Severe GVHD Research Articles

The prognostic impact of previously infectious complications on allogeneic hematopoietic stem cell transplantation for patients with severe aplastic anemia: A single-center, retrospective study.

Whether infections before transplantation impair the survival of patients with severe aplastic anemia (SAA) remains unclear. The aim of this retrospective cohort analysis was to compare survival between patients with SAA who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) with infection (n=66) and patients without infection (n=189) from one medical center. There were no differences in baseline characteristics, except that more patients in the infection group were diagnosed with VSAA (59.09% vs. 30.69%, P<0.001), and their grafts were more peripheral blood stem cells (89.39% vs. 76.72%, P=0.042). In addition, the percentage of patients with multidrug-resistant organism colonization or infection in the infection group was larger (16.7% vs. 0.5%, P<0.001). The median days of engraftment were similar between the two groups; however, the 28-day engraftment rates of neutrophils and platelets were lower in the infection group. No differences were observed in terms of grades II–IV acute graft-versus-host disease (aGVHD) (P=0.418), grades III–IV aGVHD (P=0.075), mild to severe chronic GVHD (cGVHD) (P=0.899), and moderate to severe cGVHD (P=0.342). Patients in the infection group had more bloodstream infections before engraftment (28.8% vs. 15.3%, P=0.016), and the primary cause of death was infection instead of aGVHD in contrast to patients without infection (16.7% vs. 4.2%, P=0.002). Finally, the estimated overall survival (OS), failure-free survival (FFS), and GVHD-free FFS at 5 years were 63% (95% CI, 51–78), 60% (95% CI, 47–74), and 55% (95% CI, 43–70) in patients with infection before transplantation versus 86% (95% CI, 81–92) (P<0.001), 82% (95% CI, 76–88) (P<0.001), and 75% (95% CI, 69–82) (P=0.003) in patients without infection before transplantation, respectively. Multivariate analysis identified haploidentical HSCT and pre-HSCT anti-infection response, defined as partial remission (PR) or stable disease (SD), as adverse factors of OS and FFS. In conclusion, our study demonstrated that SAA patients with infection defined as PR or SD but not complete remission before allo-HSCT showed inferior survival compared with patients without infection. Therefore, more attention should be paid to prophylaxis and complete control of infectious complications before transplantation among SAA patients.

Role of Ruxolitinib in Steroid-Refractory Graft versus Host Disease in Patients Undergoing Allogeneic Stem Cell Transplant.

The objective of this study was to evaluate the role of Ruxolitinib in steroid-refractory graft versus host disease. This retrospective descriptive study was conducted from January 2018 to December 2021. A total of 157 patients underwent allogeneic stem cell transplants during the study period. Of these, 20 patients having steroid-refractory GVHD treated with Ruxolitinib were selected for the study. The primary endpoint was the overall response rate to Ruxolitinib measured at 4 weeks and 24 weeks for acute and chronic GVHD, respectively. The secondary endpoints were overall survival and failure-free survival. Of these 20 patients, 7 (35%) had acute GVHD, and 13 (65%) had chronic GVHD. Of acute GVHD, 2 (10%) had grade II, 4 (20%) had grade III, and 1 (5%) had grade IV acute GVHD. Of 13 patients with chronic GVHD, 7 (35%) had moderate and 6 (30%) had severe chronic GVHD. In steroid-refractory acute GVHD, the overall response rate to Ruxolitinib was 85.7%, and in chronic GVHD, it was 84.6%. The failure-free survival was 80% and overall survival was 85%. Adverse events of any grade occurred in 16 (80%) patients with grade III/IV adverse events in 4 (20%) patients only. The study showed that Ruxolitinib is a safe and effective second-line therapy for acute and chronic steroid-refractory GVHD. Key Words: Ruxolitinib, GVHD, Allogeneic stem cell transplant.

Long-term transplant outcomes after allogeneic hematopoietic transplant in pediatric patients with hematological malignancies are influenced by severe chronic graft vs. host disease and immune reconstitution.

Long-term follow-up studies are crucial to ensure surveillance and intervention for late complications after allogeneic stem cell transplantation, but they are scarce on the pediatric population. This study aims to analyze risk factors for long-term transplant outcomes. We report a landmark analysis of 162 pediatric patients who underwent allogeneic transplantation between 1991 and 2016, and survived for at least 12 months after the transplant. With a median follow-up time of 10 years for the survivors, the probability of disease-free survival (DFS) and overall survival (OS) is 81 ± 3 and 88 ± 2%, respectively. Variables that influenced DFS in the univariate analysis were: disease phase (early phase 87 ± 3% vs. advanced phase 74 ± 5%; p = 0.04), acute graft vs. host disease (aGvHD; yes 73 ± 5% vs. no 87 ± 3%; p = 0.038), severe chronic GvHD (cGvHD; yes 41 ± 13% vs. no 85 ± 3%; p = 0.0001), and CD4+ lymphocytes 2 years after the transplant (above the median of 837/μl 98 ± 2% vs. below the median 82 ± 6%, p = 0.026). However, in the multivariate analysis, the only variable that influenced DFS was presence of severe chronic GvHD (yes vs. no, HR 6.25; 95% CI, 1.35–34.48; p = 0.02). Transplant strategies should aim to reduce the risk of severe cGvHD. Immune reconstitution surveillance may help clinicians to better deal with late transplant complications.

