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Introduction: A correct diagnosis of long-term complications in COVID-19 convalescents is of great importance for their therapeutic management. Aim(s): To identify long-term post-COVID-19 damages related to lymphocytes T to search prevention and treatments in future. Material(s) and Method(s): Data from 10 healthy volunteers, 23 patients (moderate/severe) COVID-19 were analysed. Responses of lymphocytes to LPS, ConA, CD3/CD28 mitogens and spike protein were measured in all groups during acute phase, 3- and 6-months post-hospitalization. Main lymphocyte T subpopulations (CD4, CD8) and CD25 expression on the lymphocyte subpopulations were also examined. Result(s): 6 of 13 severe patients were ventilated mechanically. The remaining 6 patients improved after high-flow nasal oxygen therapy and were discharged with normalized respiratory functions, the same as the mild/moderate COVID-19 group. We found that the decrease in total lymphocytes is equally due to the decrease in CD4 and CD8 cells. These changes persist in moderate and severely ill groups over 3 months post-COVID-19. In the case of CD4 lymphocytes, the changes concerned both naive (CD4+/CD25-) and activated (CD4+/CD25+) cells. A significant decrease in the CD8 cells was also observed, but only for the absolute number of naive CD8 lymphocytes (CD8+/CD25-). During the acute COVID-19 a significant impaired responses to ConA and CD3/CD28 were found. No difference in spike protein response was noticed. Conclusion(s): Long-term reductions (3- and 6-months) in the total count of lymphocytes in subpopulations and proliferative responses to mitogens suggest a severe impairment of the cellular immune response.
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Background/Purpose: The 2019 outbreak of coronavirus disease COVID-19 causes immune system disruption. Recent studies reported that the decrease or depletion of regulatory T cell (Treg) may be responsible for overstimulation of the immune system and lung damage in patients with severe COVID-19. This study aims to find the molecular mechanisms and genetic biomarkers associated with Tregs in COVID-19, providing new ideas for the treatment of COVID-19. Method(s): RNA sequencing data of peripheral blood mononuclear cells (PBMC) from 252 COVID-19 infected patients and 69 healthy controls (HC) were obtained from the GEO database. The Tregs composition of COVID-19 samples was quantified using the CIBERSORT deconvolution method. The differential genes (DEGs) were identified by the limma R package. Gene co-expression network analysis (WGCNA) was used to identify the gene. Differentially expressed Tregs-related genes (DETregRGs) were obtained by intersecting DEGs with the highly related modular genes obtained in the previous step. The potential biological functions and pathways of DETregRGs were then explored. Protein-protein interaction (PPI) networks were subsequently constructed to identify hub genes. In addition, the prediction of small molecule drugs for the potential treatment of COVID-19 was made using the CMap database. Result(s): After the weighted gene co-expression network analysis (WGCNA), the turquoise module was highly correlated with Treg expression and a total of 134 DEGs was identified as DETregRGs. These genes were mainly involved in GO biological processes, such as the inflammatory response, and T cell differentiation of thymus. Then, 11 hub genes (including RPS12, RPL21, RPS3A, CD8B, CD3D, TRAT1, RPS6, CD3E, CD28, RPL3, and CD4) were ranked based on Molecular Complex Detection (MCODE) analysis. The TregRG score of COVID-19 patients showed significantly lower than HC, calculated by the 'singscore' algorithms. After the signature query of the CMap database, the KU-0063794, an mTOR inhibitor ranked second in the negative enrichment score, may restore immune system dysregulation caused by increased Th17 differentiation and decreased Treg differentiation during SARS-CoV- 2 infection. Conclusion(s): Our study examined in detail the molecular mechanisms underlying the inadequacy of Tregs in patients with COVID-19 infection. mTOR inhibitors may improve COVID-19 symptoms by expanding Tregs which may be one of the potential therapeutic methods that need further investigation. (Figure Presented).
