A comprehensive report of long-term stability data for a range ATMPs: A need to develop guidelines for safe and harmonized stability studies.

BACKGROUND AIMS: Advanced therapy medicinal products (ATMPs) are novel drugs based on genes, cells or tissues developed to treat many different diseases. Stability studies of each new ATMP need to be performed to define its shelf life and guarantee efficacy and safety upon infusion, and these are presently based on guidelines originally drafted for standard pharmaceutical drugs, which have properties and are stored in conditions quite different from cell products. The aim of this report is to provide evidence-based information for stability studies on ATMPs that will facilitate the interlaboratory harmonization of practices in this area. METHODS: We have collected and analyzed the results of stability studies on 19 different cell-based experimental ATMPs, produced by five authorized cell factories forming the Lombardy "Plagencell network" for use in 36 approved phase I/II clinical trials; most were cryopreserved and stored in liquid nitrogen vapors for 1 to 13 years. RESULTS: The cell attributes collected in stability studies included cell viability, immunophenotype and potency assays, in particular immunosuppression, cytotoxicity, cytokine release and proliferation/differentiation capacity. Microbiological attributes including sterility, endotoxin levels and mycoplasma contamination were also analyzed. All drug products (DPs), cryopreserved in various excipients containing 10% DMSO and in different primary containers, were very stable long term at <-150°C and did not show any tendency for diminished viability or efficacy for up to 13.5 years. CONCLUSIONS: Our data indicate that new guidelines for stability studies, specific for ATMPs and based on risk analyses, should be drafted to harmonize practices, significantly reduce the costs of stability studies without diminishing safety. Some specific suggestions are presented in the discussion.

Phase II Study of Sequential Infusion of Donor Lymphocyte Infusion and Cytokine-Induced Killer Cells for Patients Relapsed after Allogeneic Hematopoietic Stem Cell Transplantation.

Seventy-four patients who relapsed after allogeneic stem cell transplantation were enrolled in a phase IIA study and treated with the sequential infusion of donor lymphocyte infusion (DLI) followed by cytokine-induced killer (CIK) cells. Seventy-three patients were available for the intention to treat analysis. At least 1 infusion of CIK cells was given to 59 patients, whereas 43 patients received the complete cell therapy planned (58%). Overall, 12 patients (16%) developed acute graft-versus-host disease (aGVHD) of grades I to II in 7 cases and grades III to IV in 5). In 8 of 12 cases, aGVHD developed during DLI treatment, leading to interruption of the cellular program in 3 patients, whereas in the remaining 5 cases aGVHD was controlled by steroids treatment, thus allowing the subsequent planned administration of CIK cells. Chronic GVHD (cGVHD) was observed in 11 patients (15%). A complete response was observed in 19 (26%), partial response in 3 (4%), stable disease in 8 (11%), early death in 2 (3%), and disease progression in 41 (56%). At 1 and 3 years, rates of progression-free survival were 31% and 29%, whereas rates of overall survival were 51% and 40%, respectively. By multivariate analysis, the type of relapse, the presence of cGVHD, and a short (<6 months) time from allogeneic hematopoietic stem cell transplantation to relapse were the significant predictors of survival. In conclusion, a low incidence of GVHD is observed after the sequential administration of DLI and CIK cells, and disease control can be achieved mostly after a cytogenetic or molecular relapse.

Neural stem cell transplantation in patients with progressive multiple sclerosis: an open-label, phase 1 study.

Innovative pro-regenerative treatment strategies for progressive multiple sclerosis (PMS), combining neuroprotection and immunomodulation, represent an unmet need. Neural precursor cells (NPCs) transplanted in animal models of multiple sclerosis have shown preclinical efficacy by promoting neuroprotection and remyelination by releasing molecules sustaining trophic support and neural plasticity. Here we present the results of STEMS, a prospective, therapeutic exploratory, non-randomized, open-label, single-dose-finding phase 1 clinical trial ( NCT03269071 , EudraCT 2016-002020-86), performed at San Raffaele Hospital in Milan, Italy, evaluating the feasibility, safety and tolerability of intrathecally transplanted human fetal NPCs (hfNPCs) in 12 patients with PMS (with evidence of disease progression, Expanded Disability Status Scale ≥6.5, age 18-55 years, disease duration 2-20 years, without any alternative approved therapy). The safety primary outcome was reached, with no severe adverse reactions related to hfNPCs at 2-year follow-up, clearly demonstrating that hfNPC therapy in PMS is feasible, safe and tolerable. Exploratory secondary analyses showed a lower rate of brain atrophy in patients receiving the highest dosage of hfNPCs and increased cerebrospinal fluid levels of anti-inflammatory and neuroprotective molecules. Although preliminary, these results support the rationale and value of future clinical studies with the highest dose of hfNPCs in a larger cohort of patients.

