Steroid-refractory Acute Graft-versus-host Disease Research Articles

Decreasing the steroid rapidly may help to improve the clinical outcomes of patients with intestinal steroid-refractory acute graft-versus-host disease receiving basiliximab treatment.

Intestinal steroid refractory acute graft-versus-host disease (SR-aGVHD) is the major cause of mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT). This retrospective cohort study aimed to identify the relationship between different steroid decreasing velocity and therapeutic response in patients with intestinal SR-aGVHD receiving basiliximab treatment, and also aimed to propose a reasonable steroid decreasing regimen for these patients. The median time for steroid dose decreasing to the 50% of initial dose and decreasing to the low-dose steroid for patients achieving ORR was 5 days and 12 days, respectively, which was both shorter than patients without achieving ORR. The ORR, NRM and survival in rapid and medium steroid decreasing group were all better than slow group. The cumulative incidence of ORR at any time was 90.4%, 78.1% and 62.3%, respectively, in rapid, medium, and slow group. The cumulative incidence of NRM at 1 year after basiliximab treatment was 18.7% (95% CI 11.3%-26.1%), 22.8% (95% CI 14.2%-31.4%) and 32.8% (95% CI 24.1%-41.5%), respectively, in rapid, medium, and slow group. The probability of OS at 1 year after basiliximab treatment was 76.9% (95% CI 68.9%-84.9%), 72.7% (95% CI 63.7%-81.7%), and 62.3% (95% CI 53.5%-71.1%), respectively, in rapid, medium, and slow group. Hence, it was helpful to decrease steroid to the 50% of initial dose ≤ 5 days and to the low-dose steroid ≤ 12 days after basiliximab treatment for intestinal SR-aGVHD patients, which may also be the reasonable steroid decrease protocol for these patients.

Mesenchymal stromal cells plus basiliximab improve the response of steroid-refractory acute graft-versus-host disease as a second-line therapy: a multicentre, randomized, controlled trial

BackgroundFor patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD), effective second-line regimens are urgently needed. Mesenchymal stromal cells (MSCs) have been used as salvage regimens for SR-aGVHD in the past. However, clinical trials and an overall understanding of the molecular mechanisms of MSCs combined with basiliximab for SR-aGVHD are limited, especially in haploidentical haemopoietic stem cell transplantation (HID HSCT).MethodsThe primary endpoint of this multicentre, randomized, controlled trial was the 4-week complete response (CR) rate of SR-aGVHD. A total of 130 patients with SR-aGVHD were assigned in a 1:1 randomization schedule to the MSC group (receiving basiliximab plus MSCs) or control group (receiving basiliximab alone) (NCT04738981).ResultsMost enrolled patients (96.2%) received HID HSCT. The 4-week CR rate of SR-aGVHD in the MSC group was obviously better than that in the control group (83.1% vs. 55.4%, P = 0.001). However, for the overall response rates at week 4, the two groups were comparable. More patients in the control group used ≥ 6 doses of basiliximab (4.6% vs. 20%, P = 0.008). We collected blood samples from 19 consecutive patients and evaluated MSC-derived immunosuppressive cytokines, including HO1, GAL1, GAL9, TNFIA6, PGE2, PDL1, TGF-β and HGF. Compared to the levels before MSC infusion, the HO1 (P = 0.0072) and TGF-β (P = 0.0243) levels increased significantly 1 day after MSC infusion. At 7 days after MSC infusion, the levels of HO1, GAL1, TNFIA6 and TGF-β tended to increase; however, the differences were not statistically significant. Although the 52-week cumulative incidence of cGVHD in the MSC group was comparable to that in the control group, fewer patients in the MSC group developed cGVHD involving ≥3 organs (14.3% vs. 43.6%, P = 0.006). MSCs were well tolerated, no infusion-related adverse events (AEs) occurred and other AEs were also comparable between the two groups. However, patients with malignant haematological diseases in the MSC group had a higher 52-week disease-free survival rate than those in the control group (84.8% vs. 65.9%, P = 0.031).ConclusionsFor SR-aGVHD after allo-HSCT, especially HID HSCT, the combination of MSCs and basiliximab as the second-line therapy led to significantly better 4-week CR rates than basiliximab alone. The addition of MSCs not only did not increase toxicity but also provided a survival benefit.

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.

Efficacy of off-the-shelf bone marrow mesenchymal stem cells for pediatric steroid-refractory acute graft-versus-host disease.

Temcell is a mesenchymal stem cell (MSC) product approved for steroid-refractory acute graft-versus-host disease (SR-aGVHD) in Japan. However, reports regarding Temcell's efficacy in pediatric patients have been scarce, and the appropriate use of MSC therapy against pediatric SR-aGVHD also remains to be determined. We retrospectively assessed a cohort of pediatric patients treated with Temcell for SR-aGVHD following allogeneic hematopoietic transplantation. MSCs were infused intravenously at a dose of 2 × 106 cells/kg according to the manufacturer's instructions. Twelve patients received eighteen cycles of MSC therapy (median age, 10.3 [1.7-17.8] years), with four receiving additional cycles (one cycle: n = 3, three cycles: n = 1). The severity of aGVHD before MSC therapy was grade I-II in three patients and grade III-IV in nine patients (gut stage 3-4, n= 7; liver stage 3-4; n =2). The median number of immunosuppressive therapy regimens received prior to MSC administration was two (range: 1-5). The first MSC cycle displayed the best overall response rate of 83%, including six patients with a complete response (CR) and with a 49% reduction in the mean daily dose of prednisone after eight weeks. The median time to first response was 3.5 days (range: 2-15 days). Two of the four patients who were re-administered MSCs for recurrent or persistent GVHD achieved a CR. The three-year overall survival rate was 69.4%, while the three-year failure free survival (FFS) rate was 22.2%, with a median FFS of 4.9 months. There were no observable side effects of MSC therapy. MSC therapy appears to be an effective and safe treatment for pediatric SR-aGVHD, with a steroid-sparing effect and satisfactory efficacy upon re-administration. Further studies are needed to determine its appropriate combination with additional treatments and the optimal use of re-administration of MSCs.

