Trials to begin on drug for treating Alzheimer's

The First trials of a promising new drug to treat Alzheimer's disease will begin within weeks in response to a breakthrough in removing the "sticky" brain deposits associated with the illness.

Preliminary tests in the laboratory show that the drug can dissolve the protein "plaques" that are implicated in Alzheimer's and a range of other diseases caused by the insoluble deposits.

Scientists say the drug is so promising that they are planning to set up a clinical trial involving a handful of patients to see if it can reverse the condition, which is incurable and in which the brain progressively deteriorates.

"This is far from being a cure, but the results are promising," said Professor Mark Pepys of the Royal Free and University College Medical School in London, who led the study, published today in the journal Nature.

The research was initially aimed at developing treatments for a number of rare diseases that are caused by a build-up of protein, called amyloid, in the tissues of the vital organs. Scientists now believe that other common illnesses, such as Alzheimer's and type 2 diabetes, may be caused by the protein accumulating in a similar way.

"We always find amyloid protein in Alzheimer's disease and type 2 diabetes, so the association is pretty strong, although it is not proven beyond doubt that the amyloid actually causes the condition," Professor Pepys said.

The protein accumulates because the body's immune defences seem incapable of breaking it up in the normal way. Scientists believe this is because it binds strongly to another substance made by the body, called SAP.

But the new drug, called CPHPC, breaks the chemical link between the two. This allows the protein plaques to be dissolved and destroyed in the liver by the normal process that the body uses to rid itself of waste products.

"We believe that this is the first time that such a small drug is able to deplete a specific protein circulating in the body," Professor Pepys said.

Tests on a handful of patients suffering from amyloidosis – in which the protein accumulates in the vital organs – have shown that the drug produces no harmful side-effects.

"The patients remained encouragingly stable and their condition did not get worse, but we have yet to determine whether the drug actually reduced the amount of amyloid deposits," Professor Pepys said.

A first-phase clinical trial on five patients is expected to start within the next two months and will test for safety and tolerance. "If it looks promising we'll do a larger-scale study involving thousands of patients," Professor Pepys said.

Leslie Iversen, a pharmacologist at King's College London, said the new drug might also be effective in treating Creutzfeldt-Jakob disease, another brain condition linked with insoluble protein plaques. "We can perhaps be hopeful that drugs can be found to combat the abnormal protein deposits seen in so many distressing human diseases," Dr Iversen said.