Refractory Acute Graft-versus-host Disease Research Articles

Contemporary Updates in the Prevention and Treatment of Graft-Versus-Host Disease.

Graft-versus-host disease (GVHD) is a serious complication after allogeneic HCT. Recently, several pivotal studies have been conducted demonstrating significant improvements in the management of GVHD. Here, we review important trials pertaining to GVHD prevention, acute GVHD treatment, and treatment of steroid refractory acute and chronic GVHD. Clinical trials in preventing GVHD demonstrate lower rates of severe acute GVHD and chronic GVHD with post-transplant cyclophosphamide. For acute GVHD, lower risk acute GVHD appears amenable to steroid-sparing therapies, such as sirolimus and itacitinib. Combinations with novel agents such as itolizumab appear promising for high risk acute GVHD. For steroid-refractory acute GVHD, ruxolitinib should be considered first line therapy. For chronic GVHD requiring therapy beyond steroids, ruxolitinib, belumosudil, and ibrutinib are now available and should be considered. Increasingly, GVHD has become a manageable complication after allogeneic HCT potentially translating to greater success with allogeneic HCT in the future.

Ruxolitinib Pharmacokinetics and Pharmacodynamics in Children with Acute and Chronic Graft-versus-Host Disease

IntroductionWe report pharmacokinetics of oral ruxolitinib in children with steroid refractory acute graft versus host disease (GVHD) (<12y) and chronic GVHD (≤18y) using our published pediatric dosing. MethodsPK sampling before and +2 hours after ruxolitinib was performed in patients with established chronic GVHD. More extensive PK analysis was evaluated in patients with newly diagnosed acute or chronic GVHD before, +0.5, 1, 2, 4 and 6 hours after ruxolitinib in patients >10kg, and before, +3 and +6 hours in children <10kg. We measured pSTAT1, 3 and 5 expression on CD4+ and CD8+ T-cells before and 2 hours after ruxolitinib as a pharmacodynamic marker of JAK/STAT inhibition. ResultsThirteen patients were prospectively enrolled (0-≤18y with existing chronic GVHD(n=8), 0-<12y with new onset steroid refractory acute GVHD(n=4) and newly diagnosed steroid-refractory chronic GVHD(n=1). A large variability in PK was seen. Mean oral clearance (CL/F) was 7.76 ± 4.09 L/h (±SD 4.4; range: 3.1-15.3). The average elimination half-life was 2.32 hours (±SD 1.0). Ruxolitinib clearance was higher in children <2 years versus >2 years (12.1 ± 3.0, vs 5.7 ± 2.8 L/h, p=0.005) and was reduced with concurrent azoles and azithromycin. We saw a variable reduction in pSTAT1/3/5 expression on T-cells at time of peak ruxolitinib absorption (2 hours after dose). ConclusionsChildren<10 kg have lower ruxolitinib exposure, possibly due to inherent increased drug clearance or variabilities in dosing methods leading to decreased drug absorption.

Maintenance Ruxolitinib Is Associated with Low Rates of Chronic Gvhd Requiring Systemic Treatment in Older Adults with AML/MDS Undergoing Allogeneic HCT: Results of a Phase II Multicenter Trial

Introduction: Despite recent advances in graft-versus-host disease (GVHD) prophylaxis, novel approaches to effective prevention of chronic GVHD remain of utmost importance. This is particularly true for older transplant recipients,for whom high-dose cyclophosphamide or prolonged treatment with corticosteroids is challenging. Ruxolitinib, an oral selective inhibitor of JAK1/2, is FDA-approved for the treatment of refractory acute and chronic GVHD. However, the clinical efficacy of JAK inhibition in preventing severe chronic GVHD is not well characterized. Methods: In this prospective, multicenter phase II trial (NCT03286530), older adult subjects (age 60-80) with AML in CR1 or MDS undergoing RIC allogeneic HCT were enrolled. Transplants could be conducted from HLA-matched related donors or 7/8 or 8/8 HLA-matched unrelated donors. Transplants were required to use busulfan- or melphalan-based reduced intensity conditioning and peripheral blood stem cells. Standard GVHD prophylaxis consisted of tacrolimus and methotrexate (5-10 mg/m 2 on Days +1, +3, and +6 ± +11). Subjects were enrolled prior to transplant. Ruxolitinib therapy could begin between Day +30 and Day +100, after meeting pre-treatment criteria, which included: donor engraftment, ongoing remission confirmed by biopsy, adequate hematopoietic recovery (Hgb ≥8 g/dL, PLT ≥50K/uL), and the absence of progressive acute GVHD. Ruxolitinib was administered at 10 mg BID continuously in 28-day cycles (allowing for dose reductions due to drug interactions or cytopenias), for up to 24 cycles. The primary objective was to evaluate the GRFS at 1-year after HCT. Key secondary objectives included the cumulative incidence of chronic GVHD, acute GVHD, and relapse, as well as overall survival. Results: Seventy-eight subjects were enrolled, and 63 subjects received ruxolitinib on trial. The reasons for not initiating ruxolitinib were acute GVHD (n=4), physician discretion (n=3), disease relapse (n=2), low chimerism (n=2), death (n=2), primary graft failure (n=1), and subject withdrawal (n=1). In the treated subjects, the median age was 68 years (range, 61-79). Fifty-five (87.3%) subjects had AML and 8 (12.7%) had MDS. Transplants were performed from HLA-matched related (n=16, 25.4%) or unrelated (n=47, 74.6%) donors with either Fludarabine/Melphalan (n=34, 54%) or Fludarabine/Busulfan (n=29, 46%). The median start date of ruxolitinib after HCT was day 45 (range, 32-93). The median follow-up of survivors was 19 months (range, 3-64) at last cutoff (2/14/23). At the time of analysis, the median number of cycles on treatment is 14 (range, 1-24). 17 subjects remain on therapy; the reasons for discontinuation include completed treatment (n=21), disease relapse (n=13), adverse events (n=7), and physician discretion (n=5). The most common (severe grade ≥3) adverse events experienced while on ruxolitinib were neutropenia (n=18, 29% of subjects), thrombocytopenia (n=17, 27% of subjects), and anemia (n=16, 25% of subjects). Seven subjects experienced grade ≥3 infectious events; no fungal infections have occurred. In subjects receiving ruxolitinib, the 6-month cumulative incidence of Grade II-IV acute GVHD was 14% (95%CI, 7-24) and Grade III-IV acute GVHD was 4.8% (95%CI, 1.3-12), with three cases of grade II-IV GVHD occurring prior to initiation of ruxolitinib. While the 12-month incidence of all cases of chronic GVHD is 27% (95%CI, 17-39), the 12-month incidence of chronic GVHD requiring systemic therapy is 8.4% (95%CI, 3.1-17). The 18-month cumulative incidence of NRM is 5.6% (95%CI, 1.4-14); with only one death attributed to GVHD and one death due to infection (COVID-19), thus far. The 18-month cumulative incidence of disease relapse is 27% (95%CI, 16-39). The 12-month GRFS (primary endpoint) is 70% (95%CI, 56-80). The 18-month OS, PFS, and CRFS are 78% (95%CI, 64-88), 68% (95%CI, 53-78) and 64% (95%CI, 50-76), respectively ( Figure 1). Conclusion: Prolonged administration of ruxolitinib following allogeneic HCT is associated with low rates of chronic GVHD requiring systemic treatment. The incidence of relapse is comparable to historical rates, suggesting no compromise of GVL effect. Despite the anticipated cytopenias with therapy, most subjects were able to remain on treatment. The incorporation of JAK inhibition into GVHD prevention approaches warrants further investigation.

