Moderate-severe cGVHD Research Articles

Cumulative Incidence of Subsequent Malignancy after Allo-HCT with Myeloablative Chemotherapy Plus Low-Dose Total Body Irradiation Versus Myeloablative Chemotherapy Alone.

<h3>Introduction</h3> Total body irradiation (TBI) has been described as a major risk factor for the development of subsequent malignancies (SMs) after allogeneic hematopoietic cell transplant (allo-HCT). However, a recent study found that lower doses (< 450cGy) of TBI used with non-myeloablative conditioning conferred no more risk than that attributed to treatment with myeloablative chemotherapy alone. It is not clear whether addition of low dose TBI to myeloablative chemotherapy protocols increases risk of SM. At our centre, in approximately 2004, 400 cGy TBI was added to our standard myeloablative fludarabine/busulfan regimen. We hypothesized that no significant difference in the cumulative incidence of SMs would be observed between the cohort of patients who received myeloablative chemotherapy (no TBI group) versus those who received the same plus 400cGy of TBI in 2 fractions (TBI group). <h3>Methods</h3> We identified 676 sequentially treated 1-year survivors who received a first allo-HCT between 1999 and 2014 from a provincial database. All patients but one (aplastic anemia) received HCT for hematological malignancies. The cumulative incidence of SMs in the TBI group (N=424) & no TBI group (N=252) were compared using a multivariate competing risk regression model. Death without SM was treated as a competing risk. Covariates included age at HCT, sex, moderate-severe cGVHD & stem cell source. Squamous and basal cell carcinomas of the skin, post-transplant lymphoproliferative disease, and relapse of primary malignancy were excluded. <h3>Results</h3> Median age at HCT was 47 (IQR 36-56). A total of 47 patients developed 54 SMs at a median of 5.7 years post HCT (IQR 1.2-12.9 years). At a median follow-up for surviving patients of 8.1 years (range 1.1-19.8 years), the cumulative incidence of SM was 7.0% (95% CI: 5.3-9.1%). Sites of malignancy were: gastrointestinal (N=11), genitourinary/gynecologic (N=10), lung (N=9), skin (N=7), prostate (N=5), breast (N=4), thyroid (N=3), oropharyngeal (N=3) and hematologic (N=2). TBI was not associated with increased risk of SMs when compared to the chemotherapy-alone regimen (figure 1, sHR 0.68, 95% CI 0.39-1.19, p=0.18), while older age at HCT (sHR 1.07, 95% CI 1.04-1.1, p<0.001) and a history of moderate-severe cGVHD (sHR 1.76, 95% CI 0.99-3.14, p=0.056) were. <h3>Conclusion</h3> Low dose TBI added to myeloablative chemotherapy does not appear to be associated with an increased risk of SMs when compared to myeloablative chemotherapy alone. These data may inform patient counselling and cancer screening practices for allo-HCT recipients that have been treated with myeloablative chemotherapy plus low dose TBI protocols.

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.

Outcomes of Haploidentical Haematopoietic Stem Cell Transplantation for Paroxysmal Nocturnal Haemoglobinuria

Background: Haematopoietic stem cell transplantation (HSCT) is the only curative therapy for paroxysmal nocturnal haemoglobinuria (PNH). Haploidentical HSCT (haplo-HSCT) is an alternative treatment method for PNH patients lacking suitable identical donors. The current study evaluated the feasibility of haplo-HSCT in PNH patients. Methods: We retrospectively analysed the outcomes of 28 PNH patients who received haplo-HSCT between October 2010 and December 2018. Results: The median age was 28 (range 6-54) years. One patient (underwent HSCT in December 2018) was not evaluable for engraftment or haematopoietic recovery because of early death on day +14 due to septicaemia. The 27 evaluable patients all achieved myeloid engraftment and complete chimerism, and one patient experienced secondary graft failure. Three patients demonstrated delayed platelet recovery, and one patient demonstrated platelet graft failure. The median time to neutrophil recovery was 12 (range, 9-26) days, and the median time to platelet recovery was 16 (range, 11-75) days. The cumulative incidences were 29.63% for grades I to IV acute graft-versus-host disease (aGVHD) and 14.82% for grades II to IV aGVHD. No patient experienced grades III to IV aGVHD. With a median follow-up time of 37 (range 4-78) months, the cumulative incidence of chronic graft-versus-host disease (cGVHD) was 28.81%, and the cumulative incidence of moderate-severe cGVHD was 11.73%. No patient relapsed during the follow-up period. The 12-month transplantation-related mortality (TRM) rate was 15.25%. The probabilities of 3-year overall survival (OS) and graft-versus-host disease-free, failure-free survival (GFFS) were 84.8 ± 7.1% and 77.0 ± 8.3%, respectively. Conclusions: The preliminary results indicated that haplo-HSCT is a feasible option for PNH patients lacking suitable identical donors. Disclosures No relevant conflicts of interest to declare.

Differential Expression of Immunity Related Genes Can Predict Moderate-Severe Chronic GvHD Early after Myeloablative Hematopoietic Stem Cell Transplantation.

