New Alzheimer's drug may help seniors at risk

A new study is intended to help those who could develop Alzheimer's disease.

Scientists are beginning a major study to see if an experimental drug can protect healthy seniors whose brains harbor silent signs that they're at risk of Alzheimer's.

It's one of the most ambitious attempts yet to thwart Alzheimer's.

Researchers expect to screen thousands of volunteers ages 65 to 85, hunting those whose brain scans show they have a sticky build-up believed to play a key role in development of Alzheimer's.

That doesn't guarantee someone will get sick.

But the study will test if early use of a drug designed to target the gunk makes a difference for those who do.