Inhibition of Bromodomain and Extra Terminal (BET) Domain Activity Modulates the IL-23R/IL-17 Axis and Suppresses Acute Graft-Versus-Host Disease.

Acute graft-versus-host disease (GVHD) is the leading cause of non-relapse mortality following allogeneic hematopoietic cell transplantation. The majority of patients non-responsive to front line treatment with steroids have an estimated overall 2-year survival rate of only 10%. Bromodomain and extra-terminal domain (BET) proteins influence inflammatory gene transcription, and therefore represent a potential target to mitigate inflammation central to acute GVHD pathogenesis. Using potent and selective BET inhibitors Plexxikon-51107 and -2853 (PLX51107 and PLX2853), we show that BET inhibition significantly improves survival and reduces disease progression in murine models of acute GVHD without sacrificing the beneficial graft-versus-leukemia response. BET inhibition reduces T cell alloreactive proliferation, decreases inflammatory cytokine production, and impairs dendritic cell maturation both in vitro and in vivo. RNA sequencing studies in human T cells revealed that BET inhibition impacts inflammatory IL-17 and IL-12 gene expression signatures, and Chromatin Immunoprecipitation (ChIP)-sequencing revealed that BRD4 binds directly to the IL-23R gene locus. BET inhibition results in decreased IL-23R expression and function as demonstrated by decreased phosphorylation of STAT3 in response to IL-23 stimulation in human T cells in vitro as well as in mouse donor T cells in vivo. Furthermore, PLX2853 significantly reduced IL-23R+ and pathogenic CD4+ IFNγ+ IL-17+ double positive T cell infiltration in gastrointestinal tissues in an acute GVHD murine model. Our findings identify a role for BET proteins in regulating the IL-23R/STAT3/IL-17 pathway. Based on our preclinical data presented here, PLX51107 will enter clinical trial for refractory acute GVHD in a Phase 1 safety, biological efficacy trial.

Mesenchymal Stromal Cell (MSC) Compassionate Use in France in Treatment of Steroid-Refractory Graft-Versus-Host-Disease (GVHD) after Approval By the Expert Committee of Société Française De Greffe De Moelle Et Thérapie Cellulaire (SFGM-TC)

Mesenchymal Stromal Cell (MSC) Compassionate Use in France in Treatment of Steroid-Refractory Graft-Versus-Host-Disease (GVHD) after Approval By the Expert Committee of Société Française De Greffe De Moelle Et Thérapie Cellulaire (SFGM-TC)

Mesenchymal Stromal Cells in Pediatric Hematopoietic Cell Transplantation a Review and a Pilot Study in Children Treated With Decidua Stromal Cells for Acute Graft-versus-Host Disease.

Mesenchymal stromal cells (MSCs) are rare precursors in all organs of the body. MSCs have profound anti-inflammatory effects and reduce alloreactivity in vitro and in vivo. In pediatric allogeneic hematopoietic cell transplantation (HCT), MSCs have mainly been used to treat acute graft-versus-host disease (GVHD). MSCs are commercially available for this indication in Canada, Japan, and New Zeeland. More rare indications for MSCs in pediatric patients include graft failure and chronic GVHD. MSCs from bone marrow, adipose tissue, umbilical cord, Wharton's jelly, placenta tissue, and decidua have been used, but the optimal clinical stromal cell source has not been compared in clinical trials. More experimental clinical indications using MSCs, such as sepsis, acute respiratory distress syndrome, hemorrhages, pneumo-mediastinum, and neuroinflammation have primarily been explored in animal models or adult HCT patients. MSCs have almost no if any side-effects. In this pilot study we report the outcome of six children treated with decidua stromal cells (DSCs) for steroid refractory acute GVHD. At 6 months, complete response was seen in four patients and partial response in two patients. One child with high-risk ALL died from relapse and a boy with sickle cell disease died from a cerebral hemorrhage. Five-year survival was 67% and all survivors showed a Lansky score of 100%. To conclude, MSCs from various organs are well-tolerated and have shown an encouraging outcome for acute GVHD in pediatric patients.