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Background: Patients with relapsed/refractory follicular lymphoma (R/R FL) often experience multiple relapses and require various lines of therapy. The ELARA and ZUMA-5 trials demonstrated high response rates along with acceptable safety profiles. We perform a phase 1b/2 single-center clinical trial of autologous point-of-care (POC) academic anti-CD19 chimeric antigen receptor (CAR) T-cells for patients with R/R FL treated with at least 2 lines of systemic therapy (NCT02772198). Aims: To report outcomes of POC CAR T-cell therapy in patients with R/R FL. Methods: Adults with R/R FL underwent a single leukapheresis procedure. Fresh peripheral blood mononuclear cells were isolated, activated, and transduced with a gammaretrovirus encoding for a CD19 CAR (based on an FMC63-derived ScFv, a CD28 costimulatory domain, and a CD3-ζ signaling domain). Lymphodepletion included fludarabine 25 mg/m2 over 3 days (days-4 to-2) and cyclophosphamide 900 mg/m2 once (day-2), followed by infusion of 1×106/kg CAR T-cells in the inpatient setting. Primary endpoints were response (by PET-CT, per Lugano criteria) at day 28, best response, and safety. Secondary endpoints included overall survival, progression-free survival (PFS), and production feasibility. Last follow-up was as of 02/2022. Results: All 19 patients enrolled received CAR T-cell infusion in a median of 11 days (IQR 10-11) after leukapheresis. The median age was 61 years (IQR 52-66). Five (26%) patients had Karnofsky performance status < 90%. Disease stage at enrollment was III-IV in 16 (84%) patients. Two (11%) patients had bulky disease;8 (42%) had LDH > upper limit of normal;and 16 (84%) had Follicular Lymphoma International Prognostic Index ≥ 3. Disease status at enrollment was progressive disease (n=14, 74%), stable disease (n=3, 16%), or partial response (PR;n=2, 11%). Twelve patients (64%) were refractory to last treatment. Disease grade at most recent lymph node biopsy was 1 (n=3, 16%), 2 (n=11, 58%), or 3a (n=5, 26%). The median time from FL diagnosis was 3.9 years (IQR 2.5-4.6). Sixteen (84%) patients had progression of disease within 24 months of initial therapy. The number of prior therapies was ≥ 4 in 6 (32%) patients;and 5 (26%) patients underwent prior autologous transplantation. Grade III-IV cytokine release and immune effector cell-associated neurotoxicity syndromes occurred in 1 (5%) and 4 (21%) patients, respectively. One patient was infected with COVID-19 on the 5th day following cell infusion and was admitted to the intensive care unit. One patient had grade 3 atrial fibrillation. Severe neutropenia (absolute neutrophil count <500/μL), thrombocytopenia (platelets <50K/μL) and anemia (hemoglobin <10g/dl) occurred in 15 (79%), 5 (26%), and 7 (37%) patients, respectively. No bleeding events or death were recorded following cell infusion. Response was evaluated in all patients. Overall response rate on day 28 was 84% (79% complete response [CR]). One patient with PR on day 28 achieved a CR after a year of follow-up. Three patients (16%) continued to progress following CAR infusion. All patients were alive at the last follow-up (median follow-up, 11.5 months [IQR 4-21]). One-year PFS was 74% (95% CI, 53-100). The median duration of response (DOR) was not reached (95% CI, 12.5-not reached). Estimated DOR at 1-year was 89% (95% CI, 71-100). Image: Summary/Conclusion: Point-of-Care anti-CD19 CAR T-cell therapy, performed following a very short production time, induced high CR rate with an acceptable safety profile in a cohort of patients with high-risk R/R FL.