Introduction Chronic graft versus host disease is the major cause of poor outcomes after allogeneic hematopoietic cell transplantation (HCT). Clinically significant moderate-severe chronic GvHD (cGvHD) rarely shows a sustained complete response to immunosuppressive drugs and non-responders either die or suffer long-term. Early and accurate prediction of ensuing cGvHD can help identify high risk patients to make preemptive treatment possible. In the present study, we retrospectively analyzed the transcriptome of immunity related genes at one month post-transplant with the aim to identify a potential early and accurate predictor of clinically significant cGvHD. Methods An adult retrospective cohort of 73 human leukocyte antigen (HLA) matched myeloablative allogeneic HCT recipients were included. All patients received 4.5 mg/kg antithymocyte globulin as GvHD prophylaxis. Diagnosis of cGvHD was based on National Institutes of Health consensus criteria with the median day of diagnosis being 126 days. Total RNA extracted from cryopreserved peripheral blood mononuclear cells at one month post-transplant was used to run a gene expression CodeSet profiling of 594 immunity related genes including 15 internal reference genes using Nanostring Technology. Benjamini Hochberg procedure was used to calculate the P value and the false discovery rate (FDR) of differentially expressed genes. Results A set of 12 differentially expressed genes with a Benjamini Hochberg P-value (BHP) of 7 in this panel of 12 genes was able identify patients with high risk of developing mod-severe cGVHD with a sensitivity of 79% and specificity of 88% (AUC = 0.88, P Conclusion The robust and rapid technique of Nanostring based transcriptome profiling identified a gene panel consisting of 12 genes for an early prediction of moderate-severe cGVHD (one month) with high sensitivity and specificity. A precision medicine approach of preemptive treatment of cGVHD can be possible using this study leading to improved outcomes of HCT.

Optimizing Post-Allogeneic Hematopoietic Cell Transplant Outcomes for Lymphoma Using Ibrutinib: Early Safety Results of a Multicenter Study

Background Ibrutinib is approved for a variety of B-cell malignancies, including CLL and MCL, and for chronic GVHD (cGVHD), failing ≥ 1 line of systemic therapy. Allogeneic HCT is curative for CLL and MCL, but success is limited due to relapse or GVHD morbidity/mortality. We hypothesized that use of ibrutinib early post HCT would optimize outcomes by improving progression-free survival (primary outcome) and decrease incidence of moderate-severe cGVHD (secondary endpoint). We describe our findings regarding safety and feasibility in the first 16 patients (NCT02869633). Methods Adult patients (pts) undergoing T-replete HCT from related or unrelated donors (7/8 or 8/8) without post-transplant cyclophosphamide for CLL (>CR1, or after 1st line if 17p) or MCL (>CR1, or after 1st line if blastoid variant) were enrolled, along with an exploratory cohort of FL and HL (max 10 patients). Use of ibrutinib prior to HCT was permissible. Enrollment was prior to HCT, but pts had to meet secondary eligibility criteria to ensure no critical illness, adequacy of graft and organ function, prior to starting ibrutinib (420 mg daily) between day 60-90. Ibrutinib was continued until 12 m post HCT. Results Sixteen pts (CLL 44%, MCL 13%, FL 25%, HD 13%), median age 49.5 y, underwent HCT from unrelated (94%) or related donors (6%), that were 8/8 (88%) or 7/8 (12%) HLA matched, at a median of 30.2 m after diagnosis. Median follow up from HCT is 5.1 m and 1 y survival is 75%. Regimens included FCR-thymoglobulin (44%), TLI-ATG (31%), Flu Bu (13%) or Flu Mel (12%). GVHD prophylaxis was tacrolimus-MTX (69%) or CSA-MMF (31%). Of the 14 pts eligible to start ibrutinib (> 60 d post HCT), 9 started ibrutinib (64%), while 5 did not (4-not meet secondary eligibility criteria, 1-physician preference). The median starting dose was 140 mg (protocol specified due to drug interactions). Of the 9 pts who started ibrutinib, 2 (22%) had to stop it prematurely (cytopenias, confounded by concomitant medications), 3 (33%) completed therapy and 4 (45%) are on therapy. Table 1 outlines key ≥ grade 3 adverse events (AEs) at any time point after enrollment. In this group of 9 pts, aGVHD grade 0, 1, 3 and 4 was seen in 57%, 22%, 7% and 14%, and cGVHD was seen in 3 pts (7%-mild, 14%-severe). No pts had progression of disease (CR-67%, PR-11%, SD-22%); 2 pts are deceased (1-infection at 14 m post HCT in CR, and 1 from acute GVHD (onset prior to start of ibrutinib with SD). Conclusions Our data in this ongoing study shows that majority of patients could initiate early post HCT ibrutinib and most are expected to tolerate it until 1 y post HCT. No unexpected side effects have been seen with use of ibrutinib early post HCT, and there have been no relapses.

A Phase I/2 Study of Ixazomib for Chronic Graft-Versus-Host Disease (cGVHD) Prophylaxis after Allogeneic Transplantation (alloHCT).

Background Chronic GVHD (cGVHD) causes significant morbidity and mortality after alloHCT. Oral proteasome inhibitor, ixazomib (Ixa) regulates dendritic cell maturation, decreases proinflammatory cytokines and modulates GVHD in murine model. The efficacy of Ixa in preventing cGVHD is unknown. Methods We report here a phase 1/2 trial (NCT02250300) evaluating safety and efficacy of Ixa for cGVHD prophylaxis. Adult hematologic malignancy patients (pts) status post a peripheral blood (PB) alloHCT with tacrolimus/methotrexate-based GVHD prophylaxis and no grade 3-4 aGVHD or steroid-refractory aGVHD were eligible. Recipients of matched related donor (MRD) and matched unrelated donor (MUD) alloHCT were enrolled in 2 independent cohorts. In vivo and ex vivo T-cell depletion was not permitted. Oral Ixa was started days 60-90 post-HCT for 4 weekly doses. Primary outcome was cumulative incidence (CI) of cGVHD at 1-yr by NIH criteria. The cGVHD was graded by an Independent Review Panel (IRP). Results No dose-limiting toxicities were seen in phase I and recommended phase II dose was 4 mg. 25 MRD and 26 MUD alloHCT pts were enrolled. The IRP assessed CI of cGVHD at 1-yr was 31% and 37% in MRD and MUD cohorts, respectively. The respective figures for moderate-severe cGVHD were 22% and 28%. 1-yr non-relapse mortality and relapse in MRD and MUD cohorts were 0% and 4% and 20% and 35%, respectively. 1-yr PFS of 80% and 64% and 1-year OS of 92% and 88% were seen in MRD and MUD cohorts, respectively. Serum B-cell activating factor (BAFF) levels before and after Ixa exposure increased significantly in pts who did not develop cGVHD (median, 2459 vs. 6969 pg/mL, p=.001), and in those without moderate/severe cGVHD (median, 2989 vs. 6438 pg/mL, p=.002). Treg counts before and after Ixa (median, 34 vs. 34.5/µL) for the overall cohort were similar. Conclusion Ixa is feasible, safe and potentially effective for cGVHD prophylaxis after PB alloHCT. BAFF level after Ixa may serve as a biomarker for later development of cGVHD.