Children and Adults with Refractory Acute Graft-versus-Host Disease Respond to Treatment with the Mesenchymal Stromal Cell Preparation "MSC-FFM"-Outcome Report of 92 Patients.

(1) Background: Refractory acute graft-versus-host disease (R-aGvHD) remains a leading cause of death after allogeneic stem cell transplantation. Survival rates of 15% after four years are currently achieved; deaths are only in part due to aGvHD itself, but mostly due to adverse effects of R-aGvHD treatment with immunosuppressive agents as these predispose patients to opportunistic infections and loss of graft-versus-leukemia surveillance resulting in relapse. Mesenchymal stromal cells (MSC) from different tissues and those generated by various protocols have been proposed as a remedy for R-aGvHD but the enthusiasm raised by initial reports has not been ubiquitously reproduced. (2) Methods: We previously reported on a unique MSC product, which was generated from pooled bone marrow mononuclear cells of multiple third-party donors. The products showed dose-to-dose equipotency and greater immunosuppressive capacity than individually expanded MSCs from the same donors. This product, MSC-FFM, has entered clinical routine in Germany where it is licensed with a national hospital exemption authorization. We previously reported satisfying initial clinical outcomes, which we are now updating. The data were collected in our post-approval pharmacovigilance program, i.e., this is not a clinical study and the data is high-level and non-monitored. (3) Results: Follow-up for 92 recipients of MSC-FFM was reported, 88 with GvHD ≥°III, one-third only steroid-refractory and two-thirds therapy resistant (refractory to steroids plus ≥2 additional lines of treatment). A median of three doses of MSC-FFM was administered without apparent toxicity. Overall response rates were 82% and 81% at the first and last evaluation, respectively. At six months, the estimated overall survival was 64%, while the cumulative incidence of death from underlying disease was 3%. (4) Conclusions: MSC-FFM promises to be a safe and efficient treatment for severe R-aGvHD.

Clinical Outcomes Related to the Use of Monoclonal Antibody Therapy for Steroid Refractory Acute Graft-Versus Host Disease after Allogeneic Hematopoietic Cell Transplantation

Background: Acute graft versus host disease (aGVHD) is the leading cause of morbidity and mortality following allogenic hematopoietic cell transplantation (HCT). Corticosteroids are the first line treatment although <50% of patients with severe aGVHD (grades III-IV) achieve durable remissions. Monoclonal antibodies (mAb) are often used as second line agents for steroid refractory aGVHD (SR-aGVHD) (Patriarca et. al.; 2004). However, data regarding their tolerability and efficacy is retrospective and limited. We carried out this study to assess the clinical outcomes related to mAb therapy (Infliximab and Tocilizumab) for SR-aGVHD.Methods: Patients with SR-aGVHD that received therapy with either Infliximab or Tocilizumab between January 2003 and May 2016 were retrospectively identified. Clinical grading of aGVHD was per the Glucksberg criteria (Glucksberg et. al.; 1974). SR-aGVHD was defined as any grade progression within 3 days or failure to achieve at least one grade improvement within 7 days of initiation of systemic steroids. Infliximab and Tocilizumab were administered intravenously at 10mg/kg and 8mg/kg weekly for a total of 4 doses, respectively. Clinical response was evaluated at 4 weeks and 12 weeks post mAb treatment. Complete response (CR) was defined as sustained resolution of all clinical signs of aGVHD; partial response (PR) was defined as overall improvement of 1 or more grades; no response (NR) was defined as neither improvement nor worsening of the overall aGVHD grade. Overall response (OR) was defined as either CR or PR. Overall survival (OS) was calculated from the first day of mAb treatment until death or last available follow up.Results: Forty-three patients (median age 54, range 29-74 years; male 67%) with severe SR- aGVHD were included in the study. Of these, 35 (81%) received Infliximab for a median of 4 (range 1-6) cycles and 8 (19%) received Tocilizumab for a median of 3 (range 1-4) cycles. Both groups were comparable with regards to age, gender, conditioning regimen, graft source, degree of HLA match, ABO blood group, CMV incompatibility, and GVHD prophylaxis regimens. Only differences seen were a higher proportion of unrelated donor (p = 0.004) and cord blood HCT (p = 0.031) in the Tocilizumab group. Twenty (57%) of 35 patients treated with Infliximab and 6 (75%) of 8 patients treated with Tocilizumab had an overall aGVHD grade of IV prior to initiation of mAb therapy (p = 0.44). Organ specific distribution and severity of aGVHD are described in table 1.At 4 weeks post mAb therapy, 17 (40%) patients had an OR, 7 (16%) had no response, and 19 (44%) had died. Twenty-six (60%) patients died at 12 weeks, with OR and no response observed in 9 (21%) and 8 (19%) patients, respectively (table 2). Overall response for Tocilizumab versus Infliximab was comparable at 4 weeks (38% vs. 40%; p = 1.0) and at 12 weeks (38% vs. 17%; p = 0.33). Outcomes per aGVHD grade and gastrointestinal-specific stage at 4 weeks and 12 weeks are shown in figures 1-A and 1-B, with organ specific responses shown in figures 1-C and 1-D, respectively. The estimated median OS was 41 (range 4-3837) days for patients treated with Infliximab and 60 (range 10-756) days for those treated with Tocilizumab (p = 0.48). Disease relapse occurred in 5 (11%) patients treated with Infliximab and in none (0%) treated with Tocilizumab (p = 0.56).Thirty-four (79%) patients had infectious complications during and up to one month after mAb therapy. These included 31 (72%) patients with bacterial blood stream infection and 10 (23%) with invasive fungal infections. Overall, infectious complications were comparable (Infliximab - 83% vs. Tocilizumab - 63%; p = 0.33). CMV reactivation occurred in 11 (31%) and in 2 (25%) patients who were treated with Infliximab and Tocilizumab, respectively (p = 1.0). Given the retrospective nature of the study and the concomitant presence of aGVHD, it was difficult to attribute and grade gastrointestinal and hepatobiliary side effects.Conclusions: The use of anti-inflammatory monoclonal antibody therapy in patients with steroid refractory acute GVHD is associated with significant infectious complications (~80%) and poor response rates (~20% at 12 weeks). Current data, limited by a small sample size, does not show any advantages of using Tocilizumab over Infliximab or vice versa. Prospective clinical trials addressing this question are needed. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Human Mesenchymal Stem Cell Therapy for Acute Graft Versus Host Disease

