Alzheimer’s Treatment Has Changed. Here’s What That Really Means.

For decades, Alzheimer’s treatment was essentially about managing symptoms.

There were medications that could temporarily help with memory, thinking, or behavior. They could make life somewhat easier for some people, but they did not attack the underlying disease process.

That has changed.

In 2023 and 2024, the FDA gave traditional approval to two drugs—lecanemab (Leqembi) and donanemab (Kisunla)—that target beta-amyloid, one of the characteristic abnormalities found in the brains of people with Alzheimer’s disease.

These drugs don’t cure Alzheimer’s. They don’t restore memories that have already been lost.

But in people with early Alzheimer’s disease, they have been shown to slow the rate of cognitive and functional decline.

That is a genuine change in what is possible.

Why this is different

Alzheimer’s is a complicated disease involving several processes in the brain.

Two of the best-known abnormalities are:

• Beta-amyloid plaques, which accumulate between brain cells
• Tau tangles, which develop inside brain cells

The new drugs target amyloid.

Lecanemab and donanemab are monoclonal antibodies—laboratory-produced antibodies designed to recognize specific targets.

They are given as treatments that enter the bloodstream and help the body’s immune system remove beta-amyloid from the brain.

The idea is surprisingly simple:

Remove some of the amyloid, and perhaps slow what happens downstream.

The clinical trials suggest that it works—at least to a modest degree.

What did lecanemab actually accomplish?

Lecanemab was studied in nearly 1,800 people with early Alzheimer’s disease and confirmed amyloid buildup.

After 18 months, people receiving lecanemab experienced less decline on the primary cognitive-and-functional measure than people receiving placebo.

The difference represented about a 27% reduction in the rate of decline compared with placebo.

That number sounds impressive.

But there’s an important distinction:

A 27% slowing of decline does not mean that someone’s memory improved by 27%.

People taking lecanemab still declined. They simply declined more slowly, on average, than those receiving placebo.

That’s an important distinction—and one that can easily get lost in headlines.

What about donanemab?

Donanemab was tested in more than 1,700 people with early symptomatic Alzheimer’s disease and confirmed amyloid pathology.

After 76 weeks, the drug also produced a statistically significant reduction in cognitive and functional decline compared with placebo.

On the Clinical Dementia Rating Scale, the decline was about 29% slower than placebo. On other measures, the reduction in decline ranged from about 20% to 28%.

Like lecanemab, donanemab does not reverse Alzheimer’s disease.

It slows the disease.

That may sound like a subtle distinction.

For someone with Alzheimer’s—and for a spouse or family member watching the disease unfold—it may not be subtle at all.

So how much extra time are we talking about?

This is where things get interesting.

The Alzheimer’s Association’s 2026 report cites analyses suggesting that these treatments may extend the period during which people can maintain independence.

One analysis estimated that lecanemab could extend independence in instrumental activities of daily living by about 10 months, while donanemab could extend it by about 13 months.

Other longer-term modeling of lecanemab suggests that starting treatment earlier may potentially delay progression from mild cognitive impairment to mild dementia by years.

But those longer-term estimates involve modeling and observational or extension data rather than the original randomized trial itself.

So they are promising—not guarantees.

And that brings us to one of the most important ideas about these drugs:

Earlier appears to matter.

These drugs aren’t for everyone with memory problems

This is crucial.

Lecanemab and donanemab aren’t general-purpose treatments for “memory loss.”

They’re intended for people with early Alzheimer’s disease—generally people with:

• Mild cognitive impairment due to Alzheimer’s, or
• Mild Alzheimer’s dementia

And there needs to be evidence that amyloid is actually present in the brain.

That usually involves specialized testing such as amyloid PET imaging or cerebrospinal-fluid testing, depending on the clinical setting.

Someone with memory problems caused by depression, medication side effects, vascular disease, another neurological condition, or another type of dementia isn’t automatically a candidate.

In other words:

The first step isn’t getting the drug. It’s getting the diagnosis right.

There’s a catch—and it’s a significant one

These aren’t simple pills you pick up at the pharmacy.

Both treatments can cause a complication called amyloid-related imaging abnormalities, or ARIA.

