Transplant-related Toxicity Research Articles

Changing the Natural History of Fanconi Anemia Complementation Group-À with Gene Therapy: Early Results of U.S. Phase I Study of Lentiviral-Mediated Ex-Vivo FANCA Gene Insertion in Human Stem and Progenitor Cells

Background Fanconi anemia (FA) is a rare genetic disorder characterized by defective cellular DNA repair, associated developmental abnormalities, progressive bone marrow failure (BMF), and a predisposition to hematologic malignancies and solid tumors. 80% of FA patients develop BMF due to progressive depletion of their BM stem cells. Although allogeneic HSCT is a curative treatment for BMF, its utilization and efficacy is limited by availability of donors, risk of GVHD and transplant-related toxicities. Pre-clinical studies showed that ex-vivo insertion of a functional FANCA gene into autologous FA-A CD34+ HSPCs provides a survival advantage to the gene-modified stem cells, leading to correction of BMF. Feasibility of this approach was established in the FANCOLEN-1 clinical trial (Spain). Modifications to the collection and manufacturing processes were made in the Phase I study in the U.S. Design and Methods RP-L102-0418 (clinicaltrials.gov # NCT03814408) is a Phase I clinical trial evaluating the feasibility and safety of autologous CD34+ cells transduced with a lentiviral vector (LV) carrying the FANCA gene (PGK-FANCA-WPRE) in children with FA-A. Patients with early evidence of cytopenias, and with BM CD34+ count >30/µL were eligible for treatment. PBMCs were collected via leucocytapheresis after mobilization with G-CSF and Plerixafor. CD34+ HSPCs were enriched, placed in culture with cytokines, and transduced with PGK-FANCA-WPRE LV. The investigational drug product (DP) (RP-L102) was infused fresh in patients within 4 hours of release, without any conditioning regimen. Patients are being followed for safety assessments (replication competent lentivirus, insertion site analysis) and efficacy (increasing peripheral blood vector copy number and BM mitomycin-C resistance), along with monitoring of cytopenias. Results Two FA-A patients (aged 5 and 6 years) were consented and enrolled on the study at Stanford University. Mobilization and apheresis procedures were performed successfully without any serious adverse events. Both the patients needed RBC priming of the apheresis circuit because of their weight Conclusions DP was successfully manufactured and infused in the Phase I study and both FA-A patients are showing early signs of stabilization of cytopenias. Plans for opening the Phase II study are in progress. Preventing BMF by gene therapy without any exposure to chemo-radiotherapy has the potential to change the natural history of FA.

Farmakogenomika i regulacija apoptoze u akutnoj mijeloidnoj leukemiji

Acute myeloid leukaemia (AML) is a heterogenous clonal hematopoietic malignancy primarily treated with combination of cytarabine (ara-C) and anthracyclines. Despite high remission rates, especially in younger patients, a vast majority of patients die due to relapse or chemotherapy/stem cell transplantation-related toxicity. The partial explanation for this grim clinical outcome lies in the patients' genetic variability. In this review, we will summarize how genetic polymorphisms of proteins, in metabolic paths of cytarabine and anthracyclines and proteins involved in regulation of apoptosis, influence efficacy and toxicity in the AML treatment.

The effect of graft-versus-host disease on outcomes after allogeneic stem cell transplantation for refractory lymphoblastic lymphoma in children and young adults.

Patients with relapsed or refractory lymphoblastic lymphoma (LBL) have a poor prognosis. The efficacy of allogeneic blood stem cell transplantation for treatment of this disease remains unclear in terms of transplantation-related toxicity. Acute and chronic graft-versus-host diseases (GVHD) are both harmful to patients after allogeneic transplantation, but may have some positive effects through a substitute graft-versus-lymphoma effect. To investigate the effect of GVHD on the survival of patients with refractory LBL, we retrospectively studied the outcomes of 213 patients with LBL who underwent first allogeneic stem cell transplantation before the age of 18 years, between 1990 and 2015 in Japan. The five-year overall survival (OS) and event-free survival rates after stem cell transplantation were 50.3% (95% confidence interval [CI], 43.2-56.9) and 47.8% (95% CI, 40.8-54.4), respectively. In univariate landmark analyses, the probability of OS was significantly better in patients with aGVHD than in those without (P=0.002, five-year OS 58.1% vs 39.0%). The probability of OS was also better in patients with cGVHD than in those without (P=0.036, five-year OS 72.2% vs 54.7%). Multivariate analysis demonstrated that only aGVHD was associated with better OS (hazard ratio, 0.63; 95% CI, 0.42-0.94, P=0.024). Progression and recurrence statuses at SCT were associated with poor prognosis. The patients with grade II aGVHD showed the best prognosis (five-year OS: 65.6%). Our results suggest that the occurrence of aGVHD may be associated with better outcomes in patients with relapsed/refractory LBL who undergo allogeneic transplantation.

A Phase IB Study of Blinatumomab (blina) in Patients with B Cell Acute Lymphoblastic Leukemia (ALL) and B-Cell Non-Hodgkin Lymphoma (NHL) As Post-Allogeneic Blood or Marrow Transplant (allo-BMT) Remission Maintenance