Acute graft versus host disease (GVHD) is the most critical complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The understanding of major histocompatibility complex (MHC) and the development of acute GVHD prophylaxis have contributed to decreasing the incidence of severe acute GVHD. However, these progresses expand the chance of receiving allo-HSCT from human leukocyte antigen (HLA) mismatched donor. In addition, the expanding of indication for allo-HSCT to elderly patients or patients with organ dysfunction by the pervasiveness of reduced-intensity conditioning is associated with increased risk of acute GVHD. Unexpectedly, severe refractory acute GVHD can occur even in allo-HSCT from HLA matched sibling donor. The first line therapy for severe acute GVHD is corticosteroid, but the second line therapy has not been established and the prognosis of steroid-resistant acute GVHD remains poor. Recently, the efficacy of human bone marrow mesenchymal stem cell (MSC) therapy for steroid-resistant acute GVHD has been consistently reported. MSCs are approved as a cell therapy drug for steroid-resistant acute GVHD in some countries. We here review the history and the future of MSC therapy for acute GVHD.

Efficacy and safety of intra-arterial steroid infusions in patients with steroid-resistant gastrointestinal acute graft-versus-host disease

There is no established second-line treatment for steroid-resistant acute graft-versus-host disease (GVHD). We prospectively assessed the safety and efficacy of intra-arterial steroid infusions (IASIs) for steroid-resistant acute gastrointestinal (GI) GVHD and compared the outcomes with those of historical controls at our institution. Nineteen consecutive, allogeneic hematopoietic stem cell transplantation subjects aged 31-67 years (median 52) were enrolled between October, 2008, and November, 2012. Acute GVHD was confirmed by biopsy in all cases. The enrolled patients were treated with infusions of methylprednisolone into the mesenteric arteries and/or gastroduodenal and left gastric arteries. Fourteen consecutive patients who developed steroid-resistant acute GI GVHD between 2001 and 2008 were used as controls. For the primary endpoint at day 28, the overall and complete responses in the IASI group trended higher (79% vs. 42%, p = 0.066) and were significantly higher (63% vs. 21%, p = 0.033) than those in the control group. Although not statistically significant, owing to the small population, the crude day-180-nonrelapse mortality rate was about 20% lower and the day-180-overall-survival rate tended to be higher than the control (11% vs. 29%, p = 0.222; 79% vs. 50%, p = 0.109, respectively). There were no serious IASI-related complications. Our results suggest that IASI can safely provide excellent efficacy for refractory acute GI GVHD without increasing infection-related complications and may improve prognosis.

The Number of Organ Failures, but Not Graft-Versus-Host Disease, Determines Outcome of Allogeneic Stem Cell Transplantation Recipients Requiring Intensive Care

▪Background: Although the prognosis of patients with hematological malignancies admitted to the intensive care unit (ICU) has improved over the past years, it remains poor in allogeneic stem cell transplantation (SCT) recipients and thus admission of these patients to the ICU remains controversial. Our center has flexible admission criteria, especially regarding graft-versus-host disease (GVHD). We thus performed a retrospective study to assess prognostic factors of survival in allogeneic SCT recipients who are admitted according to this policy.Methods: All allogeneic SCT recipients between 2002 and 2013 who were admitted to the medical ICU in our center were included. Details on patients, graft procedures, GVHD, ICU admission, and outcome were collected from individual medical records. Potential prognostic factors were explored by logistic regression analysis for ICU and hospital discharge. Cox regression analysis was performed for overall survival.Results: Of 344 patients who underwent allogeneic SCT during the study period, 92 patients (27%) were admitted to the ICU. Median time from transplantation to ICU admission was 53 days (range: -4 to 2273 days). Median age was 52 (range: 20-69). They received myeloablative (27%), sequential treatment with chemotherapy and reduced-intensity conditioning (RIC) (27%) or RIC (46%). Donors were mostly unrelated donors (59%) while graft source was mostly peripheral blood stem cells (78%) (bone marrow: 13%, cord blood: 9%). 66% patients could be discharged from the ICU and 46% from hospital whereas one year survival was 24%. No demographic or SCT parameter was associated with ICU or hospital discharge, or with overall survival. Grade 2-4 acute GVHD (34 patients, 37%) and refractory acute GVHD (12 patients, 13%) had a significant impact on hospital discharge (11/34 patients alive, OR: 2.4, 95% CI: 1-5.8, p=0.05; 2/12 patients alive, OR: 5, 95% CI: 1-24, p=0.05, respectively) but not with ICU discharge (20/34 patients alive, p=0.25; 7/12 patients alive, p=0.53, respectively). Chronic GVHD was present in 11 patients (12%) without impact on survival. At admission to the ICU, patients had a median SOFA (Sequential Organ Failure Assessment) of 7 (range 1-16), a median LODS (Logistic Organ Dysfunction System) of 4 (range 0-17), and a median APACHE II (Acute Physiology And Chronic Health Evaluation II) of 19 (range 8-42). The SOFA and LODS are efficient for determining ICU discharge (OR: 1.3, 95% CI: 1.1-1.5, p=0.003; OR: 1.3, 95% CI: 1.1-1.5, p=0.002, respectively). 46 patients (50%) required invasive mechanical ventilation, 28 patients (30%) required vasopressors, 16 patients (17%) required renal replacement therapy, and 26 patients (28%) had liver failure (bilirubin >34µmol/l). Mortality was greatly associated with the number of organ failures: each new organ failure worsens the prognosis (Figure). One year OS rates were 31%, 27%, 23%, and 0% among patients with 0 (26 patients, 28%), 1 (26 patients, 28%), 2 (26 patients, 28%), and 3 to 4 (14 patients, 15%) organ failures, respectively (HR: 1.7, 95% CI: 1.4-2.1, p<0.001).Conclusion: Allogeneic SCT recipients with 3 or 4 organ failures require further improvement of care. GVHD cannot be considered as a contraindication for transfer in the ICU per se, even with 2 organ failures. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Alpha 1 Anti-Trypsin (AAT) Offers Potent Therapy for Steroid Resistant Gut Gvhd: Interim Results of a Phase I/II Clinical Study