The association between physical functioning, symptom burden, and coping strategies with quality of life (QOL) in patients with chronic graft-versus-host disease (cGVHD).

178 Background: Allogeneic stem cell transplant survivors with cGVHD experience substantial psychological distress and impairments in QOL. However, the relationship between patients’ physical functioning, symptom burden, coping strategies, and QOL over time is unknown. Methods: We conducted a longitudinal study of patients with moderate-severe cGVHD. We assessed patient-reported psychological distress (Hospital Anxiety and Depression Scale), QOL (Functional Assessment of Cancer Therapy-General), physical functioning (Human Activity Profile), cGVHD symptom burden (Lee Symptom Scale), and coping (Coping Inventory for Stressful Situations) at baseline, 3 months, and 6 months. Using mixed linear effects models, we examined the longitudinal relationship between QOL and physical functioning, cGVHD symptoms, and coping strategies. Results: We enrolled 53 patients with moderate (71.7%, 38/53) or severe (28.3%, 15/53) cGVHD. The rate of clinically significant depression and anxiety symptoms at baseline was 32.1% (17/53) and 30.2% (16/33), respectively, and did not change over time. Patients reported low QOL at baseline [M = 70.33, SD = 18.96], which did not change significantly over time [β = -0.66, SE = 1.11, P = 0.550]. Over time, higher physical functioning was associated with better QOL [β = 0.17, SE = 0.05, P = 0.001], while greater symptom burden was associated with worse QOL [β = -0.38, SE = 0.06, P &lt; 0.001]. While the use of emotion-oriented coping was associated with lower QOL over time [β = -0.70, SE = 0.14, P &lt; 0.001], the use of avoidance-oriented coping was associated with higher QOL over time [β = 0.38, SE = 0.10, P &lt; 0.001]. Task-oriented coping was not associated with psychological distress or QOL. Conclusions: Patients with moderate-severe cGVHD report substantial psychological distress and persistently impaired QOL over time. Higher physical function and lower symptom burden are associated with improved QOL. The use of certain coping strategies was associated with changes in QOL. These data underscore the need for supportive care interventions to promote effective coping and enhance physical functioning in patients with cGVHD.

Early Prediction of Moderate-Severe Chronic GvHD By Immunity Related Transcriptome

Introduction:Graft versus host disease (GvHD) is the most common and debilitating complication of allogeneic hematopoietic cell transplantation (HCT). Among the two clinically significant forms, moderate-severe chronic GvHD (cGvHD) is more difficult to treat than grade 2-4 acute GvHD (aGvHD). Chronic GvHD rarely shows a sustained complete response to immunosuppressive drugs and non-responders either die or suffer long-term. However, if an early and accurate prediction of ensuing cGvHD is posiible, then the high risk patients can be identified and treated preemptively. In the present investigation, we retrospectively analyzed the transcriptome of immunity related genes at one month post-transplant with the aim to identify a potential early and accurate predictor of clinically significant cGvHD.Methods:A cohort of 73 HLA matched first allogeneic HCT recipients with moderate-severe cGvHD (n = 31) and no chronic GvHD (n = 42) were included in the study. All patients received similar myeloablative conditioning regimens along with 4.5 mg/kg antithymocyte globulin as GvHD prophylaxis. The diagnosis of cGvHD was based on National Institutes of Health consensus criteria and median day of diagnosis in our cohort was 126 days. Total RNA was extracted from cryopreserved peripheral blood mononuclear cells (PBMNCs) at one month post-transplant. Gene expression CodeSet profiling of 594 immunity related genes including 15 internal reference genes was performed using Nano string Technology Immunology panel. Differential gene expression and receiver operating characteristic (ROC) analyses was performed using R statistical packages and GraphPad PRISM software. Benjamini Hochberg procedure was used to calculate the P value and the false discovery rate (FDR). Differentially expressed genes with a Benjamini Hochberg P value (BHP) of <0.05 and FDR of <0.01 were considered significant. Cumulative incidence of moderate-severe chronic GvHD was calculated using Fine-Gray competing risk analysis.Results:A gene panel consisting of immunity related 12 genes was identified at one month post-transplant whose transcriptome profile was significantly different between patients that developed moderate-severe cGvHD compared to the patients who did not develop cGvHD. The identified gene panel included highly upregulated T cell activation and proliferation markers like CD3D (BHP=0.005), CD3E (BHP=0.01), CCR7 (BHP=0.005), CD5 (BHP=0.006); TNF receptor superfamily markers like B- and T-lymphocyte attenuator-BTLA (BHP=0.004), CD27 (BHP=0.004), CD40LG (BHP=0.005); and Costimulatory signaling molecules like Inducible T-cell Co-stimulator ICOS (BHP=0.001), CD28 (BHP=0.006) in patients with cGVHD. A gene score of >7 in this panel of 12 genes was able to differentiate patients with high risk of developing mod-severe cGvHD with a sensitivity of 79% and specificity of 88% (AUC = 0.88, P <0.0001) (Figure 1).Conclusions:The cGvHD gene panel consisting of 12 genes from multiple immune regulatory pathways identified in the present study provided an early prediction of moderate-severe cGvHD (one month) with high sensitivity and specificity. The robust and rapid technique of nanostring based transcriptome profiling has the potential to be implemented in the clinic. Differentiating patients at high risk of mod-severe cGvHD can help develop new strategies for preemptive therapy and pave the way towards precision medicine leading to improved outcomes of HCT. DisclosuresNo relevant conflicts of interest to declare.

