Aventis licenses novel dementia drug
of dementia from Japan's Dainippon; AC-3933 is claimed to have a
completely novel mechanism of action.
Aventis has licensed a candidate drug for Alzheimer's disease and other forms of dementia from Japan's Dainippon. The Franco-German company said that the compound, AC-3933 appears to have a completely novel mechanism of action.
Aventis gets exclusive worldwide development and marketing rights to AC-3933, excluding Japan and with an option for a license in China, Taiwan and South Korea.
At present, there are only two classes of drug approved to treat Alzheimer's disease, the most common form of dementia that accounts for around half of all cases. These are the acetylcholinesterase inhibitors, including Pfizer/Eisai's Aricept (donepezil) and Novartis' Exelon (rivastigmine), and Merz' glutamate antagonist memantine. However, these have limited efficacy, and there is still a significant unmet medical need for treatments that can both treat the memory and cognitive impairment that characterises the disease and its underlying pathology.
It is believed that decreased cholinergic activity may be partially responsible for the cognitive decline that is usually observed in Alzheimer's patients. AC-3933 acts as a partial inverse agonist at the GABA-benzodiazepine receptor complex, which leads to enhanced cholinergic function.
In preclinical tests with memory-impaired animals, orally administered AC-3933 demonstrated procognitive (memory enhancing) activity at very low doses, according to Aventis.
In addition, AC-3933 may also exert some activity through the glutamate pathway, as it has also demonstrated a memory-improving effect in animal models with memory impairments resulting from glutamatergic hypofunction. "This is a new and promising result not observed in existing antidementia agents," said Aventis in a statement.
AC-3933 has already completed initial clinical testing in healthyvolunteers and the results suggest fewer adverse drug reactions versus currently marketed antidementia agents, especially gastrointestinal-related events such as vomiting. Phase IIa trials are due to start later this year in Europe.