ECP versus ruxolitinib in steroid-refractory acute GVHD - a retrospective study by the EBMT transplant complications working party.

Extracorporal Photophoresis (ECP) is in clinical use for steroid-refractory and steroid-dependent acute GVHD (SR-aGVHD). Based on recent Phase-III study results, ruxolitinib has become the new standard of care for SR-aGVHD. Our aim was to collect comparative data between ruxolitinib and ECP in SR-aGVHD in order to improve the evidence base for clinical decision making. We asked EBMT centers if they were willing to participate in this study by completing a data form (Med-C) with detailed information on GVHD grading, -therapy, -dosing, -response and complications for each included patient. 31 centers responded positively (14%) and we included all patients receiving alloSCT between 1/2017-7/2019 and treated with ECP or ruxolitinib for SR-aGVHD grades II-IV from these centers. We identified 53 and 40 patients with grades II-IV SR-aGVHD who were treated with ECP and ruxolitinib, respectively. We performed multivariate analyses adjusted on grading and type of SR-aGVHD (steroid dependent vs. refractory). At day+90 after initiation of treatment for SR-aGVHD we found no statistically significant differences in overall response. The odds ratio in the ruxolitinib group to achieve overall response vs. the ECP group was 1.13 (95% CI = [0.41; 3.22], p = 0.81). In line, we detected no statistically significant differences in overall survival, progression-free survival, non-relapse mortality and relapse incidence. The clinical significance is limited by the retrospective study design and the current data can't replace prospective studies on ECP in SR-aGVHD. However, the present results contribute to the accumulating evidence on ECP as an effective treatment option in SR-aGVHD.

Update on the Use of Mesenchymal Stem Cells and their Products in Hematopoietic Stem Cell Transplantation

Graft Versus Host Disease (GVHD) is a major limitation to the success of allogeneic Hematopoietic Stem Cell Transplantation (HSCT) as Steroid-Refractory (SR) acute GVHD carries poor prognosis due to the absence of an efficacious second-line therapy. Mesenchymal Stem Cells (MSCs) which have immunosuppressive, immunomodulatory, and regenerative properties may become a highly effective therapeutic modality for SR-GVHD in the near future. MSCs have already been approved to treat childhood SR-GVHD in Japan, and they have been conditionally licensed in New Zealand and Canada. It is expected that MSCs will be approved for the treatment of SR-GVHD in adults in Europe, North America, and other parts of the world within a few years. Utilization of the recently introduced techniques including the use of MSC products such as exosomes and Extracellular Vesicles (ECVs) instead of the parent MSCs, robotic manufacturing technology, and genetic engineering of MSCs will ultimately overcome the remaining obstacles facing the widespread utilization of MSCs and their products as therapeutics not only in HSCT but also in other medical fields. The aim of this review is to provide an update on the remarkable progress achieved in the use of MSCs and their products in the field of HSCT.

Inhibition of Bromodomain and Extraterminal Domain (BET) Proteins Alleviates Chronic Graft- Versus-Host-Disease Via Modulating the CXCR5/CXCL13 Axis

Introduction: Chronic graft-versus-host disease (cGVHD) is a severe complication of allogeneic hematopoietic cell transplant (allo-HCT) often leading to transplant-mediated mortality. Studies have shown that T follicular helper cells (Tfh) upregulate CXCR5 and migrate into the lymphoid organ follicles in response to CXCL13 promoting germinal center (GC) B cell proliferation and differentiation of plasma cells resulting in pathogenic antibody production and profibrotic pathways associated with cGVHD. In contrast, T follicular regulatory cells (Tfr) modulate the magnitude of the GC response; thus, the balance of Tfr/Tfh could be crucial to mitigating cGVHD.Bromodomain and extra-terminal domain (BET) proteins are epigenetic readers influencing transcription of a multitude of inflammatory genes and our lab has previously reported pharmacological inhibition of BET, through OPN-51107, improves survivability and limits disease progression in murine models of acute GVHD that led to opening the first-in-human clinical trial of OPN-51107 in steroid refractory acute GVHD. We demonstrated BET proteins to be important in modulating acute GVHD pathogenesis, however, mechanisms of BET regulation within cGVHD are largely unknown. Here, using OPN-51107 we aim to further investigate mechanisms of cGVHD pathogenesis and identify successful BET inhibition-based therapeutic approaches. Methods: We used a Bronchiolitis Obliterans model (B6-&amp;gt;B10.br) of cGVHD. Mice were administered 120mg/kg cyclophosphamide (D-3 and D-2) and 8Gy irradiation (D-1) as a conditioning regimen followed by B6 T-cell depleted bone marrow cells with and without CD45.1 B6 splenocytes. Mice that did not receive allogeneic splenocytes served as controls and did not develop GVHD. Recipients of allogeneic splenocytes were treated with a BET inhibitor - OPN-51107 at 10mg/kg 3x/weekly, or vehicle, from D28-54(+ 4) via oral gavage. Resting lung elastance and resistance was measured using the Flexivent system. At the time of lung function analysis, lung and liver tissue was harvested and stained via Hesson's Trichrome to identify and quantify collagen deposition. We performed immunofluorescence to quantify alveolar alloantibody deposition. Spleen and lung cells were stimulated with PMA/I and analyzed via spectral flow cytometry. An inflammatory murine cytokine array (#ARY006, R&amp;D Systems) was used to analyze circulating plasma cytokine levels. Results: BET inhibition via OPN-51107 treatment decreased lung resistance (vehicle vs OPN-51107 =1.16Rrs vs 0.83Rrs p&amp;lt;0.05) and elastance (vehicle vs. OPN-51107=62Ers vs. 45Ers p&amp;lt;0.05). OPN-51107 treatment also significantly reduced alveolar antibody (Ig) deposition per area compared to vehicle (vehicle vs. OPN-51107= 4.91% vs. 3.3% p=0.01) and collagen deposition (vehicle vs. OPN-51107=19.0% vs. 12.9% p&amp;lt;0.05) and liver (vehicle vs. OPN-51107=19.3% vs. 2.35% p&amp;lt;0.0001). Congruently, BET inhibition decreased B220-CD19- CD138+mature plasma cells (vehicle vs. OPN-51107=15% vs 9.1% p&amp;lt;0.05) in the lung. Serum cytokine array analysis revealed a significant decrease in circulating CXCL13, relevant to Tfh migration as well as a decrease in other proinflammatory cytokines - CXCL9, MCP-1, IL3, RANTES and G-CSF important for macrophage activation and pathogenicity in OPN-51107 compared to vehicle treated mice. BET inhibition reduced splenic Tfh while increasing Tfr, thereby increasing Tfr:Tfh ratio (vehicle vs. OPN-51107= 5% vs. 9% p&amp;lt;0.05). Furthermore, total splenic CD19+ B-cells (vehicle vs. OPN51107= 70% vs. 33% p&amp;lt;0.001) as well as CXCR5 expression on B-cells were decreased in OPN-51107 treated mice (MFI vehicle vs. OPN-51107= 4744 vs. 571.5 p&amp;lt;0.0001). Conclusion: OPN-51107 improved lung function which correlated with significantly decreased lung fibrosis and antibody deposition in a BO model of cGVHD. BET inhibition reduces cGVHD immune pathology through decreased inflammatory cytokine production, promotion of GC Tfr cell population and modulates B-cell proliferation and/or trafficking. Significance: Using OPN-51107 in a BO model of cGVHD we demonstrate that BET inhibition is a feasible therapeutic strategy to reduce disease severity and improve lung function.

