gsk239512 and Alzheimer-Disease

Histaminergic H3 receptors may play a role in modulating cholinergic and monoaminergic neurotransmission. This Phase II study evaluated the efficacy and safety of GSK239512, a highly potent, brain penetrant H3 receptor antagonist as monotherapy treatment for subjects with mild-to-moderate probable Alzheimer's disease (AD).. In this 16-week, double-blind, randomized, parallel group study, 196 currently untreated subjects with mild-tomoderate AD (Mini Mental State Examination [MMSE] 16-24) received GSK239512 (n=97); or placebo (n=99) administered orally each morning. After a two-week placebo run-in period GSK239512 was up-titrated over 4 weeks in a flexible manner (10-20-40-80 microgram [µg]) followed by a 12-week Maintenance Phase. Co-primary efficacy endpoints were change from baseline in Episodic Memory and Executive Function/Working Memory composite scores from the CogState neuropsychological test battery (NTB) at Week 16.. Compared to placebo, GSK239512 improved Episodic Memory at Week 16 (Effect Size [ES] =0.35; p=0.0495). No statistically significant differences were observed on other cognitive domains or on clinical measures including the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADASCog). GSK239512 treatment was associated with mild to moderate adverse events with headache, dizziness and events related to sleep disturbances being the most common and more pronounced in the early titration period when subjects were first being exposed to GSK239512 at the lower 10µg and 20µg doses. There were no clinically relevant changes in other safety parameters.. GSK239512, at doses up to 80µg/day, improved Episodic Memory in patients with mildto- moderate AD. However, no improvements were observed on Executive Function/Working Memory or other domains of cognition. No changes were observed on any of the clinical measures included as secondary endpoints (including ADAS-Cog) indicating that GSK239512 failed to show benefit in this population. GSK239512 had an acceptable safety and tolerability profile. These findings suggest that H3 antagonists may, at most, have modest and selective effects on cognitive function in patients with mild-to-moderate AD.

Topics: Aged; Alzheimer Disease; Benzazepines; Double-Blind Method; Executive Function; Female; Histamine Antagonists; Humans; Male; Medication Adherence; Memory, Episodic; Memory, Short-Term; Neuropsychological Tests; Nootropic Agents; Severity of Illness Index; Treatment Outcome

The histamine H3 receptor plays a critical role in the negative neuromodulation of neurotransmitters involved in cognitive function. H3 receptor antagonists/inverse agonists have been shown to exert pro-cognitive effects in pre-clinical models. GSK239512 is a potent and selective H₃ receptor antagonist developed for the treatment of cognitive dysfunction in neurodegenerative disorders. In this study we examined the safety, tolerability, pharmacokinetics and pro-cognitive effects of GSK239512 (oral) in patients with mild to moderate Alzheimer's disease using ascending dose titration regimens.. The study was conducted in two parts. Part A was a single-blind, placebo run-in, flexible dose titration over 9 days in two cohorts, each consisting of two patients. Part B was a double-blind, randomised, placebo controlled, parallel group, which investigated 3 flexible dose titration regimens over 4 weeks in 3 cohorts, each consisting of eight patients.. Overall, the 5/10/20/40 μg and 10/20/40/80 μg regimens were well-tolerated. The regimen of 20/40/80/150 μg showed the poorest tolerability likely due to the higher starting dose. There were no clinically significant abnormalities in haematology, clinical chemistry, urinalysis parameters and cardiovascular parameters. GSK239512 had positive effects on tasks of attention and memory with effect sizes between 0.56 and 1.37.. GSK239512 displayed asatisfactory level of tolerability in patients with Alzheimer's disease with evidence for positive effects on attention and memory. The findings suggest that a titration regimen with a starting dose of 5-10 μg and a maximum dose of 80 μg is likely to be a well-tolerated and potentially efficacious regimen for future clinical trials in patients with Alzheimer's disease. These findings await replication in a larger study.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Attention; Benzazepines; Dose-Response Relationship, Drug; Double-Blind Method; Female; Histamine H3 Antagonists; Humans; Male; Memory; Single-Blind Method