Background: AlloBMT can be curative as consolidation for high risk B ALL and NHL. However, long term survival is limited by transplant-related toxicity and particularly by disease relapse. Post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis limits GVHD and facilitates the use of alternative allograft sources. Moreover, following PTCy, cellular immune reconstitution is favorable for the integration of strategies to augment anti-tumor immunity. Blina, a CD19/CD3 bispecific T cell engager antibody construct, is effective in the treatment of CD19+ ALL and NHL. Blina leads to T cell activation that may enhance established posttransplant tumor-specific T cell responses, leading to a more potent graft-versus-tumor effect. Thus, we have undertaken a phase Ib trial to assess the tolerability and preliminary efficacy of blina as post-alloBMT remission maintenance in B-cell ALL and NHL. Methods: Patients ³18 years-old with high risk CD19+ B ALL or NHL who underwent alloBMT using PTCy were eligible including those with prior blina exposure. Patients had to be 60-180 days from transplant with documented count recovery and no evidence of disease progression. Patients had to be off all post-transplant immunosuppression including steroids for the treatment of GVHD for ≥4 weeks prior to treatment initiation, and without a history of grade ≥3 acute GVHD or severe chronic GVHD. Patients could receive two cycles of blina if they had evidence of disease (including MRD) at their pre- and/or post-transplant evaluations but otherwise received only one cycle. Blina was given as a continuous infusion at 9 mcg/day on C1D1-7 and 28 mcg/day on C1D8-28 and C2D1-28. Results: As of July 23, 2019, 12 adults (10 males/2 females) have enrolled including 4 patients with B ALL and 8 patients with NHL. Among the B ALL patients, two with known TP53 mutations were transplanted in CR1, while two with relapsed disease were transplanted in CR3. Among the NHL patients, five had large cell transformation (3 from follicular and 2 from CLL); one had relapsed primary CNS lymphoma (PCNSL); one had relapsed mantle cell lymphoma (MCL); and one had diffuse large B cell lymphoma (DLBCL). The median age was 53 (range, 30-73). All patients underwent alloBMT using a conditioning regimen of fludarabine, cyclophosphamide, and total body irradiation (TBI). Eight patients received allografts from haploidentical donors, three from matched-unrelated donors, and one from a matched-related donor. Five patients received peripheral blood allografts, and seven bone marrow. Two patients were enrolled after a second alloBMT, and 3/4 ALL patients previously received blina. Baseline characteristics are presented in Figure 1. Patients started blina a median of 144 days post-transplant (range, 90-180). One patient stopped treatment on day 5 due to a grade 2 tremor, and one patient required dose reduction on day 25 due to grade 4 neutropenia. Toxicities were otherwise mild and are presented in Figure 2. There were no exacerbations of GVHD. At a median follow-up of 13.7 months after BMT (range 3.8-23 months), ten patients remain in remission, while one patient suffered a third CNS relapse of ALL at 20.6 months after his 2nd transplant and another had relapse of his transformed lymphoma. Data on biomarkers including changes in T cell subpopulations in both BM and PB, and co-signaling molecule expression will be presented. Conclusions: Post-alloBMT maintenance therapy with blina is feasible with minimal toxicity. 83% of the very high risk patients treated on study remain in CR at a median of 13.7 months post-transplant. Based on promising safety and efficacy data from the phase IB, the plan is to proceed to the phase II portion of the study. Disclosures Webster: Amgen: Consultancy; Genentech: Research Funding; Pfizer: Consultancy. Wagner-Johnston:Jannsen: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees. Luznik:Merck: Research Funding, Speakers Bureau; Genentech: Research Funding; AbbVie: Consultancy; WindMiL Therapeutics: Patents & Royalties: Patent holder. Gojo:Abbvie: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Merck: Research Funding; Jazz: Consultancy, Honoraria; Amgen Inc: Consultancy, Honoraria, Research Funding; Juno: Research Funding; Amphivena: Research Funding. OffLabel Disclosure: Blinatumomab is not labeled for use as post-transplant maintenance therapy or for use in the non-Hodgkin lymphoma.

Changing the Natural History of Fanconi Anemia Complementation Group-A with Gene Therapy: Early Results of U.S. Phase I Study of Lentiviral-Mediated Ex-Vivo FANCA Gene Insertion in Human Stem and Progenitor Cells

Background: Fanconi anemia (FA) is a rare genetic disorder characterized by defective cellular deoxyribonucleic acid (DNA) repair, associated with developmental abnormalities, progressive bone marrow failure (BMF), and a predisposition to hematologic malignancies and solid tumors. 80% of FA patients develop BMF. Although allogeneic hematopoietic stem cell transplant (allo-HSCT) is a curative treatment for BMF, its utilization and efficacy is limited by availability of suitable human leukocyte antigen (HLA)-matched donors, risk of graft-versus-host disease (GVHD) and transplant-related toxicities. Ex-vivo insertion of a functional FANCA gene into autologous FA-A CD34+ enriched hematopoietic stem and progenitor cells (HSPCs) has been shown in preclinical studies to provide a survival advantage to the gene-modified stem cells, leading to correction of BMF. Feasibility of this approach was established in the FANCOLEN-1 clinical trial (Spain), although cell doses and transduction levels varied considerably. Modifications to the collection and manufacturing processes were made in the clinical studies to enhance the dose of transduced HSPCs, with the goal of preventing progression of BMF to obviate the need of an allo-HSCT. Design and Methods: RP-L102-0418 (clinicaltrials.gov # NCT03814408) is a U.S. Phase I clinical trial evaluating the feasibility and safety of autologous CD34+ cells transduced with a lentiviral vector (LV) carrying the FANCA gene (PGK-FANCA-WPRE) in two pediatric patients with FA-A. Patients <12 years of age, with early evidence of cytopenias, but with bone marrow (BM) CD34+ count >30/µL were eligible for treatment. Peripheral blood mononuclear cells were collected via leucocytapheresis on two consecutive days after mobilization with granulocyte-colony stimulating factor (G-CSF) and Plerixafor (Mozobil). CD34+ HSPCs were enriched, placed in culture with cytokines, and transduced with PGK-FANCA-WPRE LV. The investigational drug product (DP) (RP-L102) was infused fresh into patients within 4 hours of release, without any prior conditioning regimen. Patients are being followed for 3 years post-infusion for safety assessments (replication competent lentivirus (RCL), insertion site analysis (ISA)) and to ascertain early evidence of efficacy (increasing peripheral blood vector copy number (VCN) and BM mitomycin-C (MMC) resistance), along with stabilization/correction of cytopenias. Results: Two FA-A patients (aged 5 and 6 years) were consented and enrolled on the study at Stanford University. Mobilization and apheresis procedures were performed successfully without any serious adverse events. DP was successfully manufactured using "Process B" optimization including transduction enhancers, commercial-grade vector, and modified cell processing. Because of higher transduced CD34+ and colony forming cell (CFC) doses, we anticipate early development of BM MMC resistance in the current study patients. Safety and efficacy data 4 to 6 months post-treatment, including peripheral blood VCN, blood counts and bone marrow MMC resistance, will be available at the time of presentation. Conclusions: DP has been successfully manufactured in the Phase I study (N=2) to meet the required specifications.Patients are being monitored for early efficacy assessments; 6+ months of follow-up may be required to observe the proliferative advantage of transduced HSPCs.Plans for Phase II portion of the study are in progress. Disclosures Czechowicz: Rocket Pharmaceuticals, Inc.: Research Funding. Beard:Rocket Pharmaceuticals: Employment, Equity Ownership. Law:Rocket Pharmaceuticals: Employment, Equity Ownership. Nicoletti:Rocket Pharmaceuticals, Inc.: Employment, Equity Ownership. Río:Rocket Pharmaceuticals: Equity Ownership, Patents & Royalties, Research Funding. Bueren:Rocket Pharmaceuticals, Inc.: Consultancy, Equity Ownership, Patents & Royalties: Inventor on patents on lentiviral vectors filled by CIEMAT, CIBERER and F.J.D and may be entitled to receive financial benefits from the licensing of such patents, Research Funding. Schwartz:Rocket Pharmaceuticals: Employment, Equity Ownership.