High Pre-HCT Exposure to Thymoglobulin Is Associated with a Low Incidence of Relapse

IntroductionThe most frequent serious complications of allogeneic hematopoietic cell transplant (HCT) are leukemia relapse and graft-vs-host disease (GVHD). Rabbit anti-T cell globulin (ATG, Thymoglobulin) reduces GVHD without increasing relapse, as shown in 3 randomized studies (Chang et al. Cancer 2017, Walker et al. Lancet Oncol 2016, Bacigalupo et al. BBMT 2006). ATG has a direct anti-leukemic effect in vitro (Dabas et al. BBMT 2016, Dabas et al. BMT 2018 in press). In spite of that, in the randomized studies ATG did not reduce relapse. We hypothesized that this could be due to differential effects of ATG pre- vs post-HCT on relapse. Specifically, post-HCT (but not pre-HCT), the anti-leukemic effect of ATG could be countered by ATG impairing graft-vs-leukemia effect (GVL). Here we set out to determine whether pre- vs post-HCT ATG area-under-the-curve (AUC) is associated with relapse and GVHD, the latter possibly being a surrogate for GVL.MethodsA total of 153 patients were studied. All received first allogeneic HCT using conditioning with fludarabine (250 mg/m2), busulfan (~12.8 mg/kg) + TBI (4 Gy) and GVHD prophylaxis with rabbit ATG (0.5 mg/kg on day -2, 2 mg/kg on day -1 and 2 mg/kg on day 0 before graft infusion), methotrexate and cyclosporine. Serum was collected at the end of the last ATG infusion, immediately pre-graft infusion, 30 minutes after the end of graft infusion and days 7 and 28.Serum levels of ATG capable of binding to total mononuclear cells (MNCs) were determined using a flow cytometry-based assay (similar to Podgorny et al. BBMT 2010). Pre-HCT ATG AUC was estimated from ATG levels at the end of the last ATG infusion and pre-graft infusion. Post-HCT ATG AUC was estimated from the ATG levels 30 minutes post graft infusion and on days 7 and 28. AUCs were split into above and below median for analysis.Multivariate competing risks regression (according to Fine and Gray) was used to determine whether high ATG AUC was associated with the cumulative incidence of relapse. Multivariate Cox regression was used to determine if high ATG AUC was associated with relapse-free survival (RFS).ResultsHigh (above median) pre-HCT AUC was associated with a lower incidence of relapse (SHR=0.430, P=0.029) (Fig. 1, top). It was also associated with improved RFS (HR=0.534, P=0.040). For post-HCT AUC, there appeared to be a trend toward an opposite association - high (above median) post-HCT AUC associated with a higher incidence of relapse (SHR=1.470, P=0.302) (Fig. 1, bottom). There was no association between high post-HCT AUC and RFS.Regarding GVHD, there appeared to be a trend toward an association between high pre-HCT AUC and a lower incidence of significant GVHD (grade 2-4 aGVHD or moderate-severe cGVHD) (SHR=0.667, P=0.128) (Fig. 2, top). A strong and significant association was observed between high post-HCT AUC and a lower incidence of significant GVHD (SHR=0.462, P=0.005) (Fig. 2, bottom).ConclusionHigh pre-HCT ATG AUC appears to result in less relapse and improved RFS. This may be the in vivo reflection of the known anti-leukemic activity of ATG in vitro. In contrast, high post-HCT AUC appears to have a neutral or deleterious impact on relapse. As high post-HCT AUC is strongly associated with a low incidence of GVHD, which may be a surrogate for weak GVL, it is possible that after HCT, the anti-leukemic effect of ATG is overshadowed by its anti-GVL effect. DisclosuresNo relevant conflicts of interest to declare.

Haploidentical Allogeneic Hematopoietic Cell Transplantation for Mantle Cell Lymphoma Using Post-Transplantation Cyclophosphamide Graft-Versus-Host Disease Prophylaxis

