Pharmacokinetics of QMF149 in Japanese versus Caucasian subjects: an open-label, randomized phase I study.

OBJECTIVES: This study aimed to evaluate influence of ethnic factors on the pharmacokinetics of orally inhaled QMF149, a novel combination of an approved longacting ß2-agonist, indacaterol (Onbrez® Breezhaler® for COPD), and an approved inhaled corticosteroid, mometasone furoate (MF), (Asmanex® Twisthaler® for asthma), following multiple dose administration of QMF149 (indacaterol acetate/MF) 150/80 µg and 150/320 µg via the Breezhaler® device in healthy Japanese and Caucasian subjects. METHODS: This was a single-center, openlabel, multiple-dose, two-period, complete crossover study that randomized healthy Japanese and, age and weight matched Caucasian subjects to QMF149 150/80 µg or 150/320 µg once daily (o.d.) for 14 days in each period. Pharmacokinetics (PK) were assessed up to 24 hours on days 1 and 14. RESULTS: 24 Japanese and 24 Caucasian healthy subjects were enrolled. Indacaterol and MF had similar PK profiles across both the doses and both ethnic groups. The maximum geometric mean ratios (90% confidence interval (CI)) for Japanese vs. Caucasian subjects for Cmax were 1.23 (1.11 - 1.38) and 1.24 (1.11 - 1.38) for indacaterol and MF, respectively. For AUC, the maximum ratios were 1.22 (1.09 - 1.36) and 1.30 (1.18 - 1.44) for indacaterol and MF, respectively. The mild trend towards higher exposure in Japanese subjects could be explained by the fact that the mean body weight was 14% higher for Caucasians compared to their Japanese counterparts. No serious adverse events or discontinuations related to study medication were reported. CONCLUSION: The study demonstrated increase of mean exposure parameters in Japanese subjects vs. Caucasian subjects, which ranged between 19 - 23% and 17 - 30%, for indacaterol and MF components, respectively. Multiple doses of both the QMF149 dose levels were safe and well-tolerated in all subjects. Body weight was considered a key contributory factor for the observed difference in exposure. These results suggest no dose adjustment for QMF149 is required in Asian populations.

Pharmacological assessment of methamphetamine-induced behavioral hyperactivity mediated by dopaminergic transmission in planarian Dugesia japonica.

The freshwater planarian Dugesia japonica has a simple central nervous system (CNS) and can regenerate complete organs, even a functional brain. Recent studies demonstrated that there is a great variety of neuronal-related genes, specifically expressed in several domains of the planarian brain. We identified a planarian dat gene, named it D. japonica dopamine transporter (Djdat), and analyzed its expression and function. Both in situ hybridization and immunofluorescence revealed that localization of Djdat mRNA and protein was the same as that of D. japonica tyrosine hydroxylase (DjTH). Although, dopamine (DA) content in Djdat(RNAi) planarians was not altered, Djdat(RNAi) planarians showed increased spontaneous locomotion. The hyperactivity in the Djdat(RNAi) planarians was significantly suppressed by SCH23390 or sulpiride pretreatment, which are D1 or D2 receptor antagonists, respectively. These results suggest that planarians have a Djdat ortholog and the ability to regulate dopaminergic neurotransmission and association with spontaneous locomotion.

Protective effect of planarian DJ-1 against 6-hydroxydopamine-induced neurotoxicity.

DJ-1/PARK7 has multiple functions as an antioxidant, an oncogene, and a molecular chaperone in vertebrates, and loss-of-function mutations in DJ-1 cause early onset of Parkinson's disease. However, the function of invertebrate DJ-1 remains unknown. In order to investigate the function of planarian DJ-1, we isolated the planarian DJ-1 gene Dugesia japonica DJ-1 (DjDJ-1) and analyzed its expression and function. In situ hybridization analysis revealed that DjDJ-1 mRNA was expressed throughout the body, including the central nervous system, cells surrounding the pharynx, and stem cells. Planarian DjDJ-1 protein exhibited antioxidant function, similar to human DJ-1, as evidenced by the fact that recombinant DjDJ-1 protein reduced reactive oxygen species and protected human neuroblastoma SH-SY5Y cells from cell death. In addition, dopaminergic neurons in DjDJ-1(RNAi) planarians became susceptible to 6-hydroxydopamine, a dopaminergic neurotoxin. These results suggest that planarians have a DJ-1 ortholog, which has conserved antioxidant and neuroprotective functions.