Outcomes Following Intolerance to Tacrolimus/Sirolimus for Graft-Versus-Host Disease Prophylaxis in Allogeneic Hematopoietic Stem Cell Transplant

INTRODUCTION: Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic cell transplant (HCT) resulting in significant morbidity and mortality. The combination of tacrolimus and sirolimus (TAC/SIR) has emerged as a GVHD prophylaxis platform preferred by many institutions given its association with rapid engraftment and acceptable transplant-related toxicity. However, overlapping toxicities between the two drugs can lead to intolerance and premature discontinuation in some patients. There is limited literature describing outcomes and subsequent management of such patients. The goal of this study is to investigate the clinical outcomes of patients becoming intolerant to the combination of TAC/SIR prophylaxis. METHODS: We retrospectively evaluated consecutive adult patients (n=100) at the Moffitt Cancer Center who received allogeneic HCT with TAC/SIR for GVHD prophylaxis in 2018. TAC/SIR intolerance was defined as discontinuation due to the toxicity of either TAC or SIR before post-transplant day 100. Survival analyses were estimated from the time of transplant with the Kaplan-Meier method and compared using the log-rank test. Patients intolerant of this prophylaxis regimen were compared to patients who completed >100 days of therapy, using Mann-Whitney U test for continuous variables and Pearson Chi-square tests for categorical variables. All statistical analyses were performed using SPSS v25 and NCSS v11. RESULTS: Demographics and clinical characteristics of all patients are summarized in Table 1A. TAC/SIR intolerance occurred in 25% (24 discontinued TAC, 1 discontinued SIR) of patients at a median duration of therapy of 19 days (range 4-92). The most common TAC/SIR toxicity (Table 1B) was acute kidney injury (AKI, n=11, 44%), followed by thrombotic microangiopathy (TMA, n=3, 12%). Baseline metabolic and clinical variables including creatinine, liver function, and conditioning intensity were not predictive of TAC-SIR intolerance. At a median follow-up of 10 months, the median overall survival (OS) for patients intolerant of TAC/SIR was 10 months versus was not reached for the patients without intolerance (HR 5.42; 95% CI 1.71-17.14; p<0.001). The 1-year PFS was 16% (95% CI 0% - 42%) vs 75% (95% CI 65% - 86%) and OS was 35% (95% CI 8% - 63%) vs. 79% (95% CI 68% - 90%) for patients who were TAC/SIR-intolerant compared to those who were TAC/SIR-tolerant (p<0.01) (Figure 1A). The cumulative incidence (CuI) of non-relapse mortality (NRM) at 1 year in patients intolerant of TAC/SIR was 47% (95% CI: 28% - 81%) and in patients tolerant of TAC/SIR was 4.4% (95% CI: 1.5% - 14%), (p<0.001). The Cul of relapse at 1 year was 45% (95% CI: 20% - 100%) in patients who were TAC/SIR-intolerant compared to 18% (95% CI: 10% - 30%) in patients who tolerated TAC/SIR (p=0.07) (figure 1B). Overall, 31 patients (31%) developed grade II-IV acute GVHD (aGVHD). The Cul of grade II-IV aGVHD at 100 days in patients who were TAC/SIR-intolerant was 29% (95% CI 15% - 58%) compared to 17% (95% CI 10% - 29%) in patients who tolerated TAC/SIR, (p=0.38). The Cul of cGVHD at 1 year in patients who were TAC/SIR-intolerant was 44% (95% CI: 25% - 79%) compared to 52% (95% CI: 40% - 68%) in patients who were TAC/SIR-tolerant (p=0.89). CONCLUSIONS: Outcomes for patients completing over 100 days of TAC/SIR for GVHD prophylaxis following allogeneic HCT are favorable. However, early intolerance of TAC/SIR GVHD prophylaxis occurred in 25% of allogeneic HCT in 2018 alone and predicted a poor prognosis with increased NRM and overall mortality, largely from drug-related toxicities. Notably, premature discontinuation of TAC/SIR did not contribute to higher subsequent risks of GVHD. Strategies to mitigate the risks of TAC/SIR toxicity are warranted. Future studies are also needed to identify the optimal GVHD prophylactic regimen for patients after TAC/SIR intolerance. Disclosures Nishihori: Novartis: Research Funding; Karyopharm: Research Funding. Bejanyan:Kiadis Pharma: Other: advisory board.

