Optimization of Mesenchymal Stromal Cell (MSC) Manufacturing Processes for a Better Therapeutic Outcome

MSCs products as well as their derived extracellular vesicles, are currently being explored as advanced biologics in cell-based therapies with high expectations for their clinical use in the next few years. In recent years, various strategies designed for improving the therapeutic potential of mesenchymal stromal cells (MSCs), including pre-conditioning for enhanced cytokine production, improved cell homing and strengthening of immunomodulatory properties, have been developed but the manufacture and handling of these cells for their use as advanced therapy medicinal products (ATMPs) remains insufficiently studied, and available data are mainly related to non-industrial processes. In the present article, we will review this topic, analyzing current information on the specific regulations, the selection of living donors as well as MSCs from different sources (bone marrow, adipose tissue, umbilical cord, etc.), in-process quality controls for ensuring cell efficiency and safety during all stages of the manual and automatic (bioreactors) manufacturing process, including cryopreservation, the use of cell banks, handling medicines, transport systems of ATMPs, among other related aspects, according to European and US legislation. Our aim is to provide a guide for a better, homogeneous manufacturing of therapeutic cellular products with special reference to MSCsThis manuscript has been supported by the Instituto de Salud Carlos III (ISCIII) through the project “RD16/0011: Red de Terapia Celular” (Groups: 0001, 0002, 0004, 0005, 0013, 0015, and 0029), fromthe sub-programme RETICS, integrated in the “Plan Estatal de I+D+I 2013-2016” and co-financed by the European Regional Development Fund (ERDF) “A way to make Europe”, and also by the ISCIII through the project RICORS “RD21/0017;TERAV” (Groups: 001, 002, 003, 006, 009 and 010) that is supported by the Next Generation EU program (Plan de Recuperación, Transformación y Resiliencia); and the Regional Government of Madrid (S2017/BMD-3962, Avancell-CM

Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: long-term follow up of a multicenter randomized controlled clinical trial (phase I/II)

Background: Mesenchymal stromal cells (MSCs) are a promising option to treat knee osteoarthritis (OA). Their safety and usefulness have been reported in several short-term clinical trials but less information is available on the longterm efects of MSC in patients with osteoarthritis. We have evaluated patients included in our previous randomized clinical trial (CMM-ART, NCT02123368) to determine their long-term clinical efect. Materials: A phase I/II multicenter randomized clinical trial with active control was conducted between 2012 and 2014. Thirty patients diagnosed with knee OA were randomly assigned to Control group, intraarticularly administered hyaluronic acid alone, or to two treatment groups, hyaluronic acid together with 10×106 or 100×106 cultured autol‑ ogous bone marrow-derived MSCs (BM-MSCs), and followed up for 12 months. After a follow up of 4 years adverse efects and clinical evolution, assessed using VAS and WOMAC scorings are reported. Results: No adverse efects were reported after BM-MSCs administration or during the follow-up. BM-MSCs-adminis‑ tered patients improved according to VAS, median value (IQR) for Control, Low-dose and High-dose groups changed from 5 (3, 7), 7 (5, 8) and 6 (4, 8) to 7 (6, 7), 2 (2, 5) and 3 (3, 4), respectively at the end of follow up (Low-dose vs Control group, p=0.01; High-dose vs Control group, p=0.004). Patients receiving BM-MSCs also improved clinically accord‑ ing to WOMAC. Control group showed an increase median value of 4 points (−11;10) while Low-dose and Highdose groups exhibited values of −18 (−28;−9) and −10 (−21;−3) points, respectively (Low-dose vs Control group p=0.043). No clinical diferences between the BM-MSCs receiving groups were found. Conclusions: Single intraarticular injection of in vitro expanded autologous BM-MSCs is a safe and feasible proce‑ dure that results in long-term clinical and functional improvement of knee OA

Autologous mesenchymal stromal cells embedded with Tissucol Duo® for prevention of air leak after anatomical lung resection: results of a prospective phase I/II clinical trial with long-term follow-up

Abstract Background Prolonged air leak (PAL) is the most frequent complication after pulmonary resection. Several measures have been described to prevent the occurrence of PAL in high-risk patients, however, the potential role of mesenchymal stem cells (MSCs) applied in the parenchymal suture line to prevent postoperative air leak in this setting has not been fully addressed. Objective To analyse the feasibility, safety and potential clinical efficacy of the implantation of autologous MSCs embedded in Tissucol Duo® as a prophylactic alternative to prevent postoperative prolonged air leak after pulmonary resection in high-risk patients. Study design Phase I/II single-arm prospective clinical trial. Methods Six patients with high risk of PAL undergoing elective pulmonary resection were included. Autologous bone marrow-derived MSCs were expanded at our Good Manufacturing Practice (GMP) Facility and implanted (embedded in a Tissucol Duo® carrier) in the parenchymal suture line during pulmonary resection surgery. Patients were monitored in the early postoperative period and evaluated for possible complications or adverse reactions. In addition, all patients were followed-up to 5 years for clinical outcomes. Results The median age of patients included was 66 years (range: 55–70 years), and male/female ratio was 5/1. Autologous MSCs were expanded in five cases, in one case MSCs expansion was insufficient. There were no adverse effects related to cell implantation. Regarding efficacy, median air leak duration was 0 days (range: 0–2 days). The incidence of PAL was nil. Radiologically, only one patient presented pneumothorax in the chest X-ray at discharge. No adverse effects related to the procedure were recorded during the follow-up. Conclusions The use of autologous MSCs for prevention of PAL in patients with high risk of PAL is feasible, safe and potentially effective. Trial registration No. EudraCT: 2013-000535-27. Clinicaltrials.gov idenfier: NCT02045745