HUC-EVs-ATO reduce the severity of acute GVHD by resetting inflammatory macrophages toward the M2 phenotype

BackgroundBoth extracellular vesicles from mesenchymal stromal cell-derived human umbilical cords (hUC-EVs) and arsenic trioxides (ATOs) have been demonstrated to treat acute graft-versus-host disease (aGVHD) via immunomodulation. Apart from immunomodulation, hUC-EVs have a unique function of drug delivery, which has been proposed to enhance their efficacy. In this study, we first prepared ATO-loaded hUC-EVs (hUC-EVs-ATO) to investigate the therapeutic effect and potential mechanisms of hUC-EVs-ATO in a mouse model of aGVHD after allogeneic hematopoietic stem cell transplantation (HSCT).MethodsAn aGVHD model was established to observe the therapeutic effects of hUC-EVs-ATO on aGVHD. Target organs were harvested for histopathological analysis on day 14 after transplantation. The effects of hUC-EVs-ATO on alloreactive CD4+ were evaluated by flow cytometry in vivo and in vitro. Flow cytometry, RT-PCR, immunofluorescence colocalization analysis and Western blot (Wb) analysis were performed to examine macrophage polarization after hUC-EV-ATO treatment. The cytokines in serum were measured by a cytometric bead array (CBA). TEM, confocal microscopy and Wb were performed to observe the level of autophagy in macrophages. A graft-versus-lymphoma (GVL) mouse model was established to observe the role of hUC-EVs-ATO in the GVL effect.ResultsThe clinical manifestations and histological scores of aGVHD in the hUC-EVs-ATO group were significantly reduced compared with those in the ATO and hUC-EVs groups. The mice receiving hUC-EVs-ATO lived longer than the control mice. Notably, hUC-EVs-ATO interfering with alloreactive CD4+ T cells differentiation were observed in aGVHD mice but not in an in vitro culture system. Additional studies showed that depletion of macrophages blocked the therapeutic effects of hUC-EVs-ATO on aGVHD. Mechanistically, hUC-EVs-ATO induced autophagic flux by inhibiting mammalian target of rapamycin (mTOR) activity to repolarize M1 to M2 macrophages. Additionally, using a murine model of GVL effects, hUC-EVs-ATO were found not only to reduce the severity of aGVHD but also to preserve the GVL effects. Taken together, hUC-EVs-ATO may be promising candidates for aGVHD treatment.ConclusionshUC-EVs-ATO enhanced the alleviation of aGVHD severity in mice compared with ATO and hUC-EVs without weakening GVL activity. hUC-EVs-ATO promoted M1 to M2 polarization via the mTOR-autophagy pathway. hUC-EVs-ATO could be a potential therapeutic approach in aGVHD after allo-HSCT.

P1332: PROMISING OUTCOME OF PATIENTS OLDER THAN 70 YEARS WHO UNDERWENT PERIPHERAL BLOOD HAPLOIDENTICAL HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR ACUTE MYELOID LEUKEMIA OR HIGH RISK MYELODYSPLASTIC SYNDROME

Background: Allogeneic stem cell transplantation is a curative option of patients older than 60 years of age with AML and high risk MDS. In this situation, the development of haploidentical transplantation (Haplo-SCT) using post transplantation cyclophosphamide (PT-Cy) allowed extending the feasibility of Allo-HSCT. However, there is few data specifically focusing on Haplo-SCT in patients over 70 years of age with AML and MDS, for whom the benefit-risk balance of Haplo-SCT is still a matter of debate. Aims: To evaluate the outcome of patients older than 70 years with AML or high risk MDS who underwent Haplo-SCT. Methods: This retrospective study included consecutive AML or MDS patients older than 70 years who received first Haplo-SCT from 2013 to 2021 in our center. All patients had the same transplantation modalities: 1) Non-myeloablative conditioning regimen as described by the Baltimore’s group (Fludarabine, cyclophosphamide and 2-Gray TBI); 2) Peripheral blood stem cells (PBSC) as graft source; 3) GVHD prophylaxis using PT-Cy, cyclosporine A and mycophenolate mofetil; 4) G-CSF from day+5 to neutrophil recovery. Prophylactic donor lymphocyte infusion (DLI) was initially planned after day+60 in absence of GVHD. Results: We analyzed 45 patients who met inclusion criteria, 23 with AML and 22 with MDS. The median age was 72 years (range: 70-75). HCT-CI was >= 3 in 22 patients (49%). At the time of Haplo-SCT, 22/23 AML patients were in CR (17 CR1 and 5 CR2) and one patient had refractory AML. Disease status at Haplo-SCT was CR, PR, marrow CR and active disease in 12, 2, 1 and 7 patients, respectively. All patients received pre transplantation treatment with intensive chemotherapy and/or azacytidine, except one MDS patients who underwent upfront Haplo-SCT. Disease risk index was high or very high in 11 patients (24%), and intermediate in 34 patients (76%). Median follow up using the reverse Kaplan Meier method was 36 months (95%CI: 25-43). Grade 2-4 and 3-4 acute GVHD at day+100 was 33% and 7%, respectively. There was no early death (at day+100: OS=100%; NRM=0%). At 3 years after Haplo-SCT, the cumulative incidence of all grades and moderate to severe chronic GVHD was 37% and 28%. Half of the cases of chronic GVHD occurred after prophylactic DLI. The 3-year cumulative incidence of NRM was 20%. In AML patients, the 3-year CIR, PFS and OS were 17%, 61% and 64% respectively. Corresponding values for MDS patients were 26%, 56% and 66%, respectively. Ten patients received prophylactic DLI. Among them, one died from late NMR (urothelial metastatic cancer after 2 years post Haplo-SCT) and one patient relapsed and subsequently died from AML (complex karyotype, CR2). The 8 remaining patients who received prophylactic DLI are still disease free at last follow up. As surrogate marker of quality of life, we evaluated the prevalence of GVHD and immunosuppressive treatment (IST) in disease free patients. At 2 years after Haplo-SCT, 87% of disease free patients are living without GVHD and without IST. Summary/Conclusion: Haplo-SCT in patients older than 70 years with AML or high risk MDS is feasible without early NRM. The use of PBSC and prophylactic DLI may explain the low incidence of relapse and long-term survival. Our results support that selected patients older than 70 years can achieve promising outcomes after non-myeloablative Haplo-SCT using PBSC, confirming that age by itself and the absence of an HLA-matched donor should not be considered as firm contraindication for transplantation.