Background: Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic cell transplantation (HCT). Severe acute GVHD of the gastrointestinal tract can be life threatening and is associated with a loss of acute phase proteins including alpha1-antitrypsin (AAT). AAT acts as a potent anti-inflammatory agent. We and others have shown in allogeneic murine models that administration of AAT during HCT suppresses serum levels of pro-inflammatory cytokines, interferes with GVHD and reduces transplant-related mortality. We embarked upon a phase I/II clinical study to evaluate the feasibility and safety of AAT given to HCT recipients with steroid non-responsive acute GVHD. We aimed at characterizing pharmacodynamic effects of AAT and assess clinical responses as determined by changes in stool volume and overall clinical improvementMethods: Seven patients (3 female, 4 male) with hematologic malignancies were enrolled in the first and second cohort. Patients were 35-59 (median 50.4) years old and were given transplants from HLA-matched siblings (n=5) or received cord blood (n=2) following high intensity (myeloablative) or reduced intensity conditioning with cyclophosphamide +TBI (n=2), Fludarabine+TBI (n=4), or busulfan +cyclophosphamide (n=1). All patients received cyclosporine and MMF for GVHD prophylaxis. Acute GVHD of grades III-IV developed at 49 to 71 (median of 48) days, and treatment with systemic methylprednisolone, 2 mg/kg/day was instituted. Patients showing no clinically satisfactory responses after 5 days were given AAT (GlassiaTM) at 90 mg/kg iv on day 1, followed by 30 mg/kg (first cohort) or 60 mg/kg (second cohort) every other day for a total of 8 doses (15 days).Results: As AAT levels vary considerably from person to person, we determined plasma AAT concentrations before and after administration of exogenous AAT. Pre-treatment AAT levels ranged from 1.25mg/ml to 2.3mg/ml (mean 1.76 mg/ml), while post-treatment AAT levels were 2.5 mg/ml to 5 mg/ml (mean 3.18 mg/ml), i.e. in the normal range. Concurrently, levels of Angptl4, IL10 and IL-15 protein increased in all patients, while TIM-3, a marker of lymphocyte activation, was down-regulated. RQ-PCR analysis of donor-derived cells showed up-regulation of IL-10 and IL-1Ra (50 log2 and 10 log2, respectively, compared to pre-treatment samples). FACS analysis of peripheral blood cells showed a 5-fold increase in CD4+CD24+FoxP3+ Treg cells and a 3 fold increase in CD8+CD205+ dendritic cells (DC) in comparison to pre-treatment samples in all 7 patients. Concurrently, the numbers of TIM-3 expressing CD4+ T lymphocytes decreased. While endoscopic evaluation of patients before treatment revealed severe intestinal GVHD with mucosal denudation, endoscopic evaluation one week after completion of AAT administration showed evidence of re-epithelialization of the bowel wall. Concurrently, five of the seven patients developed formed stools, associated with decreased intestinal loss of AAT. One patient required additional therapy and died with biopsy proven liver GVHD. With a median follow-up of 8 months (range 3.5-12 months), five of of seven patients are alive, no longer requiring treatment for GVHD.Summary and conclusions: Continuous administration of AAT as salvage therapy for steroid resistant gut GVHD is feasible without clinically relevant toxicity. Stool sampling showed a decrease in intestinal AAT loss, as measured by AAT clearance and endoscopic evaluation confirmed healing of the bowel mucosa. These data are encouraging, and further exploration of AAT therapy in extended phase II and randomized trials as therapy of steroid refractory acute GVHD or as first line therapy are warranted. DisclosuresOff Label Use: Off label use of Alpha 1 Anti-Trypsin (AAT) as second line therapy for steroid-refractory gut GVHD..

