Drug that attacks Alzheimer’s cause found effective

PHILADELPHIA – The first pill designed to attack what is believed to be the cause of Alzheimer’s disease rather than just symptoms appears to be safe and also seems to substantially reduce levels of a troublesome protein implicated in the disease, researchers said Sunday.

And after being on the medication for more than a year, patients with mild Alzheimer’s disease appear to have mental skills that have stabilized.

However, researchers who have been testing the drug and others in the field cautioned that the findings from the small study are preliminary and need to be confirmed in a more rigorous clinical trial.

“It’s a relatively modest group of people,” said William Thies, vice president of medical and scientific affairs with the Alzheimer’s Association. “It’s still short of what we would look for in (seeking) FDA approval.”

Still, he said, the results are “very encouraging” and represent “terrific progress.”

If the drug proves to be effective in a just-begun trial involving 950 patients in the United States and Canada, it could be a major breakthrough, he said.

The findings, which were presented at the ninth International Conference on Alzheimer’s Disease and Related Disorders of the Alzheimer’s Association, represents the first human trial of an oral medication designed to remove beta-amyloid peptide, one of two troublesome proteins that build up in the brains of people with Alzheimer’s.

The drug, known as Alzhemed, is being developed by Neurochem Inc., the Canadian biopharmaceutical firm that funded the study. It is designed to clear so-called beta-amyloid fibrils from the brain before they form the plaques that are associated with the death of brain cells.

“This does represent a new approach,” said lead researcher Paul Aisen, a professor of neurology and medicine and director of the memory disorders program at Georgetown University School of Medicine and a consultant to Neurochem.

After three months of treatment of Alzhemed, beta-amyloid concentrations in cerebrospinal fluid were reduced by as much as 70 percent, an indication that the protein was being cleared from the brain.

However, only 58 patients were in the trial. And researchers were not able to measure actual beta-amyloid concentrations in the brain.

In addition, over the course of 20 months, the cognitive skills of the patients with mild Alzheimer’s appeared to have stabilized based on mental tests, Aisen said.

But slowing progression, especially in a small group, is not a cure, said Mark Sager, a professor of medicine at the University of Wisconsin-Madison and director of Wisconsin Alzheimer’s Institute.

“The drug will slow progression, but not actually reverse or cause improvement,” Sager said. “It doesn’t appear to be a magic bullet.”

At the moment, approved Alzheimer’s drugs affect symptoms, primarily by regulating levels of various brain chemicals known as neurotransmitters. Those drugs have a relatively modest effect on the progression of the disease.

So a drug that halts the advance of the disorder by affecting the disease process would be an important development, said Samuel Gandy, an Alzheimer’s researcher and professor of neurology at Thomas Jefferson University Medical School.

“Stabilization is something,” Gandy added. “We have to be happy with baby steps just to prove we are on the right track.”

Gandy said the results from the phase 2 trial were exciting and represented the “next logical step” in the treatment of Alzheimer’s, a disorder that afflicts 4.5 million Americans.

Gandy noted that Alzhemed is one of several drugs now in development that seek to attack the believed cause of the disease.

“These drugs are the first drugs in the history of medicine that are targeted at the pathology of Alzheimer’s,” said Gandy, whose university is taking part in the phase 3 part of the Alzhemed trial. “It’s a very exciting time.”