Retrospective Comparison of Efficacy and Safety of Rabbit Anti-Thymocyte Globulin and Porcine Anti-Lymphocyte Globulin in Patients With Acquired Aplastic Anemia Undergoing Hematopoietic Stem Cell Transplantation From Matched Sibling Donors.

We compared the efficacy and safety of porcine anti-lymphocyte globulin (pALG) (n=140) and rabbit anti-thymocyte globulin (rATG) (n=86) in patients with acquired aplastic anemia (AA) receiving hematopoietic stem cell transplantation (HSCT) from matched sibling donors (MSD) in two transplantation centers in China ranging from 2005 to 2020. The groups had similar baseline characteristics except for a higher number of infused mononuclear cells (P<0.001) and a higher proportion of peripheral blood stem cells as graft sources (P=0.003) in the pALG group. The rates of neutrophil engraftment at day 28 (P=1), platelet engraftment at day 28 (P=0.228), bloodstream infection before engraftment (P=0.867), invasive fungal diseases (P=0.362), cytomegalovirus viremia (P=0.667), and graft rejection (P=0.147) were similar in the two groups. A higher cumulative incidence of grades II-IV acute graft versus host disease (aGvHD) at 100 days occurred in the pALG group (19% vs. 8%, P=0.035) while no significant differences in grades III-IV aGvHD (P=0.572), mild to severe chronic GvHD (cGvHD) (P=0.181), and moderate to severe cGvHD (P=0.586) were observed. The actuarial 5-year overall survival (OS), failure-free survival (FFS), and GvHD-free, FFS rates of the pALG group were 87% (95% confidence interval [CI], 82-93), 85% (95% CI, 80-92), and 78% (95% CI, 72-92) versus 91% (95% CI, 86-99) (P=0.33), 88% (95% CI, 82-97) (P=0.428), and 79% (95% CI, 72-90) (P=0.824) in the rATG group, respectively. A busulfan-containing conditioning regimen was the only adverse risk factor for OS and FFS in multivariate analysis. In conclusion, pALG is an alternative to rATG in patients with severe AA receiving MSD-HSCT. A prospective, large-sample study is needed to explore this therapy further.

Combined treatment of graft versus host disease using donor regulatory T cells and ruxolitinib

Donor derived regulatory T lymphocytes and the JAK1/2 kinase inhibitor ruxolitinib are currently being evaluated as therapeutic options in the treatment of chronic graft versus host disease (cGvHD). In this work, we aimed to determine if the combined use of both agents can exert a synergistic effect in the treatment of GvHD. For this purpose, we studied the effect of this combination both in vitro and in a GvHD mouse model. Our results show that ruxolitinib favors the ratio of thymic regulatory T cells to conventional T cells in culture, without affecting the suppressive capacity of these Treg. The combination of ruxolitinib with Treg showed a higher efficacy as compared to each single treatment alone in our GvHD mouse model in terms of GvHD incidence, severity and survival without hampering graft versus leukemia effect. This beneficial effect correlated with the detection in the bone marrow of recipient mice of the infused donor allogeneic Treg after the adoptive transfer.

Retrospective, Landmark Analysis of Long-term Adult Morbidity Following Allogeneic HSCT for Inborn Errors of Immunity in Infancy and Childhood

PurposeAllogeneic hematopoietic stem cell transplant (HSCT) remains the treatment of choice for patients with inborn errors of immunity (IEI). There is little published medical outcome data assessing late medical complications following transition to adult care. We sought to document event-free survival (EFS) in transplanted IEI patients reaching adulthood and describe common late-onset medical complications and factors influencing EFS.MethodsIn this landmark analysis, 83 adults surviving 5 years or more following prior HSCT in childhood for IEI were recruited. The primary endpoint was event-free survival, defined as time post-first HSCT to graft failure, graft rejection, chronic infection, life-threatening or recurrent infections, malignancy, significant autoimmune disease, moderate to severe GVHD or major organ dysfunction. All events occurring less than 5 years post-HSCT were excluded.ResultsEFS was 51% for the whole cohort at a median of 20 years post HSCT. Multivariable analysis identified age at transplant and whole blood chimerism as independent predictors of long-term EFS. Year of HSCT, donor, conditioning intensity and underlying diagnosis had no significant impact on EFS. 59 events occurring beyond 5 years post-HSCT were documented in 37 patients (45% cohort). A total of 25 patients (30% cohort) experienced ongoing significant complications requiring active medical intervention at last follow-up.ConclusionAlthough most patients achieved excellent, durable immune reconstitution with infrequent transplant-related complications, very late complications are common and associated with mixed chimerism post-HSCT. Early intervention to correct mixed chimerism may improve long-term outcomes and adult health following HSCT for IEI in childhood.