Optimisation of mesenchymal stromal cells karyotyping analysis: Implications for clinical use

[Purpose]: The aim of this study was to optimise the yield of metaphases in mesenchymal stromal cells (MSC) in vitro cultures and to study the karyotype of MSC expanded in good manufacturing practice (GMP) conditions for clinical use. [Background]: MSC are being increasingly used in clinical trials for a number of diseases. Biosafety demonstration in all cases is mandatory. Unfortunately, current standard karyotyping methods fail to obtain enough number of evaluable metaphases. [Methods and materials]: In the present work, to optimise the yield of metaphases in MSC expanded in vitro, we have tested several conditions by modifying colcemid concentration (we have tested 0·01, 0·05 and 0·1 μg mL -1) and exposure time (during 5, 15 and 24 h). We further applied these optimised conditions to 61 MSC expansions in GMP conditions for clinical use. [Results]: Our results show that the highest number of metaphases was obtained when MSC were incubated with 0·05 μg mL -1 of colcemid overnight (15 h), compared to the remaining experimental conditions. In most cases (59/61 cases) enough number of metaphases was obtained. And what is more relevant, only in one case a karyotypic abnormality was found (trisomy of chromosome 10), and cells were subsequently discarded for clinical use. [Conclusion]: We describe here an optimal method to obtain enough number of metaphases for karyotype analysis of in vitro expanded MSCs, what is essential for their clinical use in cell therapy programmes. © 2012 The Authors. Transfusion Medicine © 2012 British Blood Transfusion Society.This project had been partially supported by a grant from Ministerio de Ciencia e Innovación (reference code PLE2009-0094).Peer Reviewe

Autologous mesenchymal stromal cells embedded in tricalcium phosphate for posterolateral spinal fusion: results of a prospective phase I/II clinical trial with long-term follow-up

Abstract Background Posterolateral spinal fusion with autologous bone graft is considered the “gold standard” for lumbar degenerative disc disease (DDD) when surgical treatment is indicated. The potential role of mesenchymal stromal cells (MSCs) to replace the bone graft in this setting has not been fully addressed. Objective To analyze the safety, feasibility and potential clinical efficacy of the implantation of autologous MSCs embedded with tricalcium phosphate as a therapeutic alternative to bone graft in patients with DDD during posterolateral spine fusion. Study design Phase I/II single-arm prospective clinical trial. Methods Eleven patients with monosegmental DDD at L4–L5 or L5–S1 level were included. Autologous bone marrow-derived MSC were expanded in our Good Manufacturing Practice (GMP) Facility and implanted during spinal surgery embedded in a tricalcium phosphate carrier. Monitoring of patients included a postoperative period of 12 months with four visits (after the 1st, 3rd, 6th, and 12th month), with clinical and radiological assessment that included the visual analog scale (VAS), the Oswestry disability index (ODI), the Short-Form Health Survey (SF-36), the vertebral fusion grade observed through a simple Rx, and the evaluation of possible complications or adverse reactions. In addition, all patients were further followed up to 5 years for outcome. Results Median age of patients included was 44 years (range 30–58 years), and male/female ratio was (6/5) L4–L5 and L5–S1 DDD was present five and six patients, respectively. Autologous MSCs were expanded in all cases. There were no adverse effects related to cell implantation. Regarding efficacy, both VAS and ODI scores improved after surgery. Radiologically, 80% of patients achieved lumbar fusion at the end of the follow-up. No adverse effects related to the procedure were recorded. Conclusions The use of autologous MSCs for spine fusion in patients with monosegmental degenerative disc disease is feasible, safe, and potentially effective. Trial registration no. EudraCT: 2010–018335-17; code Identifier: NCT01513694 (clinicaltrials.gov)

Both expanded and uncultured mesenchymal stem cells from MDS patients are genomically abnormal, showing a specific genetic profile for the 5q− syndromeMesenchymal stem cells of 5q− syndrome