The MAGIC Algorithm Probability Predicts Long-Term Outcomes and Treatment Response to Second-Line Therapy for Acute Gvhd

Introduction: Risk stratification approaches using clinical criteria or biomarkers in acute graft-versus-host disease (GVHD) have traditionally been implemented at diagnosis or initiation systemic treatment with corticosteroids. For patients who require second-line treatment, the significance of biomarkers at salvage therapy and the relationship between biomarker risk and choice of therapy are unknown. Methods: We studied adult patients who received second-line treatment for acute GVHD between January 2016 and December 2021 in the Mount Sinai Acute GVHD Consortium (MAGIC) database, which collects clinical data and longitudinal serum samples from allogeneic HCT recipients using a rigorous PRoBE study design. Exclusion criteria included relapse of underlying malignant disease prior to second-line therapy, missing response data, or missing serum sample. Serum samples collected from 7 days prior to 3 days after initiation of second-line therapy met criteria for biomarker analysis. The MAGIC algorithm probability (MAP) was calculated as a single value based on concentrations of ST2 and REG3α and was stratified at a threshold of 0.290 to define high MAP and low MAP groups. The primary objective evaluated the association between MAP and survival for patients receiving second-line therapy for acute GVHD. The key secondary objective was to investigate the MAP and choice of second-line systemic agent on Day 28 overall response rate (ORR) and survival. Results: In total, 316 adult patients received second-line treatment for acute GVHD; 149 patients (47%) were excluded for disease relapse (n=27), missing response data (n=48), or missing sample (n=74).Of the 167 evaluable patients, most had steroid-refractory acute GVHD (n=146, 87%), rather than steroid-dependent (n=8, 5%) or steroid-sensitive (n=14, 8%) disease. 62 patients received ruxolitinib while 102 received other systemic agents (best available therapy: BAT). Baseline clinical characteristics of the study population according to treatment choice were similar, except for donor type (Rux: MRD 15%, MUD 74%, haplo 11%; BAT: MRD 30%, MUD 67%, haplo 3%; P=0.014) and median days from corticosteroids to second-line treatment (Rux: 18, BAT: 12; P=0.02).In total, 81 patients had high MAPs and 86 patients had low MAPs, with similar distribution in each treatment cohort (P=0.53). For the entire cohort, the median follow-up for survivors was 22 months (range, 1.5-27).The MAP separated patients into 2 groups (high vs low) with significantly different mortality (NRM at 2 years, 76% vs 29%, P&amp;lt;.0001) and survival (OS at 2 years, 12% vs 63%, P&amp;lt;.0001). Patients who received ruxolitinib as second-line therapy had lower mortality (NRM at 2 years, 35% vs 60%, P&amp;lt;.002) and improved survival (OS at 2 years, 51% vs 32%, P&amp;lt;.008), compared to those who received other systemic agents. However, the outcomes of patients with high MAP were poor, regardless of second-line treatment choice ( Figure 1A). The MAP (low vs high), time from corticosteroids to second-line treatment (≥14 days vs &amp;lt; 14 days), GVHD grade at second-line (0-2 vs 3-4), and choice of second-line therapy (Rux vs BAT) were all significant (P&amp;lt;0.05) predictors of lower NRM and higher OS in multivariate analysis. The MAP also separated patients into 2 groups with significantly different D28 ORR (low: 49%, high: 30%, P&amp;lt;.0001). In agreement with prospective trials, ruxolitinib resulted in higher D28 response rates compared to other systemic therapies (ORR 54.9% vs 30.5%, P=0.005), which was observed in both low MAP (ORR, 64.5% vs 38.5%, P=0.017) and high MAP cohorts (ORR, 42.9% vs 22.6%, P=0.06) ( Figure 1B). The MAP (low vs high), GVHD grade at second line (0-2 vs 3-4), and choice of second-line therapy (Rux vs BAT) were significant predictors (P&amp;lt;0.05) of higher D28 ORR in multivariate analysis. Conclusion: The MAP measured at the initiation of second-line systemic treatment for acute GVHD predicts NRM and OS, as well as treatment response. The outcomes of patients with high MAP are poor, regardless of second-line treatment choice, and the higher CR rate in low MAP patients may drive higher survival rates. Incorporation of MAP into clinical trials in this setting warrants investigation. The results also support the current use of ruxolitinib as second-line treatment for acute GVHD, particularly in patients with low MAP.