393 - Prolonged Post-Transplant Ruxolitinib Therapy is Associated with Protection from Severe Gvhd after Allogeneic HCT

393 - Prolonged Post-Transplant Ruxolitinib Therapy is Associated with Protection from Severe Gvhd after Allogeneic HCT

Posttransplant cyclophosphamide for prevention of graft-versus-host disease: results of the prospective randomized HOVON-96 trial

AbstractGraft-versus-host disease (GVHD) is the most important complication of allogeneic hematopoietic stem cell transplantation (alloHSCT). We performed a prospective randomized, multicenter, phase 3 trial to study whether posttransplant cyclophosphamide (PT-Cy) combined with a short course of cyclosporine A (CsA) would result in a reduction of severe GVHD and improvement of GVHD-free, relapse-free survival (GRFS) as compared with the combination of CsA and mycophenolic acid (MPA) after nonmyeloablative (NMA) matched related and unrelated peripheral blood alloHSCT. Between October 2013 and June 2018, 160 patients diagnosed with a high-risk hematological malignancy and having a matched related or at least 8 out of 8 HLA-matched unrelated donor were randomized and allocated in a 1:2 ratio to CsA/MPA or PT-Cy/CsA; a total of 151 patients were transplanted (52 vs 99 patients, respectively). The cumulative incidence of grade 2 to 4 acute GVHD at 6 months was 48% in recipients of CsA/MPA vs 30% following PT-Cy/CsA (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.29-0.82; P = .007). The 2-year cumulative incidence of extensive chronic GVHD was 48% vs 16% (HR, 0.36; 95% CI, 0.21-0.64; P < .001). The 1-year estimate of GRFS was 21% (11% to 32%) vs 45% (35% to 55%), P < .001. With a median follow-up of 56.4 months, relapse incidence, progression-free survival, and overall survival were not significantly different between the 2 treatment arms. PT-Cy combined with a short course of CsA after NMA matched alloHSCT significantly improves GRFS due to a significant reduction in severe acute and chronic GVHD.

Elevated RAP1A expression correlates with the severity of acute GVHD after umbilical cord blood transplantation

BackgroundAcute graft-versus-host disease (aGVHD) is a complication of allogeneic hematopoietic stem cell transplantation. Ras-related protein 1A (RAP1A) has been recently identified as a novel oncoprotein in several human malignancies. However, its specific role in aGVHD remains unclear. ObjectiveTo study the role of RAP1A in the pathogenesis of aGVHD. Material and methodsStudy participants included six patients with grade 2–4 aGVHD, 13 patients with grade 1 aGVHD, 11 patients without aGVHD, and 12 healthy people. The expression level of RAP1A in whole cells was detected by western blot and qRT-PCR. The proportions of CD4+CD25+FoxP3+ Treg cells (T regulatory cells) and the expression of RAP1A in Treg cells in peripheral blood mononuclear cells (PBMCs) were detected by flow cytometry and the levels of related cytokines in the serum was detected by cytometric bead array. ResultsWe found the level of RAP1A was higher in patients than in healthy individuals. A negative correlation was noted between RAP1A and the number of Treg cells. In addition, the level of IL-10 in patients with grade 2–4 aGVHD was significantly lower than that in healthy donors, however, the level of TNF-ɑ in patients with grade 2–4 aGVHD was higher. Furthermore, we found a negative correlation between levels of IL-10 and RAP1A, and a positive correlation between TNF-ɑ and RAP1A. ConclusionThe expression of RAP1A in patients with aGVHD was significantly increased, and shows potential as a target for the prevention and treatment of aGVHD.

Current Prophylaxis and Treatment Approaches for Acute Graft-Versus-Host Disease in Haematopoietic Stem Cell Transplantation for Children With Acute Lymphoblastic Leukaemia.

Acute graft-versus-host disease (aGvHD) continues to be a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). However, higher event-free survival (EFS) was observed in patients with acute lymphoblastic leukaemia (ALL) and grade II aGvHD vs. patients with no or grade I GvHD in the randomised, controlled, open-label, international, multicentre Phase III For Omitting Radiation Under Majority age (FORUM) trial. This finding suggests that moderate-severity aGvHD is associated with a graft-versus-leukaemia effect which protects against leukaemia recurrence. In order to optimise the benefits of HSCT for leukaemia patients, reduction of non-relapse mortality—which is predominantly caused by severe GvHD—is of utmost importance. Herein, we review contemporary prophylaxis and treatment options for aGvHD in children with ALL and the key challenges of aGvHD management, focusing on maintaining the graft-versus-leukaemia effect without increasing the severity of GvHD.

Rehabilitation after Allogeneic Haematopoietic Stem Cell Transplantation: A Special Challenge.

