Dementia - ispronicline

One of the consequences of an ageing population is a higher prevalence of the diseases and conditions that disproportionately affect older people. These include Alzheimer's disease and other dementias, but treatment options are limited and have focused on drugs that interact with the cholinergic system, such as the acetylcholinesterase inhibitors such as donepezil, galantamine and rivastigmine.

Ispronicline is a new drug to treat Alzheimer's being developed by Targacept in conjunction with AstraZeneca.¹ It acts at the α4β2 neuronal nicotinic acetylcholine receptor. This is thought to be inhibited by very low amounts of βamyloid, the protein whose build up in the brain is believed to be the underlying cause of Alzheimer's.

In one double blind, placebo-controlled study, 193 patients with age-associated memory impairment were given 25 or 50mg of ispronicline or placebo once a day for 16 weeks.² Those given the lower dose had improved power and continuity of attention, while for the group given 50mg doses, speed of memory and quality of episodic memory also improved.

A double blind, placebo-controlled crossover study was also carried out in 76 elderly patients with age associated memory impairment. They were given ascending oral doses of 50 to 150mg for 21 days, and at the highest dose, both continuity and speed of memory improved.³ A third trial, this time in 20 patients over the age of 60 with age-associated memory impairment, 50mg doses of the drug once a day for 21 days improved both power and continuity of attention, as well as the quality of episodic memory and speed of memory.⁴

Trials continue; it is also being investigated as a possible treatment for schizophrenia patients with cognitive dysfunction.