Efficacy of Treatment Options for Children with Steroid-Refractory Acute Gvhd

Background: Approximately half of patients with acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic cell transplantation (alloHCT) experience steroid-refractory aGVHD (SR-aGVHD) disease. Patients with SR-aGVHD require intense and prolonged immunosuppression resulting in high risk of severe opportunistic infections and risk of relapse of malignancy which ultimately results in significant increase in short- and long-term morbidity and mortality, poor quality of life for children and their families and increases financial burden on families and health care system. Corticosteroids have been the mainstay of therapy for new onset acute GVHD. However, treatment for SR-GVHD in children is a serious unmet need. To date, few therapies have been investigated for SR-aGVHD in robust clinical trials for children. Moreover, long-term benefits and survival data from these trials are often lacking or unclear. A systematic literature review (SLR) was conducted to better understand the efficacy of therapies under investigation in this population. Methods: Literature database searches of Embase, MEDLINE, Cochrane, and Econlit, were performed on 22 May 2023 according to Cochrane guidelines to identify randomized and non-randomized clinical trials in which the pediatric population with SR-aGVHD represented at least 50% of the trial population. Clinical trials extensions and long-term follow-up reports were also included. Studies published in English from 2009 onwards were retrieved. Additional manual searches of relevant conference abstracts published in the past 3 years were performed. Results: Overall, 29 publications (23 unique studies) met the selection criteria, representing a total of 801 patients aged 18 years or younger with SR-aGVHD. A limited number of interventions were investigated in this population and most studies had a non-randomized design (19 out of 23 studies). Overall survival (OS) and response rates (ORR) were analyzed from studies enrolling more than 20 pediatric patients with SR-aGVHD (9 studies, Table), which investigated therapies such as mesenchymal stromal cells (MSC), remestemcel-L (MSC manufactured by Mesoblast), ruxolitinib, etanercept and extracorporeal photopheresis. At least 80% of patients treated with cellular therapies (remestemcel-L/MSC) and etanercept had grade III or IV disease. ORR on day 28 was 92% with etanercept, 77% to 91% with ruxolitinib, 61% to 92% with mesenchymal stromal cells, 61% to 70% with remestemcel-L, and 55% with extracorporeal photopheresis. Durable response rates of 69% at day 56 and 70% at day 100 and were noted for remestemcel-L and ruxolitinib, respectively. OS at 6 months was 69% with remestemcel-L, and 71% with mesenchymal stromal cells. OS at 1 year was reported for remestemcel-L (63%) and etanercept (59%). Long-term survival data beyond 1 year of patients enrolled in the clinical trial was available only for remestemcel-L and showed an OS rate of 51% at 2 years and 49% at 3 and 4 years. 4-year OS probability for patients with grade III or IV (48% in both cases) was similar to that for the overall population. Conclusions: Only a few small size clinical trials were conducted for children with SR-aGVHD which poses a unique challenge for FDA to approve new therapies for SR-aGVHD. Despite a small number (n=9: 5 ruxolitinib arm and 4 control arm) of children (12-18 years) enrolled in REACH II study, ruxolitinib was FDA approved for children&amp;gt;12 years of age. Long-term efficacy outcomes of children enrolled in clinical trials were reported only for remestemcel-L and showed that approximately half survived beyond 3 years. While other reports showed that grade III/IV disease is associated with poorer outcomes compared to grade I/II, similar survival rates were noted for patients with grade II, III and IV treated with remestemcel-L. In children with SR-aGVHD, other therapies such as ruxolitinib or etanercept demonstrated good response rates, however, the associated survival benefit is unclear.

Efficacy and Safety of Fecal Microbiota Transplantation in the Treatment of Chronic Steroid-Refractory Graft-Versus-Host Disease after Hematopoietic Stem Cell Transplantation

Efficacy and safety of fecal microbiota transplantation in the treatment of chronic steroid-refractory graft-versus-host disease after hematopoietic stem cell transplantation Introduction The majority of patients who undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) with acute gut graft-versus-host disease has lost the diversity of gastrointestinal microbiota and associated to adverse clinical outcome. Despite glucocorticoids treatment has been considered as the first-line therapy regardless acute or chronic GVHD, the curative efficiency and durable response remains unsatisfactory. Several studies suggesting that fecal microbiota transplantation (FMT) from healthy donor effectively alleviated gut steroid-refractory acute GVHD (SR-aGVHD) by restoring diversity of gastrointestinal microbiota, resistance to potential pathogens, and transforming essential materials to metabolites for immunomodulating donor T cell which improved clinical outcomes in allo-HSCT. However, it is still unclear whether FMT therapy have similar potential efficacy in treating steroid-refractory chronic GVHD (SR-cGVHD). Here, we report the results of a pilot study from our single center using FMT from unrelated healthy donor to treat patients with SR-cGVHD. Method 12 patients aged 16-60 years with SR-cGVHD after allo-HSCT were enrolled. A total of 31 FMTs were performed via colonoscopy in 12 patients with SR-GvHD over three consecutive months. Adverse events with reasonable suspicion for being associated with FMT were monitored after treatment for 28 days. Partial response was defined as a decrease at least one stage in severity of GVHD or able to taper steroid dose. No response was defined as unable to taper steroid dose or need to increase or add immunosuppressor for controlling GVHD progression. CR was defined as the complete resolution of GVHD manifestations in all organs. To characterize the impact of the FMT on the gut microbiota, stool samples from recipients were collected the day before FMT treatment and 4 weeks after FMT treatment then carried out 16s rRNA sequencing. Result The overall response rate (ORR) in the patients with SR-cGvHD reached 50% (6/12), including CR in 0/0 (0%) cases and PR in 6/12 (50%). Most common adverse events were 3 abdominal bloating (9.68%), 2 diarrhea cases (6.45%) and 1 fever (3.23%). No serious adverse events were observed. The diversity of gastrointestinal microbiota remarkable decreased during SR-GVHD and it recovered after FMT (Figure B). After FMT treatment, similar α diversity of gastrointestinal microbiota in PR and NR patients was observed, whereas β-diversity analysis showed significant differences in the composition and abundance of the bacterial colonization between groups (Figure C and D). Conclusion The present study indicates that FMT as a new potential therapy in the treatment of SR-cGvHD is safe, well tolerated, and effective. Disclosures No relevant conflicts of interest to declare.