Simple SummaryAfter undergoing an allogeneic haematopoietic stem cell transplantation (alloHCT), patients need intensive physiological and psychological rehabilitation. This should start immediately after discharge from the transplant ward as in- or outpatient rehabilitation. The rehabilitation centres should be qualified and experienced because this patient group exhibits problems that differ from those of patients who have undergone oncological therapies or autologous HCT. An experienced multidisciplinary team in close consultation with the primary transplantation centre should perform the rehabilitation therapy. This review will show the special challenges of these patients according to different timepoints after HCT. Because there is so little data available, personal experience and general guidelines on patient care after alloHCT are presented.The general population is getting older and suffer more haematological malignancies despite being physically fit. These malignancies are mainly only curable via an alloHCT, and they are now carried out more frequently. Patients benefit from intensive rehabilitation earlier and may need it repeatedly in cases of severe side effects (e.g., graft-versus-host disease). They can suffer many problems that other cancer patients do not experience, such as severe infections, continued immunosuppression, nutritional restrictions, acute or chronic GvHD, or organ impairments (e.g., lung, eyes). They may also encounter various associated psychological problems, e.g., feeling like a chimera. Rehabilitation centres willing to care for patients after alloHCT should have an experienced multidisciplinary team and should work in close co-operation with the primary transplant centre.

Long-term results and GvHD after prophylactic and preemptive donor lymphocyte infusion after allogeneic stem cell transplantation for acute leukemia

We report on 318 patients with acute leukemia, receiving donor lymphocyte infusion (DLI) in complete hematologic remission (CHR) after allogeneic stem cell transplantation (alloSCT). DLI were applied preemptively (preDLI) for minimal residual disease (MRD, n = 23) or mixed chimerism (MC, n = 169), or as prophylaxis in high-risk patients with complete chimerism and molecular remission (proDLI, n = 126). Median interval from alloSCT to DLI1 was 176 days, median follow-up was 7.0 years. Five-year cumulative relapse incidence (CRI), non-relapse mortality (NRM), leukemia-free and overall survival (LFS/OS) of the entire cohort were 29.1%, 12.7%, 58.2%, and 64.3%. Cumulative incidences of acute graft-versus-host disease (aGvHD) grade II–IV°/chronic GvHD were 11.9%/31%. Nineteen patients (6%) died from DLI-induced GvHD. Age ≥60 years (p = 0.046), advanced stage at transplantation (p = 0.003), shorter interval from transplantation (p = 0.018), and prior aGvHD ≥II° (p = 0.036) were risk factors for DLI-induced GvHD. GvHD did not influence CRI, but was associated with NRM and lower LFS/OS. Efficacy of preDLI was demonstrated by decreasing MRD/increasing blood counts in 71%, and increasing chimerism in 70%. Five-year OS after preDLI for MRD/MC was 51%/68% among responders, and 37% among non-responders. The study describes response and outcome of DLI in CHR and helps to identify candidates without increased risk of severe GvHD.

Ruxolitinib for Steroid-Refractory Acute Graft-Versus-Host Disease: A Single Centre Retrospective Study

BackgroundAcute graft-versus-host disease (aGVHD) is the major cause of non-relapse morbidity and mortality after allogeneic hematopoietic stem cell transplantation(allo-HSCT). But only 40% of the patients will respond to first-line therapies Corticosteroids. Ruxolitinib, a selective Janus kinase (JAK) 1/2 inhibitor, reduces the incidence and severity of GVHD while preserving graft-versus-leukemia effects in preclinical models. The retrospective study evaluated the efficacy of ruxolitinib compared with other second-line therapies for steroid-refractory aGVHD (SR-aGVHD) in a single-center.MethodsA total of 90 patients who developed SR-aGVHD after HSCT were evaluated in this retrospective study.They were treated with ruxolitinib (n=45) or other salvage-therapies (n=45) including MTX, basiliximab, etanercept and MSC at our institution. The primary endpoint was the overall response rate (ORR) at Day 28. Additional endpoints included overall survival (OS), cumulative incidence rates of failure-free survival (FFS), relapse, non-relapse mortality (NRM) and cGVHD. Treatment failure was defined as 1) addition of new systemic therapy for aGVHD, 2) NRM, 3) relapse, 4) progression of hematologic disease. FFS and OS were calculated from the day of starting the use of second-line treatments for aGVHD.ResultsThe median age was 34 years (range 14-69). At the time of enrollment 25 patients had grade Ⅱ disease, 39 with grade Ⅲ disease, 26 with grade IV disease. The skin was involved in 54.4%, lower gastrointestinal (GI) tract in 78.9% and liver in 20.2%. With a median follow-up of 1.33 years, the ORR at day 28 was higher in ruxolitinib group than non-ruxolitinib group (62.2% [95% CI, 47.5%-77.0%] vs. 26.7% [95% CI, 13.2%-40.1%], P=0.001) (Table 1). The 1-year OS was 64.4 % and 45.5% in the two groups, respectively (P=0.0382). Ruxolitinib treatment also improved the 1-year cumulative incidence of FFS (57.8% vs. 26.6%, P=0.002), while the 1-year cumulative incidence of relapse did not differ significantly (9.6% vs. 20.0%, P=0.195). The 1-year cumulative incidence of NRM was lower in the ruxolitinib group than the non-ruxolitinib group (24.4% vs. 45.3%, P=0.023). The 1-year and 3-year cumulative incidence of cGVHD were 17.8% vs. 33.3% and 26.8% vs. 44.4% between the ruxolitinib group and non-ruxolitinib group (P=0.10 and P=0.04).ConclusionsOur study demonstrated that ruxolitinib is effective than other second-line treatments in patients with SR-aGVHD due to the higher response rates and the improvement of prognosis. Furthermore, ruxolitinib could reduce the incidence and severity of chronic GVHD in aGVHD patients.Keywords: Ruxolitinib; Steroid-refractory; Acute graft-versus-host disease; Haploidentical hematopoietic stem cell transplantation [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Safety of Anti-NKG2A Blocking Antibody Monalizumab As Maintenance Therapy after Allogeneic Hematopoietic Stem Cell Transplantation: A Phase I Study