Bortezomib and Vorinostat Therapy as Maintenance Therapy after Autologous Transplant for Multiple Myeloma

Background: In multiple myeloma (MM), relapse is a frequent complication after autologous hematopoietic stem cell transplant (ASCT). To reduce the risk of relapse, additional therapy has been added post-ASCT. In a nontransplant relapse setting, the combination of intravenous bortezomib and oral vorinostat (BV) was studied and showed efficacy. Therefore, it was reasonable to study this combination therapy post-ASCT. Patients and Methods: We report on BV given post-ASCT. All 30 patients underwent conditioning for ASCT with high-dose melphalan. After recovery from the acute transplant-related toxicity, BV therapy was started and given for a total of 12 (28-day) cycles. Results: The most common toxicities were hematological, gastrointestinal (diarrhea and nausea), fatigue, and peripheral neuropathy. The median follow-up for BV patients is 7.8 (range: 6.12–9.03) years. After BV therapy, 18 patients (60%) are alive, and 9 (30%) are alive without disease progression. Conclusions: BV can be given post-ASCT with an acceptable toxicity profile and produces reasonable disease-free and overall survival rates. A randomized study comparing the BV regimen to single-agent lenalidomide or bortezomib is needed.

Concise Review: Boosting T-Cell Reconstitution Following Allogeneic Transplantation-Current Concepts and Future Perspectives.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for a large number of malignant and nonmalignant (inherited) diseases of the hematopoietic system. Nevertheless, non‐HLA identical transplantations are complicated by a severe T‐cell immunodeficiency associated with a high rate of infection, relapse and graft‐versus‐host disease. Initial recovery of T‐cell immunity following HSCT relies on peripheral expansion of memory T cells mostly driven by cytokines. The reconstitution of a diverse, self‐tolerant, and naive T‐cell repertoire, however, may take up to 2 years and crucially relies on the interaction of T‐cell progenitors with the host thymic epithelium, which may be altered by GvHD, age or transplant‐related toxicities. In this review, we summarize current concepts to stimulate reconstitution of a peripheral and polyclonal T‐cell compartment following allogeneic transplantation such as graft manipulation (i.e., T‐cell depletion), transfusion of ex vivo manipulated donor T cells or the exogenous administration of cytokines and growth factors to stimulate host‐thymopoiesis with emphasis on approaches which have led to clinical trials. Particular attention will be given to the development of cellular therapies such as the ex vivo generation of T‐cell precursors to fasten generation of a polyclonal and functional host‐derived T‐cell repertoire. Having been tested so far only in preclinical mouse models, clinical studies are now on the way to validate the efficacy of such T‐cell progenitors in enhancing immune reconstitution following HSCT in various clinical settings. stem cells translational medicine 2019;00:1–8

Safety and Toxicities of Radiotherapy As Consolidation or Cytoreduction Around the Time of Autologous Stem Cell Transplantation for Multiple Myeloma Patients: A Single Center Retrospective Report

Introduction The efficacy and safety of palliative radiotherapy (RT) is well established for patients with multiple myeloma (MM). However, little is known regarding the safety of RT as consolidation or cytoreduction among MM patients undergoing autologous stem cell transplant (ASCT). Objectives Given that many MM patients undergo ASCT as part of treatment, we sought to characterize the safety and toxicity profile of peri-transplant RT among patients with MM that underwent ASCT at a large, tertiary-care stem cell transplant center. Methods Eligible patients included those 18 years or older with a confirmed diagnosis of MM that underwent ASCT between January 2009 and June 2018 at the Fred Hutchinson Cancer Research Center. Peri-transplant RT was defined as RT deployed within 3 months of ASCT for the explicit purpose of disease consolidation or cytoreduction, including treating lesions at risk for pathologic fracture. We excluded patients that underwent tandem autologous-allogeneic stem cell transplant and patients that received RT for disease relapse post-transplant. Transplant-related toxicity and infectious complications were graded using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Results Of 785 MM patients that underwent ASCT, 23 (2.9%) received RT, post-stem cell collection, at our institution in the peri-transplant setting. Demographics, disease characteristics, and treatment data are depicted in figure 1. Seven patients (30%) received RT to treat lesions at risk for pathologic fracture. A total of 18 patients (78%) were hospitalized within 30 days of transplant. Among these patients, 12 patients (52%) experienced grade 3 regimen-related toxicities requiring hospitalization, most frequently nausea, vomiting, and mucositis; 2 patients (9%) experienced grade 2 autologous-pseudo GVHD requiring oral steroids. Twelve patients (52%) experienced grade 3 infectious complications, the majority of which were neutropenic fever. The median time to neutrophil engraftment was 16 days (range 13-20), and the median time to platelet engraftment was 11 days (range 8-14); within this group, subjects who received RT to the hip or pelvic region had similar engraftment times. Conclusion In this analysis of the MM patients who underwent ASCT at our institution, we observed the expected degree of transplant-related toxicity among peri-transplant RT recipients, with most patients requiring hospitalization post-transplant for gastrointestinal toxicity. Peri-transplant RT, including irradiation of the hip or pelvic region (where the majority of hematopoiesis occurs), did not impact on engraftment or incidence of infectious complications. Future work is needed to evaluate whether peri-transplant RT improves disease remission among MM patients that undergo ASCT, and we are in the process of updating disease response rates in these patients.