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Background: GC012F is a B cell maturation antigen (BCMA)/CD19 dual-targeting CAR-T developed on the novel FasT CAR-T platform with overnight manufacturing and designed to improve depth of response and efficacy. Data was presented at ASCO and EHA 2021 for initial 19 pts. We present updated data for study (NCT04236011;NCT04182581) with longer follow up and 9 additional pts treated (n = 28) in 3 different dose levels. Methods: From October 2019 to November 2021, 28 heavily pretreated RRMM pts (age 27-76) median of 5 prior lines (range 2-9) were treated on a single-arm, open label, multicenter Investigator Initiated Trial receiving a single infusion of GC012F. 89.3% (25/ 28) were high risk (HR- mSMART), 8 pts had EM disease, 3 had never achieved a CR including after transplant, 1 pts presented with plasma cell leukemia, 24/28 pts were refractory to last therapy, 3 pts primary refractory. 9/28 pts had received prior anti-CD38, 27/28 pts prior IMiDs. 26/28 pts were refractory to PI, 26/28 pts to IMiDs. After lymphodepletion over 2-3 days (30 mg/m2/d, 300mg/ m2/d Flu/Cy) GC012F was administered as single infusion at 3 dose levels: 1x105/kg (DL1) n = 2, 2x105/kg (DL2) n = 10 and 3x105/kg (DL3) n = 16. Results: As of Jan 26th 2022, 28 pts - median follow-up (f/ u) 6.3 mths (1.8-29.9) - had been evaluated for response. Overall response rate (ORR) in DL1 was 100% (2/2)- DL 2 -80% (8/10) DL 3 -93.8% (15/16) with 27 pts MRD negative by flow cytometry (sensitivity 10-4-10-6). 100% of MRD assessable pts (27/27) achieved MRD negativity. One patient out of 28 could not get assessed. At d28, 21/24 assessable patients were MRD negative (81.5%), 4/ 28 pts could not get d28 MRD assessment f/u due to COVID-19 restrictions however were assessed at a later timepoint. To date best response is MRD- sCR in 21/28 patients(75.0%) across all dose levels. Some pts after short f/u show responses that are still deepening. Cytokine Release Syndrome (CRS) was mostly low grade: gr 0 n = 3 (10.7%), gr 1-2 n = 23 (82.1%), gr 3 n = 2 (7.1%) - no gr 4/5 CRS and no ICANs were observed (Graded by ASBMT criteria). Median duration of CRS was 3 d (1-8 d). PK results showed no difference amongst dose levels DL1 to DL3. Overall, CAR-T median Tmax was 10 d (range 8-14 d), median peak copy number (Cmax) was 97009 (16,011-374,346) copies /μg DNA with long duration of persistence of up to d793 (data cut-off). CAR-T geometric mean AUC0-28 for DL1, DL2 and DL3 were 468863, 631540 and 581620 copies/μg DNA×day, respectively. Pts continue to be monitored for safety and efficacy including DOR. Conclusions: BCMA-CD19 dual FasT CAR-T GC012F continues to provide deep and durable responses with a favorable safety profile in additional RRMM pts across all dose levels demonstrating a very high MRD negativity rate including in pts refractory to anti-CD38, PI and IMIDs. GC012F is currently being studied in earlier lines of therapy as well as additional indications.
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Rationale: Despite the availability of pharmacologic therapies, idiopathic pulmonary fibrosis (IPF) is still a clinical challenge with several unmet needs. Robust evidence supports monocytes as cellular biomarkers of progression in IPF. Yet, their precise role and whether specific subtypes might predict progression and drive disease is unknown. We reported, for the first time, that myeloidderived suppressor cells (MDSC), immature precursors of monocytes, are increased in numbers, functionally active in IPF. Monocytic MDSC is the predominant subtype in IPF, and yet, functional characterization and immune modulation properties have not been explored. Methods and Results: characterization of circulating myeloid populations in IPF by multicolor FACS confirmed the abundance of MDSC (Lin-, HLA-DRlo, CD33+, CD14+, S100A+, CD28L1+ and ICOSL+) in IPF (n=78) and fILD (n=83), also abundant in whole blood scRNA seq of severe Covid-19 patients that progressed into fibrosis, and not in mild Covid-19. Then, we prospectively followed 83 fILD patients (45% IPF, 55% non-IPF -EAA, CTD-ILD, NSIP-) over 1 year and immunophenotyped them every 3 months. Cross-sectional analysis showed that patients with a higher number circulating MDSC, had a higher GAP index (7-8) (p<0,001). Longitudinal follow-up showed that patients with constant higher circulating MDSC had lower transplant-free survival (p=0.0058). Primary isolated MDSC when co-cultured with autologous T cells induced CD8+ T cell exhaustion (PD1hi, Lag3hi, Tim3hi, TNFalpha lo, INFglo), and downregulation of co-stimulatory T cell signaling (CD28, ICOS, ITK, and LCK), preliminary data support the induction of de-novo FoxP3 Treg formation, creating a suppressive and immunosenescent microenvironment in IPF. FACS analysis of explanted lungs demonstrated the increase of tissue-resident MDSC in fibrosis (HP, NSIP, IPF) compared with donor lungs, as well as in bleomycin-induced fibrosis compared to PBS. Conclusion: Taking together, a high number of circulating MDSC reflects worse lung function and higher GAP index in cross-sectional analysis, and associates with lower transplant-free survival longitudinally. The role that immature and mature monocytes play during promotion of a suppressive microenvironment in IPF is an unexplored area that may lead to a paradigm shift in our understanding of the sequelae of exhaustion and immunosenescence, contributing to the identification of novel targets useful for therapeutic myeloid selection in IPF.