BackgroundFollowing allogeneic hematopoietic stem cell transplantation (Allo-HSCT), the phenotype and function of circulating NK Cells are altered; notably NK cells display an immature (CD56-bright/KIR -/CD57 -/NKG2A +) phenotype and a low cytotoxic activity. Since NK cells have demonstrated anti-leukemic activity in the context of Allo-HCT while less prone to induce GVHD than T cells, we hypothesized that NKG2A inhibition using the checkpoint inhibitor monalizumab (humanized IgG4 blocking monoclonal antibody) could improve NK cell mediated graft-versus-tumor effect, without triggering graft-versus-host disease. We thus performed the first clinical trial evaluating the safety of monalizumab as a prophylactic treatment after Allo-HSCT (NCT02921685).MethodThe objective was to determine the maximal tolerated dose (MTD) of a single infusion of monalizumab administered on day+75 or thereafter following Allo-HSCT. Inclusion criteria were: 1) adult patients who underwent first Allo-HSCT for hematological malignancy; 2) no prior history of GVHD, 3) reduced toxicity conditioning regimen, 4) ATG or PT-Cy based GVHD prophylaxis, and 5) GVHD prophylaxis with cyclosporine A ongoing at the time of monalizumab infusion.Four dose levels were investigated in this dose escalation study (0.04, 0.1, 0.3, and 1.0 mg/kg). Dose limiting toxicities (DLT) were defined by the occurrence of any grade 3 to 4 monalizumab-related adverse event within 28 days after infusion, including grade 3 to 4 acute GVHD and moderate to severe chronic GVHD. In case of DLT, a Bayesian continuous reassessment model (CRM) was used to predict the maximal tolerated dose (MTD) after each series of 3 patients treated at a given dose level. It was planned to treat 18 patients. Beyond clinical safety, blood samples were collected for NK and T cell immunomonitoring and receptor saturation assay.ResultsFifteen patients received monalizumab at a median time of 83 days (range: 75-103) after Allo-HSCT (3 at 0.04 mg/kg, 3 at 0.1 mg/kg, 3 at 0.3 mg/kg, and 6 at 1 mg/kg). Patients were transplanted for hematological diseases (9 AML, 3 MDS, 1 lymphoma, 1 CLL and 1 myelofibrosis), from a matched sibling (n=8), matched unrelated (n=6) or haploidentical donor (n=1).No DLT was observed during the dose escalation process or among the 6 patients treated at the highest dose level, justifying study early termination after 15 patients. Two patients developed transient low grade GVHD that spontaneously resolved without treatment (1 grade I acute GVHD on day+8 and 1 mild chronic GVHD on day+118). Systemic steroid requiring GVHD occurred in 3 patients (20%): 1 severe overlap GVHD (day+42, CR after treatment), 1 severe chronic GVHD (day+80, death from GVHD) and 1 late severe chronic GVHD after cyclosporine tapering for mixed chimerism (day+149, complete remission [CR] after treatment). No disease recurrence was observed, except for one patient with myelofibrosis who relapsed 3 years after monalizumab infusion. At a median follow up of 22 months (3-48) after monalizumab infusion, 13 out of 15 patients are in CR from their underlining malignancy without GVHD and immunosuppressive treatment at last contact.At the dose of 1 mg/kg, receptor saturation assays (RSA) showed persistent binding of monalizumab on peripheral blood NK cells. Indeed, more than 90% of NKG2A-positive NK cells were positive for monalizumab detection (Anti-IgG4-PE) until at least 14 weeks post treatment.ConclusionsMonalizumab can be safely administered after Allo-HSCT, with prolonged persistence on circulating NK cells. In the absence of DLT, MTD was not reached. Future trials will aim at measuring the clinical efficacy of monalizumab in this context, alone or in combination therapy. Disclosuresboyer Chammard: Innate Pharma: Current Employment. Chabannon: Sanofi SA: Other: Travel Support, Research Funding, Speakers Bureau; Bellicum Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel Support, Speakers Bureau; Novartis: Speakers Bureau; BMS/Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Terumo BCT: Speakers Bureau; Miltenyi Biotech: Research Funding; Fresenius Kabi: Research Funding; EBMT: Membership on an entity's Board of Directors or advisory committees. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Olive: ImCheck Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Alderaan Biotechnology: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Emergence Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees. Blaise: Jazz Pharmaceuticals: Honoraria.

