ARDS (5.4%). In PT-Cy group TRM were; septicemia (18%), severe aGVHD (4.5%) & ARDS (4.5%). Cumulative 4 years Disease Free Survival (DFS) & Overall survival (OS) in PT-Cy group were (51.8 %, 46.4%) respectively while (69.3%, 39%) in MTX group which is statistically non-significant (P > 0.05). Conclusions: For GVHD prophylaxis in MSD, PT-Cy is a safe alternative that reduces the risk of cGVHD in comparison with MTx based regimen without affecting Relapse rate, DFS or OS.

The management of gynecological complications in long-term survivors after allogeneic hematopoietic cell transplantation\u2014a single-center real-life experience

In everyday gynecological practice, there is an unmet need to manage survivors after allogeneic hematopoietic cell transplantation (allo-HCT). The major gynecological complications include premature ovarian insufficiency (POI), chronic graft-versus-host disease (cGVHD) of the anogenital zone (cGVHDgyn), and secondary neoplasms. Aiming to assess a real-life scale of problems associated with HCT, we performed a detailed analysis of a consecutive series of females after allo-HCT who were referred for a routine gynecological evaluation. The study includes 38 females after allo-HCT in whom gynecological examination with cervical smear and USG were performed, followed by colposcopy according to NCCN guidelines. NIH scoring system was used to classify a grade of cGVHDgyn. The incidence of cGVHD was 71% whereas GVHDgyn was 29%, including 5 patients with score 3 at the time of diagnosis. The other manifestations (frequently noted) included the skin, mucosa, eyes, and liver. Menopause was diagnosed in 93% females, and in 81% of them, POI criteria were fulfilled. Ovarian function resumed in 2 cases. The rate of abnormal cytology was 26%: 4 ASCUS, 1 AGUS, 1 LSIL, 3 HSIL/ASC-H, and one cytological suspicion of cervical cancer. GVHDgyn was documented in 10 patients, and 6 of them had abnormal cervical cytology. Early topical estrogen therapy led to a significant reduction in vaginal dryness (p < 0.05), dyspareunia (p < 0.05), and less frequent cGVHDgyn (p < 0.05). GVHDgyn develops in about 30% of long-term allo-HCT survivors. Topical estrogens and hormonal replacement therapy alleviate symptoms and prevent the occurrence of severe consequences of menopause.

Haploidentical hematopoietic stem cell transplantation in aplastic anemia: a systematic review and meta-analysis of clinical outcome on behalf of the severe aplastic anemia working party of the European group for blood and marrow transplantation (SAAWP of EBMT).

Aplastic anemia (AA) is a serious hematological disorder, which is solely cured by hematopoietic stem cell transplantation (HSCT). Haploidentical HSCT is an emerging modality with encouraging outcomes in several blood conditions. The present study aims to comprehensively assess the feasibility and safety of haploidentical HSCT in patients with severe and very severe AA. It is a systematic review and meta-analysis of studies related to haploidentical stem cell transplantation in idiopathic AA investigating rates of successful engraftment, acute graft-versus-host disease (aGvHD), chronic GvHD (cGvHD), transplant-related mortality (TRM), and posttransplantation viral infections (including cytomegalovirus [CMV]) in patients with AA. The effects of reduced-intensity conditioning (RIC) and nonmyeloablative conditioning (NMA), as well as various GvHD prophylaxis regimens on these outcomes were evaluated. In total 15 studies were identified, (577 patients, 58.9% males), successful engraftment was observed in 97.3% of patients (95% CI, 95.9-98.7) while grades II-IV aGvHD and cGvHD were reported in 26.6% and 25.0%, respectively. The pooled incidence of TRM was 6.7% per year (95% CI, 4.0-9.4). RIC regimens were associated with higher proportions of successful engraftment (97.7% vs 91.7%, P = 0.03) and aGvHD (29.5% vs 18.7%, P = 0.008) when compared with NMA regimens with no differences in cGvHD or mortality incidence. When compared with methotrexate-containing regimens and other regimens, posttransplant cyclophosphamide-containing regimens reduced the rates of aGvHD (28.6%, 27.8%, and 12.8%, respectively, P = 0.02), CMV viremia (55.7%, 38.6%, and 10.4%, respectively, P < 0.001), and CMV disease in initially viremic patients (2.1%, 33.0%, and 0%, respectively, P < 0.001). We have concluded that Haploidentical HSCT was associated with promising outcomes in terms of successful engraftment and reduced complications. Future prospective trials are needed to identify the preferred conditioning regimen, GvHD prophylaxis, and graft source in the setting of haploidentical transplant for AA.

Influence of anti-thymocyte globulin plasma levels on outcome parameters in stem cell transplanted children

IntroductionAllogenic hematopoietic stem cell transplantation is a curative option for malignant and non-malignant pediatric diseases. Serotherapy is often employed to avoid graft-versus-host disease (GvHD) on one hand and graft rejection on the other hand. Therapeutic drug monitoring is increasingly used to allow for more precise dosing especially in pediatric patients due to their specific pharmacological characteristics. Application of T-cell directed antibodies is not routinely monitored, but may benefit from more precise dosing regimens. MethodsTwo different preparations of rabbit anti-thymocyte globulin (rATG), Thymoglobuline® and ATG-F (Grafalon®), are frequently used to prevent GvHD in pediatric patients by in vivo T-cell depletion. Total rATG levels and active rATG levels were analyzed prospectively in pediatric patients undergoing HSCT. Clinical and laboratory outcome parameters were recorded. ResultsrATG levels were measured in 32 patients, 22 received thymoglobuline and 10 received ATG-F. The median total peak plasma level was 419.0 µg/ml for ATG-F and 60.4 µg/ml for thymoglobuline. For ATG-F, exposure could be predicted from the calculated dose more precisely than for thymoglobuline. Active peak plasma levels neither of ATG-F, nor of thymoglobuline correlated significantly with the number of lymphocytes prior to serotherapy. There was no significant difference in incidence of aGvHD, cGvHD, rejection, mixed chimerism or viral infections in the two cohorts. However, in our cohort, patients with high thymoglobuline exposure showed a compromised reconstitution of T cells. ConclusionsATG-F and thymoglobuline show different pharmacological and immunological impact in children, whose clinical significance needs to be investigated in larger cohorts.