Patterns of Graft-Versus-Host Disease (GvHD) Prevention and Management in the Eastern Mediterranean (EM) Region: A Worldwide Network for Blood & Marrow Transplantation (WBMT) Survey

Introduction: GvHD is a significant cause of morbidity and mortality in recipients of allogeneic hematopoietic cell transplant (HCT). The prevention, management, and treatment of GvHD vary in different regions worldwide. This WBMT study aims to better understand the current clinical practices of GvHD prevention and management around the globe. This study presents our survey results in the Eastern Mediterranean Region. Methodology: This is a cross-sectional survey-based study involving hematopoietic cell transplant (HCT) centers in the EM region. Participants of the survey were programs' directors or their designees. The survey comprised two parts; the first part aimed to study the practices of GvHD prevention, whereas the second part aimed to study GvHD management and treatment. The survey was distributed and filled out between December 2022 and May 2023. Results: Thirty participants from 28 institutions responded. Participants were from eleven different countries in the EM region. Fourteen participants (50%) filled it for combined pediatrics and adult HCT programs. The remaining participants filled it for programs performing HCT, either only in adult (27%) or pediatrics (23%) patients. The majority of participants indicated that cyclosporine and methotrexate combination is the most used GvHD prophylaxis therapy in both myeloablative and reduced intensity HCT in their centers. Cyclosporine was the predominantly used calcineurin inhibitor (CNI), followed by tacrolimus. All centers using cyclosporine indicated that they monitor its level, with 200-300 mcg/L being the target in 66% of the survey. Cyclosporine was typically given for 2-12 months after HCT, with around 80% of centers stopping it at 3-4 months post-HCT in recipients with malignant indications and around 90% of centers stopping it around 6-12 months post-HCT in recipients with non-malignant indications. When tacrolimus is used, results showed that it is typically used for similar duration to cyclosporine. Twenty-nine participants reported using post-transplant cyclophosphamide (PTCy) in their centers, with seven centers (24%) reporting its use in indications other than haploidentical transplants. Additionally, the results show that PTCy is typically used in combination with other medications, with 53% of participants reporting that it is used along with mycophenolate mofetil and cyclosporine and only one participant reported its use as a single agent. Seven participants (23%) reported that PTCy is typically used in doses less than 50 mg/kg. In patients with established GvHD, steroids were most commonly used alone as a first-line therapy in acute and chronic GvHD. The majority of centers report re-introducing or continuing the immunosuppressive agent used in GvHD prevention, with few centers indicating that they switched to another CNI. 64% and 55% of centers indicated that they have a standard-operating procedure (SOP) for steroid-refractory acute GvHD (aGvHD) and chronic GvHD (cGvHD), respectively. Only two centers reported involving steroid-refractory GvHD patients in clinical trials. Second-line therapy for steroid-refractory aGvHD and cGvHD varies significantly between centers depending on the type of GvHD and organ involved. In steroid-refractory aGvHD, ruxolitinib was the most frequently listed agent to be considered in the second line, regardless of the involved organ. Ruxolitinib was followed by Extracorporeal photopheresis in Skin aGvHD, Budesonide in lower GI tract aGVHD, and Mycophenolate Mofetil in liver aGvHD. In cGvHD, ruxolitinib was also the most frequently listed medication. However, more significant variability between centers was noted in treating organ-specific cGvHD. Conclusion: GvHD prevention and management practices vary between the different EM region centers. Some variations could be related to access to some medications. This might indicate the need for more evidence-based practices in preventing and managing GvHD and possibly adjusting the guidelines according to access and availability of some medications. WBMT is currently working on understanding the global patterns of GvHD practices in other regions and, ultimately, a global comparative study of all data combined.

Sequential Umbilical Cord Derived Mesenchymal Stromal Cells (MSCs) for the Third-Line Salvage Treatment of Steroid-Refractory Acute GvHD: A Multicenter, Open Label, Phase 1b/2 Trial