The Absence of NLRP6 in Donor T Cells Exacerbates Gvhd

The Nlrp6 (NOD-like receptor family pyrin domain containing 6) inflammasome is important for intestinal epithelial cell innate immune responses and for maintaining gut homeostasis by preventing microbial dysbiosis. Contrary to its role in epithelial cell inflammasome-mediated responses, we recently showed that Nlrp6 in gut epithelial cells exacerbates GVHD in a manner independent of the inflammasome or gut microbiota. However, donor allogeneic T cells are also critical for GVHD development, yet, the function of Nlrp6 in allogeneic T cells is unknown. We hypothesized that Nlrp6 deficient donor T cells would ameliorate experimental GVHD.To test our hypothesis, WT-BALB/crecipients were lethally irradiated and transplanted on day 0 with 5x10 6 bone marrow and 1.0x10 6 splenic CD90 +T cells from either syngeneic WT-BALB/c, allogeneic MHC-mismatched WT-B6 or Nlrp6 -/- donors. Contrary to our hypothesis, the survival of allogeneic recipients of Nlrp6 -/- donor T cells was significantly worse than those receiving WT-B6 T cells (p<0.05). Nlrp6 -/- donor T cells also caused greater GVHD mortality and morbidity in an MHC mismatched haploidentical B6 into B6D2F1 model (p<0.05) and an MHC mismatched B10.BR into B6 model. Similar results were obtained using B6 into BALB/c and B6 into B6D2F1 models performed at the University of Michigan, suggesting our results were not unique to local environmental factors. By contrast, GVHD severity and mortality were similar in an MHC matched multiple minor antigen mismatched B6 into C3H.sw model. Because the B6 into C3H.sw model is largely driven by CD8+ T cells whereas the previous models are mediated by both CD4+ and CD8+ T cells, we examined whether Nlrp6 separately regulates CD4+ and CD8+ T cell-mediated GVHD. In order to test this, we transplanted C3H.sw recipients as above except we infused either 1x10 6 CD4+ or CD8+ T cells from B6-WT or Nlrp6 -/- animals. GVHD severity and mortality (P<0.05) were enhanced only when Nlrp6 -/- CD4+ T cells were transplanted. These data suggested that Nlrp6 regulates allogeneic T cell responses in a subset-specific manner.To explore how Nlrp6 regulates intrinsic responses in donor T cell subsets, we tested naïve T cell proliferation in vitro after allogeneic or non-specific TCR stimulation. Consistent with the lack of increased GVHD induced by CD8+ Nlrp6 -/- donor T cells in the B6 into C3H.sw model, Nlrp6 -/- CD4+ but not CD8+ T cells proliferated more than WT-B6 CD4+ or CD8+ T cells, respectively, when stimulated with either anti-CD3/CD28 antibodies or lethally irradiated allogeneic antigen presenting cells in a mixed lymphocyte reaction. In addition, activation-induced apoptosis was decreased in Nlrp6 -/- CD4+ T cells compared to WT T cells. Importantly, Treg suppressive function was not altered in Nlrp6 -/- T cells. Therefore, increased proliferative responses and resistance to activation-induced apoptosis may have contributed to the enhanced GVHD caused by Nlrp6 -/- donor T cells.Increased Th1 and Th17 polarization is associated with worse GVHD. Because only CD4+ Nlrp6 -/- T cells enhanced GVHD, we tested whether Nlrp6 influenced T helper cell differentiation into Th1, Th17, and Th2 subsets. Consistent with our in vivo data, Th1 in vitro differentiation was enhanced in Nlrp6 -/- CD4+ T cells. To determine the molecular signaling events altered by Nlrp6 deficiency, we tested various T cell activation signaling pathways and found that phosphorylation of ZAP-70 was increased in Nlrp6 -/- T cells. These data suggested that Nlrp6 in donor T cells may regulate allo-immune responses via ZAP-70 pathway.GVH and graft-versus-tumor (GVT) responses are intricately linked. Because CD8+ responses were not affected by Nlrp6 deficiency, we hypothesized that GVT responses would be unaltered in Nlrp6 -/- donor T cells. Indeed, Nlrp6 -/- T cells showed equivalent in vivo GVL responses to MLL-AF4 leukemia cells as WT-T cells. Hence Nlrp6in donor T cells is not required for GVT responses.Altogether our data suggested that Nlrp6 negatively-regulates allogeneic donor CD4+ T cell responses, possibly via negative regulation of ZAP-70 signaling, resulting in mitigation of GVHD and maintenance of robust GVT responses. DisclosuresIshizawa: AbbVie: Research Funding; Eisai: Honoraria; Chugai: Honoraria; Ono: Honoraria; Celgene: Honoraria; Takeda: Honoraria; Bayer: Research Funding; Bristol Myers Squibb: Speakers Bureau; Pfizer: Research Funding; Kyowa Kirin: Consultancy; SymBio: Honoraria, Research Funding; Otsuka: Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau; Sanofi: Research Funding; IQVIA: Research Funding.

Ponatinib and Chemotherapy in Adults with De Novo Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia. Final Results of Ponalfil Clinical Trial

