We report the case of long-term persisting rheumatoid arthritis (RA), treated with CD20-CD19 CAR-T when it became associated with diffuse large B cell lymphoma (DLBCL), resulting in a sustained drug-free remission of the preceding RA, as well as of the subsequent DLBCL that formed the indication of the CAR-T therapy using zamtocabtagene autoleucel, with a 1-year follow-up. According to our best knowledge, this is the first published clinical case report of long-term persisting RA treated with CAR-T cell therapy.

without any therapy initiated while those with progressive disease will be treated per MD discretion.All pts will be followed for survival outcomes.Primary endpoint: Compare the 1-year PFS of each consolidation arm vs observation (M vs O, P vs O, M+P vs O).An estimated 120 pts (30 in each arm) are needed to detect a hazard ratio of 2 from estimated 25% 1 year PFS of the observation arm to 50% 1 year PFS of the each consolidation arm.It is estimated that 396 pts will need to be enrolled in step 1 registration to randomize 120 pts with SD/PR at one month PET-CT in the step 2 randomization.Cross-over design: Pts with SD/PR randomized to the observation arm are eligible to receive M+P if they have definitive progression within 1 year of CD19 CTCT infusion.Correlatives/PRO: Correlative and PRO assessments will occur at scheduled imaging timepoints for all pts registered to step 1. Minimal residual disease will be a focus and be followed in all pts regardless of one month PET-CT response post CD19 CTCT.

Background: Chimeric antigen receptor (CAR) T-cells can induce durable remissions in patients with relapsed or refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL). Recent data suggest that the T-cell repertoire and the phenotype of the CAR T-cell product influence expansion and contribute to the probability of response. Samples from 12 patients (pts) treated with non-cryopreserved MB-CART2019.1 (Zamtocabtagene autoleucel) in a Phase I trial (NCT03870945) were analyzed. MB-CART2019.1 is a tandem-CAR T-cell product targeting both CD20 and CD19 antigens and contains a 4-1BB co-stimulatory domain. Methods: MB-CART2019.1 products were manufactured on the CliniMACS Prodigy® system using a 13-days process with IL-7 and IL-15. Pts with complete response (CR) were defined by negative PET-CT by month 6. Cellular composition, viability, CD4:CD8 ratio, CAR transduction frequency, and expansion were monitored on process days 0, 5 and 12. In vivo CAR T-cell levels (Cmax, AUC0-28) and T-cell immunophenotype of leukapheresis (LP) and drug products (DP) were analyzed by comprehensive flow cytometry using common markers for differentiation (CD45RA, CD45RO, CD62L), activation (CD154, CD25, CD137), exhaustion (Lag-3, PD-1, Tim-3) and proliferative ability (CD27, CD127). Results were re-evaluated by descriptive statistics due to low pts number and correlated with expansion kinetics and/or clinical response by using the Wilcoxon test. Mean ± StDev values or ranges are shown. Results: Five out of 12 pts achieved CR, with ongoing remission >2 years as per investigator assessment. Significantly higher mean Cmax and AUC0-28 were detected in CR vs non-CR pts (mean Cmax: CR 1092.5 cells/µL [460.1-3147.0] vs non-CR 111.0 cells/µL [3.9-458.0]; p=0.0058) (mean AUC0-28: CR 7901 d*cells/µL [2399.2; 19574.7] vs non-CR 942.0 d*cells/µL [39.3; 3471.6]; p=0.0159), equally detectable in CD4+ and CD8+ fractions (Figure 1). LPs showed similar CD3+ cell percentages of 39.9% ± 10.9% and CD4:CD8 ratios of 1.5 ± 0.9. CR pts had higher amounts of B-cells in the LP than non-CR pts (6.0 ± 3.9 vs 0.7 ± 1.3). DPs showed a consistent T-cell expansion of 10.5 ± 3.5-fold in CD3+ cells, 9.5 ± 3.2-fold in CAR+CD4+ cells and 12.0 ± 4.5-fold in CAR+CD8+ cells, with no