It's not a cure, but it does delay the progression
Leqembi is a monoclonal antibody that targets amyloid plaques in the brain, administered via intravenous infusion every two weeks in hospital settings. Clinical trials demonstrated 27% reduction in cognitive decline rate over 18 months, though the treatment is not a cure and carries risks including brain hemorrhages and cerebral edema.
- Lecanemab reduces cognitive decline by 27% over 18 months in clinical trials
- Annual cost approximately 142,800 Brazilian reais (about $26,500 USD)
- Administered via intravenous infusion every two weeks in hospital settings
- Patients must have amyloid plaques confirmed and cannot carry the APOE-e4 gene mutation
- Donanemabe, a competing drug approved in Brazil in April 2025, shows 35% cognitive decline reduction
Brazil's health regulator approved lecanemab (Leqembi) for early-stage Alzheimer's treatment, marking the second disease-modifying therapy available in the country. The monoclonal antibody showed 27% reduction in cognitive decline but faces accessibility challenges due to high costs and strict eligibility criteria.
Brazil's health regulator has approved lecanemab, a new drug for Alzheimer's disease, marking a significant moment in the country's approach to a condition that has long offered few treatment options. The Agência Nacional de Vigilância Sanitária, or Anvisa, granted authorization to the medication, which is sold under the brand name Leqembi by pharmaceutical companies Biogen and Eisai. The approval was published in the official government gazette in late December, though no launch date has been announced yet.
Lecanemab belongs to a new class of monoclonal antibodies designed to slow—modestly—the progression of Alzheimer's disease. It works by binding to amyloid plaques that accumulate in the brain, a hallmark of the disease, and clearing them from around neurons. Patients receive the drug through intravenous infusion once every two weeks in a hospital setting, with each session lasting about an hour. The medication is approved specifically for adults in the early stages of the disease: those with mild cognitive impairment or mild dementia caused by Alzheimer's. Not everyone qualifies. Patients must have amyloid plaques confirmed through testing, and they cannot carry the APOE-e4 gene mutation, which increases both the risk of developing Alzheimer's and the likelihood of serious side effects from the drug.
In clinical trials spanning eighteen months, lecanemab reduced the rate of cognitive decline by 27 percent. When those results were published in 2022, it was the first time any medication had demonstrated the ability to directly alter the disease's course. Mychael Lourenço, a neuroscientist at the Federal University of Rio de Janeiro who studies Alzheimer's, emphasizes that while the benefit is modest, it represents genuine progress. "It's not a cure," he told a Brazilian newspaper, "but it does delay the progression of the patient's condition." Lecanemab joins donanemabe, another monoclonal antibody approved in Brazil last April, as part of this emerging generation of disease-modifying treatments.
Yet approval does not mean accessibility. The cost presents an immediate barrier. In the United States, the annual treatment runs approximately $26,500, which converts to roughly 142,800 Brazilian reais. Brazil's drug pricing authority, the Câmara de Regulação do Mercado de Medicamentos, has not yet set a maximum price for lecanemab in the country. Donanemabe, already available in some Brazilian hospitals and clinics, costs around 24,000 reais per month—more than 200,000 reais annually—and shows slightly better results, with a 35 percent reduction in cognitive decline over the same eighteen-month period. Lourenço does not expect either drug to be covered by Brazil's public health system anytime soon. "They are very expensive," he said. "I imagine the decision would be negative based on cost, the fact that it's not indicated for everyone, and that it doesn't cure the disease."
Beyond cost, both medications demand careful patient selection and specialized medical oversight. Doctors must screen patients rigorously, ordering imaging tests and other examinations to assess risk. The drugs carry serious potential side effects: brain hemorrhages, infusion-related complications, headaches, and in some cases, cerebral edema—swelling in the brain that can range from causing nothing more than a headache to proving fatal. Lourenço stresses that this is not a medication for any patient with Alzheimer's. It is a specific prescription for a specific subset of people, with clear contraindications for others.
Another complication looms beneath the surface. Most clinical trials for these medications were conducted in the United States and Europe, where the populations studied were genetically more homogeneous than Brazil's. Lourenço considers it important to evaluate how well lecanemab and similar drugs actually work in Brazilian populations, and whether the safety profile holds across different genetic backgrounds. The approval represents a genuine advance after years without new therapeutic options for Alzheimer's, but the real test—whether this drug will meaningfully reach the people who need it—remains ahead.
Notable Quotes
It's not a cure, but it does delay the progression of the patient's condition— Mychael Lourenço, neuroscientist at Federal University of Rio de Janeiro
The drug is not indicated for all Alzheimer's patients and requires careful clinical screening; some patients are contraindicated— Mychael Lourenço
The Hearth Conversation Another angle on the story
Why does it matter that this drug was approved in Brazil specifically, rather than just being available globally?
Because approval by a country's regulator is what allows it to be prescribed there legally. Without Anvisa's sign-off, Brazilian doctors couldn't use it, no matter how well it works elsewhere. It's the formal permission to enter the market.
The 27 percent reduction in cognitive decline—is that actually significant, or is it the kind of number that sounds better than it is?
It's modest, which is why the experts keep saying that word. It's not stopping the disease. But for someone watching their memory slip away, slowing that process by more than a quarter over eighteen months is the first real option medicine has offered. That's why it matters, even if it's not a cure.
Why can't people with the APOE-e4 gene mutation take this drug?
Because they're at higher risk of the drug's worst side effects—brain swelling, hemorrhages. The mutation itself makes Alzheimer's more likely, and it also seems to make the body react more dangerously to lecanemab. So doctors have to exclude them to keep them safe.
The cost in the U.S. is $26,500 a year. Why would it cost so much more in Brazil, a country with lower average income?
It might not cost more in absolute terms—the pricing authority hasn't decided yet. But the comparison matters: if it costs the same in reais as it does in dollars, it becomes prohibitively expensive for most Brazilians. That's the real problem. The drug itself doesn't change price; the country's ability to pay does.
You mentioned the trials were done mostly in the U.S. and Europe. Does that mean the drug might not work as well for Brazilian patients?
We don't know yet. That's the honest answer. The genetic diversity in Brazil is different, and disease can behave differently across populations. The drug might work the same way, or there might be surprises. That's why Lourenço thinks it's important to study it specifically in Brazil, rather than just assuming the American results apply everywhere.
If it's this expensive and risky, why approve it at all?
Because for someone in the early stages of Alzheimer's with amyloid plaques confirmed, and without that risky gene mutation, it's the only option that actually slows the disease down. No treatment is better than a modest one when nothing else exists. The approval doesn't force anyone to take it—it just makes it available for the people it might help.