Allogeneic Hematopoietic Cell Transplantation (allo-HCT) currently represents the only potentially curative therapy for patients affected by advanced Mantle Cell Lymphoma (MCL). Haploidentical HCT (haplo-HCT) allows virtually all patients to proceed to allo-HCT.We analyzed survival outcomes of 20 MCL patients who received haplo-HCT at Humanitas Cancer Center and Institut Paoli Calmettes between 2012 and 2017. Median age of patients at transplant was 64 years (range, 35-71). Ten of them (50%) relapsed after autologous transplantation, one patient relapsed after allo-HCT (HLA identical sibling), while 9 underwent directly haplo-HCT due to the high risk of relapse (primary refractory disease). All patients except one had chemosensitive disease at transplant (75% complete response, 20% partial response, 5% progressive disease). In 10 patients, novel drugs were used as bridge to transplant to obtain response (8 patients were treated with ibrutinib, one with lenalidomide and one with bortezomib).The hematopoietic-cell-transplantation comorbidity index (HCT-CI) was 0-1 in 4 patients, 2-3 in 12 patients and 4-5 in 4 of them. In 5 patients bone marrow was used as the source of stem cells, while the other 15 received peripheral blood stem cells. Sixteen patients received a nonmyeloablative conditioning regimen while 4 patients underwent a reduced intensity conditioning regimen. In all patients, post-transplant cyclophosphamide (PT-Cy) was used as graft-versus-host-disease (GVHD) prophylaxis.Acute GVHD (aGVHD) was observed in 9 patients (grade I 2 patients, grade II 6 patients, grade III-IV 1 patient) at a median of 34 days from transplant (range, 21-80). The cumulative incidence of aGVHD grade 2-4 was 30% (95% CI, 12% to 51%) at 6 months. Three patients developed chronic GVHD (cGVHD) (1 mild, 1 moderate and 1 severe). The cumulative incidence at 2 years of moderate-severe cGVHD was 11% (95% CI, 2% to 30%).With a median follow-up of 22 months (range 5-73 months), relapse or progression were observed in 2 patients at a median of 6 months (range, 3-8 months) from haplo-HCT with a cumulative incidence of disease relapse/progression of 11% (95% CI, 2% to 29%) at 3 years. The GVHD-free/relapse-free survival (GRFS) at 1 year was 68% (95% CI, 42% to 84%).Three deaths were attributed to toxicity and occurred at a median of 123 days (range, 17-274 days) after transplant. The specific causes of death were: aGVHD, 1; infection, 1; cGVHD 1. The cumulative incidence of NRM was 16% (95% CI, 4% to 36%) at 3 years. The 3-years progression-free survival (PFS) and overall survival (OS) were 73% (95% CI, 47% to 88%) and 71% (95% CI, 43% to 77%), respectively.Comparing this cohort with a similar cohort of 20 MCL patients who underwent allo-HCT from HLA identical sibling or unrelated donors in the same centers during the same time frame, the clinical outcomes (GRFS, NRM, PFS and OS) were not statistically different, even if there was a trend for better outcomes using haploidentical donor.In conclusion, our study suggests that haplo-HCT with PT-Cy in MCL patients is feasible and is associated with a low relapse rate and NRM, even in the era of new drugs. DisclosuresCarlo-Stella:Bristol-Myers Squibb: Speakers Bureau; Sanofi: Consultancy; Genenta Science: Speakers Bureau; MSD Italia: Speakers Bureau; Janssen: Speakers Bureau; ADC Therapeutics: Research Funding, Speakers Bureau; AstraZeneca: Speakers Bureau; Amgen: Speakers Bureau; Boehringher Ingelheim Italia: Consultancy; Rhizen Pharmaceuticals: Research Funding.

Very Low Dose of Anti-T-Lymphocyte Globulin Protects Against Severe Forms of Graft Versus Host Disease in High Risk Patients: The Experience in Our Center

BackgroundPatients undergoing hematopoietic stem cell transplantation (HSCT) are at high risk of multiple complications being graft versus host disease (GvHD) one of the most concerning. Addition of anti-T-lymphocyte globulin (ATG-Fresenius ®) reduces the incidence of acute and chronic GvHD however, optimal dose has not yet been established. Standard dose (60 mg/kg) has shown a significantly lower moderate-severe cGvHD yet its effect in Progression Free Survival (PFS) and Overall Survival (OS) is contradictory. Our primary objective was to analyze the efficacy of low ATG dose (21 mg/kg) in the prophylaxis of acute and chronic GvHD. As secondary objective we analyzed non-relapse mortality (NRM), infectious and non-infectious complications, GvHD and relapse free survival (GRFS), overall survival and progression free survival in high risk patients undergoing HSCT.Patients and methodsWe retrospectively analyzed 57 patients who underwent HSCT in our center from 2012 to 2017, receiving a total dose of 21 mg/kg (7 mg/kg on day -3, -2 and -1) of ATG as part of the GvHD prophylaxis, associated to cyclosporine/tacrolimus and MMF/short course-MTX. The conditioning regimen were myeloablative in 42 patients (73.7%). The donor was unrelated in 46 cases (80.7%). Seventeen (29.9%) had a mismatch (16 unrelated, 1 sibling). Stem cell source was peripheral blood in 51 patients (89.4%). Forty six (80.7%) patients were positive for CMV, from these 17 (36.9%) were paired with seronegative donors. The median age was 57 years old (18-70), 38(66.7%) were males. The most frequent diagnosis were Acute Myeloblastic Leukemia (40.4%), myelofibrosis (17.5%) and myelodisplastic syndrome (14%); 28 (49%) had a HCTI score ≥ 3 and 16 (29%) a high risk DRI score. Thirty patients (52.6%) were in complete remission at the moment of HSCT. (Table 1)ResultsHematopoietic engraftment was observed in 54 patients (94.7%). The median neutrophil and platelet engraftment were 14 (10-34) and 15 (9-28) days, respectively. Primary graft failure occurred in 3 patients (2 myelofibrosis, 1 AML). Twenty (39.2%) out of 51 evaluable patients developed grade 2-4 acute GvHD. The cumulative incidence of grade 3-4 aGvHD was 8.8% (95% CI, 3.2-17.9%). Skin was the most affected organ (62%). We found a cumulative incidence of moderate to severe cGvHD of 35.2% (95% CI 22.7-47.9%), only 5 cases (10.6%) were severe, with a median onset at day 177 (57-893). The median duration of immunosuppresive systemic therapy was 488 days (207-2046) in the group of patients with moderate to severe cGvHD.Twelve patients died due to transplant related events, 7 were reported before day 100, all of infectious etiology. The NRM at two years was 21.9% (95% CI, 12-33.7%). Eleven patients (19.2%) had at least two episodes of CMV reactivation and one had cytomegalic gastrointestinal disease. One patient developed postransplantation lymphoproliferative disorder associated to Epstein Barr virus. Twenty patients (35%) developed noninfectious complications, being hemorrhagic diathesis, hepatotoxicity and severe mucositis the most frequents.With a median follow up of 28 months in alive patients (3-67), the GRFS at one year, OS and PFS at two years were 47.6% (95% CI, 42.8-52.2%), 59% (95% CI, 54.5-63.2%) and 52% (95% CI, 46.9-56.5%), respectively. The relapse incidence at two years was 26.3% (95% CI 14.7-39.4%).ConclusionsIn our center, the use of low ATG doses is protective against severe forms of acute GvHD, offering also a moderate protection against chronic GvHD in a cohort with high prevalence of mismatched unrelated donors, high median age and high risk DRI and HCTI. This approach doesn't seem to have a significant negative impact neither in GRFS, OS and PFS at two years. DisclosuresNo relevant conflicts of interest to declare.