Infliximab Treatment for Steroid-Refractory Acute Graft-Versus-Host Disease After Reduced-Intensity Cord Blood Transplantation in Adults

Abstract 4553 IntroductionAcute graft versus host disease (GVHD) remains the most frequent complication after allogeneic hematopoietic stem cell transplantation (SCT). In reduced intensity cord blood transplantation (CBT) previous studies have reported a lower incidence of severe acute GVHD compared with conventional allo-SCT. However, in these studies the incidences of grade II-IV acute GVHD varied widely from 26% to 51% (H.Narimatsu Stem cell int. 2011: 607569). In particular, post transplant immune disorders, including early immune reactions (PIR) and acute GVHD, are potential complications following CBT in adult patients. Such reactions might increase the risk of organ dysfunction, leading to high rates of transplantation-related mortality, particularly in patients who do not respond to primary therapy, which usually consists of steroids. Infliximab, a chimeric monoclonal antibody against tumor necrosis factor alpha, has shown activity against steroid refractory acute GVHD. Patients and MethodsWe retrospectively reviewed 275 patients who underwent single-unit reduced intensity cord blood transplantation consecutively from March 2007 to December 2011 at our institute. Patients in whom PIR or acute GVHD developed received methylprednisolone 1–2 mg/kg per day. If no partial or complete resolution of symptoms occurred, they were considered steroid-refractory and proceeded to infliximab treatment. The dose of infliximab was 5 mg/kg/day once weekly for at least 1 course. An antifungal drug, itraconazole or micafungin or voriconazole was used until all immunosuppressive drus were withdrawn. ResultsIn this study we retrospectively evaluated 54 patients who had steroid refractory acute GVHD. Of these, 21 who received infliximab were analyzed. GVHD prophylaxis was with only tacrolimus(n=15) and mycophenolate mofetil+tacrolimus(n=6). All of them developed grade III to IV GVHD. Median follow-up time of survivors was 548 days (range, 222–1152). The overall response rate was 62% (n=13), and 9 patients (43%) experienced complete response (CR). 5 patients (24%) did not respond and 3 (14%) had progressive GVHD. The Kaplan-Meier estimate of overall survival was 31%, with no signs of chronic GVHD (n=2). Four patients who responded subsequently died, one of exacerbation of GVHD, three of infections. All the 8 unresponsive patients died of GVHD or infections. Five patients (21%) had non-Candida invasive fungal infections. Sixteen patients(79%) had bacterial infections. ConclusionInfliximab was well tolerated and active for the treatment of steroid-resistant acute GVHD even following reduced intensity cord blood transplantation. However, it is associated with a high rate of infections. Controlled studies to assess the pharmacokinetics and most effective dosing regimen of infliximab for the treatment of steroid refractory acute GVHD are warranted. Disclosures:No relevant conflicts of interest to declare.

Tocilizumab for the Treatment of Steroid Refractory Graft-versus-Host Disease

Corticosteroid refractory graft-versus-host disease (GVHD) is one of the major challenges in the management of allogeneic stem cell transplant recipients. Although numerous agents have been employed to treat this patient population, no standardized second-line therapy exists. In this study, we report our experience with the administration of tocilizumab, an anti-interleukin 6 receptor antibody, in the treatment of steroid refractory GVHD. Tocilizumab was administered to 8 patients with refractory acute (n = 6) or chronic GVHD (cGVHD) (n = 2) once every 3 to 4 weeks. The majority of patients with acute GVHD (aGVHD) had grade IV organ involvement of the skin or gastrointestinal tract, whereas both patients with cGVHD had long-standing severe skin sclerosis at the time of treatment. There were no allergic or infusion-related adverse events. Treatment was discontinued in one patient over concerns that tocilizumab may have worsened preexisting hyperbilirubinemia. Several patients also had transient elevations in serum transaminase values. Infections were the primary adverse events associated with tocilizumab administration. Four patients (67%) with aGVHD had either partial or complete responses apparent within the first 56 days of therapy. One patient with cGVHD had a significant response to therapy, whereas the second had stabilization of disease that allowed for a modest reduction in immune suppressive medications. These results indicate that tocilizumab has activity in the treatment of steroid refractory GVHD and warrants further investigation as a therapeutic option for this disorder.

Mycophenolic acid trough level monitoring: relevance in acute and chronic graft versus host disease and its relation with albumin

Mycophenolate mofetil (MMF) is used to treat acute and chronic graft versus host disease (GvHD). There is scant evidence in the literature about mycophenolic acid (MPA) trough level monitoring in GvHD. We therefore reviewed 32 patients treated with MMF for acute (n = 19) or chronic GvHD (n = 13). Twelve (63%) of 19 patients with acute GvHD and nine (69%) of 13 with chronic GvHD showed a good response. In all 21 patients who responded to MMF, their mean total MPA levels were therapeutic (1-3.5 mg/L), whereas five of 11 patients who did not respond had sub-therapeutic mean MPA levels (p = 0.002). Sixteen (66%) of 24 steroid refractory or dependent patients responded to MMF. Associations between the mean total MPA level for each patient and the corresponding mean serum albumin concentration showed therapeutic mean total MPA levels for all 23 patients with mean albumin ≥ 31 g/L but sub-therapeutic mean total MPA levels in five of nine patients with mean albumin <31 g/L (p = 0.0006). In conclusion, MMF is efficacious in steroid refractory and dependent acute or chronic GvHD with statistically significant correlation between therapeutic plasma total MPA trough levels and clinical response. Serum albumin levels should be taken into account when considering MMF dose adjustments.

Pentostatin and Alemtuzumab: An Immunosuppressive Nonmyeloablative Preparative Regimen for Allogeneic Peripheral Blood Stem Cell Transplantation (PBSCT).