Impact of donor and recipient characteristics on graft-versus-host disease and survival in HLA-matched sibling hematopoietic stem cell transplantation

ObjectiveTo analyze the impact of donor- and recipient-related factors on Graft-versus-host disease (GVHD) and overall survival of transplantation from matched sibling donors. Methodwe retrospectively analyzed the clinical features of 68 consecutive hematological patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) from matched sibling from 2011 and 2017. ResultsThe incidence of Ⅱ- Ⅳacute GVHD (aGVHD) and chronic GVHD (cGVHD) after transplantation was 13.6 % and 19.7 %, respectively. We also noted the donor and recipient characteristics had no impact on Ⅱ- Ⅳ aGVHD incidence.We found sex mismatch (F-M) did not increase the risk of cGVHD in the model if a female donor was younger than 30 years (P = 1.000), but cGVHD increased if the female donor was ≥30 years (P = 0.002). Recipients≥40 years undergoing HCT from donors ≥30 years were at higher risk for cGVHD (P = 0.021). Development of Ⅱ- Ⅳ aGVHD and cGVHD had no effect on overall survival (P = 0.159, 0.081). Non-remission status at allo-HCT was linked to lower overall survival (P = 0.001). ConclusionThe incidence of cGVHD was higher when male recipients received hematopoietic progenitor cells from female ≥30 years donors, and when older than 40 years recipients received hematopoietic progenitor cells from ≥30 years donors. Patients in non-remission status at allo-HCT was inclined to have lower overall survival.

Outcomes of Acute Myelogenous Leukemia Patients Undergoing Haploidentical Hematopoietic Cell Transplantation with Post-Transplant Cyclophosphamide: Impact of Total Body Irradiation Versus Chemotherapy-Based Myeloablative Conditioning

<h3>Background</h3> Optimal myeloablative conditioning (MAC) in the setting of haploidentical hematopoietic cell transplantation (haplo-HCT) with post-transplant cyclophosphamide (PTCy) is unknown. We studied the outcomes of total body irradiation (TBI) vs. chemotherapy (CT) based MAC regimens in acute myelogenous leukemia (AML) pts undergoing haplo-HCT and reported to EBMT. <h3>Methods</h3> The study included 1008 AML pts who underwent haplo-HCT during 2010-2018, following TBI (n=89, 9%) or CT (n=919, 91%) based MAC. Regimen intensity was defined by EBMT criteria and the cases with busulfan dose <9 mg/kg or TBI dose ≤6 gray were excluded. Fludarabine-TBI (78%) and Thiotepa-busulfan-fludarabine (56%) were the most common MAC regimens in TBI and CT-cohorts, respectively. Pts in TBI cohort were more likely to be younger (median age, 38 vs. 47 yrs, p<0.01) and receive BM graft (57% vs. 43%, p-0.01) Other pt, disease and transplant characteristics were similar in both groups. Median follow up for TBI and CT cohort were 25.4 and 20.7 months, respectively. <h3>Results</h3> In univariate analysis, day 100 incidence of acute GVHD (aGVHD) II-IV and III-VI was 22% vs. 27% (p-0.44) and 12% vs. 12% (p-0.92) in TBI and CT cohorts, respectively. Two-yr total and severe chronic GVHD (cGVHD) incidence were 42% vs. 27% (p<0.01) and 9% vs. 12% (p-0.33) in TBI and CT cohorts, respectively. Graft failure was reported in 2 (2%) and 65 (7%)(p-0.08) pts who received TBI and CT-based MAC, respectively. Three (1%) pts died due to graft failure in CT-group. Death from veno-occlusive disease was reported in 1(3%) TBI pt and 11(3%) CT pts. Death due interstitial pneumonitis was reported in 1 (3%) TBI and 8(2%) CT pts. One pt died from a second malignancy in each group. In multivariate analysis, TBI was associated with higher incidence of overall cGVHD [HR=1.81, 95% CI:1.14-2.87, p-0.01] compared to CT. There was no difference in other outcomes such as extensive cGVHD[HR=0.34, p-0.07], relapse incidence(RI) [HR=1.32, p-0.22], nonrelapse mortality(NRM) [HR=0.82, p-0.52] and leukemia free survival(LFS) [HR=1.09, p-0.62], overall survival(OS) [HR=1.07, p-0.71] and GVHD free relapse free survival (GRFS) [HR=1.02, p-0.92]. 2-yr LFS and OS of TBI and CT cohort were 45% vs. 49%,p-0.98 and 50% vs. 55%,p-0.79, respectively (figure 1). Factors impacting OS were pt age (per 10yrs, HR=1.1, p-0.02), KPS≥90 (HR=0.55,p<0.01) and advanced disease status before haplo-HCT (HR=2.35, p<0.01). In a subgroup analysis of pts <40 yrs old and pts with pre-HCT disease status CR2 or advance disease, no interaction was observed between type of MAC and RI, NRM, LFS, OS and GRFS. <h3>Conclusions</h3> In this large relatively homogenous cohort of AML patients who received haplo-HCT with PTCy, TBI based MAC was associated with higher incidence of overall cGVHD without impacting other transplant outcomes compared to CT based MAC. A prospective study is needed to validate these findings.

Allogeneic Stem Cell Transplantation from Two Loci Mismatched (≤6/8) Unrelated Donors in Acute Leukemia: On Behalf of the ALWP of the EBMT

Background Data on outcome of allogeneic transplantation (HSCT) from mismatched unrelated donors (MMUD) (≤6/8) in leukemic patients (pts) are limited. Methods We assess HSCT results in pts with AML/ALL in CR transplanted between 2000 and 2017 from ≤6/8 MMUD (2-4 HLA mismatches at the allelic level at loci A, B, C and DR) reported to the EBMT. Results A total of 465 pts were allocated, AML-320 and ALL-145. Median age was 50.2 years (range, 18-71.8) and 34.8 years (range, 18.2-62.9); 54% and 64% were males, respectively. Median F/U was 63 and 75 months, respectively. 69% and 66% were in CR1, while 31% and 34% were in CR2. 40% of AML pts had intermediate risk cytogenetics, 10% poor risk and 5% good risk (missing 45%),respectively. 37% of ALL pts were Ph positive, 22% Ph negative and 18% T ALL (17% B ALL with no Ph data,6% missing data). The number of HLA mismatches (HLAMM) was 6/8 - in 82% and 85%,5/8- in 11.5% and 12% and 3-4 in 6% and 3% of AML and ALL pts, respectively. 85% of AML pts and 77% of ALL pts received PBSC graft. Conditioning regimen was myeloablative in the majority of pts (89% of AML and 61% of ALL pts). 82% and 77% underwent in vivo TCD, respectively. GVHD prophylaxis was CSA/MTX in 51% and 67% and CSA/MMF in 21% and 10% of AML and ALL pts, respectively. Engraftment was achieved in 97% and 95% of pts, respectively. The incidence of acute (a) GVHD grade (Gr) II-IV and Gr III-IV was 34% and 41% and 14% and 21% for AML and ALL pts, respectively. Total and extensive chronic(c) GVHD rates at 2y were 38% and 38% and 23% and 14%, respectively. The main causes of death were disease recurrence (37% in both), GVHD (29% and 22%) and infections (22% and 26%).The 2 and 5y outcomes in the entire population were: RI-28% and 33%, NRM-28% and 30%; LFS-44% and 37%, OS- 50% and 41% and GRFS- 33% and 27%, respectively. More than 2 HLA mismatches were associated with a higher incidence of aGVHD Gr II-IV (29% vs 15%, respectively).In MVA, RI was lower for ALL vs AML HR (95% CI) 0.60, p=0.02. Disease status (CR2 vs CR1) was poor prognostic factor for RI, LFS and OS. Age was prognostic factor for NRM, LFS and OS. HLA mismatch at locus DR was poor prognostic factor, giving increased NRM: HR (95% CI) 1.68, p=0.02, and lower LFS: HR (95% CI), 1.42, p=0.03and OS HR (95% CI) 1.46, p=0.03and higher GVHD Gr II-IV HR (95% CI) 1.48, p=0.048. Results of MVA in AML pts in CR1 were similar. GVHD prophylaxis CSA/MMF in comparison to CSA/MTX resulted in higher NRM HR (95% CI) 2.2,p= 0.005 and lower GRFS HR (95% CI) 1.58, p=0.02.Notably, in 154 pts with AML in CR1 transplanted from ≤6/8 UD with T cell depletion c mismatches was associated with higher incidence of cGVHD HR (95% CI) 2.52, p=0.002. Summary and Conclusions HSCT from ≤6/8 MMUD transplantation can provide 40% 5y OS, 37% LFS and GRFS of 27% in leukemic pts. DR mismatch is a poor prognostic factor. cGVHD incidence at 5y is 41% with 21% being severe and is associated in AML pts with HLA C mismatches. CSA and MTX is the preferred GVHD prophylaxis.