Current Graft-Versus-Host Disease (GVHD), Relapse-Free Survival - a Novel, Dynamic Composite Endpoint to Better Define Effectiveness Following Allogenic Hematopoietic Cell Transplantation

▪IntroductionGVHD-free, relapse-free survival (GRFS) has been previously developed as a novel composite endpoint designed as a measure of transplant effectiveness, which attempts to take into account the morbidity associated with GVHD (Holtan et al. Blood 2015). The conventional definition of GRFS however considers grade 3-4 acute GVHD and immunosuppression-requiring chronic GVHD (cGVHD) as static endpoints, whereas in reality these outcomes are often reversible. Patients with short-lived GVHD are considered treatment failures, which may not represent an accurate measure of transplant success. Therefore, we have developed a statistical method that provides an estimate of the probability, at any time post-transplant, of being alive, in remission, and without clinically significant cGVHD, defined as moderate-severe by the NIH consensus criteria.MethodsIn this new composite endpoint, which we call current GRFS (CGRFS), death and relapse are treated as terminal events, while cGVHD is considered a dynamic event, which can "resolve" once manifestations are quiescent and systemic immunosuppression discontinued. Grade 3-4 acute GVHD was intentionally not included in this endpoint, as this event almost universally will either resolve with time or convert to either death or cGVHD, which are both captured as part of CGRFS. Statistically, the CGRFS was defined as the sum of the survival without evidence of relapse and moderate-severe cGVHD and the probability that one recovered from moderate-severe cGVHD. The probability that one recovered from moderate-severe cGVHD was calculated by looking at the differences of relevant Kaplan-Meier estimates. Comparison of CGRFS between two independent samples was implemented by the simulation-based supremum test.ResultsWe evaluated 437 consecutive patients receiving an allogeneic hematopoietic stem cell transplant at a single institution from a matched related (MRD, n=125), matched unrelated (MUD, n=165), or haploidentical (HID, n=132) donor between January 2010 and July 2015. Transplant recipients had a median age of 54 years (range 18-77), DRI high/very high in 30%, and HCT-CI ³3 in 46%. Myeloablative conditioning was used in 50% and PBSC was the stem cell source in 78%. GVHD was prospectively documented by a dedicated practitioner on an ongoing basis. With a median follow-up time of 36 months, estimated 3-yr overall and disease-free survival was 61% and 54%, respectively. Conventionally defined GRFS at 1, 2, 3 and 4 years was 33%, 26%, 23%, and 22% respectively. In contrast, when moderate-severe cGVHD was treated as a dynamic event, corresponding CGRFS was 45%, 46%, 47% and 49%, respectively (Figure 1). The corresponding gain in CGRFS survival, due to the treatment of cGVHD as a dynamic event, was 12%, 20%, 24% and 27% respectively (Figure 2). Patients living with active mod-severe cGVHD decreased over time, quantitated at 23%, 14%, 7% and 4% respectively at 1, 2, 3 and 4 years post-transplant (Figure 3). CGRFS was significantly correlated with DRI (low/intermediate vs. high/very high, p<0.01), but not transplant type, age, HCT-CI, graft source, regimen intensity or year of transplant.ConclusionWhereas only a third of patients achieve "transplant success" by conventional 1-yr GRFS, nearly half of patients by CGRFS are considered cured without the morbidity of ongoing GVHD. We propose that CGRFS may represent are more accurate estimate of transplant effectiveness. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Haploidentical Peripheral Blood Stem Cell Transplantation after Treosulfan-Based Conditioning and Rapamycin GvHD Prophylaxis in Hodgkin Lymphoma