Background and Aim: Acute graft-versus-host disease (aGVHD) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT), particularly if treatment is refractory. Human mesenchymal stromal cells (MSCs) have demonstrated safety and efficacy in steroid refractory acute graft versus host disease, due to their well-described immunosuppressive properties, however, clinical trials have resulted in variable success and an optimal source of MSC has yet to be defined. Based on the importance of maternal-fetal interface immune tolerance, the umbilical cord may provide a superior tissue source of MSC to mediate immunomodulation in aGVHD (SR-aGVHD). This study aimed to investigate the safety and efficacy of MSCs delivered as third-line salvage therapy for SR-aGVHD who had received at least two-lines of steroid-containing immunosuppressive therapy. Method: This phase1b/2, multicenter, open-label clinical trial of a third-party, off-the-shelf preparation of human umbilical cord derived mesenchymal stromal cells (hUC-MSCs) (ChiCTR2200061603) enrolled grades II to IV steroid-refractory aGVHD patients who had been treated with at least two-lines of steroid-containing immunosuppressive therapy. This trial consist of 2 parts：a phase Ib dose escalation part using a standard 3+3 design, which planed biweekly i.v. infusions of hUC-MSCs, at 0.5× 10 6 per kg, 1.0× 10 6per kg and 2.0× 10 6 per kg for 3 weeks, to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Phase II of this work is an expansion cohort study of hUC-MSCs at RP2D 1.0×10 6 per kg with 15 patients. The primary endpoint of the study was safety and RP2D. The key secondary endpoints were efficacy of the overall response rate (ORR) at Day 28 and Day 56 defined per the 2014 NIH consensus criteria. Results: From June 23, 2022, through June 12, 2023, a total of 25 patients were enrolled with the median follow up period of 106 (10,210) days. Of the included 25 cases 11 patients (44.0%) were grade III/IV and 14 patients (56.0%) were grade II aGVHD at enrollment. Median patient age was 37.0 (range:24.5-47.0) years, 44.0% male. hUC-MSCs was well tolerated without dose-limiting toxicities in aforementioned three dosages. The reported adverse events (AEs) potentially associated with hUC-MSCs were hypofibrinogenemia (12.0%), upper respiratory tract infection (4.0%), leukopenia (4.0%) and anemia (8.0%) within the median follow-up period of 106 (10, 210) days. Grade 3 or higher AEs were reported in 6 patients (6/25, 24%) with 11 events, all of them were supposed uncorrelated with hUC-MSC. Three patients unfinished the administration:1 was due to withdrawn ICF; 1 was SAE and 1 was due to participate another trial. Up to date of June 12, 2023, twenty of the initial included 25 patients were still in group. And the RP2D of this trial was identified as 1.0× 10 6 per kg. At Day 28, 20 patients (80.0%, 95% CI:59.3%-93.2%) had an overall response, including 10 (40.0%) with complete responses. And at day 56, only one patient loss response, while another non-response patient at day 28 in the dose of 1.0× 10 6 per kg achieved late responses at day 56 ( Table 1). Responses were observed across skin (19/19, 100%), gastrointestinal tract (7/11,72.7%), and liver (2/2, 100.0%) at day 28. Durable overall response at day 56 was 76% (19/25), Figure 1. The median follow-up time after the initiation of hUC-MSC treatment was 106 (10,210) days with the cutoff date of 180 days after recruitment. The probability of 180-day overall survival (OS) and non-relapse mortality was 88.0% (95% CI, 68.8-97.5%) and 8.0% (95% CI, 1.0-26.0%), respectively. The 180-day cumulative incidence of relapse of primary hematologic disease was 8.0% (95%CI,1.0-26.0%). The percentage of total T lymphocyte, neutrophil, cytokine IL-10, IP-10 were statistically decreased in CR group, while CD8+central memory T cell was significantly increased compared to non-CR groups 24h or 96h after hUC-MSC administration (P&amp;lt;0.05）. Conclusion: Collectively, our results support hUC-MSCs as an effective salvage treatment for SR-aGVHD with safe profile. Key words: Acute graft-versus-host disease; allogeneic hematopoietic stem cell transplantation; mesenchymal stromal cells

Novel therapies for graft versus host disease with a focus on cell therapies.

Graft versus host disease (GVHD) can occur at any period post allogeneic hematopoietic stem cell transplantation as a common clinical complication contributing to significant morbidity and mortality. Acute GVHD develops in approximately 30-50% of patients receiving transplants from matched related donors. High doses of steroids are used as first-line treatment, but are unsuccessful in around 40% of patients, resulting in the diagnosis of steroid-refractory acute GVHD. Consensus has yet to develop for the management of steroid-refractory acute GVHD, and prognosis at six months has been estimated at around 50%. Thus, it is critical to find effective treatments that increase survival of steroid-refractory acute GVHD. This article describes the currently known characteristics, pathophysiology, and treatments for GVHD, with a special focus on recent advances in cell therapies. In particular, a novel cell therapy using decidua stromal cells (DSCs) was recently shown to have promising results for acute GVHD, with improved effectiveness over previous treatments including mesenchymal stromal cells. At the Karolinska Institute, severe acute GVHD patients treated with placenta-derived DSCs supplemented with either 5% albumin or 10% AB plasma displayed a one-year survival rate of 76% and 47% respectively. Furthermore, patients with steroid-refractory acute GVHD, displayed survival rates of 73% with albumin and 31% with AB plasma-supplemented DSCs, compared to the 20% survival rate in the mesenchymal stromal cell control group. Adverse events and deaths were found to be attributed only to complications of hematopoietic stem cell transplant and GVHD, not to the study intervention. ASC Therapeutics, Inc, in collaboration with the Karolinska Institute, will soon initiate a phase 2 multicenter, open-label study to further assess the efficacy and safety of intravenous DSC treatment in sixty patients with Grade II-IV steroid-refractory acute GVHD. This novel cell therapy represents a promising treatment to combat the poor prognosis that steroid-refractory acute GVHD patients currently face.

Humanized anti-CD25 monoclonal antibody as a salvage therapy for steroid-refractory acute graft-versus-host disease after hematopoietic stem cell transplantation

