Last week, a major medical milestone was reached when the Food and Drug Administration approved an Alzheimer's medication. The drug, known as Leqembi and developed by Cambridge-based pharmaceutical company Biogen, is the first medicine proven to slow the course of the disease in its early stages. Now that it's FDA approved, it can also be covered by Medicare and Medicaid services, expanding access to millions. That access will be critical for the roughly 500,000 Americans diagnosed with the disease every year, which is known to cause severe memory loss, agitation and cognitive decline.
Dr. Rudolph Tanzi, the vice chair of neurology and co-director of the McCance Center for Brain Health at Massachusetts General Hospital, says that while this news is historic, the drug has caveats that limits its use for some patients.
"I would just emphasize this is just the beginning of where we're going to go," he said.
The drug, Tanzi explains, works by targeting and removing the dementia-causing amyloid plaques that build up in the brain. He compares the relationship between amyloid and Alzheimer's to cholesterol and heart disease.
"Optimally, you want to bring your cholesterol down decades before you might get heart disease," he said, "and you want to get your amyloid down in your brain decades before you get Alzheimer's disease."
While Leqembi has been proven to slow cognitive decline by 27%, it has only been approved for use in patients with early stages of Alzheimer's. Patients in the later stages of the disease are unlikely to benefit from the drug due to its inability to reverse cognitive decline that has already occured.
Tanzi says that ideally, patients would have access to a drug that can decrease amyloid buildup even before they start showing any symptoms of Alzheimer's. Unfortunately, Leqembi has drawbacks that prevent it from being used this way: its price and safety. Leqembi costs about $26,000 for a year of treatment and it has the potential to cause brain swelling or hemorrhaging. These safety risks necessitate the use of MRIs to monitor brain health, brining the total cost of administering the drug to about $70,000.
"So, if they all had the test today, how many Americans have amyloids in their brain and don't yet have any symptoms of Alzheimer's?" Tanzi explains, "It's millions. It could even be tens of millions. You can't obviously afford to give that many people the drug."
That future could be a preventative Alzhemier's medication that comes in the form of a little white pill, something Tanzi says his team is actively working on.
"We're hoping to come up with alternatives that are cheaper and safer soon," he said. "Then, it's going to be a whole new ballgame, because then we can tell the FDA, 'Look, we can move the amyloid out safely. We can do it affordably. Let's get it in people before they have symptoms and get that amyloid out before they even turn the corner.'"