Patients with advanced refractory Hodgkin Lymphoma (HL) may obtain long-term cure from haploidentical SCT. We experienced a package of haploidentical peripheral blood stem cell transplantation after Treosulfan-based conditioning and Rapamycin GvHD prophylaxis.Between July 1999 and June 2016, 57 patients with classical relapsed/refractory Hodgkin Lymphoma underwent an allogeneic stem cell transplantation (alloSCT) at san Raffaele Scientific Institute in Milan (Italy). Eleven patients received a matched related donor alloSCT, 7 patients received a matched unrelated donor alloSCT, one patient underwent a double cord blood transplant and 38 patients, lacking identical related or unrelated donor, received an haploidentical transplant (haploSCT); 32 out of 38 patients underwent an unmanipulated peripheral blood stem cell transplant.This retrospective study analyzes the outcome of these 32 patients allografted after a Treosulfan based conditioning and a backbone GvHD prophylaxis with the mTOR inhibitor Rapamycin.Median age at alloSCT was 30 years; twenty patients (62,5%) had a primary refractory disease. Median number of previous lines before haploSCT was 4 (range 2-8); thirty patients (94%) received at least one or more autologous stem cell transplant and 12 of them were considered in an auto-allo program. Median time from diagnosis to haploSCT were 30 months (range 8-146).At haploSCT after receiving the last salvage treatment, 10 patients were in complete remission (CR), 6 were in partial remission (PR) and 16 patients had progressive disease (PD).A combination of Melfalan or Thiotepa or TBI4Gy to Treosulfan mieloablative conditioning regimens (MAC) were used in 16 (50%) patients; the others received a Treosulfan-alone based reduced intensity conditioning regimen (RIC). GvHD prophylaxis consisted of in vivo T cell depletion with pre transplant anti-Thymocyte Globulin (ATG) in 19 patient and of post transplant Cyclophosphamide (PT-Cy) in 13 patients; all patients received also Mycophenolate Mofetil till day + 30 and Rapamycin till day + 90. Median numbers of infused CD34+/Kg were 5,4 x 10^6 (range 5-5,8) and median numbers of infused CD3+/Kg were 2.34 x 10^8 (range 1.00-4.76).Median follow up was 46 months (range 1-109); two and 4 years Overall survival (OS) was 52% and 48% respectively, Progression Free Survival (PFS) and Relapse Incidence (RI) were 29% and 59% at both two and four years. Transplant related mortality was 9.5% at 100 days, 13% at 1 year and for the entire follow-up. The 100-day Cumulative Incidence (CI) of grade ≥ 2 and grade ≥ 3 aGvHD were 31% and 19% respectively; CI of cGvHD was 38% and CI of moderate-severe cGvHD was 27% at both a 2 and 4 years.No difference in OS, PFS, RI were found if patients were stratified according to disease status at transplant or according to the use of ATG or PT-Cy. CI of cGvHD and CI of moderate-severe cGvHD were significantly better after RIC regimens vs MAC ones (p value 0.01 and 0.001 respectively), but no difference were found between the two groups in term of OS, PFS and RI.Twelve out of twenty-two patients with active disease at haploSCT achieved a CR after transplantation and median time from aploSCT to CR was 3 months (range 2-6); six of them (4 PD and 2 PR at transplant) achieved and maintained a CR for the entire follow-up without the need for other post transplant treatment.Unmanipulated peripheral blood haploSCT after Treosulfan based conditioning regimen and GvHD prophylaxis with Rapamycin is feasible, even in heavily pretreated patients and with active disease, with acceptable toxicities. Intensification of conditioning increased the toxicities. Disease relapse or progression was the major cause of treatment failure in our series, but 22 patients (69%) had detectable disease at the time of transplant. Six out of those very poor prognosis patients (28%) achieved a long term CR. Hodgkin Lymphoma is characterized by high mTOR activity, and Rapamycin is known to inhibit in vitro and in vivo cell proliferation and to induce apoptosis in Lymphoma cells. Rapamycin in these patients could have played an important role in disease control in immediate post transplant phase by increasing the apoptotic effect of chemotherapeutic agents, until the onset of the Graft versus Lymphoma effect. DisclosuresBonini:Molmed SpA: Consultancy; TxCell: Membership on an entity's Board of Directors or advisory committees. Ciceri:MolMed SpA: Consultancy.

Activated Circulating T Follicular Helper Cells with Increased Function during Chronic Graft Versus Host Disease after Allogeneic Stem Cell Transplantation

T follicular helper cells (TFH) interact with B cells in the germinal center to support B cell proliferation, differentiation and immunoglobulin class switch. Previous studies have demonstrated that donor B cells contribute to the immune pathology of chronic GVHD (cGVHD) and studies in murine models of cGVHD have suggested that TFH play a central role in this process. Although TFH are located primarily within germinal centers of secondary lymphoid organs, TFH can also be found in the peripheral blood and are identified as a subset of memory CD4 T cells expressing CXCR5. Circulating TFH (cTFH) share functional and phenotypic characteristics of TFH including the ability to interact with B cells and provide helper signals. To examine the potential role of cTFH in the pathogenesis of cGVHD we monitored the reconstitution of cTFH (CD4+CD45RA-CXCR5+ T cells) in fresh blood samples obtained at different times after allogeneic HSCT. Recovery of cTFH mirrored the recovery of CD4 T cells and absolute numbers of cTFH gradually increased over time, reaching a plateau at 24 months post-HSCT in the range of normal values. Within the CD4 T cell population, the frequency of cTFH was low initially, but reached normal levels 6-9 months post-HSCT.Detailed phenotypic and functional analysis of cTFH was undertaken in a cohort of 66 adult patients (>9 months post-HSCT): 16 had no cGVHD, 12 had resolved cGVHD, and 38 had active cGVHD (mild = 15, moderate = 14, severe = 9). Results were compared to 22 healthy donors (HD). Overall, the frequency of cTFH was significantly reduced in HSCT patients compared to HD (median: 9.87 vs. 13.65 % of CD4+ T-cells, respectively, p =0.0003). cTFH frequency was lower in active cGVHD compared to no cGVHD patients (median: 9.44 vs. 11.65 % of CD4+ T-cells, p = 0.029); while cTFH in patients with resolved cGVHD was similar to patients without cGVHD (Figure 1). CXCL13 chemokine facilitates T-B interaction, thus promoting the GC reaction. CXCL13 levels were increased in active cGVHD compared to no cGVHD (137.7 pg/mL vs. 33.74 pg/mL, p < 10-4) suggesting that trafficking of cTFH to lymphoid organs was promoted in cGVHD. cTFH activation results in increased surface expression of ICOS and PD1 and increased proliferation. ICOShi PD1hi cTFH were increased in active cGVHD compared to no cGVHD (2.035 % vs 1.065 %, p = 0.016) in association with high proliferative activity (Ki67) (3.38 % vs. 2.31 % respectively, p = 0.0086). Functional cTFH subsets are also characterized by expression of CXCR3 and CCR6 as follows: Th1 (CXCR3+CCR6-), Th2 (CXCR3-CCR6-), Th17 (CXCR3-CCR6+). Within these subsets, Th2 and Th17 cTFH provide greater levels of B cell help measured by in vitro co-cultureassays (plasmablast generation and IgG production). Although not statistically significant, Th1 cTFH frequency was decreased during active cGVHD (33.95 vs 37.6 for no cGVHD) and Th2 and Th17 cTFH frequencies were increased in the moderate-severe cGVHD group (31.1 and 30.5, respectively) compared to no cGVHD (27.05 and 24.45, respectively). Within active cGVHD patients, the frequencies of Th1 and Th17 were associated with clinical grade of cGVHD (Th1: 40, 34, 19, p=0.008; Th17: 21, 26, 37, p=0.02; for mild, moderate, severe, respectively). We used the ratio (Th2+Th17)/Th1 cTFH to normalize B cell help capacity, and found a higher ratio in severe cGVHD compared to no cGVHD (3.59 vs 1.36, p = 0.0006). To measure cTFH functional activity, cTFH and naive B cells were purified from patient samples by cell sorting and co-cultured for 6 days. cTFH from patients with active cGVHD induced greater plasmablast generation (CD27hi CD38hi B cells) compared to cTFH from non-active cGVHD (Fig. 2). Increased functional activity of cTFH was confirmed when patient cTFH were purified and cocultured with naive B cells from a normal allogeneic donor (Fig. 2). In patients with cGVHD, there was also a significant correlation between the proliferative activity of cTFH and the generation of CD27hi CD38hi B cells (r = 0.48, p = 0.0029).These results indicate that active cGVHD is characterized by phenotypic and functional abnormalities of cTFH. In cGVHD, cTFH show high levels of activation, proliferation and switch toward Th2 and Th17 phenotype. These changes enhance cTFH function, promoting GC reactions and B cell differentiation. These data support the involvement of cTFH in the immune pathology of human cGVHD, suggesting the investigation of novel therapies targeting the GC reaction. [Display omitted] DisclosuresArmand:Merck: Consultancy, Research Funding; Infinity Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Research Funding. Antin:Gentium S.p.A.: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

