More than 5 million Americans are living with Alzheimer’s disease today. Every 66 seconds, someone in the United States develops the disease. It’s the sixth leading cause of death in the country.
Despite its prevalence, little progress has been made in terms of treatment.
“It has been over a decade of various failed drugs in Alzheimer’s disease,” RBC analyst Michael Yee told Yahoo Finance. “Part of that is driven by the fact that scientists don’t have great conviction on exactly what’s driving Alzheimer’s.”
“Alzheimer’s disease is a progressive neurological disorder that gradually deprives patients of their memory and ability to carry out daily activities,” Yee explained in a recent note. “As Alzheimer’s disease progresses, individuals may experience difficulties with language, perception, and mobility, as well as face detrimental changes in personality and behavior, such as anxiety, depression, agitation, delusions, or hallucinations.”
Analysts say that a successful medicine for the neurodegenerative disease could draw $10 billion annually, but so far it’s mostly been disappointments.
The beta-amyloid approach
Companies, led by pharmaceutical giant Eli Lilly (LLY) and biotech leader Biogen (BIIB), are developing antibodies that target what’s known as “beta amyloid,” a sticky protein that clumps together and forms nerve-killing plaque in the brain.
The thesis from researchers follows that removing the plaque from the brain could slow or end Alzheimer’s disease progression. However, clinical trials thus far have fallen short.
Eli Lilly’s drug, solanezumab, has failed in prior phase 3 trials. Biogen’s drug, aducanumab, has only showed positive results in early-stage studies involving small sets of patients. And drugs from Johnson & Johnson (JNJ), Pfizer (PFE) and Roche (RHHBY) also have all failed in prior phase 3 studies.
But the past study failures may provide some promise.
“We think that the failed study actually has moved the space forward,” Yee said, explaining that while the study did fail, a subset of the patients did respond positively to the drug. “In that study, we determined that ... the more mild patients — which is about half the population — appeared to do much better on the drug.”
In other words, it may be that drugs don't work as well at the later stages of Alzheimer's.
Eli Lilly is currently conducting a phase 3 study with a more limited patient enrollment, focused on patients with mild Alzheimer’s and with a focus on cognitive improvement specifically. Results are expected in December.
The company is also working on a study aimed to clip base inhibitors that stop the creation beta amyloids, an area where Merck (MRK) has also made some headway.
Yee still said it’s too early to get too excited about Alzheimer’s drug potential, and sees only a 35% probability that Eli Lilly’s drug will show positive results in December.
“There’s a long history of disappointing results within Alzheimer’s,” Yee said. “We do not know if beta amyloid is the right target."
He still calls for potential upside, however.
"There are reasons to believe that study could work. So we’re optimistic,” he added.
June is Alzheimer's and Brain Awareness month. For more on the financial and emotional toll of America's Alzheimer's problem, see here.