New Alzheimer's drug inspires hope

Canterbury Alzheimer's patients will be among the first to benefit from a breakthrough medicine now undergoing a worldwide drug trial.

Specialists are hailing the new drug as one of the most exciting developments in Alzheimer's disease research in decades.

Rather than merely slow the progression of the disease, initial results show the new drug, bapineuzumab, may actually treat the underlying causes of the debilitating dementia.

Global pharmaceutical companies Wyeth and Elan are behind the trial, now in its third and final phase. They are recruiting 1250 patients with mild to moderate Alzheimer's from more than 20 countries.

In New Zealand, the trial will be in Christchurch and Auckland.

The trial involves infusion of either the drug or a placebo into patients every three months, with eight follow-up MRI scans over an 18-month period.

The drug is thought to work by acting on a protein which accumulates in the brain, causing cellular degeneration.

Christchurch geriatrician Dr John Elliot, one of the doctors leading the Canterbury trial, said the science behind the research was exciting. "It's the most interesting thing I've seen crop up in Alzheimer's in the last 20 years," Elliot said.

It would be too strong to suggest the drug would offer a cure for the disease, he said, but for the first time it offered hope of an "actual treatment".

It could offer more than existing drugs, which slowed the progression of the disease but did not address its cause, he said.

Initial results from phase two of the trial, released by Wyeth and Elan last month, showed "statistically significant and clinically meaningful benefits" in some people.

Preliminary evaluation of MRI scans revealed less loss of brain volume in some participants, although adverse effects were common among drug and placebo recipients. These included vasogenic edema a condition in which abnormally large amounts of fluid accumulate in the brain.

Despite the adverse effects, researchers have determined that over all the phase two safety findings support progressing to a third phase.

Detailed results of phase two will be released at an international Alzheimer's conference in Chicago next week, with the trial expected to end in April 2011.

Alzheimer's New Zealand national director Lucille Ogston was cautious about championing the drug's benefits while final results and other crucial details such as cost were still unknown.

Bapineuzumab is a mono-clonal antibody, a type of drug which stimulates a patient's own immune system.

Other mono-clonal antibody therapies include herceptin the expensive breast cancer drug.

"Without sounding cynical or sceptical, we get information often that says this is the most exciting thing ...," Ogston said.

"I hope that's right. I just hope something's around the corner."

Elliot said recruiting for the trial in Christchurch would be targeted rather than voluntary, as participants needed to meet certain clinical criteria.

WHAT IS DEMENTIA?

Dementia is an umbrella term for neurological disorders where brain function is impaired, affecting language, memory, perception, personality and cognitive skills.

The most common cause is Alzheimer's disease.

An estimated 40,749 kiwis 1 per cent of the population have dementia. 60.22 per cent of those affected are women.

About 12,333 new cases are diagnosed each year.

Dementia will kill 1378 people this year.

- © Fairfax NZ News