Abstract 4312 IntroductionCurrent nonmyeloablative and reduced-intensity preparative regimens for allogeneic (allo) PBSCT are associated with significant myelosuppression and neutropenia. We evaluated a novel, purely immunosuppressive preparative regimen of continuous-infusion pentostatin (PEN) plus alemtuzumab (ALEM) in patients (pts) undergoing related and unrelated allo PBSCT for high-risk hematological malignancies. Patients and Methods12 pts (median age, 58.5 yr; range, 23-69 yr; 7 male, 5 female) with high-risk, relapsed or refractory acute myelogenous leukemia (AML; 5 pts), Hodgkin's disease (HD; 2 pts), multiple myeloma (MM; 2 pts), chronic lymphocytic leukemia (CLL; 1 pt), low-grade non-Hodgkin's lymphoma (NHL; 1 pt) or myelodysplastic syndrome (1 pt) were enrolled on this study; 6 pts had failed previous autologous PBSCT. The median interval between most recent conventional chemotherapy and allo PBSCT was 3.5 months (range, 1.5-19.5 months). Pts received continuous-infusion PEN (12 mg/m2 over 72 hr, days -8 through -6) and ALEM (20 mg/day, days -5 through -1) followed by allo PBSCT from 8/8 HLA-matched related (3 pts) or unrelated (9 pts) donors. All pts received single-agent cyclosporine (CSP) for prophylaxis of acute graft-versus-host disease (GVHD). ResultsMedian cell doses were 5.45 (range, 1.86-7.90) x 106 CD34+ cells/kg and 2.71 (range, 1.40-4.46) x 108 CD3+ cells/kg. Ten pts had asymptomatic transient elevations of AST and ALT (CTCAE grade 2-3) between days -6 and +21. No pts developed mucositis. Median duration of post-PBSCT hospitalization was 7 days (range, 3-62 days). The median nadir of the absolute neutrophil count (ANC) was 1.24 (range, 0.55–5.11) x 109/L at day +15, and the median nadir of the platelet count was 70 (range, 16-244) x 109/L at day -1. In contrast, the median nadir of the absolute lymphocyte count (ALC) was zero (range, 0-0.72) x 109/L at day -4. ALC remained low at day +28 (median, 0.09 × 109/L; range, 0.05-0.91 × 109/L) and increased by day +100 to a median of 0.34 × 109/L (range, 0.23-2.63 × 109/L). One pt developed grade 2 acute GVHD at day +21. No pts developed chronic GVHD. Evaluation of chimerism in bone marrow at day +28 showed that 3 pts had zero donor DNA and 9 pts had a median of 17% (range, 3-68%) donor DNA. At day +100, 2 of 8 evaluable pts (one with zero and one with 13% donor DNA at day +28) had zero donor DNA in bone marrow, and 6 pts had a median of 64% (range, 21.3-100%) donor DNA. Cumulative actuarial probability of sustained engraftment (defined as at least 50% donor DNA in bone marrow) is 53.4%. Doses of infused CD34+ cells or CD3+ cells were not statistically significantly different in pts with or without allogeneic engraftment (P=0.34, Mann-Whitney test). Three pts had asymptomatic reactivation of cytomegalovirus at 5, 11, and 35 days, respectively, after allo PBSCT. Two pts developed disseminated toxoplasmosis, which was fatal in 1 pt. One pt developed Mucor sinusitis and died with Enterococcus sepsis. One pt developed nonfatal Nocardia pneumonitis and sepsis at 175 days after allo PBSCT. Relapses occurred in 5 pts (1 AML, 1 CLL, 1 HD, 2 MM) at a median of 106 days (range, 28-360 days) after allo PBSCT; 1 of these pts had had engraftment failure and autologous hematopoietic recovery. The actuarial probability of relapse is 56.4%. Seven pts died at a median of 60 days (range, 44-347 days) after allo PBSCT: 1 relapse of HD, 2 infection (1 toxoplasmosis, 1 Enterococcus sepsis), 1 pulmonary hemorrhage with multiorgan failure, and 3 refractory acute GVHD that occurred following treatment of relapse with donor lymphocyte infusion (1 pt), withdrawal of CSP (1 pt) or second allo PBSCT (1 pt). Four subjects (2 AML, 1 HD, 1 NHL) are alive in remission at a median of 513 days (range, 267-787 days) after allo PBSCT. Actuarial probabilities of overall survival and event-free survival are 40.0% and 31.3%, respectively. ConclusionsA preparative regimen of continuous-infusion PEN plus ALEM can allow engraftment of HLA-matched allogeneic PBSCs without significant myelosuppression. However, engraftment failure is greater after this purely immunosuppressive regimen than with standard nonmyeloablative or reduced-intensity regimens. Relapsed or refractory disease at time of allo PBSCT, the absence of cytoreduction with this preparative regimen, and potentially a decrease in graft-versus-tumor effect as a result of profound and prolonged immunosuppression are factors that contribute to the relapse rate observed in this study. Disclosures:Off Label Use: Pentostatin administered as a continuous infusion according to FDA IND #67,067.

Impact of macrophage infiltration of skin lesions on survival after allogeneic stem cell transplantation: a clue to refractory graft-versus-host disease

We retrospectively reviewed 104 biopsy specimens of previously untreated skin acute graft-versus-host disease (GVHD) within 100 days after allogeneic stem cell transplantation, and analyzed the relationship between types of infiltrating cells and clinical outcomes. Counting the total number of CD8(+) T cells, CD163(+) macrophages, and CD1a(+) dendritic cells in 4 fields under original magnification x200, the infiltration of more than 200 cells of CD163(+) macrophages (many macrophages [MM]) was the only significant predictor for refractory GHVD (odds ratio, 3.79; 95% confidence interval, 1.22-11.8; P = .02). In 46 patients given steroid treatments, MM was the only significant predictor for refractory acute GVHD (odds ratio, 5.05; 95% confidence interval, 1.19-21.3; P = .03). Overall survival of patients with MM was significantly lower than that of those with an infiltration of less than 200 cells of CD163(+) macrophages. Macrophage infiltration of skin lesions could be a significant predictive factor for refractory GVHD and a poor prognosis.

