An experimental Alzheimer’s treatment slowed mental decline in patients with early stages of the disease by 34 percent, the first evidence that a medication may be able to alter the course of the disease, according to research presented by scientists meeting in Boston on Monday.
Scientists were quick to note that the results they found in their analysis of the drug, known as Solanezumab, were modest and that much more study needs to be done to confirm that the medication truly is effective.
But they said the findings give a powerful boost to a growing belief by researchers that medications such as Solanezumab, designed to clear abnormal proteins in the brains of Alzheimer’s patients, are the way to battle the disease that affects more than 5 million Americans.
That number is expected to nearly triple by the year 2050 as baby boomers age, adding urgency to the search for an effective medication.
“What we were looking for is, is there [a positive] effect of treatment” for patients, said Dr. Rachelle Doody, chairwoman of Alzheimer’s Disease Research at Baylor College of Medicine, who led the panel of independent scientists that analyzed results of the medication made by Eli Lilly.
“I think the question has been answered favorably, especially on cognition and perhaps activities of daily living in patients with milder” Alzheimer’s disease, Doody said at the American Neurological Association meeting in Boston.
Preliminary results of the 2,000-patient study released by Lilly in August suggested that the company’s drug did not have a significant benefit on patients with mild-to-moderate Alzheimer’s disease. But the findings released Monday by the Alzheimer’s Disease Cooperative Study, an independent panel of researchers, found that patients with mild disease who were given the medication for 18 months did show improvement, albeit modest, compared with those in the study who were given a fake drug.
“We are very encouraged,” said Maria Carrillo, vice president of medical and scientific relations at the Alzheimer’s Association, a national nonprofit organization that funds and advocates for Alzheimer’s research, education, and improved patient care.
“This is the first time we see a slowing of cognitive decline in Alzheimer’s patients with an anti-amyloid treatment,” Carillo said.
Amyloid is the abnormal protein found in Alzheimer’s patients that is believed to be a hallmark of the disease.
There is no known cure for Alzheimer’s disease, and several drug trials have produced disappointing results.
But a growing number of researchers believe that the lack of progress may be because the drugs are now tested only in people whose Alzheimer’s is too advanced.
Researchers are searching for ways to detect the disease at its earliest stages, before it damages critical brain cells, because they believe that is when potential treatments would be most effective. Many believe that an accumulation of amyloid in the brains of Alzheimer’s patients may be a reliable marker to identify the disease early on.
Results from a different study also presented Monday detailed trials of another anti-amyloid experimental drug, known as Bapineuzumab. That study found the drug produced no significant benefit in mental or physical functioning for roughly 2,400 patients with mild-to-moderate Alzheimer’s disease.
“Unfortunately, the test results are disappointing,” said Dr. Reisa Sperling, an Alzheimer’s specialist from Brigham and Women’s Hospital in Boston who led the study.
But Sperling said test results showed that the drug did successfully clear amyloid plaques from Alzheimer’s patients’ brains, and it also appeared to decrease one measure of nerve cell damage.
While both drugs, Bapineuzumab and Solanezumab, clear amyloid from Alzheimer’s patients’ brains, they target different types of the protein, further complicating the mission to find an effective treatment, scientists said.
Sperling said she believes that if patients with mild Alzheimer’s were to be given higher doses of Bapineuzumab than were given in her trial, that drug might also provide some benefits. But the study suggested that higher doses could be problematical, because some of the patients suffered serious side effects, including seizures.
“We are between a rock and a hard place,” Sperling said.
Side effects reported in the Solanezumab trial were lower, by comparison.
The issue of which drug may be more effective is a pressing one for Sperling, who is awaiting final word on government funding of what would be a first-of-its kind Alzheimer’s medication study on older people who have no symptoms of the disease.
Medication research up till now has focused on patients who already are showing signs of the disease, but Sperling and many other scientists think they may have success in slowing the illness if the right drug is given before symptoms appear — much the same way patients with high cholesterol are given statin drugs to head off cardiovascular problems.
Scientists believe that more than 50 percent of certain critical brain cells are already lost by the time a patient displays even mild cognitive impairment.
Sperling’s study would enroll 1,000 adults over age 70 who have amyloid plaque revealed by brain scans and who are exhibiting very subtle cognitive problems that are typically reported in people years before they are diagnosed with Alzheimer’s.
“My hope is that by this time next year,” Sperling said, “we will have started enrolling patients.”
Kay Lazar can be reached at email@example.com. Follow her on Twitter @GlobeKayLazar.