Sustained Donor Chimerism and Rapid Immune Cell Reconstitution with a Low Probability of Gvhd Following Familial Haploidentical (FHI) CD34 Enriched Stem Cell Transplantation with Pbmnc Addback in Patients with High Risk Sickle Cell Disease (SCD) (IND 14359)

Background Allogeneic stem cell transplantation (AlloSCT) from an HLA-matched sibling donor is the only known curative therapy in high-risk SCD patients (Talano/Cairo, EJH, 2015). Unfortunately only about 15% of high-risk SCD patients have an HLA-matched unaffected sibling donor. T cell depletion has been employed to reduce AGVHD. We reported a very low incidence of GVHD in pediatric recipients receiving CD34 enriched HPC products with PBMNC addback from MUD donors (Geyer/Cairo et al, BJH, 2012). Rapid NK cell reconstitution after AlloSCT is associated with a significant improvement in 1yr OS (Pical-Izard, BBMT, 2015). Recently, we reported promising results for high-risk SCD patients at 1 yr follow-up after FHI CD34 enriched/PBMNC with addback with the probability of 1-yr OS 88.2% (Cairo, et al, JAMA Peds, 2019). Objective To investigate donor chimerism, immune reconstitution and the incidence of GVHD in high-risk SCD patients following AlloSCT using FHI CD34 enrichment/PBMNC (2 × 105 CD3/kg) addback. Methods CD34 cells were enriched using the CliniMACS® system, kindly provided by Miltenyi Biotec, with a target dose of 10 × 106 CD34+ cells/kg. PBMNC were added back to the final CD34 product at a dose of 2 × 10*5 CD3/kg. Whole blood and CD71-enriched erythroid lineage chimerism were determined by STR. Immune cell, subset reconstitution, NK function, CD107a and granzyme B were assessed by flow cytometry as previously described (Geyer/Cairo et al. BJH, 2012, Chu/Cairo et al, Can Imm Res, 2015). Results The cumulative incidence of grade II-IV and late AGVHD was 6.2 % and moderate and/or severe CGVHD incidence was 6.7%, respectively (Fig. 1A). There was 100% engraftment of neutrophils and platelets. The median day post-HISCT to neutrophil and platelet engraftment was +9 and +19, respectively. Whole blood donor chimerism (mean±SEM) at 1-yr, 2-ys, and 3-ys post-HISCT was 97±1%, 97±1%, 97±1%, respectively (Fig.1B). Donor chimerism for CD71-enriched erythroid lineage cells (mean±SEM) at 1-yr, 2-yrs, 3-yrs post-HISCT was 97±2%, 98±1%, 98±1%, respectively (Fig.1B). The time to recovery of minimal normal levels for CD3 (800 cells/ul), CD4 (400 cells/ul), CD8 (200 cells/ul), & CD19 cells (200 cells/ul), was approximately 365, 365, 270, and 60 days post-HISCT, respectively (Fig.1C). NK reconstitution was rapid and peaked at d+30 (36±9%) with higher level of activating receptors NKp46, NKG2D & KIR2DS and inhibitory receptors NKG2A, CD94 and KIR2DL2/3. NK cytotoxicity against K562 (E:T = 10:1) peaked at d+30 and d+180 vs pre-transplant (p Conclusion The PBMNC addback facilitated rapid donor chimerism & immune reconstitution with a low probability of Grade II-IV AGVHD. The rapid NK reconstitution may have in part contributed to the excellent 1yr OS in this study (FDA R01FD004090 (MSC)). This approach is comparable to the method of CD3 TCRa/b-CD19 depletion.

Celiac Disease Risk Determined By HLA-DQ Genotype Protects Against Gvhd in a Dose-Responsive Manner

Graft versus host disease (GVHD) causes significant morbidity and mortality after allogeneic stem cell transplant (SCT). Little is known about genetic determinants of GVHD risk, including human leukocyte antigen (HLA) genotypes outside of HLA-mismatch. HLA-DQ2 and DQ8 genotypes are associated with celiac disease (CD) and are present in ≥90% of patients with CD. Both GVHD and CD are systemic inflammatory conditions that may have T cell-mediated enteropathy. We hypothesized HLA-DQ alleles associated with CD risk would confer increased risks of acute (a) and chronic (c) GVHD in pediatric SCT recipients. We performed a retrospective cohort study of children aged 0-21 years undergoing first allogeneic SCT at the Children's Hospital of Philadelphia from 10/1/12 — 7/1/16. Patients with primary graft failure or missing HLA-DQ genotypes were excluded. We grouped patients by low, moderate or high CD risk (<i>Clin Gastroenterol Hepatol</i> 2009, 7:966). Primary outcomes were 1) 100-day aGVHD incidence; 2) day 100 — 1-year cGVHD incidence; and 3) time to GVHD with relapse, death, secondary graft failure, second SCT, or donor lymphocyte infusion as competing risks. Logistic regressions were used to calculate odds ratios (OR) and 95% confidence intervals (CI). Sub-distribution hazard models were used to estimate crude and adjusted sub-distribution hazard ratios (sHR) in time-to-event analyses. Multivariate models were adjusted for race-ethnicity, malignant/nonmalignant SCT indication, donor/mismatch, and graft source. We identified 167 patients (mean age 9.2 ±6.2 years). Proportions by CD risk were: low-risk n=108 (64.7%), moderate n=33 (19.8%), and high n=26 (15.6%). Day 100 incidence of ≥grade 2 aGVHD was 14.4% (8.4% had ≥grade 3). cGVHD 1-year incidence was 42.7% (14% had extensive). CD risk was protective against GVHD but did not reach statistical significance (Table 1). Risk of clinically significant GVHD (≥grade 2 or any chronic) was reduced in children with CD risk in the adjusted time-to-event model (moderate: sHR 0.42, 95% CI 0.18 — 0.95, p=0.037; high: sHR 0.31, 95% CI 0.12 – 0.8, p=0.016; Figure 1A). The protective effect of high CD risk was more pronounced for severe GVHD (≥grade 3 or chronic extensive) but did not reach statistical significance (adjusted sHR 0.14, 95%CI 0.02-1.09, <i>P =</i> 0.061; Figure 1B). In contrast to our hypothesis, CD risk by HLA-DQ is protective against GVHD in a dose-responsive manner. Reports of HLA-DQ2 and DQ8 protecting against other non-CD autoimmune diseases (rheumatoid arthritis and inflammatory bowel disease) support our observations. These results require confirmation and evaluation in a larger patient sample to define this novel GVHD risk modifier more robustly.