Combination antithymocyte globulin and soluble TNFα inhibitor (etanercept) +/− mycophenolate mofetil for treatment of steroid refractory acute graft-versus-host disease

Antitumor necrosis factor-alpha antibodies are increasingly being used for the treatment of steroid-refractory acute graft-versus-host disease (GVHD) complicating allogeneic stem cell transplantation. We retrospectively reviewed the outcomes of 16 patients with refractory acute predominantly visceral GVHD treated with combination antithymocyte globulin (ATG), tacrolimus and etanercept +/- mycophenolate mofetil (MMF) at our institution. Overall response rate (CR+PR) was 81%, with median survival post commencing salvage immunosuppression 224 days (range 20-1216 days). In total, eight patients (50%) died, including from progressive GVHD in two cases (13%), infection in five (31%) and relapse of underlying malignancy in one (6%). In comparison to our previous experience of ATG+tacrolimus as treatment for refractory visceral GVHD, both response rate and overall survival were improved with addition of etanercept, with no apparent increase in infectious complications. As such, use of etanercept in combination with ATG +/- MMF for treatment of steroid refractory acute GVHD appears to be associated with high response rates, significant survival and no unexpected toxicity. Further study of this immunosuppression combination in a larger cohort of patients in this setting is indicated.

Mycophenolate Mofetil Is Effective and Well Tolerated in the Treatment of Refractory Acute and Chronic Graft-versus-Host Disease

We enrolled 11 patients with refractory graft-versus-host disease (GVHD) in a prospective trial evaluating the efficacy of mycophenolate mofetil (MMF). Four (67%) of the 6 patients with acute GVHD and all 5 patients with chronic GVHD responded to MMF. Ten (91%) of the 11 patients were able to decrease steroid use (median decrease, 86%; range, 25%-100%). After a median follow-up of 18 months (range, 1-65 months), 7 patients (64%) remained alive. The adverse events were infectious complications (36%), diarrhea (27%), and neutropenia (18%); the only patient discontinuing MMF did so because of grade 4 neutropenia. This preliminary study suggests that MMF is a well-tolerated agent and has a beneficial effect in the treatment of refractory acute and chronic GVHD.

Low-Dose Methotrexate as Salvage Therapy for Refractory Graft-Versus-Host Disease (GVHD) after Reduced-Intensity Conditioning (RIC) for Allogeneic Stem Cell Transplantation (allo-SCT).

Background. RIC regimens are increasingly used for allo-SCT. Although such regimens are associated with a relatively low early transplant-related mortality (TRM) in comparison to standard myeloablative allo-SCT, GVHD remains a matter of concern. Of note, corticosteroid-resistant GVHD is associated with high morbidity and mortality, and therapeutic options are limited for those patients. Furthermore, patients undergoing RIC allo-SCT are older than patients undergoing myeloablative allo-SCT, and are thus more exposed to the side effects and complications of long term corticosteroids (CS) administration. Low dose methotrexate (MTX) therapy is a well established modality for prophylaxis of GVHD after standard myeloablative allo-SCT. However, little is known about the role of this drug in the treatment of CS-resistant GVHD.Patients and Methods. The aim of this pilot single center study was to investigate the role and benefit of MTX in a curative setting after failure of CS treatment in 20 consecutive patients undergoing RIC allo-SCT. 20 patients experiencing severe GVHD received IV infusions of low dose MTX (5 mg/m2/infusion) at weekly intervals, for at least four weeks. Reasons for MTX administration were: refractory acute GVHD (after at least one week of 2 mg/Kg CS administration), CS-refractory chronic GVHD, chronic GVHD exacerbation after CS taper, or CS side effects and complications (CS-induced diabetes requiring insulin therapy, severe metabolic or psychiatric disorders). Responses to low dose MTX infusions were assessed one month after the last infusion in each involved organ.Results. 12 patients were treated for severe acute GVHD, while 8 patients received MTX for extensive chronic GVHD. Median age of patients was 51 (range, 22–60). Median time of administration of MTX was day +89 (range, 32–300) after allo-SCT. Of note, none of the patients received any other concomitant therapy for refractory GVHD. 13 patients responded to MTX administration (65 %) with 5 complete responses (25%). Among the 12 patients treated for acute GVHD, 7 responded (58%) of whom 5 CRs (42%). 3 patients did not respond and died from resistant GVHD. Interestingly, 5 patients from the group of grade 3–4 acute GVHD responded. Among the 8 patients treated for chronic GVHD, 6 were responders (75%). In addition, MTX allowed a significant reduction of CS daily dosage ranging from 25% to 80%, as assessed one month after the last administration of MTX. With a median follow-up of 287 days, no increase of CS therapy was necessary among these 6 MTX-responding patients. In the whole study population, toxicity of low dose MTX administration was low (transient and mild reversible cytopenia in 3 cases, 15%). Among the 20 patients, 14 are still alive (70%) with a median follow-up of 293 (range, 65–513) days. Overall, 2 patients died of progressive disease, while 4 patients died from refractory GVHD.Conclusions. In this study, the global response rate of severe GVHD to low dose MTX was impressively high (65%) if considered in terms of salvage therapy in this relatively elderly and high risk population. Low dose MTX appears to be a well-tolerated, inexpensive and likely steroid-sparing agent that is worthy of further investigation in prospective trials for treatment of refractory GVHD, but also as frontline therapy in combination with CS.