Objective: To investigate the efficacy of humanized anti-CD25 monoclonal antibody for steroid-refractory acute graft-versus-host disease (SR-aGVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: A total of 64 patients with SR-aGVHD between June 2019 and October 2020 in Suchow Hopes Hematology Hospital were enrolled in this study. Humanized anti-CD25 monoclonal antibodies 1 mg·kg(-1)·d(-1) were administered on days 1, 3, and 8, and then once per week according to the disease progression. Efficacy was assessed at days 7, 14, and 28 after humanized anti-CD 25 treatment. Results: Of the 64 patients with a median age of 31 (15-63) years, 38 (59.4%) were male and 26 (40.6%) were female. The overall response (OR) rate of the humanized CD25 monoclonal antibody in 64 patients with SR-aGVHD on days 7, 14, and 28 were 48.4% (31/64), 53.1% (34/64), and 79.7% (51/64), respectively. Liver involvement is an independent risk factor for poor efficacy of humanized CD25 monoclonal antibody for SR-aGVHD at day 28 (OR=9.588, 95% CI 0.004-0.291, P=0.002). The median follow-up time for all patients was 17.1 (0.2-50.8) months from the start of humanized CD25 monoclonal antibody therapy. The 1- and 2-year OS rates were 63.2% (95% CI 57.1% -69.3%) and 52.6% (95% CI 46.1% -59.1%), respectively. The 1- and 2-year DFS rates were 58.4% (95% CI 52.1% -64.7%) and 49.8% (95% CI 43.4% -56.2%), respectively. The 1- and 2-year NRM rates were 28.8% (95% CI 23.1% -34.5%) and 32.9% (95% CI 26.8% -39.0%), respectively. The results of the multifactorial analysis showed that liver involvement (OR=0.308, 95% CI 0.108-0.876, P=0.027) and GVHD grade Ⅲ/Ⅳ (OR=9.438, 95% CI 1.211-73.577, P=0.032) were independent risk factors for OS. Conclusion: Humanized CD25 monoclonal antibody has good efficacy and safety for SR-aGVHD. This study shows that SR-aGVHD with pretreatment grade Ⅲ/Ⅳ GVHD and GVHD involving the liver has poor efficacy and prognosis and requires early intervention.

Health-related quality of life in patients with steroid-refractory acute graft-versus-host disease.

Evidence regarding health-related quality of life (HRQoL) in patients with steroid-refractory acute graft-versus-host disease (SR-aGvHD) is lacking. Evaluating HRQoL was a secondary objective of the HOVON 113 MSC trial. Here we describe the outcomes of the EQ-5D-5L, EORTC QLQ-C30, and FACT-BMT for all adult patients who completed these questionnaires at baseline (i.e., before the start of treatment; n = 26). Descriptive statistics were used to describe baseline patient and disease characteristics, EQ-5D dimension scores and values, EQ VAS scores, EORTC QLQ-C30 scale/item and summary scores, and FACT-BMT subscale and total scores. The mean EQ-5D value was 0.36. In total, 96% of the patients reported problems with usual activities, 92% with pain/discomfort, 84% with mobility, 80% with self-care, and 72% with anxiety/depression. The mean EORTC QLQ-C30 summary score was 43.50. Mean scale/item scores ranged from 21.79 to 60.00 for functioning scales, from 39.74 to 75.21 for symptom scales, and from 5.33 to 91.67 for single items. The mean FACT-BMT total score was 75.31. Mean subscale scores ranged from 10.09 for physical well-being to 23.94 for social/family well-being. Our study showed that HRQoL in patients with SR-aGvHD is poor. Improving HRQoL and symptom management in these patients should be a top priority.

Differential protein expression in endothelial cells exposed to serum from patients with acute graft-vs-host disease, depending on steroid response.

Graft-versus-host disease (GVHD) is a complication of allogeneic haematopoietic cell transplantation. Endothelial injury is crucial as pathophysiological substrate for GVHD. GVHD first-line treatment is high-dose corticosteroids, although some patients are steroid-refractory. Through the present study, we compared the endothelial proteomic profiles in response to serum from steroid-refractory acute GVHD (SR-aGVHD) and steroid-sensitive acute GVHD (SS-aGVHD) patients. Blood samples from SR-aGVHD (n= 4) and SS-aGVHD (n= 8) patients were collected at aGVHD diagnosis. Endothelial cell cultures were exposed (48 h) to patients' serum. Protein extraction and proteomic analysis were performed. Differences were statistically evaluated by multivariate analysis. Forty-four proteins contributed to separate all samples into the two study groups, among which 15 participated significantly (p< 0.05), 10 exhibiting a fold change >1.2. Differentially expressed proteins were mainly associated with oxidative phosphorylation (Cytochrome C oxidase subunit 6B1, CX6B1), inflammation and angiogenesis (Apolipoprotein D, APOD), cell survival (Rapamycin-insensitive companion of mTOR, RICTR), and oxidative stress (Riboflavin kinase, RIFK). This pilot study used a novel approach to distinguish the aGVHD response to steroid treatment. The proteins differentially expressed could constitute potential biomarkers for steroid-treatment response. These findings signify a step forward to identify the mechanisms of response to steroids, of high clinical relevance considering the SR-aGVHD elevated mortality.

A Calcineurin Inhibitor Free Graft Versus Host Disease Prophylaxis for Patients Undergoing Matched Related and Matched Unrelated Donor Allogeneic Hematopoietic Cell Transplant

Post-transplantation cyclophosphamide (PTCy) and calcineurin inhibitor (CNI)-based graft versus host disease (GVHD) prophylaxis has been associated with lower rates of acute and chronic GVHD compared with the traditional prophylaxis of CNI and methotrexate (MTX) in matched related donor (MRD) and matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo-HCT). The combination of PTCy with sirolimus (PTCy-Siro) as CNI-free GVHD prophylaxis has shown promising results, with cumulative rates of grade II-IV acute and chronic GVHD in the range of 15% to 27% and 20% to 27%, respectively, in patients undergoing MRD, MUD, and haploidentical allo-HCT. We report a single-center, nonrandomized comparison of patients undergoing matched donor allo-HCT receiving PTCy-Siro with those receiving the standard GVHD prophylaxis of tacrolimus and methotrexate (Tac-MTX). One hundred and sixteen consecutive patients who had undergone an MRD or MUD allo-HCT between January 2018 and January 2021 and received either PTCy-Siro (n = 29) or Tac-MTX (n = 87) as GVHD prophylaxis regimens were eligible for inclusion. Patients receiving PTCy-Siro had a significantly shorter median time to immunosuppression withdrawal than patients receiving Tac-MTX (138 days [range, 37 to 312 days] versus 232 days [range, 66 to 1120 days]; P < .001). There was no significant difference between the 2 arms in the incidence of grade II-IV acute GVHD, grade III-IV acute GVHD, steroid-refractory acute GVHD, or clinical infections. At a median follow-up of 1.1 years (range, 0 to 1.8 years), patients receiving PTCy-Siro were significantly less likely to have chronic GVHD, with 2-year freedom from GVHD of 75% (95% confidence interval [CI], 58% to 98%) versus 20% (95% CI, 10% to 40%) for those receiving Tac-MTX (P = .005).

