Glycopyrronium does not affect QT interval in healthy subjects: a randomized, three- period, cross-over, placebo- and positive-controlled study.

OBJECTIVE: Glycopyrronium (NVA237), a once-daily long-acting muscarinic antagonist, has recently been approved for the treatment of patients with chronic obstructive pulmonary disease (COPD). This study evaluated the effect of glycopyrronium on the QT interval and other cardiac parameters in healthy subjects. METHODS: This randomized, partially blinded, single-dose, placebo- and positive- (moxifloxacin) controlled, three-way cross-over study investigated the effect of a single inhaled supra-therapeutic dose (8-fold clinical dose in COPD patients) of 400 µg glycopyrronium on the Fridericia-corrected QT interval (QTcF; primary objective), Bazettcorrected QT interval (QTcB), heart rate, blood pressure, pharmacokinetics (PK), safety, and tolerability. RESULTS: A total of 73 healthy male (n = 35) and female (n = 38) subjects, aged between 18 and 45 years, were randomized. Glycopyrronium did not cause significant QTcF prolongation compared to placebo. The largest time-matched mean difference to placebo was 2.97 ms at 5 minutes, with the upper limit of the two-sided 90% confidence interval (CI) being 4.80 ms, excluding a relevant QT effect as defined by the ICH E14 guideline. Glycopyrronium had a slight bradycardic effect with a mean change of -2.88 (90% CI: -3.78, -1.99) beats per minutes (bpm) and a maximum of -5.87 (90% CI: -7.82, -3.92) bpm at 5 hours post-inhalation. No clinically relevant effects were seen on QTcB, other electrocardiogram (ECG) intervals, or blood pressure. Maximum plasma concentration (Cmax) of glycopyrronium was achieved shortly after inhalation (median tmax = 7 minutes). All the treatments were well tolerated with no serious adverse events. CONCLUSION: A supra-therapeutic dose of glycopyrronium had a favorable cardiovascular safety profile with no clinically relevant effect on QT interval.

Chondrocyte cluster formation in agarose cultures as a functional assay to identify genes expressed in osteoarthritis.

Understanding altered gene expression in osteoarthritic cartilage can lead to new targets for drug intervention. We established a functional assay based on chondrocyte cluster formation, a phenotype associated with osteoarthritis (OA), to screen an OA cartilage gene library. Previous reports have demonstrated that normal chondrocytes grown in suspension culture maintain their chondrocytic phenotype, however, certain growth factors such as basic fibroblast growth factor (bFGF) will induce the cells to proliferate in tight clusters similar to those seen in osteoarthritic cartilage. In this study we validate that overexpression of bFGF by retrovirally transduced normal chondrocytes would similarly induce the proliferation of tight cell clusters. We then used this approach as a basis to set up a functional screen where an entire OA cartilage cDNA library was tranduced into normal chondrocytes to search for other genes that would also induce cluster formation. Seven potential genes were isolated from the OA gene library, including BPOZ, IL-17 receptor C, NADH ubiquinone oxidoreductase, COMP, Soluble carrier 16 (MCT 3), C1r, and bFGF itself. None of the identified genes were upregulated by bFGF, however, all of them upregulated the expression of bFGF suggesting a common pathway. Although cluster formation is not considered to be destructive in OA cartilage, it is consistent with the disease and could yield answers to the altered phenotype. Further studies are needed to elucidate how these genes are linked to the disease state.

Fluorescently labeled mesenchymal stem cells (MSCs) maintain multilineage potential and can be detected following implantation into articular cartilage defects.

Several studies have reported enhanced repair of damaged cartilage following implantation of mesenchymal stem cells (MSCs) into full-thickness cartilage defects suggesting that the cells in the repair tissue were derived from the implant. However, it cannot be excluded that the enhanced tissue repair is derived from host cells recruited to the defect in response to the implant, rather than the re-population of the tissue by the implanted MSCs. Our objective was to study the short-term fate of fluorescently labeled MSCs after implantation into full-thickness cartilage defects in vivo. The fluorescent dye used in our studies did not affect MSC viability or their ability to undergo osteogenic and chondrogenic differentiation in vitro. MSC gelatin constructs were implanted into full-thickness cartilage defects in goats. These cells retained the dye and were detectable by histology and flow cytometry. At intervals spanning 2 weeks post-implantation we observed gradual loss of implanted cells in the defect as well as fragments of gelatin sponge containing labeled MSCs in deep marrow spaces indicating fragmentation, dislodgement and passive migration. Fluorescent labeling enabled us to determine whether the implanted cells were lost during early time points after implantation as well as their spatial orientation throughout the defect. By determining the fate of implanted cells, new biomaterials could be engineered to correct undesirable characteristics. Testing of new biomaterials in short-term in vivo models would provide faster optimization for cell retention needed for successful, long-term cartilage regeneration.