difference between CR and non-CR pts. Independent of the starting material, all DPs had a high CD3+ cell purity (99.3% ± 0.7%) and viability (94.0% ± 3.1%) with a higher proportion of CD4+ cells (CD4:CD8 ratio: 2.65 ± 1.9). Mean transduction frequency was 18.0% (21.0% ± 4.8% in CR vs 15.9% ± 6.7% in non-CR; p=0.19) with mean CD4:CD8 ratio of 4.5 in CAR+ cells (6.0 ± 4.5 in CR vs 3.5 ± 2.1 in non-CR; p=0.19). LP showed different distributions of naïve (TN), central memory, (TCM), effector memory (TEM) and effector T-cells (TEFF) among CD4+ and CD8+ fractions, whereas TCM was the predominant CAR T-cell population among CD4+ (81.3% ± 20.7%) and CD8+ cells (84.6% ± 13.7%) (Figure 2). CR pts showed a slightly higher proportion of less differentiated CD4+ TN and TCM (TN + TCM: 63.9% ± 6.5% in CR vs 53.8% ± 27.5% in non-CR) in the LP and CAR+CD4+ TCM (89.8% ± 7.8% vs 75.2% ± 25.3%) and CAR+CD8+ TCM (91.3% ± 4.7% vs 79.8% ± 16.3%) in the DP. Immunophenotype of the DP showed generally a low expression of exhaustion markers Lag-3 and PD-1 in CD4+ and CD8+ CAR T-cell fractions. In vivo proliferative ability of CAR+ T-cells as assessed by CD27 and CD127 expression showed a trend for increased expression in CR pts (CAR+CD4+CD127+ in CR vs non-CR [p=0.035] and CAR+CD8+CD27+ [p=0.051]). CAR+ T cell repertoire at Cmax displayed high TCM proportions, more pronounced in CR pts at Cmax, (mean TCM content: 40.58% ± 22.37% in CR vs 26.76% ± 12.48% in non-CR) and maintained at D28 (42.48% ± 24.06% vs 27.97% ± 17.89%) in CD4+ and CD8+ subpopulations. Conclusion: All 12 MB-CART2019.1 DPs exhibited a consistent and reproducible expansion profile, high CD4:CD8 ratio, high TCM proportion and low expression of exhaustion markers. Increased proliferative ability in the DP, higher Cmax, as well as maintaining higher levels of TCM during invivo expansion were characteristically elevated parameters of pts with CR. Other product characteristics, e.g. CD4:CD8 ratio or number of infused T-cells, were not significantly associated with in vivo performance. The high proportion of TCM is a prominent characteristic of MB-CART2019.1 DP which may be important for improved persistence and durable clinical response. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract Introduction This phase I first-in-human clinical study assesses the safety and preliminary efficacy of a CD19-directed, CAR (4-1BBz) gene-modified, autologous T-cell immunotherapy (MB-CART19.1) intended for use in pediatric and adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL) and Non-Hodgkin lymphoma (NHL). The study also evaluates the feasibility of a hybrid manufacturing model, combining central and academic manufacturing capabilities with central QP oversight. Methods MB-CART19.1 is evaluated in a Phase I (EudraCT 2017-002848-32) multi-center, open label, dose escalation trial enrolling 33 to 48 patients in three disease cohorts, defined by disease biology and age. Pediatric (1-17 years) and adult patients are eligible if diagnosed with relapsed/refractory (r/r) CD19-expressing B-cell ALL or B-cell high-grade and low-grade (adults) NHL, including chronic lymphocytic leukemia (CLL). Enrollment is still ongoing. The starting material, a fresh patient leukapheresis product, is enriched for CD4/CD8 T-cells, transduced with a lentiviral vector (LV) and expanded using the CliniMACS Prodigy System allowing a high degree of control and consistency of the manufacturing process in both a central and decentralized facilities. MB-CART19.1 is presented as fresh cellular dispersion for single infusion and undergoes central release. Subjects undergo lymphodepletion with fludarabine (25 mg/m 2 daily for 3 days) and cyclophosphamide (1000 mg/m 2 on day -3). Dose escalation includes 3 dose levels (DL) 5x10 5 (DL I), 1x10 6 (DL II), 3x10 6 (DL III) CAR T cells/kg BW, respectively, and a safety dose level 0. The primary objective is to determine the recommended dose of MB-CART19.1. Secondary objectives are preliminary efficacy parameters evaluation of as well as CART persistence. Results Disease cohort I: pediatric ALL and aggressive NHL, 1-17 years. Up to the data lock point for interim analysis (DLP, 02 June 2021), 9 pediatric ALL patients were treated, 6 at DL I and 3 at DL II. All 9 patients completed the 28 days safety follow-up. At DL I, 5 of 6 patients experienced CRS (4 grade I-II, 1 grade III,) starting 5 to 7 days after IMP infusion. Two CRS cases were managed with tocilizumab and resolved within 1-2 weeks. 1 patient developed signs of neurotoxicity (grade IV seizure) concurrently with grade II CRS, which was effectively managed and fully resolved within 48 hours. The event was evaluated as DLT and led to the extension of the dose group from 3 to 6 patients. No further neurotoxicities occurred. Four of 6 patients treated at DL I finished the active part of the trial (12 months after administration of IMP) in CR-MRD and entered the long term follow-up. Two patients had CD19-negative relapses 4 and 10 months post MB-CART19.1 infusion. At DL II, 1 patient completed the 6 months follow up in ongoing CR, and 2 patients relapsed. Disease cohort II adult ALL: Up to the DLP, 4 adult ALL patients were treated at DL I. 1 patient died due to progression of disease on day 20 after the IMP infusion. All 4 adult patients experienced a grade I or II CRS all cases were reversible within 1-2 weeks , 1 patient received tocilizumab One patient developed neurologic symptoms (grade III visual impairment and grade III muscle weakness right-sided) with onset 41 and 72 days after administration of MB-CART19.1, respectively. 2 of the 3 patients who completed the safety follow-up finished the active part of the trial and entered the long-term follow-up, both in molecular CR up to Month 6. Disease cohort III adult NHL/CLL: 4 patients were enrolled with the starting dose of 1x10 6 CAR+ cells/kg (DL II). 1 patient experienced grade III CRS and was treated with tocilizumab. 3 patients completed the 28 days safety follow up. One patient with CLL achieved a CR, which is maintained at 6 months. Another CLL patient was in PR at the assessment visit Day 28. Data from the 2 other patients, 1 with MCL and 1 with DLBCL were in PR at month 3. Later data is not yet available. Conclusions 18 of 19 patients completed the follow-up safety period of 28 days defined as observation period for dose limiting toxicity (DLT). One DLT was observed as well as 3 grade III CRS events and 1 grade III neurological event. Early efficacy results are very encouraging. Longer follow-up will establish whether treatment results in durable responses. The hybrid manufacturing model provides flexibility and a timely delivery of the fresh drug product to the patients Disclosures Hanssens: Miltenyi Biomedicine GmbH: Current Employment. Stelljes: MSD: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Medac: Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau. Bethge: Novartis: Consultancy, Honoraria, Speakers Bureau; Kite-Gilead: Consultancy, Honoraria, Speakers Bureau; Miltenyi Biotec: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Yakushina: Miltenyi Biomedicine GmbH: Current Employment. Holtkamp: Miltenyi Biomedicine GmbH: Current Employment. Assenmacher: Miltenyi Biotec: Current Employment. Jurk: Miltenyi Biotec: Current Employment. Rauser: Miltenyi Biomedicine GmbH: Current Employment. Schneider: Employee of Lentigen Technology, a Miltenyi Biotec Company: Current Employment. Rossig: AdBoards by Amgen: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; BMS and Celgene: Honoraria.

Hematopoietic stem cell transplantation (HSCT) from haploidentical donors is a viable option for patients lacking HLA-matched donors. Here we report the results of a prospective multicenter phase I/II trial of transplantation of TCRαβ and CD19-depleted peripheral blood stem cells from haploidentical family donors after a reduced-intensity conditioning with fludarabine, thiotepa, and melphalan. Thirty pediatric and 30 adult patients with acute leukemia ( n = 43), myelodysplastic or myeloproliferative syndrome ( n = 6), multiple myeloma ( n = 1), solid tumors ( n = 6), and non-malignant disorders ( n = 4) were enrolled. TCR αβ/CD19-depleted grafts prepared decentrally at six manufacturing sites contained a median of 12.1 × 10 6 CD34 + cells/kg and 14.2 × 10 3 TCRαβ + T-cells/kg. None of the patients developed grade lll/IV acute graft-versus-host disease (GVHD) and only six patients (10%) had grade II acute GVHD. With a median follow-up of 733 days 36/60 patients are alive. The cumulative incidence of non-relapse mortality at day 100, 1 and 2 years after HSCT was 5%, 15%, and 17% for all patients, respectively. Estimated probabilities of overall and disease-free survival at 2 years were 63% and 50%, respectively. Based on these promising results in a high-risk patient cohort, haploidentical HSCT using TCRαβ/CD19-depleted grafts represents a viable treatment option.

Background CD19 redirected chimeric antigen receptor (CAR) T-cell therapy has proven efficacy in relapsed or chemotherapy-refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL). However, targeting a single B-cell antigen leads to selective pressure with potential antigen-escape and subsequent relapse. A tandem CAR targeting CD20 and CD19 (pLTG1497) has been developed to overcome this limitation. Preclinical evaluation showed improved anti-lymphoma activity. Thus, we initiated a first-in-human, phase I clinical study of autologous pLTG1497-transduced CAR T-cells (MB-CART2019.1) in r/r B-NHL patients. Aims In this phase I prospective multi-center trial (NCT03870945) we aimed to evaluate the maximum tolerated dose (MTD) of MB-CART2019.1 in adult patients with CD20 and CD19 positive r/r B-NHL as determined by dose limiting toxicities (DLTs). Methods This was a 6+3 trial design with two predefined dose levels (DL1 1x106 and DL2 2.5x106 CAR T-cells/kg body weight, respectively). Secondary endpoints included adverse events (AEs) and best overall response rate (ORR). Pharmacodynamic assessments included maximum concentration (Cmax) of CAR T-cells, time to peak expansion (tmax), AUC (d0 to d28), and persistence. MB-CART2019.1 was produced by lentiviral transduction of autologous fresh leukapheresis in the closed automated CliniMACS Prodigy® System (Miltenyi Biotec, Bergisch Gladbach, Germany). Re-infusion (Day 0) of fresh MB-CART2019.1 was scheduled 14 days after leukapheresis. Fludarabine/cyclophosphamide lymphodepleting chemotherapy was administered from day -5 to -3. Results A total of 12 patients, 6 per dose level have been enrolled and treated between February and December 2019, 5 female and 7 male patients. Median age was 72 y (range 20, 78 y), with 10 patients >65 y and 8 >70 y. Histologies included aggressive B-NHL (11) and mantle cell lymphoma (1). Five (5) patients had refractory disease at study entry and IPI was ≥3 in 7 patients. Median time from leukapheresis to re-infusion was 14 d (range 13, 14 d). No DLT and no cytokine release syndrome (CRS) or neurotoxicity grade ≥3 were observed. One patient in dose level 1 experienced a grade 5 AE, which was due to disease progression. CRS grade 1 occurred in 3/6 patients on DL1 and DL2 each, and CRS grade 2 in 2 patients on DL2. Tocilizumab was given in 1 patient. Neurotoxicity grade 1 occurred in 1 patient on DL2. The above described CRS and neurotoxicity resolved completely. Mean Cmax of MB-CART2019.1 was 348.3 cells/µl (range 3.9, 830.4 cells/µl) on DL1 and 692 cells/µl (range 5.3, 3147.8 cells/µl) on DL2. Mean tmax was 15.8 d (range 9, 21 d) on DL1 and 11.5 d (range 9, 14 d) on DL2. Mean AUC was 3155 d*cells/µl (DL1) and 4339 d*cells/µl (DL2). Persistence of MB-CART2019.1 was observed in 12/12 patients until data cut-off. Altogether 9/12 patients (ORR 75%) responded to MB-CART2019.1 with 5/12 CRs. In DL1 3/6 patients responded (ORR 50%) and in DL2 6/6 patients (ORR 100%). The 3 patients without response to MB-CART2019.1 had a mean AUC0-28 of 870 d*cells/µl, whereas mean AUC0-28 in 9 responders was 4843 d*cells/µl reflecting the correlation between the pharmacodynamic parameters and the clinical response. Responses are ongoing in 5/9 patients, with a maximum duration of response of 330 days at data cut-off. Summary/Conclusions In this first-in-human dose finding study of MB-CART2019.1 no DLT and no severe (grade ≥3) CRS or neurotoxicity were observed. Feasibility and safety were very good in this cohort of elderly r/r B-NHL patients. The sustained expansion of tandem CAR T-cells was accompanied by efficacy: all patients (6/6) treated on DL2 responded and all 5 patients with CR (5/5) are in ongoing remission by the time of this report. Based on the promising risk-to-benefit ratio observed in our study, evaluation of MB-CART2019.1 at a dose of 2.5x106/kg body weight in clinical phase II and phase III trials for patients with relapsed aggressive B-NHL is underway. Disclosures Borchmann: Miltenyi Biotec B.V. & Co. KG: Honoraria. Balke-Want:Miltenyi Biotec B.V. & Co. KG: Honoraria. Ayuk:Celgene: Consultancy, Honoraria; Kite/Gilead: Honoraria; Therakos/Mallinckrodt: Honoraria, Research Funding; Neovii: Research Funding; Novartis: Honoraria. Holtkamp:Miltenyi Biomedicine GmbH: Current Employment. Preussner:Miltenyi Biomedicine GmbH: Ended employment in the past 24 months. Zadoyan:Miltenyi Biomedicine GmbH: Current Employment. Hanssens:Miltenyi Biomedicine GmbH: Current Employment. Kaiser:Miltenyi Biotec B.V. & Co. KG: Current Employment. Jurk:Miltenyi Biotec B.V. & Co. KG: Current Employment. Bürger:Miltenyi Biotec B.V. & Co. KG: Current Employment. Schneider:Lentigen Technology Inc., A Miltenyi Company: Current Employment, Patents & Royalties. Dropulic:Lentigen Technology Inc., A Miltenyi Company: Current Employment. Overstijns:Miltenyi Biomedicine GmbH: Current Employment, Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotec B.V. & Co. KG: Current Employment, Membership on an entity's Board of Directors or advisory committees. Scheid:Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; BMS: Honoraria; Amgen: Honoraria; Takeda: Honoraria, Research Funding. Holtick:Miltenyi Biotec B.V. & Co. KG: Honoraria. Miltenyi:Miltenyi Biomedicine GmbH: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Lentigen Technology Inc., A Miltenyi Company: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Miltenyi Biotec B.V. & Co. KG: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

Abstract Abstract: Here we report for the first time on long term follow-up data of a cohort of 60 patients who received TCRαβ and CD19 depleted peripheral blood stem cell grafts from haploidentical family donors within a prospective, multi-center, single-arm, phase I/II clinical study (EudraCT No.: 2011-005562-38). As planned, 30 pediatric and 30 adult patients were enrolled in this trial: All patients received a reduced-intensity conditioning regimen consisting of fludarabine (160 mg/m2), thiotepa (10 mg/kg), melphalan (140 mg/m2) and either antithymocyte globulin (Grafalon, 15 or 30 mg/kg, N=53) or 7 Gy total nodal irradiation (N=7). MMF (40 mg/kg/day) was administered as single-agent GVHD prophylaxis until Day 30. Results: Sixty patients with a median age of 18.5 years (range 1-63) were treated. Twenty-five patients had AML, 17 ALL, 6 MDS/MPS and 1 each had multiple myeloma and acute undifferentiated leukemia. Six patients had solid tumors (soft tissue sarcomas and neuroblastomas) and 4 non-malignant disorders (SCID, Wiskott-Aldrich syndrome, lysosomal storage disorder and sickle cell anemia). Of the 56 patients with malignant disease, 33 were transplanted in complete (CR), 11 in partial (PR) and 12 in non-remission (NR). Twenty of the 56 patients with malignant diseases received a 2nd or 3rd transplantation within this protocol. In total, 88 depletion procedures were performed with the CliniMACS plus System (Miltenyi Biotec, Germany) at 7 GMP laboratories and resulted in a median T and B cell log depletion of 4.7 (range 3.6-5.3) and 3.4 (range: 2.3-4.5), respectively. The median number of infused CD34+ cells and TCRαβ T cells was 12.4 × 106 /kg BW (range 4.0 - 54.9) and 1.4× 104 /kg BW (range 0.06-6.4), respectively. Engraftment was rapid with a median of 13 (range 9-41) and 15 (11-38) days to reach ANC >500 cell/µl and PLT > 20,000 cells/µl. Nine patients rejected the graft. Eight of them were successfully re-transplanted and 1 patient died. One patient received stem cell boosts from the original donor due to poor graft function. On day 100, peripheral T cell chimerism was completely donor-type in 44 of 47 evaluable patients, and mixed in 3. None of the patients developed grade III/IV aGVHD and only 6 patients (10%) had grade II aGVHD. Of 47 evaluable patients 4 had severe cGVHD (9%), and 6 (13%) and 5 (11%) had moderate and mild cGVHD, respectively. CMV reactivation was seen in 25 (42%) mainly adult patients, and only 1 (2%) patient developed disease. Twenty-one (35%) patients had ADV reactivation and 7 children and 1 adult (13%) developed disease. Only 1 case of EBV disease (encephalitis) occurred (2%). A median of 221 (range 8-1230) CD3+ cells/µl was reached on day 100. The median numbers of CD3/CD4+ and CD3/CD8+ cells at 1 year post transplant were 316 (range 1-1173) and 308 (range 0-2203) /µl. As of July 15 2018, 57 patients have completed the 2 year follow-up, died or discontinued the study resulting in a median follow-up of 706 days (range 18-800). 37 patients (62%) are alive and 23 (38%) died. Relapse was the major cause of death (N=12) followed by ADV infection (N=3), ARDS (N=3) and 1 case each of cardiac arrest, multi organ failure, sepsis due to graft failure and demyelinating neuropathy. Cause of death was not reported in 1 patient. Eight of the 20 patients who received the 2nd or 3rd transplantation are alive; 1 discontinued the study prematurely. Of the 23 patients transplanted in PR or NR, 13 are alive. The Kaplan-Meier estimated probabilities of overall survival, disease-free survival (DFS) were 62% and 53%, respectively. Cumulative incidences of relapse and NRM at 2 years were 34% and 20%, respectively. For those patients with leukemia receiving a first SCT in CR, the overall survival, DFS and relapse rate were 75%, 64% and 20%, respectively. Conclusion: The transplantation of TCRαβ and CD19 depleted haploidentical hematopoietic stem cell grafts was safe and feasible. Decentralized production using the CliniMACS System was feasible and reliably resulted in grafts containing sufficient numbers of stem cells with only minimal numbers of co-infused TCRαβ T cells. None of the patients developed grade III-IV aGVHD and incidence of cGVHD was acceptable. Given the heterogeneous patient cohort with respect to age, disease, remission status and number of previous transplants, the outcome of patients after 2 years follow-up is promising. Disclosures Lang: Miltenyi Biotec: Patents & Royalties, Research Funding. Handgretinger:Miltenyi Biotec: Patents & Royalties: Co-patent holder of TcR alpha/beta depletion technologies, Research Funding. Meisel:Amgen: Consultancy. Mielke:KIADIS Pharma: Speakers Bureau; Miltenyi Biotec: Speakers Bureau; DGHO: Speakers Bureau; EHA: Speakers Bureau; Celgene: Speakers Bureau. Niederwieser:Novartis: Research Funding; Miltenyi: Speakers Bureau. Bader:Neovii: Research Funding; Medac: Patents & Royalties, Research Funding; Riemser: Research Funding; Cellgene: Consultancy; Novartis: Consultancy, Speakers Bureau. Kuball:Gadeta (www.gadeta.nl): Consultancy, Equity Ownership, Patents & Royalties: on gd T cells and receptors and isolation strategies, Research Funding; Miltenyi Biotec: Research Funding; Novartis: Research Funding. Bonig:Miltenyi Biotec GmbH: Honoraria, Research Funding. Karitzky:Miltenyi Biotec GmbH: Employment. Holtkamp:Miltenyi Biotec GmbH: Employment. Malchow:Miltenyi Biotec GmbH: Employment. Siewert:Miltenyi Biotec GmbH: Employment. Biedermann:Miltenyi Biotec GmbH: Employment. Bethge:Neovii GmbH: Honoraria, Research Funding; Miltenyi Biotec GmbH: Consultancy, Honoraria, Research Funding.

We report the first prospective, multi-center, open-label, single-arm phase I/II clinical trial that assesses the safety and feasibility of stem cell transplantation with TCRalpha/beta and CD19-depleted haploidentical grafts generated with the CliniMACS plus System (Miltenyi Biotec, Germany) in combination with a reduced-intensity conditioning in pediatric patients suffering from various malignant and non-malignant diseases (www.clinicaltrialsregister.org; 2011-005562-38). All patients received single agent MMF as short-term GVHD prophylaxis (40mg/kg/day for 30 days). The speed of immune reconstitution was measured in two core labs using standardized methods and the MACSQuant flow cytometry device (Miltenyi Biotec, Germany).

We report the first prospective, multi-center, single-arm phase I/II study that assesses the safety and feasibility of haploidentical transplantation with TCRalpha/beta and CD19+ cells depleted peripheral blood stem cell grafts using the CliniMACS plus System (Miltenyi Biotec, Germany) in combination with a reduced-intensity conditioning (RIC) (www.clinicaltrialsregister.org; 2011-005562-38). The grafts were processed in 7 GMP laboratories and immune cell assays were performed in two core labs using standardized methods and the MACSQuant flow cytometry device (Miltenyi Biotec, Germany). The RIC regimen consisted of 15 or 30 mg ATG (Fresenius/Grafalon) or 7 Gy total nodal irradiation, 160 mg/m2 fludarabine, 10 mg/kg thiotepa, and 140 mg/m2 melphalan. MMF (40mg/kg/day) was used for GVHD prophylaxis until Day 30. The Day 100 data of the 30 pediatric patients have been presented at ASH2016; this report presents the data of the 30 adult patients with at least 100 days follow-up alive.

Several single center experiences have shown favorable outcomes using in-vitro depletion of T cell receptor (TCR)-alpha/beta cells and B cells.