For most of modern history, an Alzheimer’s diagnosis was a sentence with no appeal — a slow erasure that medicine could describe but not slow. Then came lecanemab, sold under the brand name Leqembi: the first treatment shown not merely to ease symptoms but to slow the disease itself. It is real, and it is historic. It also arrives with an asterisk that falls hardest on the people already failed most.

What the drug actually does

Lecanemab is an antibody, given by infusion every two weeks, that clears a sticky protein called amyloid from the brain. In its pivotal trial — CLARITY AD, published in the New England Journal of Medicine with nearly 1,800 participants — it slowed cognitive decline by roughly 27 percent over eighteen months. Not a reversal. Not a stop. A slowing. The FDA granted it full approval in 2023.

Read the label closely, though, because the entire story lives in one line: lecanemab is approved only for early Alzheimer’s — mild cognitive impairment or mild dementia, with the presence of amyloid confirmed by a scan or spinal fluid. The agency states plainly that there is no evidence it helps if you start later. Early diagnosis is not a nicety here. It is the whole ballgame. Miss the window, and the breakthrough simply isn’t for you.

The double bind

Now lay our reality over that window. First, the risk: African Americans are about twice as likely as white Americans to develop Alzheimer’s, according to the Alzheimer’s Association. Second, the diagnosis: Black Americans are more likely to be diagnosed later in the disease — or never formally diagnosed at all — too often because the early signs get waved off, by families and clinicians alike, as “just getting old.” That sentence, repeated, is what runs out the clock on a drug that only works early.

Third, and most quietly damning: the science itself. KFF Health News reported that many Black volunteers were screened out of the lecanemab trials because their PET scans showed comparatively lower levels of amyloid — and because the drug targets amyloid, they were excluded regardless of their symptoms. The result is an evidence base that underrepresents us, and open questions about how neatly an amyloid-targeting drug maps onto Alzheimer’s as it actually shows up in Black patients, whose dementia more often travels with vascular disease. We were, in a real sense, designed out of the study that defined the cure.

Then there’s the bill

Even for those diagnosed in time, the drug lists around $26,500 a year, demands biweekly infusions, and requires repeated brain MRIs to watch for swelling and bleeding — a side effect that showed up in more than one in ten trial participants. That means specialists, imaging centers, time off work, and a care setting equipped to manage it. The patients diagnosed latest and treated in the most under-resourced settings — disproportionately Black and low-income — are precisely the ones least able to use the thing, even if they reach it. As critics told KFF, a treatment that only helps people who are caught early and can afford the apparatus around it isn’t a cure for the disease. It’s a cure for some of the people who have it.

Standing in the gap differently

Naming the cliff is not the same as surrendering to it. If memory changes show up in someone you love, do not accept “it’s just age.” Ask, directly, for a cognitive evaluation and a referral to a memory specialist. Know your family history and say it out loud in the exam room. Ask about brain-health research registries, which need Black participants both to serve patients now and to fix the evidence gap for the next drug. Information is the first intervention, and it is the one we can hand each other today. The cure, as it stands, was not built for us to reach. Reaching anyway — earlier, louder, together — is the work.

Sources: New England Journal of Medicine — CLARITY AD trial of lecanemab in early Alzheimer’s (~27% slowing of decline; ARIA in ~12.6%) · U.S. Food and Drug Administration — traditional approval of Leqembi for early-stage disease only · Alzheimer’s Association — African Americans about twice as likely to develop Alzheimer’s; later/missed diagnosis · KFF Health News — Black volunteers screened out of the lecanemab trial; cost (~$26,500/year) and access barriers.