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Introduction: CLL is characterized by deficient immunity which clinically manifests as an increased predisposition toward malignancies and infectious complications. T-cells from patients with CLL exhibit a skewed repertoire with a predominance of Tregs as well as impaired immune synapse formation and cytotoxic function. Unlike chemotherapy, novel targeted agents may have beneficial immunomodulatory effects, which may be particularly relevant in the COVID-19 era. Small ubiquitin-like modifier (SUMO) family proteins regulate a variety of cellular processes, including nuclear trafficking, gene transcription, and cell cycle progression, via post-translational modification of target proteins. Sumoylation regulates NFjB signaling, IFN response, and NFAT activation, processes indispensable in immune cell activation. Despite this, the role of sumoylation in T cell biology in the context of cancer is not known. TAK-981 is a small molecule inhibitor of the SUMO-activating enzyme (SAE) that forms a covalent adduct with an activated SUMO protein, thereby preventing its transfer to the SUMO-conjugating enzyme (Ubc9). Here, we investigated the immunomodulatory effects of TAK-981 in CLL. Methods: T cells from patients with CLL were purified using Dynabeads. Activation, proliferation, and apoptosis of CD3+ T cells were studied following T-cell receptor engagement (TCR;aCD3/CD28) with/without 0-1 lM TAK-981. Cytokines were measured after in vitro stimulation. For polarization assays, FACS-sorted naïve CD4+ T cells were cultured for 7 days in control or differentiation media. For gene expression profiling (GEP;Clariom S), RNA was harvested after 3 and 24 h of TCR engagement from FACS-sorted naïve CD4+ T cells. For in vivo immunization experiments, CD4+KJ1-26+ cells were inoculated IV into BALB/cJ mice. Mice received 100 mg IV ovalbumin ± R848 followed by TAK-981 7.5 mg/kg or vehicle control IV twice weekly for 10 days before spleen collection. Both recipient and transplanted splenocytes were analyzed. For analysis of tumor-infiltrating lymphocytes (TILs), BALB/c mice were injected with 1×106 A20 lymphoma cells and treated as above. TAK-981 was provided by Millennium Pharmaceuticals, Inc. (Cambridge, MA, USA). Results: T cells from patients with CLL demonstrated high baseline protein sumoylation that slightly increased following TCR engagement. Treatment with TAK-981 significantly downregulated SUMO1 and SUMO2/3-modified protein levels, yet did not disrupt early TCR signaling as evidenced by sustained ZAP70, p65/NFjB, and NFAT activation detected by immunoblotting, immunocytochemistry, and GEP. Treatment with TAK-981 resulted in dose-dependent upregulation of the early activation marker CD69 in CD4+ T cells following 72 and 96 h of TCR stimulation vs. control. Meanwhile, the expression of CD25, HLA-DR, and CD40L was delayed in the presence of TAK-981. Interestingly, CD38, an IFN response target, was induced 2-fold in TAK-981-treated cells after 24 h and persisted at high levels at subsequent timepoints. T cell proliferation was reduced in the presence of high (1 lM) but not low/intermediate concentrations of TAK-981, accompanied by reduced S phase entry and decreased synthesis of IL- 2. However, T cells did not undergo apoptosis under those conditions. Targeting SAE in either control or Th1/Treg polarizing conditions facilitated an increase in IFNc and loss of FoxP3 expression (accompanied by decreased IL-2/STAT5), suggesting a shift toward Th1 and away from Treg phenotype, respectively. GEP (Reactome, GSEA) confirmed a dramatically upregulated IFN response in TAK-981-treated CD4+ naïve T cells. Furthermore, targeting SAE enhanced degranulation (CD107a), IFNc, and perforin secretion in cytotoxic CD8+ T cells and potentiated T cell cytotoxicity in allogeneic assays with lymphoma cells (OCI-LY3, U2932) as targets. Consistent with our in vitro data, OVA-stimulated transplanted transgenic KJ1-26+ splenocytes, as well as total CD4+ T cells from recipient mice treated with TAK-981 in vivo exhibited a significant reduction in express on of FoxP3 and an increased production of IFNc. In the A20 syngeneic model, treatment with TAK-981 similarly downregulated FoxP3 expression in CD4+ TILs and induced IFNc secretion in CD8+ TILs. Conclusion: Using a combination of in vitro and in vivo experiments, we demonstrate that pharmacologic targeting of sumoylation with TAK-981 does not impair proximal TCR signaling in T cells obtained from patients with CLL, but leads to rebalancing toward healthy immune T cell subsets via induction of IFN response and downmodulation of Tregs. These data provide a strong rationale for continued investigation of TAK-981 in CLL and lymphoid malignancies.