Effect of rhG-CSF Combined with Decitabine Prophylaxis on Relapse in High-Risk Acute Myeloid Leukemia Patients after Hematopoietic Stem Cell Transplantation: An Open-Label, Multicenter, Randomized, Controlled, Phase 2 Trial

Background: Recurrence is a major cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for high-risk acute myeloid leukemia (HR-AML). Recent studies have indicated that granulocyte colony-stimulating factor (G-CSF) and DNA methyltransferase inhibitor Decitabine (Dec) have regulatory effects on T/B/NK lymphocytes and could help enhance the graft versus leukemia (GVL) effect after allo-HSCT. The aim of this study was to prove G-CSF combined with minimal-dose Dec could effectively prevent AML relapse after allo-HSCT. Methods: We did an open-label, multicenter, randomized, controlled, phase 2 trial. 204 HR-AML patients 60-100 days after allo-HSCT were randomized 1:1 to either rhG-CSF combined with minimal-dose decitabine (G-Dec: G-Dec group: 100 µg/m2 of rhG-CSF subcutaneous injection on days 0-5 and 5 mg/m2 of Dec infusion on days 1-5) or no intervention (non-G-Dec) groups. The primary outcome of the trial was relapse after transplantation, and the secondary outcomes were chronic graft-versus-host disease (cGVHD), the safety of the treatment, leukemia-free survival and overall survival. Findings: Between Apr 1, 2016, and Mar 21, 2019, 220 patients from 12 transplant centers were included in the clinical study, and 204 patients were randomly assigned to the study groups (102 patients in the G-Dec group and 102 patients in non-G-Dec group). Median follow-up was 30 months (IQR 6-38). Of 204 evaluable patients, the estimated cumulative incidence of 2-year relapse in the G-Dec group was 15.1 (95% CI 8.0-22.2) %, compared with 38.3 (95% CI 28.9-47.7) % in the non-G-Dec group (P<0.001). There was no difference between the two groups in the incidence of cGVHD without relapse (23.8[95% CI 15.4-32.2] % and 25.6[95% CI 16.2-35.0] %, p=0.844). The most common treatment-emergent adverse event (TEAE) was hypoleukocytosis. After rhG-CSF combined with minimal-dose Dec maintenance, increasing numbers of NK, CD8+ T and regulatory T (Treg) cells were observed. Interpretation: Our findings suggest that rhG-CSF combined with minimal-dose Dec maintenance after allo-HSCT can reduce the incidence of relapse, accompanied by changes in the numbers and subtypes of lymphocytes, leading to the acquisition of graft-versus-leukemia and immune tolerance. Trial Registration: This study is registered with www.chictr.org.cn, number ChiCTR-IIR-16008182. Funding Statement: This research was supported by the National Key Research and Development Program of China (2016YFA0202104 and 2017YFA0105504), the Chinese National Natural Science Foundation (No. 81370593, No. 81570131 and No. 81570097), the Chongqing Social Undertakings, People's Livelihood Guarantee and Technology Innovation Foundation (cstc2016shms-ztzx10003), the Chongqing Key Project of Basic and Frontier Research Program (cstc2015jcyjBX0077), the Chongqing National Natural Science Key Foundation (cstc2019jcyj-zdxmX0023), the Research Fund from the Clinical Foundation of Army Medical University (2018JSLC0034) and Xinqiao Hospital (2018YQYLY007). Declaration of Interests: All authors have agreed to the submission of this manuscript and have no conflicting financial interests to disclose. Ethics Approval Statement: The protocol and all amendments were approved by the China Registered Clinical Laboratory Ethics Committee and the institutional review boards at each of the 12 participating institutions.

Delay of Regulatory T Cell Reconstitution in Elderly Patients Increases the Frequency of Chronic Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Background: Regulatory T cells (Treg) play important roles in onset of graft-versus-host disease (GVHD) and chronic GVHD (cGVHD) in elderly people is more frequent than in younger people after allogeneic hematopoietic stem cell transplantation (HCT). However, little is known about the differences in the number and function of Treg and natural killer (NK) cells in elderly and young patients. In this study, we examined the cause of the difference in incidences of cGVHD in these patient populations by measuring Treg and NK cells over time after HCT. Patients and Methods: The subjects were 65 consecutive patients aged &gt;18 years who underwent HCT for different hematologic diseases at our hospital between December 2008 and December 2018 and survived for &gt;100 days after HCT. The median age was 57 years (range: 19-73 years), and those aged ≥58 (n=33) and ≤57 (n=32) were classified as elderly and younger patients, respectively. Evaluated variables included recipient and donor characteristics, and transplant-related factors, including conditioning regimen, donor type, degree of match, and GVHD prophylaxis. After obtaining informed consent, blood was drawn from all patients on day 100 and at 12-month intervals thereafter. Analysis of CD4+CD25+Foxp3+ Treg cells, CD3+CD4+ T cells, CD3+CD8+ T cells, CD19+ B cells, and CD3-CD56+ NK cells was performed using flow cytometry, and the absolute numbers of these cells were calculated. NK activity was measured by the standard 51Cr release assay at an effector:target (E:T) ratio of 20:1. Results: The incidence of grades II-IV acute GVHD was 29.2% at 100 days. There was no difference in the incidence of acute GVHD between elderly and younger patients [HR=0.85, 95% CI 0.34-2.09, p=0.72]. However, the overall incidence of cGVHD was 37.1%. In univariate analysis, the incidence of cGVHD in elderly patients was significantly higher than that in younger patients [HR=3.61, 95% CI 1.13-11.59, p=0.031]. Elderly patients had a significantly lower percentage of B cells than younger patients at 24 months (13.4±9.6% vs. 27.0±15.6%, p=0.024) and 36 months (16.4±10.3% vs. 31.1±11.2%, p&lt;0.01); and also had a lower percentage and absolute number of Treg cells at 12 months (0.24±0.10% vs. 0.47±0.32%, p=0.010; 14.8±7.7 /µl vs. 24.0±18.4 /µl, p=0.061) and 36 months (0.17±0.15% vs. 0.37±0.20%, p&lt;0.01; 12.7±8.54 /µl vs. 20.9±12.9 /µl, p=0.046). The percentage and absolute number of CD8+ cells were higher in elderly patients at 12 months (50.4±17.2% vs. 33.5±12.9%, p&lt;0.01; 1130.5±588.5 /µl vs. 611.8±365.9 /µl, p=0.016) and 24 months (46.2±10.8% vs. 26.1±9.7%, p&lt;0.01; 1115.7±484.2 /µl vs. 584.2±372.2 /µl, p&lt;0.01). However, elderly patients had a lower percentage of NK cells at 12 months (11.9±8.0% vs. 20.1±14.5%, p=0.045) and lower NK activity at 24 months (24.0±14.0% vs. 47.6±16.3%, p&lt;0.01). The same results were obtained in 50 cases after exclusion of patients who developed cGVHD (≥58, n=22; ≤57, n=28). Thus, the 22 elderly patients had a lower percentage and absolute number of Treg cells at 12 months (0.22±0.16% vs. 0.47±0.32%, p=0.015; 14.1±8.3 /µl vs. 24.0±18.4 /µl, p=0.071) and 36 months (0.16±0.11% vs. 0.40±0.20%, p&lt;0.01; 12.2±9.2 /µl vs. 22.7±12.7 /µl, p=0.023), and a higher percentage and absolute number of CD8+ cells at 12 months (49.0±18.8% vs. 33.5±12.9%, p=0.031; 1181.9±619.0 /µl vs. 611.8±365.9 /µl, p=0.015) and 24 months (45.6±11.4% vs. 25.4±9.6%, p&lt;0.01; 1067.6±494.1 /µl vs. 587.1±382.9 /µl, p=0.012). Conclusion: The percentage and absolute number of Treg cells in elderly patients were significantly lower than those in younger patients, whereas CD8+ T cells were significantly higher in elderly patients after HCT. The absolute number of Treg cells tended to reconstitute one year after HCT in younger patients, but tended to decrease gradually in elderly patients, with no recovery even three years after HCT. In contrast, there was no change in NK cells. Similar results were obtained in an analysis excluding patients who developed cGVHD. These results suggest that a difference in immunological reconstitution between elderly and younger patients may explain the difference in the incidence of cGVHD between these patients. This may be useful in determining the choice of therapy with consideration of the immunologic mechanism. Disclosures Suzumiya: Celgene, Kyowa Kirin, Chugai-Roche, Eisai, Takeda, Celltrion, SymBio, Astellas, Ono, AstraZeneca, Ootsuka, Taiho, Mundi, Dainihon-Sumitomo: Research Funding.