ARIA can involve:

• Temporary swelling or fluid buildup in the brain
• Small areas of bleeding
• Sometimes larger brain hemorrhages

Most cases don’t cause symptoms, but some can cause headache, confusion, dizziness, vision changes, difficulty walking or seizures. Rare cases can be serious or fatal.

That’s why treatment requires MRI monitoring.

And the FDA has actually strengthened monitoring requirements for lecanemab. In 2025, the FDA recommended an additional MRI between the second and third infusions because earlier detection of brain swelling could help reduce the risk of serious complications.

Your genes can matter

There’s another wrinkle.

A gene called APOE influences the risk of developing Alzheimer’s—and people who carry two copies of the APOE ε4 variant have a higher risk of ARIA when receiving these anti-amyloid treatments.

The FDA recommends APOE ε4 testing before donanemab treatment to help inform the risk discussion.

That doesn’t mean having APOE ε4 automatically rules someone out.

It means the risk-benefit conversation becomes more important.

What about blood thinners and aspirin?

This is another issue that has to be considered individually.

Some medications that reduce blood clotting can increase concerns about bleeding in the brain while someone is receiving an anti-amyloid drug.

That includes certain anticoagulants and antiplatelet medications.

Even aspirin needs to be discussed as part of the overall treatment picture.

Nobody should stop an important medication because they read this article.

The point is to make sure the treatment team knows about everything a person is taking before starting an anti-amyloid drug.

There’s also a practical burden

These treatments require more than taking a pill every morning.

Lecanemab was originally administered by IV infusion every two weeks.

Donanemab is administered by IV infusion every four weeks.

That means appointments, transportation, monitoring, brain imaging, and dealing with potential infusion reactions.

And there’s the financial side.

Medicare coverage became available for FDA-approved lecanemab after its traditional approval, although coverage requirements and patients’ out-of-pocket costs depend on the circumstances and insurance arrangement.

So the decision isn’t simply:

“Does this drug work?”

It’s more like:

“For this particular person, is the amount of slowing worth the treatment burden, risks, monitoring, and cost?”

That’s a much more useful question.

And there’s some good news about how treatment is delivered

The field is already moving.

In July 2026, the FDA approved a subcutaneous starting regimen for lecanemab, allowing patients to begin treatment with an injection under the skin that can be administered at home by the patient or caregiver.

After the initial treatment period, patients can also transition to subcutaneous or IV maintenance treatment.

That’s a significant practical development.

A treatment that once meant regular trips to an infusion center is beginning to look a little more like something that could eventually fit into ordinary life.

But let’s keep our feet on the ground

It would be easy to call these drugs a cure.

They’re not.

It would also be easy to say they “stop Alzheimer’s.”

They don’t.

And it would be misleading to suggest that someone taking one of these drugs will necessarily gain an extra year of healthy life.

Clinical trials give us average effects across groups of people. Individuals can respond differently.

The more accurate description is:

For carefully selected people with early Alzheimer’s disease, anti-amyloid drugs can slow the progression of the disease.

That’s enough.

We don’t need to turn it into a miracle to recognize that it matters.

The bigger breakthrough may be what comes next

Perhaps the most exciting thing about these drugs isn’t simply the modest slowing we’ve seen so far.

It’s what they tell us about the possibility of treating Alzheimer’s earlier and more precisely.

If removing amyloid can slow the disease after symptoms have begun, researchers naturally want to know what happens if the disease is attacked even earlier.

Could treatment before significant cognitive symptoms appear work better?

Could combinations targeting amyloid, tau, inflammation, vascular health, or other biological processes work better than attacking any one pathway alone?

Those questions are still being studied.

We don’t know the answers yet.

But Alzheimer’s research is no longer entirely trapped in the old model of:

“The brain is deteriorating. Let’s try to manage the symptoms.”

We’re beginning to enter a different era:

“The disease is developing. Can we identify what’s happening early enough to change its trajectory?”

That’s a very different question.

And for millions of older adults and their families, it’s an important one.

The Watchdog Takeaway

Alzheimer’s hasn’t been cured—but something genuinely important has changed. For people with early Alzheimer’s disease, two FDA-approved drugs can now slow the progression of the disease itself. The benefit is modest, the treatment isn’t risk-free, and it requires careful diagnosis and monitoring. But for the first time, slowing the disease—not simply treating its symptoms—is a realistic part of Alzheimer’s care.