Alzheimer’s disease currently affects 5.3 million Americans, and one more is added to the list every 70 seconds.
That’s why it’s so critical that research continue, and why it was such a blow to families worldwide when Eli Lilly and Co. announced it would halt development of Semagacestat, its promising treatment for Alzheimer’s. Phase III clinical trials showed that Semagacestat-treated patients not only fared worse than their placebo-treated counterparts, they also may have been put at increased risk of skin cancer.
“We always go into this knowing there is a chance that [a treatment] is not going to help or that it can cause side effects, but we didn’t see that coming,” says Dr. Ann Marie Hake, an associate professor of clinical neurology Indiana University School of Medicine. Hake, who is involved in Alzheimer’s disease research at IU, says Lilly’s setback “doesn’t prove that this approach itself doesn’t work.”
MOVING FORWARDWhile admitting disappointment, Lilly’s chairman, president and CEO, John C. Lechleiter, has vowed that Lilly is committed to slowing the progression of Alzheimer’s disease and will move forward.
“Lilly’s innovation strategy, based on advancing a pipeline of nearly 70 molecules currently in clinical development, does not rest on the success or failure of any single compound,” he stated in a recent press release.
Lilly currently has another Alzheimer’s drug in Phase III study. Like Semagacestat, Solanezumab focuses on amyloid-beta proteins. People with Alzheimer’s disease have more of the “sticky” protein in their brains than people who do not have Alzheimer’s. IU also has studies focusing on amyloid proteins that target people with mild to moderate stages.
“We thought if we could just solve the amyloid problem, then we’d have Alzheimer’s cured,” Hake says. “But it’s not that easy. That doesn’t mean we can forget about amyloid. Many studies are still working on ways to reduce the amount of that enzyme in the brain.”
Other studies at IU focus on how to calculate earlier who is at risk for developing Alzheimer’s—whether by blood test, a scan or a spinal fluid test. “If we could nip it in the bud before they develop full-blown Alzheimer’s disease, maybe medications could be given in time to prevent it,” Hake says.
A third focus of research is on the development of medications to help people with severe Alzheimer’s disease who do not benefit from currently available medications.
GETTING TO MARKET
Don’t expect to see any of these on the market anytime soon. Testing is a lengthy process that begins with test tubes, then graduates to testing on animals. It can take up to five years before a product is ready to test on humans.
“Alzheimer’s disease research can only progress if people are willing to volunteer for clinical trials and studies,” says Linda Altmeyer, director of programs for the Greater Indiana Chapter of the Alzheimer’s Association. “Other than funding, recruiting and retaining trial participants are the main barriers to slowing the disease or finding a cure.”
Human testing begins with a few healthy subjects to see if they can tolerate the treatment, then progresses to a small number of people who have Alzheimer’s disease. Phase III involves large numbers of people over a longer period of time. That’s when the actual measures of the effectiveness of a drug takes place.
“Many people are coming up with different ideas and different angles to do it from,” Hake says. “It’s a pretty exciting time.”