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Background: The information on seroprevalence rates of COVID-19 infection among patients with inflammatory bowel disease (IBD) and its comparison to healthy controls is sparse. We compared the seroprevalence rates in immunocompromised and immunocompetent IBD patients and healthy controls. Methods: Patients with IBD under follow-up at the IBD clinic, All India Institute of Medical Sciences, New Delhi, were included. After obtaining informed consent, patients underwent SARS-CoV-2 antibody testing (chemiluminescent immunoassay: Seimens kit IgG against antigen S1RBD) and information on demography, drug history, past history of COVID infection and vaccination status were noted. Patients with IBD on 5-aminosalicylic acid or not on any treatment were considered immunocompetent and those who had received steroids, thiopurines or methotrexate within 6 months of sample collection were considered immunocompromised. Results: 235 patients (51.9%-males;mean age at enrolment- 38.7±12.4 years;median disease duration-60 months [IQR:36- 120]) (UC-69.4%, CD-28.9%, IBDU-1.7%) and 73 healthy controls (HCs- mean age-39.6± 10.9 years, 79% males) were enrolled from July 2020 - April 2021 (Table1). 128 (54.5%) patients were immunocompromised and 107 were immunocompetent (treatment details: 5 ASA-72.3%, steroids-15.3%, Thiopurines-40%, methotrexate-2.6%). Seventy-four (31.5%) patients were positive for IgG antibody against SARS CoV2, 2 patients (0.9%) had previous history of COVID infection and none received COVID vaccine. Seroprevalence rates between immunocompromised and immunocompetent patients with IBD and healthy controls was similar (28.1% vs 36% vs 28%, p>0.05) (Figure1). Demographic and disease characteristics such as age, gender, disease type, disease activity in last 6 months, disease duration and medication use was similar between patients with positive and negative serology (Table2). There was progressive increase in seroprevalence from July 2020 to April 2021 Conclusion: Upto 1/3rd patients with IBD were seropositive for IgG SARS Cov2 antibody indicating asymptomatic COVID-19 infection. The seroprevalence was similar to healthy controls and was not different between immunocompromised and immunocompetent patients with IBD.
