More than one year has passed since Eisai’s anti-amyloid drug Leqembi hit the market in the U.S. and Japan. Here’s what neurologists have learned so far.
Since Leqembi was approved in the U.S. in the summer of 2023, controversy has roiled among clinicians over whether the Alzheimer’s anti-amyloid drug’s risks of side effects outweigh its benefits. The drug has since received approval in Japan, China, South Korea, Hong Kong, Israel, the UAE, and the UK — but it was recently rejected by regulators in the EU and Australia, and the UK’s state insurer has refused to cover its cost for patients.
At the 2024 Clinical Trials on Alzheimer’s Disease conference, researchers presented what they know about the drug, based on learnings from the people already taking Leqembi in the U.S. and Japan. Here are five big takeaways.
1. How long it takes to go from diagnosis to start Leqembi
The Komodo Research Database tracks 3,155 insured patients who received Leqembi since it was first approved. For those diagnosed with Alzheimer’s or mild cognitive impairment in 2023, it took an average of five months to start treatment.
However, the average doesn’t tell the whole story — many patients started Leqembi up to 4.5 months sooner or later than average. This data reflects a growing body of research showing nationwide disparities in access to clinical care.
What does the care pathway look like from start to finish?
“As a practicing neurologist who has prescribed a lot of the mAbs, they’ll get a confirmatory diagnosis via [amyloid] CSF or PET and then they have to come and see me in follow-up,” Dr. Marwan Sabbagh, a neurologist at the Barrow Neurological Institute, who presented the data explained.
After that, he tells patients the risks and benefits of Leqembi, and the patient decides whether to take it. “Then we put the paperwork, insurance authorization, and select [the] infusion center,” Sabbagh said.
A Trial Participant’s Inside Look at New Alzheimer’s Drug Leqembi
2. Black and Hispanic Americans aren’t taking Leqembi in the U.S.
Older Black and Hispanic Americans are one-and-a-half to two times more likely to develop Alzheimer’s than their white counterparts. Despite that, among the 3,155 participants in the research database, 84.3 percent were white. Black and Hispanic Americans are less likely to receive a timely diagnosis — by the time they know they have Alzheimer’s, they’re no longer eligible for Leqembi.
3. Most U.S. infusions are occurring in urban centers
Earlier this year, we mapped out drug infusion centers across the U.S. and found that patients living in the counties with the nation’s highest prevalence of Alzheimer’s need to travel several hours to receive a Leqembi infusion.
According to data presented at the CTAD panel, 93.3 percent of patients received infusions in urban settings, highlighting the challenge that many Americans in sparsely populated or under-resourced areas face in accessing these new Alzheimer’s drugs.
Alzheimer’s Rates Are Highest In These Counties—But No Leqembi Access
4. Japan is treating more people, and seeing fewer ARIA cases
Takeshi Iwatsubo, a professor at the University of Tokyo, provided a snapshot of what treatment looks like in Japan. More than 7,000 patients have received Leqembi so far. Iwatsubo noted that there is a shortage of dementia experts licensed to prescribe and use Leqembi and an uneven distribution of infusion centers and PET centers, mirroring the situation in the U.S.
In line with data from Leqembi’s Phase 3 trial, the rates of ARIA are lower in Japanese patients than in Americans. So far, only 4.5 percent of patients developed ARIA compared to 14 percent in the Phase 3 Leqembi trial. The results follow the same surprising pattern that researchers first spotted in clinical trials: Asian populations were less prone to ARIA.
Alzheimer’s Drugs and ARIA: Leqembi ‘Brain Bleeds’ Side Effect, Explained
5. Doctors say blood tests aren’t adequate to confirm Alzheimer’s biomarkers — yet
Although blood tests for Alzheimer’s have made headlines all year, panelists at the CTAD session weren’t ready to use them instead of CSF tests or amyloid PET scans to determine whether someone is eligible for Leqembi.
“I don’t feel quite ready to put an infusion patient infusion chair on the blood based biomarkers,” Sabbagh said.
Lawrence Honig, a neurologist at Columbia University, also said he felt uncomfortable using blood tests to confirm amyloid status. This could change in the future, he said, for patients who present with the typical symptoms of Alzheimer’s.
So what was the result? Would a placebo have worked as well