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Johnston T.H.,University of Western Ontario | Fox S.H.,University of Western Ontario | Piggott M.J.,University of Western Australia | Savola J.-M.,Santhera Pharmaceuticals Switzerland Ltd. | Brotchie J.M.,University of Western Ontario
Movement Disorders | Year: 2010

Reduction in the antiparkinsonian benefit of levodopa is a major complication of long-term levodopa treatment in advanced Parkinson's disease (PD). Such loss of benefit arises because of reduced duration of action and appearance of disabling dyskinesia. We assess the potential of the α2 adrenergic antagonist fipamezole to reduce motor complications in parkinsonian macaques. MPTP-lesioned macaques were treated acutely with fipamezole (10 mg/kg) alone and in combination with two doses of levodopa. Fipamezole extended both duration and quality of antiparkinsonian action of levodopa. Duration of antiparkinsonian action, on time, was increased by up to 75% while "good-quality" on time, i.e., that not associated with disabling dyskinesia, was increased by up to 98%. Combination of fipamezole with the lower dose of levodopa provided antiparkinsonian benefit at least equivalent to that provided by the higher dose levodopa alone. However, with the combination, antiparkinsonian benefit was of much better quality. The proportion of on time without disabling dyskinesia (79%) was significantly greater than that with high dose levodopa alone (45%). Increased duration and quality of levodopa action may represent therapeutically valuable actions of α2 adrenergic antagonists. © 2010 Movement Disorder Society. Source


LeWitt P.A.,Ford Motor Company | LeWitt P.A.,Wayne State University | Hauser R.A.,University of South Florida | Lu M.,Ford Motor Company | And 5 more authors.
Neurology | Year: 2012

Objective: Fipamezole, a selective α 2-adrenergic receptor antagonist, reduced levodopa-induced dyskinesias (LID) in 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine-lesioned monkeys. In 10 dyskinetic subjects with Parkinson disease (PD), a proof-of-concept study showed beneficial effects at single doses of 60 and 90 mg. The primary study objective was to assess suppression of LID by fipamezole at day 28, as measured by the Levodopa-Induced Dyskinesia Scale (LIDS), a modification of the Abnormal Involuntary Movement Scale. Methods: This was a double-blind, randomized, placebo-controlled, dose-escalating 28-day study in levodopa-treated patients with PD experiencing LID, conducted at 25 centers in the United States (115 subjects) and 7 centers in India (64 subjects). Dyskinesias were evaluated 3 times after subjects became "on" from levodopa. Outcome assessment was performed with analysis of variance, which evaluated fipamezole dose-effects in a hierarchical stepwise manner and the Jonckheere test for dose responsiveness. Results: The total study population showed no statistically significant primary endpoint difference. However, because of inhomogeneita recognized between US and Indian study populations, a prespecified subgroup analysis of US subjects was conducted, showing fipamezole at 90 mg reduced LID (mean, 95% CI, LID rating improvement vs placebo -1.9 [0.0 to -3.8; p = 0.047]). Dose responsiveness was demonstrated (p = 0.014 for placebo, 30, 60, and 90 mg fipamezole). Fipamezole induced mild, transient blood pressure elevation and was associated with an acceptable profile of adverse effects. Conclusions: The evidence of efficacy in the US subgroup suggested that fipamezole at 90 mg TID may be useful to treat LID in PD without exacerbating parkinsonism. Classification of evidence: This study provides Class III evidence that fipamezole is well-tolerated and, in the US subpopulation, lessens LID at 90 mg TID. Copyright © 2012 by AAN Enterprises, Inc. Source


Dallmann R.,Santhera Pharmaceuticals Switzerland Ltd. | Dallmann R.,University of Zurich | Weyermann P.,Santhera Pharmaceuticals Switzerland Ltd. | Anklin C.,Santhera Pharmaceuticals Switzerland Ltd. | And 24 more authors.
Journal of Cachexia, Sarcopenia and Muscle | Year: 2011

Background: Under physiological conditions, the melanocortin system is a crucial part of the complex network regulating food intake and energy expenditure. In pathological states, like cachexia, these two parameters are deregulated, i. e., food intake is decreased and energy expenditure is increased-a vicious combination leading to catabolism. Agouti-related protein (AgRP), the endogenous antagonist at the melanocortin-4 receptor (MC-4R), was found to increase food intake and to reduce energy expenditure. This qualifies MC-4R blockade as an attractive mode of action for the treatment of cachexia. Based on this rationale, a novel series of small-molecule MC-4R antagonists was designed, from which the orally active compound BL-6020/979 (formerly known as SNT207979) emerged as the first promising development candidate showing encouraging pre-clinical efficacy and safety properties which are presented here. Methods and results: BL-6020/979 is an orally available, selective and potent MC-4R antagonist with a drug-like profile. It increased food intake and decreased energy expenditure in healthy wild-type but not in MC-4R deficient mice. More importantly, it ameliorated cachexia-like symptoms in the murine C26 adenocarcinoma model; with an effect on body mass and body composition and on the expression of catabolic genes. Moreover, BL-6020/979 showed antidepressant-like properties in the chronic mild stress model in rats and exhibits a favorable safety profile. Conclusion: The properties of BL-6020/979 demonstrated in animal models and presented here make it a promising candidate suitable for further development towards a first-in-class treatment option for cachexia that potentially opens up the opportunity to treat two hallmarks of the disease, i. e., decreased food intake and increased energy expenditure, with one drug. © 2011 The Author(s). Source

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