343 - Chronic Gvhd Following Steroid Sensitive, Dependent, and Refractory Acute Gvhd: Incidence and Clinical Outcomes

343 - Chronic Gvhd Following Steroid Sensitive, Dependent, and Refractory Acute Gvhd: Incidence and Clinical Outcomes

The efficiency of human umbilical cord mesenchymal stem cells as a salvage treatment for steroid-refractory acute graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) is a life-threatening complication after hematopoietic stem cell transplantation (HSCT) and is primarily treated with steroids. However, there is no standard treatment for steroid-refractory acute graft-versus-host disease (SR-aGVHD). Although mesenchymal stem cells (MSCs) have proven effective for SR-aGVHD, few reports have focused on human umbilical cord blood-derived MSCs (hUCB-MSCs). Here, we report on the efficiency of hUCB-MSCs as the salvage therapy for SR-aGVHD in 54 patients. The overall response rate (ORR) reached 59.3% (32/54) 28days later. Twenty-four patients achieved complete remission (CR), and 8 achieved partial remission (PR). The median follow-up time after the initiation of hUCB-MSC treatment was 19.3 (0.6-59.0) months. The probability of overall survival (OS) and progression-free survival (PFS) was 60.9% (47.4-74.4%, 95% CI) and 58.8% (45.3-72.3%, 95% CI), respectively, while that of GVHD/relapse-free survival (GRFS) was only 30.8% (17.86-43.74%, 95% CI). Multivariate analysis revealed that response on Day 28 was an independent favorable prognostic factor (OS, P < 0.001; PFS, P < 0.001; GRFS, P = 0.001), but an age of ≥ 18years suggested an unfavorable long-term prognosis (OS, P < 0.001; PFS, P < 0.001; GRFS, P = 0.003). In addition, liver involvement was adversely associated with PFS (P = 0.021) and GRFS (P = 0.009). An infused MNC ≥ 8.66 × 108/kg was also detrimental to GRFS (P = 0.031). Collectively, our results support hUCB-MSCs as an effective treatment for SR-aGVHD.

Novel Drugs in the Treatment of Steroid Refractory Acute Graft Versus Host Disease

Steroid refractory acute graft versus host disease (SR-aGVHD) remains an area of unmet needs with more therapeutic options required. Here, we review novel treatment options for SR-aGVHD. Methods: A comprehensive data search was done across various data sets, including PubMed, Cochrane, and Embase, using MeSH terms and keywords to look for all the different drug types that have been studied for SR-aGVHD. A summary of the results is described here. Results: Denilekin diftitox (Ontak), a recombinant protein composed of IL-2 fused to diphtheria toxin, was studied in a phase 1 trial by Vincent et al. Thirty patients receiving 9 g/kg of Ontak at different intervals showed a Complete response (CR) of 38% and a partial response (PR) of 38%. Remetemcel-L, ex vivo cultured adult human mesenchymal stem cells were studied in a multicenter phase III trial in 260 patients by Kebraei et al. compared to placebo. At a dose of 2 x 106 hMSC/kg, an overall response rate (ORR) of 58% vs. 54% in the placebo group was seen with CR of 35 and 30% respectively at day 28. Third-party bone marrow-derived mesenchymal stromal cells (MSC) expanded in platelet lysate were studied by Introna et al. in a phase 1 trial. Forty patients received a median dose of 1.5 x 10(6)/kg per infusion and showed an ORR of 67.5% with a CR of 27.5%. OS at 1 and 2 years was 50% and 38.6%, respectively. Pentostatin, an adenosine deaminase inhibitor, was studied by Meade et al. in a phase 1 trial in 23 patients. Pentostatin was administered at a dose of 1 to 4 mg/m2/day. Study showed a CR of 63%. Sirolimus, an mTOR Inhibitor, was studied by Benito et al. in a pilot study in 21 patients. On an average dose of 5 mg/m2, sirolimus showed a CR of 23% and PR of 33%. Couriel et al., in a phase III trial, 63 patients were randomized and received either methylprednisone (MP) 2mg/kg or infliximab plus MP. On days 7 and 28 response rate for infliximab + MP vs. MP was 52% vs. 78% and 62% vs. 58%, respectively. Przepiorka et al. reported the results of an open-label phase II study in 20 patients with SR-aGVHD treated with BTI-322 (LO-CD2a), an anti-human CD2 SR-aGVHD IgG2b monoclonal antibody (MAB). ORR was achieved in 55% of the patients. Deeg et al. resulted from a dose-escalation study in 59 patients with steroid-refractory aGVHD treated with ABX-CBL MAB. Reported ORR was 51%. Carpent et al. reported the results of a phase II trial in which 44 patients were treated with visilizumab with ORR of 32% at day 42. Bordigoni et al. treated 62 patients with daclizumab in a phase II trial with reportef ORR of 68.80% at 44 months follow up. Groth et al. studied anti-CD3, anti CD7 antibodies separately conjugated to recombinant ricin A (CD3/CD7-1 T) in adults, 18 years and older with grade III to IV aGVHD following HSCT for myeloid and lymphoid malignancies. Twenty patients were treated with an ORR of 60% on day 28. Adverse events are listed in the Table 2. Conclusion Different targeted drugs focused on the specific pathways show promising results. Monoclonal antibodies in particular showed good treatment outcomes with tolerable safety profile. Further studies are required to identify a valuable therapeutic option, SR-aGVHD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal