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Mesenchymal stem cells (MSCs) have been widely investigated as a treatment for graft versus host disease (GvHD), but with mixed results. Factors such as MSC donor variability and the effects of prolonged culture expansion may have contributed to disappointing outcomes. The novel Cymerus™ manufacturing process facilitates virtually limitless production of well-defined and consistent MSCs from a single iPSC bank, using proprietary clonogenic progenitor-based technology. This avoids both inter-donor variability and the need for excessive culture expansion once MSCs are formed. This is a multi-center, open label study of Cymerus MSCs (CYP-001) in adults with steroid-resistant acute GvHD, following allogeneic hematopoietic stem cell transplantation (NCT02923375). Prior to enrolment, all subjects had failed to respond to at least three days of steroid treatment (≥1 mg/kg/day), administered in accordance with standard management at each center. Subjects received two intravenous infusions of CYP-001 one week apart, at a dose of 1 × 106 cells/kg (Cohort A) or 2 × 106 cells/kg (Cohort B), in addition to standard of care medications. The study involves follow-up over two years, with primary evaluation at 100 days. GvHD was staged and graded according to the 1994 Consensus Conference on Acute GvHD Grading. An Overall Response (OR) was defined as at least a one-grade improvement in GvHD severity, while a Complete Response (CR) was defined as the absence of any GvHD signs or symptoms. The primary objective was assessment of safety and tolerability, while the secondary objective was efficacy, based on overall survival (OS) and best responses by Day 28/Day 100. Eight subjects were enrolled per cohort, but one subject in Cohort B withdrew prior to the initiation of CYP-001 treatment. All subjects had Grade II or III GvHD at baseline. The treatment was well tolerated in all cases, and there were no treatment-related Serious Adverse Events (SAEs) reported. One patient in Cohort A died after developing pneumonia, which was not considered to be CYP-001 treatment-related. One patient in Cohort B did not show a response to CYP-001 treatment, and withdrew from the trial on Day 22 to commence palliative care. All other patients showed an OR and remained alive at Day 100. Overall, outcomes by Day 100 were similar in both cohorts, but Day 28 data suggest a faster response to the higher dose level used in Cohort B (see Table 1 and Figure 1). In conclusion, CYP-001 infusions were found to be safe and well tolerated in this study, and we believe the encouraging treatment response and overall survival rates support progression to a Phase II trial. [ABSTRACT FROM AUTHOR]

Introduction Transfusion-dependent β-thalassemia (TDT) is a severe genetic disease characterized by anemia, iron overload and serious comorbidities for which gene therapy may be an effective treatment option. LentiGlobin gene therapy contains autologous CD34+ hematopoietic stem cells (HSCs) transduced ex vivo with the BB305 lentiviral vector (LVV) encoding β-globin with a T87Q substitution. Objective Evaluate the efficacy and safety of LentiGlobin in patients with TDT in the phase 1/2 Northstar (HGB-204; NCT01745120) and phase 3 Northstar-2 (HGB-207; NCT02906202) studies. Methods Patients with TDT (≥100 mL/kg/yr of red blood cells [RBCs] or ≥8 RBC transfusions/yr) received G-CSF and plerixafor for mobilization and HSCs were transduced with the BB305 LVV. Patients underwent single agent busulfan myeloablative conditioning, were infused with transduced cells, and were followed for engraftment, safety, and efficacy. Statistics are presented as median (min – max). Results As of March 7, 2018, 18 patients (12 – 35 yrs) were treated in Northstar (follow-up 32.1 [23.1 – 41.9] months) and as of May 15, 2018, 11 patients (12 – 24 yrs) were treated in Northstar-2 (follow-up 8.5 [0.3 – 16.2] months). Patients received a median cell dose of 8.0 (5.0 – 19.4) CD34+ cells × 106/kg in both studies. The median time to neutrophil and platelet engraftment in both studies was 19 (14 – 30) days and 44 (19 – 191) days, respectively; 1 patient in Northstar-2 (0.3 months follow-up) had not engrafted at time of analysis. Of 6 patients with platelet engraftment ≥ Day 60, 4 had non-serious bleeding events prior to engraftment. All 6 had intact spleens and 3/6 received G-CSF between Days 0 – 21. Both factors appeared associated with time to platelet engraftment. In Northstar, 8/10 patients with non-β0/β0 genotypes and 2/8 patients with β0/β0 genotypes achieved transfusion independence (TI; weighted average hemoglobin [Hb] ≥ 9 g/dL without RBC transfusions for ≥ 12 months). Median Hb during TI was 10.0 (9.3 – 13.1) g/dL. In Northstar-2, 7/8 patients with non-β0/β0 genotypes and ≥ 6 months follow-up stopped RBC transfusions with Hb of 11.1 – 13.3 g/dL at last visit; the first patient treated achieved TI. Non-hematologic grade ≥ 3 adverse events post-infusion in ≥ 5/29 (15%) patients were stomatitis, febrile neutropenia, and pharyngeal inflammation. Veno-occlusive liver disease attributed to busulfan occurred in 4/29 patients (Table 1). There was no transplant-related mortality, vector-mediated replication competent lentivirus, or clonal dominance. Conclusion In Northstar, 80% of patients with non-β0/β0 genotypes achieved TI and early Northstar-2 data suggest that patients can achieve near-normal Hb without transfusions. The safety profile of LentiGlobin is consistent with myeloablative busulfan conditioning. Longer time to platelet engraftment was observed in few patients, but no graft failure or deaths were reported. [ABSTRACT FROM AUTHOR]