Sleeping Beauty-engineered CAR T cells achieve antileukemic activity without severe toxicities.

BACKGROUNDChimeric antigen receptor (CAR) T cell immunotherapy has resulted in complete remission (CR) and durable response in highly refractory patients. However, logistical complexity and high costs of manufacturing autologous viral products limit CAR T cell availability.METHODSWe report the early results of a phase I/II trial in B cell acute lymphoblastic leukemia (B-ALL) patients relapsed after allogeneic hematopoietic stem cell transplantation (HSCT) using donor-derived CD19 CAR T cells generated with the Sleeping Beauty (SB) transposon and differentiated into cytokine-induced killer (CIK) cells.RESULTSThe cellular product was produced successfully for all patients from the donor peripheral blood (PB) and consisted mostly of CD3+ lymphocytes with 43% CAR expression. Four pediatric and 9 adult patients were infused with a single dose of CAR T cells. Toxicities reported were 2 grade I and 1 grade II cytokine-release syndrome (CRS) cases at the highest dose in the absence of graft-versus-host disease (GVHD), neurotoxicity, or dose-limiting toxicities. Six out of 7 patients receiving the highest doses achieved CR and CR with incomplete blood count recovery (CRi) at day 28. Five out of 6 patients in CR were also minimal residual disease negative (MRD-). Robust expansion was achieved in the majority of the patients. CAR T cells were measurable by transgene copy PCR up to 10 months. Integration site analysis showed a positive safety profile and highly polyclonal repertoire in vitro and at early time points after infusion.CONCLUSIONSB-engineered CAR T cells expand and persist in pediatric and adult B-ALL patients relapsed after HSCT. Antileukemic activity was achieved without severe toxicities.TRIAL REGISTRATIONClinicalTrials.gov NCT03389035.FUNDINGThis study was supported by grants from the Fondazione AIRC per la Ricerca sul Cancro (AIRC); Cancer Research UK (CRUK); the Fundación Científica de la Asociación Española Contra el Cáncer (FC AECC); Ministero Della Salute; Fondazione Regionale per la Ricerca Biomedica (FRRB).

The washouts of discarded bone marrow collection bags and filters are a very abundant source of hMSCs.

BACKGROUND AIMS: Human multipotent mesenchymal stromal cells (hMSC) are considered good candidates for a growing spectrum of cell therapies. We have validated a protocol that makes use of the washouts of discarded collection sets, left over at the end of the filtration of bone marrow (BM) explants performed for hematopoietic stem cell (HSC) transplantation. METHODS: The method consists of direct plating of cells without density-gradient isolation followed by two detachment steps and expansion in 5% human platelet lysate (hPL). RESULTS: In a median of 26 days, 14 bags for adult patients and nine bags for pediatric patients for a standard dose of 1x10(6) hMSC/kg body weight could be prepared from the expansion of a fraction of the cells recovered from seven independent washouts. Moreover, 151 vials could be frozen from the remaining cells. The theoretical full expansion of all the frozen vials (validated by the expansion of two independent vials) could have allowed the production of 173 bags for adults and 348 bags for pediatric patients. CONCLUSIONS: The washouts of discarded bags and filters left over at the end of routine BM explants filtration are a very abundant source of hMSC precursors that can be easily utilized for clinical applications.

Full GMP-compliant validation of bone marrow-derived human CD133(+) cells as advanced therapy medicinal product for refractory ischemic cardiomyopathy.

According to the European Medicine Agency (EMA) regulatory frameworks, Advanced Therapy Medicinal Products (ATMP) represent a new category of drugs in which the active ingredient consists of cells, genes, or tissues. ATMP-CD133 has been widely investigated in controlled clinical trials for cardiovascular diseases, making CD133(+) cells one of the most well characterized cell-derived drugs in this field. To ensure high quality and safety standards for clinical use, the manufacturing process must be accomplished in certified facilities following standard operative procedures (SOPs). In the present work, we report the fully compliant GMP-grade production of ATMP-CD133 which aims to address the treatment of chronic refractory ischemic heart failure. Starting from bone marrow (BM), ATMP-CD133 manufacturing output yielded a median of 6.66 × 10(6) of CD133(+) cells (range 2.85 × 10(6)-30.84 × 10(6)), with a viability ranged between 96,03% and 99,97% (median 99,87%) and a median purity of CD133(+) cells of 90,60% (range 81,40%-96,20%). Based on these results we defined our final release criteria for ATMP-CD133: purity ≥ 70%, viability ≥ 80%, cellularity between 1 and 12 × 10(6) cells, sterile, and endotoxin-free. The abovementioned criteria are currently applied in our Phase I clinical trial (RECARDIO Trial).