Background and objective. The combination of HyperCVAD and ponatinib resulted in a high molecular response rate and survival in adults with Ph+ ALL, suggesting improved outcome compared with combinations of chemotherapy with first- or second-generation tyrosine kinase inhibitors (TKI) (Jabbour E, et al, Lancet Haematol. 2018;5:e618-e627). The Spanish PETHEMA group conducted the phase 2 PONALFIL trial, which incorporates ponatinib to the same chemotherapy as that of the ALL Ph08 trial that used imatinib as TKI (Ribera JM et al. Cancer 2019;125:2810-17). Final results of this trial are reported.Patients and method. PONALFIL trial (NCT02776605) combined ponatinib (30 mg/d) and induction chemotherapy (vincristine, daunorubicin, prednisone) followed by consolidation (high-dose methotrexate, high-dose ARA-C, mercaptopurine, etoposide) and allogeneic hematopoietic stem cell transplantation (alloHSCT). Ponatinib was scheduled after alloHSCT only for patients (pts) with persistence/reappearance of MRD. Response to therapy (complete morphological [CR], molecular [complete -CMR- or major -MMR-] after induction and before alloHSCT) (assessed by centralized BCR-ABL1/ABL1 ratio), disease-free survival (DFS), overall survival [OS]) and toxicity were analyzed. The following genetic studies were performed: 1. Additional gene abnormalities (Copy Number Alteration [CNA] analysis by SNP array Affymetrix 750K), 2. ABL1 mutation status at diagnosis (Sanger sequencing), 3. T315I mutation at diagnosis (allele-specific PCR). A propensity score comparison with the results of the ALL Ph08 trial was performed.Results. Median age was 49 (19-59) years (y), and 13/30 pts were female. One pt showed CNS involvement at diagnosis. ECOG score was <2 in 90% of pts. Median WBC count was 6.4 x10 9/L (0.6-359.3), Hb 90 g/L (63-145), platelets 38 x10 9/L (11-206). Immunologic phenotype was common in 26 cases, with p190 isoform in 20 pts (67%), p210 in 9 (30%) and p230 in 1 (3%). CR was attained in 30/30 pts, CMR in 14/30 (47%), MMR in 5/30 (17%) and no molecular response in 11/30 (37%). Two pts withdrew the trial during induction (thrombosis of central retina artery and severe intestinal infection, one case each). Consolidation was given to 28 pts, 2 pts withdrew the trial (physician's decision and lack of molecular response, one case each) and 26 pts received alloHSCT (20 in CMR, 6 in MMR). No relapses before HSCT were detected. One pt died by severe GVHD and two withdrew the trial (grade IV hepatic toxicity:1, protocol deviation after molecular relapse:1). One pt relapsed in BM after HSCT. Ponatinib was given after HSCT in 4/26 pts and dasatinib in 1/26 due to MRD reappearance, and 1/26 received dasatinib in CMR because of refusal to receive CNS prophylaxis, whereas 20/26 pts did not receive any TKI therapy after HSCT. Twenty-nine pts are alive (median follow-up 2.3y, range 1.3-4). 2y DFS and OS probabilities were 97% (91%-100%) and 97% (91%-100%) (Figure 1).Among 7/16 pts without CMR after consolidation and genetic material available, 4 showed IKZF1 deletion (IKZF1 plus in 2), 1 showed CDKN2A/B and PAX5 deletion and 2 did not show any CNA. Among 5/19 pts with molecular relapse, 3 showed IKZF1 deletion (1 being IKZF1 plus), and 2 pts did not show any CNA. No ABL1 mutations or T315I mutation at diagnosis were found.Propensity score with 1:1 matching identified 30 pts in each cohort (variables: age, gender, ECOG, WBC, CNS involvement, cytogenetic risk and BCR/ABL isoform). 2y DFS rates for PONALFIL and ALL Ph08 trials were 97% and 62%, (p=0.005), and 2y OS rates were 97% and 66% (p=0.001) (Figure 2).107 adverse events (AE) were registered in 20 pts (21 severe in 11 pts), prompting to withdrawn of the trial in 3 (thrombosis of central retina artery, severe bowel infection, grade IV hepatic toxicity). The most frequent AE were hematologic (28%), gastrointestinal (14%), hepatic (11%), infections (7%), and cutaneous (5%). Cardiovascular events occurred in 2 patients (angor pectoris and thrombosis of central artery of the retina).Conclusions. The results of the PONALFIL trial show a high antileukemic efficacy with acceptable toxicity profile and compare favorably with the same chemotherapy schedule and imatinib.Supported in part by grant 2017 SGR288 (GRC) Generalitat de Catalunya and “La Caixa” Foundation.Figure 1. OS (A) and DFS (B). PONALFIL.Figure 2. OS (A) and DFS (B). PONALFIL vs. ALL Ph08. [Display omitted] DisclosuresRibera: AMGEN: Consultancy, Research Funding, Speakers Bureau; NOVARTIS: Consultancy, Speakers Bureau; TAKEDA: Consultancy, Research Funding, Speakers Bureau; ARIAD: Consultancy, Research Funding, Speakers Bureau; SHIRE: Consultancy, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau. Esteve: Novartis: Consultancy, Research Funding; Pfizer: Consultancy; Abbvie: Consultancy; Bristol Myers Squibb/Celgene: Consultancy; Novartis: Research Funding; Jazz: Consultancy; Astellas: Consultancy. Mercadal: Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences, Inc.: Honoraria, Speakers Bureau. Martínez-López: Roche, Novartis, Incyte, Astellas, BMS: Research Funding; Janssen, BMS, Novartis, Incyte, Roche, GSK, Pfizer: Consultancy. OffLabel Disclosure:This trial includes Ponatinib in off-label indication.

Propensity Score Matching Analysis Comparing Ruxolitinib Vs Historical Controls in 2 nd Line or Beyond Treatment for Chronic Gvhd after Therapy Failure

Propensity Score Matching Analysis Comparing Ruxolitinib Vs Historical Controls in 2 nd Line or Beyond Treatment for Chronic Gvhd after Therapy Failure

Galectin-3 Signaling in Donor T Cells Regulates Acute Graft Versus Host Disease (aGvHD) after Allogenic Transplantation

Galectin-3 Signaling in Donor T Cells Regulates Acute Graft Versus Host Disease (aGvHD) after Allogenic Transplantation