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Background: Tisagenlecleucel (Kymriah) is an autologous CD19-directed CAR-T-cell therapy, approved in Aug-2017 for treating children and young adults with relapsed/refractory (r/r) acute lymphoblastic leukemia and in May-2018 for treating adults with r/r diffuse large B-cell lymphoma. Post-approval, a key goal has been to upscale and continuously improve manufacturing success and turnaround time in the commercial settings to meet the needs of a global patient population. Here we report accrued experience from our 4-year journey of optimizing the commercial tisagenlecleucel manufacturing process at the US site (Morris Plains, NJ), for faster and successful delivery to patients in the US. Methods: As reported previously, the tisagenlecleucel manufacturing process includes leukapheresis of the patient's peripheral blood mononuclear cells, enrichment and activation of T cells, transduction of the lentiviral vector containing the anti-CD19 CAR transgene, activation with anti-CD3/CD28 antibody-coated beads, expansion in cell culture, washing, and formulation of the viable cells into a cryoformulation medium. The final product is then cryopreserved, shipped back to the treatment center and infused to patients (Tyagarajan, 2020). Use of cryopreserved leukapheresis material as the starting point in commercial manufacturing is unique to tisagenlecleucel;this allows flexibility in terms of scheduling leukapheresis when a patient's health is optimal to provide T cells, and also helps offset logistical challenges (Tyagarajan, 2019). Results: As of Jun-2021, tisagenlecleucel has been manufactured for >5000 patients worldwide, enabled by Novartis's significantly increased global manufacturing footprint at six sites strategically located across six countries (US, France, Switzerland, Germany, Japan and Australia) and a global treatment network of >340 certified centers, including 127 centers in the US. Specifically for the US manufacturing site, between Dec-2020 and Jun-2021, 376 patients in the US had starting material available for manufacturing. Overall, the manufactured product was available for shipment for 98% of patients (shipping success rate [SSR]). The commercial manufacturing success rate (MSR) was 96%, with an out-of-specification (OOS) rate of <3% and no OOS for viability. All ten OOS batches were released for infusion as benefit:risk assessment was positive. Manufacturing was cancelled for two patients upon physician's request. Immediate manufacturing capability without waiting time was available on receipt of all apheresis starting materials. The median time from start of manufacturing to shipping was 20 days. As is evident, the COVID-19 pandemic did not appear to have significantly affected the success rate or manufacturing turnaround time. These latest success metrics, reflecting significant improvements from 2018 to 2021 in MSR (69% to 96%), SSR (93% to 98%), and overall OOS rate (26% to 2%) including viability OOS rate (from 25% to 0%), are a result of upscaling the manufacturing capabilities, enhancements with hospitals focusing on optimizing apheresis collection and cryopreservation procedures, and continuous evaluation and improvement of the manufacturing process since tisagenlecleucel was first launched (Figure). Two key process and analytical improvements that were considered to have improved robustness of manufacturing and testing processes, reduced OOS rates, and minimized variability in turnaround time were introduced towards the end of 2020. Firstly, a simplified sample preparation procedure for final product cell count and viability measurement, which is more reflective of final product at infusion. Secondly, an alternate serum source (5% plasma-derived human AB serum [PD hABs]) which further improves process robustness with a trend towards improved growth and higher peak cell counts. Conclusions: Tisagenlecleucel's current global commercial manufacturing footprint and treatment network are well-positioned to meet anticipated future increase in demand for CAR-T therapies. Recent process improvements h ve significantly increased the MSR (to 96%) and SSR (to 98%), and immediate product availability for patients in need of CAR-T cells. Ongoing and upcoming process improvements are anticipated to further reduce the throughput time, thus allowing more patients faster access to CAR-T therapy. [Formula presented] Disclosures: Rodrigues: Novartis: Current Employment. Duran: Novartis: Current Employment. Eschgfaeller: Novartis: Current Employment. Kuzan: Novartis: Current Employment. Habucky: Novartis: Current Employment.
