Biological triggers behind disease development remain largely unproven, although certain factors like age increase the risk of getting it. Scientists believe changes in the brain of a person with Alzheimer's begin several years before the patient shows symptoms of the disease. That means that by the time diagnosis happens, the brain may be essentially too damaged for potential treatments to work.
Doctors diagnosed John Baker, 71, of Watertown, S.D., with early-stage Alzheimer's disease in 2010. The former mechanical engineer said his family has watched him become forgetful, tell the same stories over and over and misplace things. He said he has no expectation that scientists will make a breakthrough soon enough to help him.
"Realistically, I'm not going to wait and worry and read every line on every report," he said.
Still, he's taking Aricept, a treatment for the disease made by Pfizer and Japanese company Esai Co. Ltd, to try to control the symptoms. He's also participating in a brain scan study to help doctors find a cure for future generations.
Lilly officials cautioned Friday that their study did not show that solanezumab slowed the progression of Alzheimer's. Even so, they were encouraged.
Solanezumab binds to beta-amyloid protein, which scientists believe is a key component to sticky plaque that basically gums up the brain of a patient with Alzheimer's disease. The drug is designed to bind to the protein and help the body remove it from the brain before it can form that plaque. Lilly said that while the individual trials missed their main goals, the combined results showed there may be some validity to this approach.
"We really think this idea of attacking amyloid plaques is a valid hypothesis, that's important news," said Dave Ricks, president of Lilly Bio-Medicines.
But Dr. Sam Gandy, head of Alzheimer's disease research at Mount Sinai School of Medicine in New York, said Lilly's statement on the results "is very tentative."
"I believe in the notion that an amyloid-lowering agent like solanezumab will eventually work in early disease or pre-symptomatically, but whether these data provide compelling evidence that solanezumab has 'cleared the bar' just cannot be concluded" until full results are presented, Gandy wrote in an email.
Dr. Tim Anderson, an analyst who covers Lilly for Bernstein Research, said in a research note the solanezumab results would be viewed positively because expectations for the drug were low.
Lilly is counting on drugs in its development pipeline to help replace revenue it is losing due to patent expirations for key products. The company lost U.S. patent protection for its all-time best-selling drug, the antipsychotic Zyprexa, last year, and it will lose protection for its current top-seller, the antidepressant Cymbalta, next year. Those drugs totaled $8.78 billion in revenue last year, or 36 percent of the company's total.
Lilly shares climbed 3.4 percent, or $1.46, to $43.86 Friday, outpacing broader trading indexes that rose less than 1 percent.
AP Chief Medical Writer Marilynn Marchione in Milwaukee contributed to this report.
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