Early studies found that people with Alzheimer’s overproduced amyloid or couldn’t effectively clear it from the brain, Lawrence says. Evolving PET scans (the three-dimensional imaging process that can detect amyloid) led to a study that examined the brains of those with mild cognitive impairment, which, in turn, paved the way for the A4.
Scientists in that precursor trial discovered that they needed to tackle amyloid before people started exhibiting any cognitive impairment. That’s why the 1,000 participants in the A4 will have to meet a number of criteria: Among other requirements, they will simultaneously need to perform normally on cognitive tests and show amyloid buildup in their brains (it’s estimated that about one in three people over 65 have such a buildup).
“We may have to screen a lot of people, because someone may seem like they could be at risk but their scans will be negative,” Lawrence says. Infusions, additional scans and cognitive testing (targeting attention, reaction time, facial recognition, and so on) will follow for participants, half of whom will receive solanezumab, while the other half will receive a placebo.
“It’s exciting to see changes over the years,” Lawrence says. “It still feels very hopeful.”
Moving the field forward
You can detect hope in Cohen’s voice, too, as she speaks about the Toronto Memory Program’s many projects. Only a few years ago, she points out, the program would enroll people without being able to tell whether they had amyloid buildup or not.
Amyloid studies are now smarter and more efficiently designed, she says.
“Most physicians are not aware that this research is going on in Canada or at all,” Cohen says, adding that family doctors are often hesitant to advise their patients to join amyloid-focused clinical trials because of a lack of knowledge.
“If you haven’t been following this field, amyloid is a bit of a black box.”
But once you have an understanding of the potential of amyloid studies — namely, the ability to identify and treat the underlying causes of Alzheimer’s — it’s easy to see why Cohen describes people such as the Stantons as heroes.
Aside from the A4, the Toronto Memory Program runs anywhere from 10 to 20 additional clinical trials, about half of which deal with amyloid. It’s all part of providing care, she adds.
“To me, it’s absolutely unacceptable to be an Alzheimer’s doctor and not be a part of moving the field forward,” Cohen says. “There’s a lot to be said for compassionate and supportive care. We do that everyday in our clinic. But we want people to be getting better. We need to offer that extra piece.”
Luc Rinaldi is a Toronto-based freelancer.