ABSTRACT
The introduction of post-transplant cyclophosphamide (PTCy) has circumvented the need for T-cell depletion following haploidentical stem cell transplantation (SCT). By expanding the donor pool for patients from certain ethnic minorities, this has addressed to some degree an important health care disparity issue in SCT. However, a recent registry study showed increased incidence GvHD and inferior outcomes in patients receiving haploidentical SCT with PTCy, tacrolimus and mycophenolate mofetil for GvHD prevention as opposed to matched unrelated donor SCT with PTCy-based GvHD prevention. Seeking to improve the results of GvHD prevention in the setting of haploidentical SCT, we examined a combination of PTCy, abatacept and a short course of tacrolimus (CAST). Abatacept is a recombinant soluble fusion protein composed of the extracellular domain of cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) fused to the Fc region of IgG1. Abatacept blocks CD28-CD80I86 axis and prevents T-cell co-stimulation. In early studies, abatacept has shown promising results when added to methotrexate and tacrolimus in matched and mismatched donor SCT. We initiated a phase Ib-II clinical trial for patients with hematological malignancies undergoing haploidentical SCT. Patients received G-CSF mobilized peripheral blood grafts from related haploidentical donors. GvHD prevention consisted of PTCy 50mg/kg IV on day +3 and +4 with forced hydration, abatacept 10mg/kg IV on day +5, +14 and +28 and tacrolimus. Tacrolimus was started on day +5 at 0.02mg/kg/day by continuous IV and adjusted thereafter to maintain a trough level of 5-12ng/mL. Tacrolimus taper was planned to begin on day +60 and complete by day +90 in the absence of GvHD. All patients received standard supportive care including levofloxacin until neutrophil engraftment, posaconazole until day +75, acyclovir for 1 year and, if CMV positive by serology, letermovir until day +100. Pneumocystis Jiroveci prophylaxis was started after neutrophil engraftment and continued until 6 months post-transplant. G-CSF was administered routinely until neutrophil engraftment. Since September 2020, 19 patients were enrolled. Three patients are too early in their post-transplant course and were excluded from this analysis. Patients' characteristics are summarized in the table. All but 2 patients received cryopreserved products. Median times to ANC and platelet engraftment were 18.5 days (14-30) and 28.5 (16-61). All 16 patients achieved full whole blood donor chimerism by day +30. There was no secondary graft failure. With a median follow-up was 149.5 days (41-308) with 10 patients having >120 days and 8 >180 days of follow-up, 4 patients developed skin acute GvHD (all grade I). No patient developed grade II-IV acute GvHD. Two patients developed skin chronic GvHD (limited, both moderate). Both cases were diagnosed following COVID-19 vaccination. Fifteen patients completed tacrolimus taper by day +90. Two patients received systemic steroids, one for treatment of cGvHD. The remaining patients required no further immunosuppressive therapy beyond day +90. CMV activation rate was 25%. One patient had EBV reactivation and required preemptive therapy with 2 weekly rituximab doses. There were no cases of adenovirus, HHV-6 virus or BK virus reactivation. Four patients developed renal insufficiency (3 in the setting of acute sepsis and 1 with thrombotic microangiopathy, which resolved after tapering off tacrolimus. One patient with adult T-cell leukemia/lymphoma relapsed and died. All other patients are alive and well. In summary, our preliminary results suggest that CAST with shortened course of tacrolimus is feasible and seems to offer very promising outcomes with low rates of acute GvHD. The study is accruing actively and the results of a larger cohort with longer follow-up will be presented at the meeting. If confirmed, by improving the outcomes of haploidentical SCT, this regimen may further address a health care disparity issue, offering almost every patient in need of allogeneic SCT an alternative donor op ion with equal outcomes. [Formula presented] Disclosures: Al-Homsi: Daichii Sanyko: Consultancy;Celyad: Other: Advisory Board. Abdul-Hay: Abbvie: Consultancy;Servier: Other: Advisory Board, Speakers Bureau;Jazz: Other: Advisory Board, Speakers Bureau;Takeda: Speakers Bureau;Amgen: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Abatacept - off label use as GvHD prevention Cyclophosphamide - off label use as GvHD prevention
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Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to unprecedented healthcare challenges on a global scale. Impressive efforts have led to rapid development of multiple efficacious vaccines against SARS-CoV-2, however concerns remain over the degree of protection vaccination offers to immunocompromised recipients. To answer this question, we have designed a prospective study to evaluate response to vaccination in patients with haematological malignancies (Harrington, Leukaemia 2021;Harrington, BJHaem, 2021). 