Outcomes of Total Body Irradiation- Versus Chemotherapy-Based Myeloablative Conditioning Regimen in Haploidentical Hematopoietic Cell Transplantation with Post-Transplant Cyclophosphamide for Acute Myelogenous Leukemia: ALWP of the EBMT Study

Background The use of haploidentical hematopoietic cell transplantation (haplo-HCT) with post-transplant cyclophosphamide (PTCy) is rapidly increasing. The safety and efficacy of myeloablative conditioning (MAC) in haplo-HCT has been reported in patients with acute leukemia. However, optimal MAC in haplo-HCT setting is unknown. We studied the outcomes of total body irradiation (TBI) vs. chemotherapy (CT) based MAC regimens in acute myelogenous leukemia (AML) patients undergoing haplo-HCT and reported to the Acute Leukemia Working Party of the EBMT. Methods The study included 1008 AML patients (secondary AML=149, 15%) who underwent haplo-HCT with PTCy during the years 2010-2018, following TBI (n=89, 9%) or CT (n=919, 91%) based MAC. Regimen intensity was defined by EBMT criteria and cases with busulfan dose &lt;9 mg/kg or TBI dose ≤6 gray were excluded. Baseline AML cytogenetic risk group was good, intermediate and poor in 8%, 65% and 27% of patients respectively. All pre-HCT disease status (CR1=434, 43%; CR2+=216, 21%; advanced=358, 36%) were included in the study. fludarabine- TBI (78%) and thiotepa- busulfan- fludarabine (56%) were the most common MAC regimens in TBI and CT-cohorts, respectively. Patients in the TBI cohort were more likely to be younger (median age, 38 vs. 47 yrs, p&lt;0.01) and receive BM graft (57% vs. 43%, p-0.01) Other patient, disease, and transplant related characteristics were similar in both groups. Median follow up for TBI and CT cohort were 25.4 (IQR-9.5-58.7) and 20.7 (IQR-11.7-40.3) respectively. Results In univariate analysis, day 100 incidence of acute GVHD (aGVHD) II-IV and III-VI was 22% vs. 27% (p-0.44) and 12% vs. 12% (p-0.92) in TBI and CT cohorts respectively. Two-year total and severe chronic GVHD (cGVHD) incidence was 42% vs. 27% (p&lt;0.01) and 9% vs. 12% (p-0.33) in TBI and CT cohorts respectively. More patients achieved neutrophil engraftment by day 30 in the TBI cohort (97% vs. 86%,p-0.05). Graft failure was reported in 2 (2%) and 65 (7%)(p-0.08) patients who received TBI and CT-based MAC respectively. There were 3 (1%) deaths related to graft failure in the CT-group. Death from veno-occlusive disease was reported in 1(3%) TBI pt and 11(3%) CT patients. The proportions of infection related deaths (TBI-29% vs. CT-32%) and GVHD related deaths (TBI-17% vs. CT-15%) were comparable. Death due to interstitial pneumonitis was reported in 1(3%) TBI and 8(2%) CT patients. Death from a second malignancy was reported in one pt in each group. In multivariate analysis, TBI was associated with a higher incidence of overall cGVHD [HR=1.81, 95% CI:1.14-2.87, p-0.01] compared to CT. There was no difference in other outcomes such as extensive cGVHD [HR=0.34, 95% CI:0.11-1.10, p-0.07], relapse incidence(RI) [HR=1.32, 95% CI:0.85-2.03, p-0.22], nonrelapse mortality(NRM) [HR=0.82, 95% CI:0.46-1.49, p-0.52] and leukemia free survival(LFS) [HR=1.09, 95% CI:0.77-1.55, p-0.62], overall survival(OS) [HR=1.07, 95% CI:0.74-1.56, p-0.71] and GVHD free relapse free survival (GRFS) [HR=1.02, 95% CI:0.74-1.40, p-0.92]. Two-year LFS and OS of TBI and CT cohorts were 45% vs. 49% (p-0.98) and 50% vs. 55% (p-0.79) respectively (Figure 1). Factors impacting OS were pt age (per 10yrs, HR=1.1, p-0.02), KPS ≥90 (HR=0.55, p&lt;0.01) and advanced disease status before haplo-HCT (HR=2.35, p&lt;0.01)(Table 1). Interestingly, cytogenetic risk groups had no impact on LFS or OS in this analysis. No interaction was observed between the type of MAC and RI, NRM, LFS, OS and GRFS in a separate subgroup univariate analysis of patients &lt;40 yrs old and patients with pre-HCT disease status CR2 or advance disease. Conclusions In this large cohort of AML patients who received first haplo-HCT with PTCy, TBI based MAC was associated with higher incidence of overall cGVHD without impacting other transplant outcomes compared to CT based MAC. In the absence of a prospective study, these findings may guide clinicians when choosing an optimal MAC in haplo-HCT with PTCy. Disclosures Dholaria: Celgene: Honoraria. Labopin:Jazz Pharmaceuticals: Honoraria. Angelucci:Jazz Pharmaceuticals: Other: Local advisory board; Roche: Other: Local advisory board; Novatis: Honoraria, Other: Chair Steering Committee TELESTO protocol; Celgene: Honoraria, Other: Participation in DMC; BlueBirdBio: Other: Local advisory board; Vertex Pharmaceuticals Incorp., and CRISPR Therapeutics: Other: Participation in DMC. Blaise:Jazz Pharmaceuticals: Honoraria; Molmed: Consultancy, Honoraria; Sanofi: Honoraria; Pierre Fabre medicaments: Honoraria. Mohty:Jazz Pharmaceuticals: Honoraria, Research Funding.