The presence of cytogenetic aberrations on mesenchymal stem cells (MSC) from myelodysplastic syndrome (MDS) patients is controversial. The aim of the study is to characterize bone marrow (BM) derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridization (FISH) and genetic changes by array-based comparative genomic hybridization (array-CGH). In all 36 cases of untreated MDS were studied. MDS-MSC achieved confluence at a significantly slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic. These results were confirmed by FISH. To confirm that genomic changes were also present in freshly obtained MSCs they were enriched by sorting BM cells with the following phenotype: CD45-/CD73++/CD34-/ CD271++. They also showed genomic changes that were confirmed by FISH. To analyze the relationship of these aberrations with clinical-biological data an unsupervized hierarchical cluster analysis was performed, two clusters were identified: the first one included the 5q- syndrome patients, whereas the other incorporated other MDS. Our results show, for the first time that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to a particular MDS subtype, the 5q- syndrome.Peer Reviewe

Allogeneic mesenchymal stem cell therapy for refractory cytopenias after hematopoietic stem cell transplantation

[Background]: Posttransplant cytopenias are a severe complication after allogeneic stem cell transplantation (allo-SCT) and their origin is often multifactorial or unknown. They are frequently refractory to standard therapy, which may include steroids and/or immunoglobulins. Mesenchymal stem cells (MSCs) are an attractive therapeutic tool in the allo-SCT setting for the ability to enhance engraftment as well as acting as immunosuppressants for graft-versus-host disease. There is no prior experience in the literature of the use of MSCs to treat cytopenias after allo-SCT. [Case Reports]: In this work we report for the first time four cases of refractory posttransplant cytopenias (three patients with thrombocytopenia and one with neutropenia) that were treated with MSCs from a third-party donor. MSCs were expanded from 100 mL of marrow obtained under standard good manufacturing practice conditions. Most patients received more than one cell dose, and median dose of MSCs administered was 1 × 10 6/kg. [Results]: All patients recovered normal blood counts, with a mean follow-up of 12.5 months. There were no adverse events related to MSC administration. [Conclusion]: MSC therapy may contribute to the recovery of refractory posttransplant peripheral cytopenias in patients undergoing allo-SCT.Peer Reviewe

Endobronchial autologous bone marrow-mesenchymal stromal cells in idiopathic pulmonary fibrosis: a phase I trial

Rationale: Idiopathic pulmonary fibrosis (IPF) has a dismal prognosis. Mesenchymal stromal cells (MSCs) have shown benefit in other inflammatory diseases. Objectives: To evaluate the safety and feasibility of endobronchial administration of bone marrow autologous MSCs (BM-MSC) in patients with mild-to-moderate IPF. Methods: A phase I multicentre clinical trial (ClinicalTrials.gov NCT01919827) with a single endobronchial administration of autologous adult BM-MSCs in patients diagnosed with mild-to-moderate IPF. In a first escalating-dose phase, three patients were included sequentially in three dose cohorts (10x10(6), 50x10(6) and 100x10(6) cells). In a second phase, nine patients received the highest tolerated dose. Follow-up with pulmonary function testing, 6-min walk test and St George's Respiratory Questionnaire was done at 1, 2, 3, 6 and 12 months, and with computed tomography at 3, 6 and 12 months. Results: 21 bone marrow samples were obtained from 17 patients. Three patients were excluded from treatment due to chromosome aberrations detected in MSCs after culture, and one patient died before treatment. Finally, 13 patients received the BM-MSC infusion. No treatment-related severe adverse events were observed during follow-up. Compared to baseline, the mean forced vital capacity showed an initial decline of 8.1% at 3 months. The number of patients without functional progression was six (46%) at 3 months and three (23%) at 12 months. Conclusions:.

IGF-1 gene therapy to protect articular cartilage in a rat model of joint damage

Rationale: Idiopathic pulmonary fibrosis (IPF) has a dismal prognosis. Mesenchymal stromal cells (MSCs) have shown benefit in other inflammatory diseases. Objectives: To evaluate the safety and feasibility of endobronchial administration of bone marrow autologous MSCs (BM-MSC) in patients with mild-to-moderate IPF. Methods: A phase I multicentre clinical trial (ClinicalTrials.gov NCT01919827) with a single endobronchial administration of autologous adult BM-MSCs in patients diagnosed with mild-to-moderate IPF. In a first escalating-dose phase, three patients were included sequentially in three dose cohorts (10×106, 50×106 and 100×106 cells). In a second phase, nine patients received the highest tolerated dose. Follow-up with pulmonary function testing, 6-min walk test and St George’s Respiratory Questionnaire was done at 1, 2, 3, 6 and 12 months, and with computed tomography at 3, 6 and 12 months. Results: 21 bone marrow samples were obtained from 17 patients. Three patients were excluded from treatment due to chromosome aberrations detected in MSCs after culture, and one patient died before treatment. Finally, 13 patients received the BM-MSC infusion. No treatment-related severe adverse events were observed during follow-up. Compared to baseline, the mean forced vital capacity showed an initial decline of 8.1% at 3 months. The number of patients without functional progression was six (46%) at 3 months and three (23%) at 12 months. Conclusions: The endobronchial infusion of BM-MSCs did not cause immediate serious adverse events in IPF patients, but a relevant proportion of patients suffered clinical and/or functional progression. Genomic instability of BM-MSCs during culture found in three patients may be troublesome for the use of autologous MSCs in IPF patients