Relative Abundance Analysis of the Oral and Gastrointestinal Microbiome during Autologous Transplantation for Multiple Myeloma: Results of a Prospective Pilot Study and Association with Transplant Outcomes

BackgroundThe human microbiome has been associated with allogeneic hematopoietic cell transplantation (HCT) outcomes. To date, there are no studies describing the longitudinal changes in the oral or gastrointestinal microbiome in the setting of autologous HCT. We conducted a prospective study to determine the longitudinal microbial profile in patients undergoing HCT for multiple myeloma (MM), and whether changes in microbial abundance correlate with HCT outcomes and/or toxicities.MethodsSamples were collected from 15 MM patients on admission (baseline, T-2), during marrow aplasia (T+7) and after engraftment (T+30) (Table 1- summarizes baseline characteristics).We evaluated the bacterial and fungal microbiome of 15 patients using Ion-Torrent PGM workflow. The amplicons generated from the 16s rRNA and the ITS genes were sequenced for bacterial and fungal identification, respectively. Sequencing reads were clustered into operational taxonomic units (OTUs, 3% distance) and taxonomically classified via Qiime bioinformatics pipeline.Statistical analysis was performed using the statistical programming language R. Multivariate distance based association between communities and outcome was performed using the Adonis function as implemented in the R package vegan using Bray-curtis dissimilarities distances with and without presence/absence standardization (BrayPA). Non-parametric Spearman correlation and wilcoxon rank-sum test were used for association with continuous outcome and binary outcome respectively.ResultsRelative abundance was determined at the phylum and genus levels across each time point, in the oral and fecal microbiome, both bacterial and fungal. At the bacterial phylum level, the oral bacterial community composition significantly changed at T+30 compared to baseline (Bray-curtis, p=0.046) and T+7 (Bray-curtis, p=0.025). When examining the changes in the mycobiome composition, test for dissimilarity showed a significant difference in the fecal fungal genus between baseline and T+30 (BrayPA, p=0.025). No other statistically significant differences were noted.Next, we correlated the microbial community (Table 2) and individual composition with outcome and transplant related toxicity, the later will be reported here. In fecal samples, the bacterial phylum Bacteriodetes present at T+7 was associated with the development and severity of diarrhea, such that patients with higher abundance of Bacteroidetes experienced lower gastrointestinal toxicity (pAdj=0.03). Additionally, the 2 genera Blautia and Ruminococcus, both belonging to the Firmicutes phylum and Clostridium Class, when detected at T+7 were associated with a higher development and severity of vomiting after exposure to high dose melphan (pAdj=0.05 for both respectively). In oral samples, the presence of the genus Glomerella at T+7 was negatively associated with rates of neutrophil engraftment (pAdj=0.03).Conclusion and Future DirectionsWhile acknowledging the limitation inherent in the small sample size, our results show that oral and fecal microbiota undergo dynamic changes in their diversity (Abstract ID 120038), composition and relative abundance during the course of transplantation. This change is likely multifactorial owing to the conditioning regimen, antimicrobial exposure and immune dysregulation. Our data suggest the bacterial and fungal microbiota present specifically at count nadir could be important players in this population of patients. Interestingly, the relative abundance of particularly the anaerobic bacterial phyla, Bacteroidetes and Firciumtes (Blautia and Ruminococcus) during marrow aplasia, correlated with transplant related toxicities in our cohort. This could further contribute to our knowledge of the role anaerobic organisms play in HCT outcomes, in accordance to what has been described in the allogeneic HCT literature.Amifostine was used as a cytoprotectant before high dose melphalan for our patients. The effect of this organic thiophosphate on the microbiota is unclear and warrants future investigations. Further studies conducted on a larger scale and incorporating metabolomics and proteomics will help elucidate the interactions between the host and the microbiome and their effect on short term and long term transplantation outcomes as well as toxicities. DisclosuresLazarus:Pluristem Ltd.: Consultancy. Malek:Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau.

A Phase II Study of Decitabine Followed By Allogeneic Hematopoietic Stem Cell Transplantation in High-Risk Patients with Myeloid Malignancies

Introduction:Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for myelodysplastic syndrome (MDS) and high-risk acute myeloid leukemia (AML). Patients with high-risk disease have a markedly increased risk of relapse and death following transplant (Armand et al, Blood, 2014). Those who remain disease-free are at risk of severe morbidity from graft-versus- host-disease (GvHD). These issues highlight the importance of improved allo-HSCT platforms designed to reduce relapse rate without increasing risk of GvHD. Decitabine has minimal non-hematologic toxicity and proven efficacy in myeloid diseases (Blum et al, PNAS, 2010). Use of post-transplant cyclophosphamide has demonstrated improved rates of GvHD following allo-HSCT using haplo-identical donors (Bashey et al, JCO, 2013). No studies have reported on outcomes in patients undergoing decitabine immediately prior to transplantation followed by post-transplant cyclophosphamide (PTCy). We hypothesized that the combination of decitabine induction prior to transplant and PTCy would be safe and result in improved disease control with low rates of GVHD, translating into improved survival in a high-risk transplant cohort.MethodsIn this single-arm, single institution trial, eligible patients received 10 days of IV decitabine at 20mg/m2 no sooner than 24 days and no later than 17 days prior to conditioning. Myeloablative conditioning included fludarabine (50mg/m2 day-5-2), busulfan (IV 3.2mg/kg/day -5-2), and 4 Gy total body irradiation on day -1. Patients above age 65 received a 25% busulfan dose reduction. Patients received a fully or partially matched related bone marrow graft on day 0. GvHD prophylaxis included 50mg/kg of IV cyclophosphamide on day +3-4. Patients with fully matched donors received only PTCy while those with partially matched donors also received mycophenolate mofetil through day +35 and tacrolimus through day +180.ResultsWe enrolled 20 patients, fifteen patients with AML and 5 with MDS. The cohort had a median age of 64 (29-73) and was predominantly male (14/20, 70%). Eight (40%) patients scored as high risk by the HSCT comorbidity index. Eighteen patients (90%) had a high or very high-risk score by the refined disease risk index.All patients received decitabine and 18/20 (90%) underwent transplantation; 2 patients did not receive a transplant due to infectious complications. The majority of patients received a haplo-identical graft (13/18, 72%), and the remaining 5 received a matched related graft.Outcomes are reported in table 2 and figure 1. There were no engraftment failures. Five patients, 3 MDS and 2 AML, are long-term survivors with median follow-up over 3 years. One patient developed donor derived MDS and required a second transplant. Most transplanted patients (13/18, 72%) survived to day 100 with a median post-transplant survival of 138 days. There were 15 deaths on study with the majority due to underlying disease. Six patients (6/20, 30%) died of infectious complications or did not receive a transplant due to infection. Incidence of grade 3-4 acute GvHD was low among those surviving at least 40 days from transplant (3/17, 17%). There were also low rates of chronic GvHD among the 12 patients alive without ongoing GvHD at day 100 (2/12, 17%).ConclusionsDecitabine induction followed by myeloablative conditioning in this high-risk population resulted in a high treatment related mortality of 40%. Still, outcomes fell into an expected range for high-risk myeloid disease in an elderly and comorbid population. Based on expected outcomes for high-risk patients from the literature (Armand et al, Blood, 2014), decitabine did not markedly improve overall survival outcomes, recognizing that no direct comparisons are available in our limited study population. Decitabine may increase the risk of peri-transplant infections by contributing to a cumulative immunologic insult combined with disease-related immunosuppression and transplant-related toxicity, highlighting the importance of strict vigilance for infections within this setting. Diligent monitoring may improve infectious outcomes as shown in the second half of the cohort; only two out of the latter 10 patients on protocol died of treatment related complications. There were no cases of engraftment failure. Rates of acute and chronic GvHD using a PTCy platform were low and support other studies reporting this benefit. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Stem Cell Transplantation in Advanced Stage Sickle Cell Disease with Haploidentical T-Cell Depleted PBSC Yields Comparable Outcomes to Matched Sibling Donor Bone Marrow: Results of a Pilot Study