Outcome of Two Loci Mismatched (≤6/8) Unrelated Donor Hematopoietic Cell Transplantation for Acute Leukemia: ALWP of the EBMT Study

Outcome of Two Loci Mismatched (≤6/8) Unrelated Donor Hematopoietic Cell Transplantation for Acute Leukemia: ALWP of the EBMT Study

Outcomes of Chronic Graft-Versus-Host Disease (cGVHD) Following Matched Sibling Donor (MSD) Versus Umbilical Cord Blood Transplant (UCBT)

Outcomes of Chronic Graft-Versus-Host Disease (cGVHD) Following Matched Sibling Donor (MSD) Versus Umbilical Cord Blood Transplant (UCBT)

Mesenchymal Stem Cells Improve the Structure and Function of the Graft-Versus-Host Disease Receptor Thymus: CCR9 Plays an Important Role in Its Homing Thymus

Background: Insufficient thymic function of allogeneic hematopoietic stem cell transplantation (allo-HSCT) receptors results in continuous production of alloreactive T cells, which leads to the development of graft-versus-host disease (GVHD), especially chronic GVHD (cGVHD). We have previously found that patients with acute GVHD (aGVHD) treated with mesenchymal stem cells (MSCs) have increased thymic output and decreased incidence of cGVHD, thus hypothesized that MSCs may reduce the incidence of cGVHD by remodeling the thymus. Chemokine receptor 9 (CCR9), the receptor that specifically guides migration of T-lineage precursors into thymus, is also expressed on MSCs, and thus may be a key factor mediating MSCs homing to the thymus. This in turn allows MSCs to reduce GVHD by repairing thymus tissue structure and saving thymus function. Methods: We carried out studies in a murine GVHD model of fully MHC-mismatched myeloablative bone marrow transplantation (C57BL/6 to BALB/c), a model that can observe the prolongation of aGVHD to cGVHD. We randomly divided GVHD mice into four groups, including three MSCs treated groups and one untreated group. CCR9 over-expressed (MSC/CCR9+), knocked-down (MSC/CCR9-) and empty-load MSCs (MSC/Control) were generated and administrated intravenously at dose of 5 × 105 cells/infusion at 7th and 21th day post HCT to the treated groups respectively to compare their thymic homing ability, and therapeutic effects of GVHD with the untreated group. Clinical scores were recorded once every five days to evaluate GVHD symptoms. Mice of MSCs treated groups and the untreated group were sacrificed at 30d, 45d and 60d after HCT. Thymuses of each group were collected and assessed for size and weight before being manufactured into frozen sections or thymic single-cell suspension. We then analyzed the number and distribution of MSCs in the thymus of the treated groups to assess the role of CCR9 in thymic homing, and analyzed the expression of thymic T cells subsets (CD4+CD8-, CD4-CD8+, CD4+CD8+ T, CD4+CD25+Foxp3+Tregs), thymic epithelial cells (TECs) substes (CD45-CD326+Ly51+ cortical TECs and CD45-CD326+UEA-1+ medullary TECs) and the level of T cell receptor rearrangement excision circles (TRECs) in thymus among the four groups to evaluate the repair effect of MSCs for thymus. Radiation-pretreated murine TECs were cultured alone or co-cultured with murine MSCs in vitro to assess the effect of MSCs on damaged TECs. Results: The infusion of MSC/CCR9+ potently alleviated the clinical signs of GVHD and prolonged the survival of GVHD mice (P&lt;0.05 versus MSC/CCR9- and untreated group). Significant increases in thymus size and weight were observed in the MSC/CCR9+ group, as well as the number of total thymocytes and the more organized cortical medullary structure compared to the other groups. MSCs enter the thymus from the microvascular region at the cortex-medium junction. MSC/CCR9+ were found to appear in the cortex-medium junction of thymus in a greater amount 24 hours after the first infusion, then distribute throughout the whole thymus and relocate in proximity with TECs 48 hours thereafter. MSC/Control could be observed in the cortical and cortex-medium junction, whereas MSC/CCR9- was observed only in the cortex-medium junction with a small amount of distribution. Immunofluorescence of thymus frozen sections showed that, compared with other groups, TECs had decreased apoptosis and significantly increased proliferation and maturation levels in MSC/CCR9+ group, indicating MSCs potently repaired injured TECs and promoted their proliferation and maturation. The number of TECs and its proportion of thymus stroma were significantly improved, including cortical TEC and medullary TECs. As for thymocyte, MSC/CCR9+ infusion significantly increased the number and proportion of CD4+CD8+T cells and Tregs, which were reported deficiency in GVHD thymus. Furthermore, MSC/CCR9+ administration resulted in a remarkable increase in the levels of TRECs in the thymocyte at 45d and 60d after HCT (P&lt;0.05 versus MSC/CCR9- and untreated group). In vitro study showed co-cultured TECs had a decreased apoptosis and increased proliferation compared to TECs cultured alone. Conclusion: This study demonstrates that CCR9 plays an important role in guiding migration of MSCs to thymus and thus highly intensify their issue repair and immunomodulatory effect to rescue thymus function in GVHD model. Disclosures No relevant conflicts of interest to declare.

Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia and Karnofsky Performance Status Score Equal or Lower Than 80%. a Study from the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia and Karnofsky Performance Status Score Equal or Lower Than 80%. a Study from the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Stem Cell Transplantation for Diamond-Blackfan Anemia. a Retrospective Study on Behalf of Severe Aplastic Anemia Working Party of the European Blood and Marrow Transplantation Group (EBMT)

Bader: Riemser, Neovii: Research Funding; Medac: Patents & Royalties, Research Funding; Amgen (Brasil), Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy. Risitano:Alexion: Honoraria, Research Funding, Speakers Bureau; Achillion: Research Funding; Apellis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Apellis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biocryst: Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria, Research Funding, Speakers Bureau; Amyndas: Consultancy; Samsung: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amyndas: Consultancy; Biocryst: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ra Pharma: Research Funding; Ra Pharma: Research Funding; Alnylam: Research Funding; Alnylam: Research Funding; Achillion: Research Funding. Peffault de Latour:Pfizer: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Alexion: Consultancy, Honoraria, Research Funding.

