Safety and Preliminary Efficacy of Mesenchymal Stromal Cell (ORBCEL-M) Therapy in Diabetic Kidney Disease: A Randomized Clinical Trial (NEPHSTROM).

SIGNIFICANCE STATEMENT: Mesenchymal stromal cells (MSCs) may offer a novel therapy for diabetic kidney disease (DKD), although clinical translation of this approach has been limited. The authors present findings from the first, lowest dose cohort of 16 adults with type 2 diabetes and progressive DKD participating in a randomized, placebo-controlled, dose-escalation phase 1b/2a trial of next-generation bone marrow-derived, anti-CD362 antibody-selected allogeneic MSCs (ORBCEL-M). A single intravenous (iv) infusion of 80×10 6 cells was safe and well-tolerated, with one quickly resolved infusion reaction in the placebo group and no subsequent treatment-related serious adverse events (SAEs). Compared with placebo, the median annual rate of decline in eGFR was significantly lower with ORBCEL-M, although mGFR did not differ. The results support further investigation of ORBCEL-M in this patient population in an appropriately sized phase 2b study. BACKGROUND: Systemic therapy with mesenchymal stromal cells may target maladaptive processes involved in diabetic kidney disease progression. However, clinical translation of this approach has been limited. METHODS: The Novel Stromal Cell Therapy for Diabetic Kidney Disease (NEPHSTROM) study, a randomized, placebo-controlled phase 1b/2a trial, assesses safety, tolerability, and preliminary efficacy of next-generation bone marrow-derived, anti-CD362-selected, allogeneic mesenchymal stromal cells (ORBCEL-M) in adults with type 2 diabetes and progressive diabetic kidney disease. This first, lowest dose cohort of 16 participants at three European sites was randomized (3:1) to receive intravenous infusion of ORBCEL-M (80×10 6 cells, n =12) or placebo ( n =4) and was followed for 18 months. RESULTS: At baseline, all participants were negative for anti-HLA antibodies and the measured GFR (mGFR) and estimated GFR were comparable between groups. The intervention was safe and well-tolerated. One placebo-treated participant had a quickly resolved infusion reaction (bronchospasm), with no subsequent treatment-related serious adverse events. Two ORBCEL-M recipients died during follow-up of causes deemed unrelated to the trial intervention; one recipient developed low-level anti-HLA antibodies. The median annual rate of kidney function decline after ORBCEL-M therapy compared with placebo did not differ by mGFR, but was significantly lower by eGFR estimated by the Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations. Immunologic profiling provided evidence of preservation of circulating regulatory T cells, lower natural killer T cells, and stabilization of inflammatory monocyte subsets in those receiving the cell therapy compared with placebo. CONCLUSIONS: Findings indicate safety and tolerability of intravenous ORBCEL-M cell therapy in the trial's lowest dose cohort. The rate of decline in eGFR (but not mGFR) over 18 months was significantly lower among those receiving cell therapy compared with placebo. Further studies will be needed to determine the therapy's effect on CKD progression. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrial.gov NCT02585622 .

Utility of routine evaluation of sterility of cellular therapy products with or without extensive manipulation: Best practices and clinical significance.

BACKGROUND: We analyzed the results of routine sterility testing performed in our center over the last 10 years, in the context both hematopoietic stem cell transplantation (HSCT) and Advanced Therapeutic Medicinal Products (ATMPs). METHODS: For sterility tests 14-day cultures were performed in culture media detecting aerobic and anaerobic microorganisms. RESULTS: In this study, 22/1643 (1.3%) of apheretic products for autologous or allogeneic HSCT were contaminated, whereas 14/73 bone marrow (BM) harvests (17.8%) were positive. In 22 cases, the contaminated HSCs were infused to patients, but there was no evidence of any adverse impact of contamination on the hematologic engraftment or on infections. Indeed none of the five positive hemocultures detected in patients following infusion could be linked to the contaminated stem cell product. Our Cell Factory also generated 286 ATMPs in good manufacturing practice (GMP) conditions since 2007 and all final products were sterile. In three cases of mesenchymal stromal cell expansions, the starting BM harvests were contaminated, but the cell products at the end of expansion were sterile, presumably thanks to the presence of an antibiotic in the culture medium. DISCUSSION: The decreased rate of contamination of cell harvests observed with time suggests that routine sterility testing and communication of the results to the collecting centers may improve clinical practices. Furthermore, we recommend the use of antibiotics in the medium for ATMP expansion, to decrease the likelihood of expanding microorganisms within clean rooms. Finally we discuss the costs of sterility testing of ATMPs by GMP-approved external laboratories.

Treatment of graft versus host disease with mesenchymal stromal cells: a phase I study on 40 adult and pediatric patients.

This phase I multicenter study was aimed at assessing the feasibility and safety of intravenous administration of third party bone marrow-derived mesenchymal stromal cells (MSC) expanded in platelet lysate in 40 patients (15 children and 25 adults), experiencing steroid-resistant grade II to IV graft-versus-host disease (GVHD). Patients received a median of 3 MSC infusions after having failed conventional immunosuppressive therapy. A median cell dose of 1.5 × 10(6)/kg per infusion was administered. No acute toxicity was reported. Overall, 86 adverse events and serious adverse events were reported in the study, most of which (72.1%) were of infectious nature. Overall response rate, measured at 28 days after the last MSC injection, was 67.5%, with 27.5% complete response. The latter was significantly more frequent in patients exhibiting grade II GVHD as compared with higher grades (61.5% versus 11.1%, P = .002) and was borderline significant in children as compared with adults (46.7 versus 16.0%, P = .065). Overall survival at 1 and 2 years from the first MSC administration was 50.0% and 38.6%, with a median survival time of 1.1 years. In conclusion, MSC can be safely administered on top of conventional immunosuppression for steroid resistant GVHD treatment. Eudract Number 2008-007869-23, NCT01764100.