Background: Sickle cell disease (SCD) is an inherited disorder with an estimate of 300,000 affected newborns per year worldwide. Despite improvements in preventive measures and conventional therapy, substantial morbidity and mortality, resulting in a reduced life expectancy persist. Allogeneic hematopoietic stem cell transplantation (HSCT) with a matched sibling donor (MSD) is currently the curative standard of care. However, matched donor availability is <20% and unrelated donor (MUD) HSCT is associated with unacceptably high rates of severe graft-versus-host disease (GvHD). A T-cell depleted HSCT from a haploidentical relative (T-haplo-HSCT) expands donor availability while exhibiting low GvHD rates and thus could offer cure to the remaining 80% of SCD patients (pts).Methods: We report the results of 29 pts with advanced stage SCD transplanted with either a T-cell depleted haploidentical regimen (20 pts, median age 13 years, range 3-31 years) or with bone marrow from a matched family donor (MSD, 9 pts, median age 14, range 9-25 years). Indication for HSCT was advanced stage SCD related complications. Pts with a MSD received a bone marrow (BM) graft. Pts requiring an alternative donor were transplanted with an αß/CD19 (n=5) or CD3/CD19 (n=15) depleted graft from a haploidentical family donor. The conditioning regimen for both groups was identical except that antithymoglobulin (ATG-Neovii®) was given upfront on day -10 to -8 in T-haplo-HSCT and on day -3 to -1 in MSD. Chemotherapy consisted of thiotepa 2 x 5 mg/kg, fludarabine 4 x 40 mg/m2 and treosulfan 3 x 14 g/m2, given between days -10 and -2. Post-HSCT immunosuppression consisted of mofetil mycophenolate and tacrolimus or cyclosporine A for a duration >6 months in T-haplo-HSCT and <6 months in MSD, depending on chimerism. The MSD group received a graft containing a median of 2.4 x 108 cells/kg body weight (BW). The T-haplo-SCT group received a peripheral stem cell allograft with a median of 13.1 x 106 CD34+ cells/kg BW.Results: The conditioning regimen was well tolerated in all pts with no high-grade transplant related toxicity. The overall (OS) and disease-free survival (DFS) with a median follow-up of 17 months in 20 advanced stage mostly adolescent and adult T-haplo-HSCT pts and 22 months in 9 MSD HSCT pts was 90% vs. 100%, respectively. Engraftment was achieved in most pts with stable chimerism over 90%, except for 4 pts with a stable MC in the T-haplo SCT group and 1 patient in the MSD group off immunosuppression. All pts presented a complete BM engraftment of red cell precursors. Only one patient in the T-haplo-HSCT group with a mixed chimerism is still under immunosuppression.The post-HSCT bacterial infectious complications were comparable in both groups and the most common observed viral infections were systemic cytomegaly virus (CMV), adenovirus (ADV), polyomavirus (BKV) and Epstein Barr virus (EBV) reactivations which were successfully treated with intravenous antiviral drugs or virus specific T-cells.Two patients in the T-haplo-HSCT group achieved a DFS off immunosuppression but succumbed to post-HSCT complications. One developed a rotavirus gastroenteritis and an uncontrolled CMV pneumonitis. The other a late graft failure and succumbed to a macrophage activation syndrome.None of our pts developed a Glucksberg Grade III-IV acute GvHD and in the T-haplo SCT group 4 pts (20%) and in the MSD group 2 pts (22%) developed a steroid sensitive mild to moderate cGvHD (fasciitis/oral as well as mild cutaneous GvHD). No extensive cGvHD was observed.To our knowledge this is the largest group of advanced stage SCD pts transplanted with either a T-haplo-HSCT or a MSD approach, according to donor availability, with an almost identical regimen in a direct comparative design. These preliminary results demonstrate increasing evidence for the feasibility, safety and efficacy of a T-haplo-HSCT using CD3/CD19 or αβ/CD19 depleted grafts, in order to offer a curative option to the majority of pts with SCD. A prospective, stratified non-inferiority trial is in preparation (EudraCT number 2018-002652-33) in order to confirm these preliminary results in a large prospective cohort. DisclosuresCorbacioglu:Gentium: Consultancy, Honoraria; Jazz Pharmaceuticals: Consultancy, Honoraria.

Strategies to improve outcomes of autologous hematopoietic cell transplant in lymphoma.