Efficacy and Safety of a FLAG-Sequential Regimen Followed By Hematopoietic Stem Cell Transplantation for Myelodysplasia or Acute Leukemia in Fanconi Anemia: A Franco-Brazilian Report

Background: Fanconi anemia (FA) is the most frequent genetic cause of bone marrow failure (BMF) due to a DNA repair mechanism defect. The natural history of FA is marked by progressive BMF during early childhood. Throughout life, the hematopoietic situation may change by clonal evolution toward myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for bone marrow failure in FA patients. The role of HSCT for FA patients with AML or advanced MDS is less defined. Currently, HSCT first line result offers 50% Overall Survival (OS) for patients with cytogenetic abnormalities only and 30% OS for patients with advanced MDS or AML in FA (Ayas et al., JCO 2013; Mitchell et al., BJH 2014). We previously reported a FLAG-sequential approach in 6 patients with FA (5 AML and 1 advanced MDS), all alive at a median follow-up of 28 months (Talbot et al., Hematologica 2014). We update here those patients and report 12 more patients treated by FLAG-sequential since then. Materials &amp; Methods: This retrospective study (2006-2019) was conducted in 7 centers in France and Brazil on behalf of the French Reference Center for Aplastic Anemia to evaluate FLAG-sequential in FA patients with morphological clonal evolution (no patients with cytogenetic abnormalities only). The study was conducted in accordance with the Declaration of Helsinki. Anonymous data collection was declared to the appropriate authorities. The FLAG-sequential treatment consisted of FLAG, Fludarabine 30 mg/m²/d for five days and Cytarabine 1 g/m²x2/d with G-CSF for five days, which was followed three weeks later by Cyclophosphamide 10 mg/kg/d for four days, Fludarabine 30 mg/m²/d for four days and TBI 2 Gy (Fig 1A). In a haploidentical setting, Cyclophosphamide at 30 mg/kg/d was performed only in post-transplantation, at Days +4 and +5 (Fig 1B). Results: Eighteen patients were included with 14 AML, 1 acute lymphoblastic leukemia (ALL), and 3 RAEB-2 (Table 1). The median age at the time of HSCT was 22 years (4-37 years). Fifteen patients (83%) were older than 10 years at the time of HSCT. The median follow-up was 31 months (3- 153 months). Eight patients (44%) had complex karyotype. None of the included patients had a history of solid malignancies before HSCT. All patients engrafted. The cumulative incidence of neutrophil engraftment at Day 60 was 94% (95% CI 63-100%) with a median of 18 days (12-343 days). The cumulative incidence of platelet engraftment at Day 60 was 83% (95% CI 50%-96%) with a median of 25 days (17-245 days). The donor chimerism was complete at Day +100 for 15 patients. The three patients without full donor chimerism at Day +100 either had a relapse (n=1) and 2 early deaths before Day+100 from steroid-refractory aGVHD (n=1) or septic shock (n=1). None of the patients received a second HSCT. Non-relapse mortality (NRM) at 3 years was 32% (95% CI 6-58%) (Fig 2). Cumulative incidence of grades II to IV aGVHD was 56% (35% grades III to IV). Cumulative incidence of extensive cGVHD was 16%. Infectious complications during HSCT include the following: CMV (n=8), EBV (n=2), adenovirus (n=4), BK virus (n=7), respiratory syncytial virus (n=1), candidaemias (n=2) and invasive aspergillosis (n=3). Progression free survival (PFS) and OS at 3 years were 53% (95%CI 32-89%) and 53% (95%CI 32-89%), respectively (Fig 2). Cumulative incidence of relapse at 3 years was 13% (95%CI 0-31%) (Fig 2). Seven patients died during the study. Causes of death were relapse (n=2), aGVHD (n=2), cGVHD (n=1), septic shock (n=1), and respiratory syncytial virus associated with invasive aspergillosis (n=1). GVHD-relapse free survival (GRFS) at 3 years was 48% (95%CI 29-78%). One patient had anal epidermoid carcinoma at 4 years after HSCT, which required multiple surgical ablations. Conclusion: With almost 3 years follow-up, which is long enough for our results to be considered robust, we report an OS and PFS of 53%, which compares favorably to historical controls since all of our 18 patients were treated with florid disease at time of HSCT (and not with cytogenetic abnormality only, known to be associated with a better prognosis). Toxicity is still a concern in this particular population of FA patients with notably a high rate of infectious complications. Future well designed prospective clinical trials will refine this sequential strategy, which appears promising in this particular difficult clinical situation. Disclosures Socie: Alexion: Consultancy. Peffault de Latour:Alexion: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding.

Graft Versus Host Disease (GVHD) after HLA-Mismatched Haploidentical Transplantation with Post-Transplant Cyclophosphamide Compared to Matched Unrelated Donor: Incidence, Distribution and Response to Therapy