Givinostat and hydroxyurea synergize in vitro to induce apoptosis of cells from JAK2(V617F) myeloproliferative neoplasm patients.

We investigated whether clinically achievable concentrations of the histone deacetylase (HDAC) inhibitors givinostat and hydroxyurea induce synergistic cytotoxicity in Jak2(V617F) cells in vitro and through which possible mechanism. Givinostat and hydroxyurea at low doses potentiated the pro-apoptotic effects of each other in the Jak2(V617F) HEL and UKE1 cell lines. Givinostat induced 6.8%-20.8% and hydroxyurea (HU) 20.4%-42.4% cell death alone and 35.8%-75.3% in combination. The effect was statistically significant using the median effect Chou-Talalay method, resulting in a combination index less than 1, indicating synergy. Givinostat alone induced cell cycle arrest of the cell lines in G0/G1 and hydroxyurea in S phase, whereas both drugs together led to a G1 block. At the molecular level, hydroxyurea counteracted the induction of p21CDKN1A by Givinostat and potentiated caspase 3 activation, explaining at least in part the increased apoptosis observed in presence of both compounds. We also verified the effect of the same drugs in colony assays of freshly isolated Jak2(V617F) polycythemia vera cells. In this case, low doses of the compounds were additive to each other. These results suggest that combined treatment with givinostat and hydroxyurea is a potential strategy for the management of Jak2(V617F) myeloproliferative neoplasms.

Therapeutic efficacy of the pan-cdk inhibitor PHA-793887 in vitro and in vivo in engraftment and high-burden leukemia models.

OBJECTIVE: The aim of the work was to determine and characterize, in vitro and in vivo, the therapeutic activity of PHA-793887, a new potent pan-cdk inhibitor, in the context of hematopoietic neoplasms. MATERIALS AND METHODS: Thirteen leukemic cell lines bearing different cytogenetic abnormalities and normal hematopoietic cells were used in cytotoxicity and colony assays. The drug activity at the molecular level was analyzed by Western blotting. PHA-793887 was also tested in vivo in several leukemia xenograft models. RESULTS: PHA-793887 was cytotoxic for leukemic cell lines in vitro, with IC(50) ranging from 0.3 to 7 microM (mean: 2.9 microM), regardless of any specific chromosomal aberration. At these doses, the drug was not cytotoxic for normal unstimulated peripheral blood mononuclear cells or CD34(+) hematopoietic stem cells. Interestingly, in colony assays PHA-793887 showed very high activity against leukemia cell lines, with an IC(50) <0.1 microM (mean: 0.08 microM), indicating that it has efficient and prolonged antiproliferative activity. PHA-793887 induced cell-cycle arrest, inhibited Rb and nucleophosmin phosphorylation, and modulated cyclin E and cdc6 expression at low doses (0.2-1 microM) and induced apoptosis at the highest dose (5 microM). It was also effective in vivo in both subcutaneous xenograft and primary leukemic disseminated models that better mimic naturally occurring human disease. Interestingly, in one disseminated model derived from a relapsed Philadelphia-positive acute lymphoid leukemia patient, PHA-793887 showed strong therapeutic activity also when treatment was started after establishment of high disease burden. CONCLUSIONS: We conclude that PHA-793887 has promising therapeutic activity against acute leukemias in vitro and in vivo.

Pleiotropic anti-myeloma activity of ITF2357: inhibition of interleukin-6 receptor signaling and repression of miR-19a and miR-19b.

BACKGROUND: The histone deacetylase inhibitor ITF2357 has potent cytotoxic activity in multiple myeloma in vitro and has entered clinical trials for this disease. DESIGN AND METHODS: In order to gain an overall view of the activity of ITF2357 and identify specific pathways that may be modulated by the drug, we performed gene expression profiling of the KMS18 multiple myeloma cell line treated with the drug. The modulation of several genes and their biological consequence were verified in a panel of multiple myeloma cell lines and cells freshly isolated from patients by using polymerase chain reaction analysis and western blotting. RESULTS: Out of 38,500 human genes, we identified 140 and 574 up-regulated genes and 102 and 556 down-modulated genes at 2 and 6 h, respectively, with a significant presence of genes related to transcription regulation at 2 h and to cell cycling and apoptosis at 6 h. Several of the identified genes are particularly relevant to the biology of multiple myeloma and it was confirmed that ITF2357 also modulated their encoded proteins in different multiple myeloma cell lines. In particular, ITF2357 down-modulated the interleukin-6 receptor alpha (CD126) transcript and protein in both cell lines and freshly isolated patients' cells, whereas it did not significantly modify interleukin-6 receptor beta (CD130) expression. The decrease in CD126 expression was accompanied by decreased signaling by interleukin-6 receptor, as measured by STAT3 phosphorylation in the presence and absence of inter-leukin-6. Finally, the drug significantly down-modulated the MIRHG1 transcript and its associated microRNA, miR-19a and miR-19b, known to have oncogenic activity in multiple myeloma. CONCLUSIONS: ITF2357 inhibits several signaling pathways involved in myeloma cell growth and survival.

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.