103 patients were included with samples collected in 60 patients after first dose and 71 patients following second dose. We have analysed humoral and T cell response to a first dose of vaccine against SARS-CoV-2 in patients post allogeneic stem cell transplantation (HSCT) and compared those to patients with CML or MPN. Methods: ELISA plates were coated with antigen Nuclear (N) protein or the S protein. Serial dilutions of plasma were added to wells and incubated for 2 h at room temperature. Control reagents included N-specific monoclonal antibody, S-specific monoclonal antibody, negative control plasma, positive control plasma and blank wells. Secondary antibody was added and incubated for 1h at room temperature. IgG was detected using goat-anti-human-Fc-AP and plates read at 405 nm. Where an EC50 was not reached at 1:25, a plasma was considered seropositive if the OD at 405nm was 4-fold above background and a value of 25 was assigned. T cell functionality was assessed using intracellular cytokine staining after incubation with SARS-CoV-2 specific peptides covering immunogenic domains of the Spike (S) protein. A response was considered positive if there was a 3-fold increase in pro-inflammatory cytokine expression from baseline, and above a threshold of 0.01. Specific peptides (0.25 µg/ml), anti-CD28 and BFA were added to cells. Unstimulated cells were utilised as negative controls. Cells were stained with viability dye, then with antibodies directed against surface markers, and fixed and permeabilised prior to staining for intracellular cytokines TNFa and IFNg. Gating on lymphocytes, single cells, live cells, CD3+ cells, CD4+ cells and CD4- (CD8+) was performed. Results: Of the 103 patients included in this study, post vaccination evaluation on 56 patients have been analysed so far, including 37 patients with chronic myeloid malignancies (MPN n=21 and CML n=16) and 19 patients post HSCT. From the latter group, median time since transplant was 53.9 months (18.7 to 76.8) with 12 participants on extracorporeal photopheresis (ECP) therapy for graft versus host disease (GvHD) with median frequency of 24.5 days (14-42). BNT162b2 vaccine was administered to 48 patients (85.7%). An anti-S IgG response was observed after a first dose in 16/21 (76.1%) of the MPN group and 14/16 (87.5%) of CML patients, but in only 7/19 (36.8%) of post HSCT patients (Fishers Exact Test - p=0.02/0.002, Fig 1a). Of the latter group a low positive value where an EC50 was not reached was observed in 4/19 (21.1%) and a moderate response in 3/19 patients (15.8%). Of the 12 patients with active GvHD on ECP, a positive response was observed in 4 patients (33.3%), however only one patient recorded a response where an EC50 was measurable. A T cell response was observed in 16/20 (80%) of the MPN group and 14/15 (93.3%) of those with CML after a single dose, with a polyfunctional T cell response (>1 cytokine) observed in 65% and 80% respectively. In comparison only 5/19 patients (38.5%) post HSCT mounted a T cell response (p=0.027/p=0.002, Fig 1b), with a CD4+ response in 4 (30.8%) and a CD8+ response in 3 (23.1%). In this group, a polyfunctional T cell response was found in 4/19 patients (30.8%). 33.3% of patients with GVHD requiring ECP had a T cell response, compared with 42.9% in post HSCT without GVHD. Summary: Despite encouraging results of antibody and T cell response to a first vaccination dose in patients with chronic myeloid malignancies, these results raise concerns regarding the humoral and T cell respo ses to vaccination in patients post HSCT, recognised as a particularly immunosuppressed group. Further longitudinal data is required to determine if these results translate into a reduction in cases and severity of infection in these groups. We are currently analysing the response to a second vaccine injection and responses to sequential doses of vaccination across the whole cohort will be presented. [Formula presented] Disclosures: Harrington: Bristol Myers Squibb: Research Funding;Incyte: Honoraria. Radia: Blueprint Medicines Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Study steering group member, Research Funding;Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Education events;Cogent Biosciences Incorporated: Other: Study Steering Committee;EXPLORER and PATHFINDER studies: Other: Member of the Response Adjudication Committee. Kordasti: Beckman Coulter: Honoraria;Celgene: Research Funding;Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Alexion: Honoraria. Dillon: Menarini: Membership on an entity's Board of Directors or advisory committees;Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Session chair (paid to institution), Speakers Bureau;Astellas: Consultancy, Other: Educational Events, Speakers Bureau;Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research Support, Educational Events;Amgen: Other: Research support (paid to institution);Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: educational events;Jazz: Other: Education events;Shattuck Labs: Membership on an entity's Board of Directors or advisory committees. Harrison: Promedior: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;AOP Orphan Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Incyte Corporation: Speakers Bureau;Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Constellation Pharmaceuticals: Research Funding;Galacteo: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Geron: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Sierra Oncology: Honoraria;Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Keros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. de Lavallade: Bristol Myers Squibb: Research Funding;Incyte: Honoraria, Research Funding;Novartis: Speakers Bureau.