Unmanipulated T-cell replete HLA-mismatched haploidentical transplantation (haplo) with post-transplant cyclophosphamide (PTCY) is now widely used for patients lacking a suitably matched donor. The use of PTCY post haplo results in lower chronic GVHD rates compared to match unrelated donors (MUD) without PTCY. GVHD after PTCY in the haplo setting may have different presentation, response to treatment and impact on survival endpoints compared to a standard GVHD prophylaxis of calcineurin inhibitor plus MMF or methotrexate for MUD patients. To check for differences in GVHD presentation and response to treatment between MUD and haplo with PTCY, we assessed 394 consecutive patients who developed acute or chronic GVHD after receiving their first allogeneic transplantation (HCT) from a 10/10 HLA MUD (n=179) or a haplo (n=215) at our center between 2008 and 2017. Median follow up for survivors was 52.5 months. Our institution has prospectively documented onset, grading and therapy of patients with GVHD using a single dedicated practitioner since 2005. All haplo patients received standard GVHD prophylaxis of tacrolimus (days 5-180), MMF (stop day 35) and PTCY at 50mg/kg on days 3 and 4. Most commonly used GVHD prophylaxis for MUD patients were tacrolimus/methotrexate (68%) and tacrolimus/MMF (26%). MUD recipients were older (median age 56 vs 53 years, p=0.007), were more likely to be white (93% vs 58%, p&lt;0.001), received mainly PBSC as graft source (76% vs 63%, p0.013) and had a higher HCT-comorbidity index (HCT-CI≥3, 64% vs 47%, p&lt;0.001) compared to haplo recipients. The cumulative incidences for grade II-IV and III-IV aGVHD at day 180 post HCT were similar between both donor sources at 35% and 11% for haplo compared to 44% and 16% for MUD (p=NS). Haplo patients had lower cumulative incidence of mod-severe cGVHD at 22% versus 31% for MUD (p=0.026).The median times to onset of grade II-IV acute GVHD and moderate-severe chronic GVHD were: acute, 56 vs 49 days (p=0.19) and chronic 213 vs 280 days (p=0.011) for haplo versus MUD patients respectively. Among patients with grade II-IV acute GVHD, there was no significant difference in organ involvement between Haplo (n=101) and MUD (n=96) with skin being most commonly affected (74% haplo vs 71% MUD), Gut (70% haplo vs 69% MUD) and liver (14% haplo vs 17% MUD). For patients who developed chronic GVHD, organ involvement distribution is shown in table 1. Haplo patients had less involvement of the eyes (46% vs 75% for MUD, p&lt;0.001) and of the joints/fascia (12% vs 36%, p=0.001). Among patients who developed grade II-IV acute GVHD, there was no difference in all-cause mortality (28% vs 19%, p=0.34) and being off immunosuppression at one 1 year (49% vs 51% p=0.80) between haplo and MUD recipients. Among patients who developed cGVHD, haplo recipients had similar all-cause mortality (22% vs 18%, p=0.89) but were more likely to be off immunosuppression at 2 years post HCT (63% vs 43% p=0.03) compared to MUD (figure 1). A cox model was conducted on survival and relapse endpoints where donor type was retained in all models. The fixed covariates tested in Cox models included age (&lt;55, &gt;=55), gender, race, diagnosis, regimen intensity, graft source (BM, PBSC), disease risk index (low/intermediate, high/very high), CIBMTR risk (low, intermediate, high), HCT-CI (0-2, &gt;=3), CMV status, year of transplantation (2008-2012, 2013-2015, 2016-2017). The following variables were evaluated as time-dependent covariates in Cox models: all-grade cGVHD, moderate-severe cGVHD, severe cGVHD, grade 2-4 aGVHD, grade 3-4 aGVHD. Variables were selected if p values were less than 0.05. Developing grade 3-4aGVHD and severe chronic GVHD were both associated with worse OS, DFS and TRM (table 2). Both aGVHD and cGVHD were not significant factors for relapse. Our analysis reveals that compared to MUD, haplo transplant results in significantly lower incidence of moderate-severe chronic GVHD, faster cGVHD onset, different organ distribution and a higher chance of coming off immunosuppression. This data, added to prior publications from our center and others showing similar OS and DFS between MUD and haplo, enforces the notion that haplo transplant with PTCY is at least equivalent to MUD transplant. An ongoing BMTCTN 1702(CTRL-ALT-D) study will help answer assess this in a prospective fashion. figure 1: Chronic GVHD patients who are Immunosuppression free at 2 years Table 1: Organ Distribution of Chronic GVHD by Donor Type Disclosures No relevant conflicts of interest to declare.

Autologous and Allogeneic Hematopoietic Stem-Cell Transplantation for Patients with Richter's Syndrome: A Large Series from the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation

Introduction. Chronic lymphocytic leukemia (CLL) has typically an indolent course but can undergo transformation into a more aggressive lymphoma so called Richter's syndrome. While the advent of novel targeted therapies is transforming the management of patients with CLL, these drugs failed to prevent the risk of RS. RS is associated with a very poor outcome and is thus becoming the main obstacle to long term CLL control. Autologous (auto-) and allogeneic (allo-) hematopoietic stem-cell transplantation (-SCT) have been recommended as the treatment of choice in eligible patients with clonally related RS (Rossi Blood 2018) but previous experience is still limited to less than 50 cases. We here aimed to investigate the safety and efficacy of both auto- and allo-SCT for patients with RS in a large cohort in a period overlapping the advent of novel agents. Methods. We report on a retrospective study of consecutive adult patients with RS who underwent auto- or allo-SCT between 2008 and 2018 in EBMT centers. Results. A total of 197 patients (M/F= 133/64) were included in the present study; 125 patients received allo-SCT and 72 auto-SCT. The main difference between these 2 cohorts was the median age at transplant that was lower in the allo- than in the auto-SCT group (median age 57 [18-71] vs 61 [39-74] years, p = 0.006). Regarding the allo-SCT cohort, median time from RS diagnosis to SCT was 10 months [1.1-322.8] and 54.2% had received &gt;2 therapeutic lines for RS. At allo-SCT, 60 (48.4%) were in CR and 53 (42.7%) in PR or SD. Most patients received reduced intensity conditioning (RIC) regimen (n= 90, 72.6%) and peripheral blood (89.6%) as stem cell source. Donors were related (matched, n=40 (33%) or mismatched, n=4 (3%)) or unrelated (matched, n= 76 (61%) and mismatched, n=4 (3%). A total of 41 patients (33.6%) received total body irradiation (TBI). With a median follow-up of 48 months, 2-year OS was 46% (36-55%) and 2-year PFS 38% (28-48%). Two-year cumulative incidence of relapse (CIR) was 31% (22-40%) as was the 2-year NRM (Figure 1). Two-year CIR was significantly reduced in patients with ≤2 therapeutic lines for RS (12% (1-22%) vs 41% (26-55%); p=0.005). Performance status affected 2-y PFS (24% (7-42%) if Karnofsky index &lt;90% vs 43% (31-54%) if ≥90%, p = 0.02) and 2-y CIR (52% (33-71%) if Karnofsky index &lt;90% vs 25% (15-35%) if ≥90%, p = 0.004). Considering death as a competing risk, the day 100 incidence of aGVHD, 2-years limited and extensive cGVHD were 34% (25-43%), 20% (11-28%) and 33% (23-43%). Main causes of death were relapse (30%), GVHD (25%) and infection (30%). Regarding the auto-HSCT cohort, median time from RS diagnosis to HSCT was 7.8 months [2.6-102.7] and 66.7% had received &gt;2 lines for RS. At auto-SCT, 36 (52.2%) were in CR and 36 (37.7%) in PR or SD. With a median follow-up of 18 months, 2-year OS was 69 % (56-82%) and 2-year PFS 47% (33-62%). Two-year cumulative incidence of relapse (CIR) was 46% (32-60%) and 2-year NRM was 7% (0-13%) (Figure 2). CR patients presented better PFS (69% (50-88%) vs 29% (9-50%); p=0.002) and OS (82% (66-97%) vs 56% (35-78%) ; p=0.03). Performance status affected 2-y PFS (25% (2-48%) if Karnofsky index &lt;90% vs 55% (38-73%) if &gt;90%, p = 0.005) and 2-y OS (55% (29-82%) if Karnofsky index &lt;90% vs 75% (60-90%) if &gt;90%, p = 0.04). Disclosures Guièze: Janssen: Honoraria; Gilead: Honoraria; Roche: Honoraria; Abbvie: Honoraria. Byrne:Ariad/Incyte: Honoraria, Speakers Bureau. Finke:Riemser: Honoraria, Other: research support, Speakers Bureau; Neovii: Honoraria, Other: research support, Speakers Bureau; Medac: Honoraria, Other: research support, Speakers Bureau. Chevallier:Incyte: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Daiichi Sankyo: Honoraria.