High-dose chemotherapy and autologous hematopoietic cell transplantation (HDT-AHCT) remains an effective therapy in lymphoma. Over the past several decades, HDT with BEAM (carmustine, etoposide, cytarabine, and melphalan) and CBV (cyclophosphamide, carmustine, and etoposide) have been the most frequently used preparatory regimens for AHCT in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). This article reviews alternative combination conditioning regimens, as well as novel transplant strategies that have been developed, to reduce transplant-related toxicity while maintaining or improving efficacy. These data demonstrate that incorporation of maintenance therapy posttransplant might be the best way to improve outcomes.

Hematopoietic stem-cell transplantation in systemic sclerosis: an update.

To provide an overview of recently published work on autologous hematopoietic stem-cell transplantation (HSCT) in patients with systemic sclerosis (SSc). Superiority of HSCT vs. intravenous cyclophosphamide pulses was demonstrated in the randomized controlled American Scleroderma: Cyclophosphamide or Transplantation (SCOT) Trial (n = 75), supporting the results from earlier studies. In the SCOT Trial, total body irradiation was used instead of the nonmyeloablative regimens used in other trials, and considered well tolerated during a follow-up time of 4.5 years. Three small uncontrolled prospective cohorts (n = 4, 14 and 18) and one retrospective analyses (n = 18), using various nonmyeloablative regimens, also showed improvement in skin involvement and lung volumes post-HSCT. Transplant-related toxicity and mortality remain an essential issue in HSCT. High treatment-related mortality was reported in one prospective cohort (n = 18), using alemtuzumab as a conditioning agent. Furthermore, cardiac complications, either treatment or disease related, require special attention. In translational studies, trends are reported in number of regulatory T cells and diversity of T-cell receptor repertoire at baseline and post-HSCT correlating with treatment response. There is increasing evidence that patients with rapidly progressive SSc may benefit from HSCT. However, optimal patient selection, pretransplantation workup and posttransplant management, still have to be established.

THUR 194 Autologous haematopoietic stem cell transplant in ms

IntroductionAutologous haematopoietic stem cell transplantation (AHSCT) is a very effective treatment in patients with highly active relapsing remitting multiple sclerosis (RRMS) who failed standard disease modifying therapies (DMTs).MethodsWe retrospectively reviewed the medical records of all patients with RRMS who received AHSCT in Sheffield.Results25 patents with RRMS received AHSCT between July 2013 and July 2017. Their median age at diagnosis was 40 (22–56) years. All had highly active disease with gadolinium enhancing lesions on their pre-transplant MRIs. Eighteen patients had previously been treated with various DMTs and seven were treatment naïve. Median pre-AHSCT EDSS was 5.5 (2.5–7.5). Median follow up was 12 (3–42) months. Median post-AHSCT EDSS at the last follow up was 3 (1–6.5), p&lt;0.001. No patient experienced further relapses following transplantation. Three patients had new lesions on their first follow up MRI at 6 months, but none had any new or enhancing lesions on subsequent MRI scans. Only routine transplant related toxicities were observed. One female and the wife of a male patient successfully conceived following AHSCT.ConclusionAHSCT is safe and effective in inducing remission in patients with highly active RRMS. Further studies are required to compare its efficacy with standard DMTs.

Outcome of treosulfan-based reduced-toxicity conditioning regimens for HSCT in high-risk patients with primary immune deficiencies.

HSCT is the curative therapeutic option in PIDs. Due to the increase in survival rates, reduced-toxicity conditioning regimens with treosulfan have become another alternative. The purpose of this retrospective study was to analyze the outcome of treosulfan-based conditioning before HSCT for patients with PID. A total of 15 patients that received a treosulfan-based conditioning regimen for HSCT were recruited. Type of diagnosis, donor and stem cell source, pretransplant organ damage, infections, engraftment, chimerism, and transplant-related toxicities were analyzed. At a median follow-up time of 32months, the overall survival was 86.7%. Following HSCT, 14 of 15 patients had engraftment, with 86.7% of the cohort having full-donor chimerism. The most common toxicity was seen on the skin (53.3%). Acute GVHD and chronic GVHD were documented in 53% and 20% of the study population, respectively. Although the cohort consisted of patients with pretransplant liver damage, SOS manifestations were documented in 20%. Treosulfan-based conditioning regimens before HSCT are associated with lower toxicity compared to myeloablative regimens, are safe, and have high engraftment rates with full-donor chimerism in patients having PID, regardless of the specified genetic diagnosis and donor type.

Сравнительная оценка влияния треосульфан- и бусульфан- содержащих миелоаблативных режимов кондиционирования на поздние осложнения аллогенных ТГСК при злокачественных заболеваниях у детей

Treosulfan-based regimens used in conditioning for allogeneic HSCT (allo-HSCT) in children allow to reduce incidence of transplant-related mortality and early toxicity, but there are no data about long-term effects. We propose a retrospective comparative study of late complications after allo-HSCT in 135 children with hematologic malignancies, who got allo-HSCT between January 1994 and July 2011 and survived at least 1 year after HSCT. Five-year event free survival was 75.6% in the group of children who got busulfan and 66.5% in patients with treosulfan-based conditioning; 5-year nonrelapse mortality was 6% and 10.2%, respectively. Late effects analysis demonstrated that treosulfan-containing conditioning allowed to reduce the incidence of some late complications: hypergonadotropic hypogonadism cumulative incidence was 0 compared to 32.8% in busulfan-conditioning group (р = 0.012); the decrease in subclinical hypothyroidism, secondary cardiomyopathy and organic central nervous system pathology incidence was revealed. Thus treosulfan-based conditioning regimen is an effective approach in reducing of serious late complications after allogeneic HSCT when compared with data of busulfan-based conditioning long-term effects.

Lomustine, cytarabine, cyclophosphamide, etoposide - An effective conditioning regimen in autologous hematopoietic stem cell transplant for primary refractory or relapsed lymphoma: Analysis of toxicity, long-term outcome, and prognostic factors.