BK Virus (BKV) Associated Haemorrhagic Cystitis Is Associated with Graft Versus Host Disease (GVHD) and Significant Morbidity Post Haematopoietic Stem Cell Transplant (HSCT).

AbstractAbstract 3040The Polyomavirus hominis 1 BK virus (BKV) is a non-encapsulated DNA virus, which infects up to 90% of the world's population, and may reactivate at times of severe immunosuppression, including post haematopoietic stem cell transplantation (HSCT).The significance of BK virus reactivation post Haematopoietic Stem Cell Transplant (HSCT) remains unclear. We collected retrospective data on viruria, viraemia, haemorrhagic cystitis (HC) and acute/chronic graft versus host disease (a/cGVHD) in patients at our institution over the period 2006 to 2011. We compared with a multivariate matched control group of 38, who did not reactivate BK. The groups were matched for age, sex, donor source and conditioning regimen including use of Alemtuzumab. Global BK reactivation incidence was 32% (38/118) of allogeneic HSCT during this period. 73% (28/38) of those who reactivated received volunteer unrelated donor (VUD) grafts, and 50% (18/38) received Alemtuzumab.Patients were sub-divided into those with high grade viraemia (HGV, VL >104 copies/ml), 47% (18/38) or low grade viraemia (LGV, VL<104 copies/ml), 53% (20/38). HGV was present in 57% of VUD transplants and 20% of sibling recipients, compared to LGV in 29% of VUDs and 70% of siblings. HGV influenced 1 year EFS; 18% versus 55% in LGV. Median OS was 173 days in HGV versus 345 days in LGV.Cumulative mortality rate in the BK group was 71% (27/38) as compared to 55% (21/38) in the control group (not significant). Relapse related mortality in the BK group was 22% (6/27) versus 57% (12/21) in the control group, at a median follow up of 229 days (p=0.088), indicating the high incidence of non-relapse causes of mortality in the BK group.79% (30/38) of patients reactivating BK developed aGVHD, including 83% (15/18) with HGV, compared to 57% (21/37) in the control group (p=0.039). The number of patients who developed grade II-IV aGVHD in the BK group was 30/38 (79%) and 11/37 (20%) in the control group (p <0.001), figure 1. In 33% of patients BK reactivation preceded aGVHD by a mean of 12 days. 84% (27/32) of patients developed cGVHD, compared to 30% (18/30) in control group (p=0.05). Moderate-severe (NIH grade) cGVHD was more prevalent in patients reactivating BK, compared to control group; 75% (24/32) versus 3% (1/30) (p<0.001), figure 2.This data suggests the association of BK with an increased incidence of acute and chronic GVHD, and significant morbidity. Notably 10 patients developed severe complications including grade 4 HC (5/10), obstructive hydronephrosis and bladder wall dysfunction requiring invasive intervention. 7/10 (70%) of these patients had HGV; 2 patients reactivated early, failed treatment, developed obstructive renal failure and died. These patients had an increased rate of mortality compared to the whole study group (p=0.005), and all failed to achieve an EFS of over 1 year. Of note, 8.5% of all allografts developed grade 4 HC and 90% of these subsequently died.BK reactivation strongly correlates with acute and chronic GVHD and an increase in non relapse mortality. Routine surveillance for BK with risk scoring may allow earlier detection and reduced morbidity of BK and GVHD. Further prospective studies are required to understand the impact of the reactivation of the virus. [Display omitted] p <0.001 [Display omitted] p <0.001 Disclosures:No relevant conflicts of interest to declare.