Study says Huntington's tests to aid drug search

Scientists have developed a new range of tests that allow them to track the progression of Huntington's disease long before symptoms appear and should aid the development of drugs for the incurable inherited disease.

In a study published in The Lancet Neurology journal, researchers said their battery of tests, which include advanced brain imaging and cognitive and motor skill assessments, were sensitive enough to detect signs of the disease many years before it takes hold and to show changes in brain function over just one year.

Sarah Tabrizi from University College London's Institute of Neurology, who led the study, said this should prove crucial in developing new medicines designed to treat the process of mental decline brought about by Huntington's disease.

"The sensitivity of our methods means we can detect changes over a short period and that should allow us to test therapeutics aimed at halting or slowing the neurodegenerative process," she said in a telephone interview.

Huntington's disease affects up to one person in every 10,000 in the Western world. It is a progressive, degenerative condition in which patients suffer from uncontrolled movements, emotional problems and mental deterioration.

There is no cure for Huntington's and people who inherit the genetic mutation that causes it are certain to develop the fatal disease. Patients typically die within 10 to 15 years after symptoms become obvious.

One drug, tetrabenazine, sold under the brand name Xenazine by Danish pharmaceuticals group Lundbeck, can help manage some of Huntington's symptoms but does not prevent the physical and cognitive decline.

Tabrizi said several drug and biotech firms, including GlaxoSmithKline, Novartis, Medivation and Neurosearch, have research teams seeking to develop new Huntington's medicines.

But one of the major barriers to finding effective new drugs has been a lack of sensitive and reliable indicators, or so-called biomarkers, of the disease's progression.

Without these researchers would need to run very long-term and hugely expensive clinical trials to be able to show whether an experimental drug is having any effect, Tabrizi said.

For this trial, Tabrizi's team analysed 366 people from Canada, France, the Netherlands, and Britain - 120 of whom carried the Huntington's gene mutation and were destined to develop the disease, 123 of whom were in the early stages of the disease, and 123 of whom were healthy subjects for comparison.

After following them for 12 months, the team found that brain imaging techniques were the strongest and most consistent at detecting disease progression in both the pre-Huntington's patients and those with early disease.

Presymptomatic people were also found to have detectable cognitive and motor function decline, and those with early disease also showed deterioration in eye movement function.