High-dose chemotherapy followed by autologous hematopoietic stem cell transplant (HSCT) is the treatment of choice for patients with relapsed and refractory (RR) lymphoma. We analyzed toxicity and long-term outcome with lomustine, cytarabine, cyclophosphamide, etoposide (LACE) conditioning in patients with primary refractory or relapsed lymphoma undergoing autologous transplant. One-hundred patients with primary refractory (23), chemotherapy sensitive relapse (74) or RR (3) Hodgkin lymphoma (HL - 70 patients), and non-HL (NHL - 30 patients) underwent HSCT with LACE (lomustine 200 mg/m 2 day-7, etoposide 1000 mg/m 2 day-7, cytarabine 2000 mg/m 2 day-6 to day-5, and cyclophosphamide 1800 mg/m 2 day-4 to day-2) conditioning between November 2007 and December 2013. At transplant, 68 patients were in complete remission (CR), 29 in partial remission, 2 had stable disease, and 1 had progressive disease. Patients were followed up for development of transplant-related toxicities and long-term survival outcome. The incidence of grades 3-4 oral mucositis and grades 3-4 diarrhea was 8% and 4%, respectively. Median days to myeloid and platelet engraftment were 10 and 13. Transplant-related mortality was 7%. At median follow-up of 3 years, probability of overall survival (OS) and progression-free survival (PFS) at 3 years was 70% and 58% in entire cohort, 78% and 62% in HL and 51% and 46% in NHL subgroup, respectively. International Prognostic Score (IPS) >2 at relapse prognosticated for poor OS (P = 0.002) and PFS (P < 0.001) in HL subgroup. Positron emission tomography positivity pretransplant (HL subgroup) and at day + 100 (NHL subgroup) predicted for poor survival. We conclude that LACE is effective and well-tolerated conditioning regimen. IPS at relapse is the most important prognostic factor in HL transplant.

High Dose Total Body Irradiation for Refractory Acute Myeloid Leukemia

Refractory acute myeloid leukemia (AML) remains difficult to manage with conventional allogeneic hematopoietic stem cell transplantation (alloHSCT) approaches. Therefore, we developed a phase I/II study to evaluate the feasibility and efficacy of dose escalated total body irradiation (TBI) to a total dose of 1800 cGy/8 fr/4 days as the primary conditioning regimen. Patients with relapsed or primary refractory AML were enrolled from Jan 2012 to Sept 2015 inclusive onto a prospective study evaluating high dose TBI as the sole conditioning agent prior to alloHSCT. A dose of 1800 cGy was delivered in 8 fractions, given in 225 cGy fractions bid for 4 days. A translating-bed technique was used to treat patients with an extended SSD approach with either 10 or 18 MV photons. Lung and kidney attenuators were devised to limit the dose to these organs to approximately 1200 cGy. A total of 14 patents were enrolled in the present study with a median age of 39 years (range 24-60) and a median Karnofsky Performance Status of 80 (range 50-90) at the time of radiotherapy. All but one patient had circulating blasts at the time of treatment. All patients completed their TBI as planned, without any significant treatment interruptions or delays. Neutrophil engraftment occurred at a median of 15 days (range 11-25) and 11/14 patients were discharged from hospital at a median of 26 days (range 19-82) post alloHSCT. Nine patients reached a normal CBC at a median of 20 days (range 15-45). Seven patients had no blasts in a post alloHSCT bone marrow biopsy at a median of 56 days (range 21-114) post alloHSCT and 3 patients achieved a complete morphologic remission. However, there was only 1 long term survivor (>3 years), while 10 patients died following relapse, and three patients died of transplant related toxicity. High dose TBI to 1800 cGy/8 fr/4 days is feasible and tolerable for patients with refractory AML but sustained remissions remain elusive, and more innovative, novel and effective strategies are needed.

Application of NSG in Newly Diagnosed AML

Acute myeloid leukemia (AML) is a hematologic disease characterized by maturation arrest and proliferation of primitive clonal hematopoietic stem cells (blasts) resulting in bone marrow (BM) failure and eventually death if not timely treated. In 2017, approximately 20,000 new cases of AML and 10,000 disease-related deaths occurred in the United States alone. The median age at diagnosis is 67 years and the incidence of the disease increases with age. According to SEER/NCI database, survival in the US AML patients’ population is 26.6% for the last 5 years. Importantly, AML comprises several distinct entities that are cytogenetically and molecularly heterogeneous. Cytogenetic and molecular heterogeneity is clinically relevant, and it has been used for disease classification, prognostication and treatment selection. Despite cytogenetic/molecular risk-based approaches, however, only approximately 40% of younger (<60 year/old) and 10% of older (>60 years) patients achieve cure when treated with currently available chemotherapies. Even if allogeneic hematopoietic stem cells (alloHCT) may improve cure rate, the long-term success of this procedure may be somewhat limited by transplant-related toxicity and disease relapse. Thus, “one size fits all” treatments are insufficient to achieve complete remission (CR) and eventually long-term survival in the vast majority of the molecularly heterogeneous AML patients. Emerging new technologies for sequencing of the human genome have provided the tools for a deeper understanding of the mechanisms of malignant myeloid transformation, and have discovered previously unreported gene mutations and aberrantly silenced or expressed genes that participate in leukemogenesis and treatment resistance and, therefore may be use as therapeutic targets. These novel approaches however have also unveiled the magnitude of the biological complexity of the single AML blasts. Indeed, a myriad of genes have been found concurrently mutated, epigenetically modified or aberrantly expressed in unique molecular profiles of individual patients and contribute to clinical outcome. Thus, the challenge is how to match these complex profiles comprising concurrent mutations, epigenetic changes and aberrantly expressed genes with the most appropriate molecular targeting therapies in individual patients. Although the most pragmatic use of genomic data analyses is to apply a reductive approach and utilize only a relatively small number of genes, novel algorithms for molecular data prioritization and comprehensive analyses must be implemented to capture the entire biologic diversity among distinct AML cells and utilize this information for “personalized” clinical intervention. We will review how the development of molecular profiling using data from different omics platforms may be used for a comprehensive view of the disease biology and to match integrated profiles with the most appropriate cutting- edge treatment for individual AML patients.