“We need your help.” These simple words are spoken by Dr. Reisa Sperling, the principal investigator of the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s study (the A4 study). The A4 study is a clinical trial for testing solanezumab, an experimental drug that is intended to slow memory loss caused by Alzheimer’s disease.

Amyloid is not an unusual protein, as it is naturally produced by the brain. But for people with Alzheimer’s, fragments of the protein builds up in the brain and begins to form plaque deposits, a signature characteristic of the disease.

What Sperling, a neuroscientist at Harvard, and her colleagues are betting is that the buildup of amyloid begins 10 to 20 years before a patient gets to the stage of significant memory loss. The new experimental drug, sponsored by Eli Lilly and Company, attempts to prevent the disease by clearing the brain of amyloid plaque before major cognitive deficits occur. Earlier trials for this drug have not proven successful; the new study will focus on using the drug preventatively in healthy people.

And so the scientists behind the A4 Study are looking for 10,000 people to come forward and volunteer, though only 1,000 or so will actually participate in the clinical trial. The eligibility requirements are highly specific and include participants be between 65 and 85 years old and still in possession of normal thinking and memory. Volunteers need to be willing to devote three years to the study while also having an A4 study partner — someone in at least weekly contact with the participant who can answer questions once a year.

As part of the study, volunteers will receive monthly IV infusions of either the experimental drug or placebo over 36 months, while also undergoing assessments, including MRIs and PET scans, throughout the study period. Certainly, this health monitoring would be well worth a volunteer’s time and energy, aside from the added pleasure of helping scientists in pursuit of a worthy medical cause.

The A4 Study will enroll participants at more than 60 sites throughout the United States, Canada, and Australia.

At random, participants will be assigned to receive either the experimental drug or a placebo during the clinical trial, which has been designed to evaluate the effectiveness, safety, and tolerability of solanezumab. If you (or someone you know) might be interested in volunteering, please call this phone number, 844-A4-Study, or go to www.A4study.org.

Note: This article was revised to include a note about earlier clinical trials.