New Alzheimer’s drug, approved by FDA, garners mixed reviews

Published on Wednesday, February 1, 2023

By: Andrea Wright Dilworth, awdilworth@umc.edu

The Food and Drug Administration approved a new drug for Alzheimer’s patients the first week of 2023, but questions remain about its efficacy, safety and cost.  

Lecanemab received accelerated approval – reserved for drugs that fill an unmet need in treating serious conditions – based on results of an early Phase 2b trial. A request for full approval, based on recently published Phase 3 data, is pending.  

In the Phase 3 clinical trial of 1,800 people with early-stage Alzheimer’s disease, the most common cause of dementia, the drug slowed cognitive decline by 27 percent over 18 months of treatment.  

Lecanemab is a monoclonal antibody man-made protein infusion given every two weeks that works by binding to amyloid beta plaques in the brain, which contribute to cognitive decline.  

Neurology experts at the University of Mississippi Medical Center’s MIND Center are weighing the benefits versus risks of the new drug that will be sold under the name Leqembi. 

While Dr. Juebin Huang, associate professor of neurology and director of The MIND Center’s Neuro-Clinical Core, has received inquiries from patients, he is in no rush to prescribe lecanemab. 

“It is not a magic pill that would cure Alzheimer’s disease based on the data we have so far,” said Huang. “I would wait until we hear more from the FDA regarding its clinical benefit. I may prescribe it at that point if it is fully approved and available. I think in a carefully selected patient population, the pros can outweigh the cons.” 

Despite promising data, “we don’t know how much receiving the medication will affect the patient’s function in real life. Could that mean an extra six months to a year of recognizing a loved one’s face, or performing a valued activity? We don’t know.” 

Huang, principal investigator of a clinical trial for the Alzheimer’s drug Gantenerumab that was just discontinued by its manufacturer due to lack of efficacy, believes there is still hope for a safer, more effective treatment for the progressive disease.  

He recalls the interest in aducanumab, a similar drug that received accelerated approval last year but for which interest has waned due to side effects and effectiveness.  

“Although lecanemab appears to have more convincing clinical benefit with less frequency of adverse events -- cerebral edema and microhemorrhage -- compared to aducanumab, it is still a baby step towards a more robust disease modifying treatment for Alzheimer’s disease,” said Huang.  

Huang’s hesitancy is based on a few factors: long-term benefits and risk are unknown, side effects are significant, bi-weekly infusions would present challenges to many, and the current cost -- $26,500 per year -- puts the drug out of reach for those most affected by the disease.  

Agnes Mayberry, 79, diagnosed with Alzheimer’s eight years ago, would not be able to afford it even with her veteran’s benefits, said daughter Pam Hooper, of Ridgeland, who has witnessed a steady decline in her mother. “She doesn’t remember anyone. She has reversed back to a child.” 

Though her mother’s case is likely too advanced to deem her eligible, as far as Hooper is concerned, the treatment’s side effects outweigh the small chance of improvement anyway.  

Dr. Kevin Sullivan, assistant professor of medicine at The MIND Center, is also “underwhelmed” by the risk-benefit of the drug. Not only is the benefit small, but the risks go beyond side effects.  

“These [microhemorrhages] occurred in 21 percent of the lecanemab group, most without symptoms, but we don’t know what the long-term consequences will be,” said Sullivan. “I consider cost and use of health care resources to be additional risks, and both of these figure to be considerable with this drug.  

“In my opinion, the small benefit of the drug we’ve seen so far does not outweigh the negatives, but this may change with additional studies. Unfortunately, I expect many of the problems to arise that we already see with aducanumab. 

“Additionally, many health care systems, especially in rural areas, simply lack the resources to provide these drugs, which require a PET scan to determine eligibility, infusions of the drug every other week, and regular MRI scans to monitor side-effects. Between cost and infrastructure limitations, equitable access to these drugs doesn’t seem possible at the moment.” 

Lecanemab, or any other drug, is not a replacement for current guidelines on preventing and delaying dementia, which comes down to managing risk factors including hypertension and diabetes to promote brain health over the entire lifespan, said Sullivan.  

Because most new drugs are being tested in people who already have or are showing signs of Alzheimer’s, doctors are likely not intervening soon enough, he said.  

 “One of the most difficult aspects of Alzheimer’s disease is that these pathological processes are thought to be in development perhaps decades before we ever see an outward sign of decline,” said Sullivan. “The best path forward for now is to continue to study drug interventions that can target these pathological processes.”   

For the more than 6 million who already have the disease, Huang is optimistic that more drugs are being developed that have a much better target engagement toward fighting the disease process.  

“And we are able to diagnose Alzheimer’s disease way earlier than in the past by applying more newly developed disease specific biomarkers,” said Huang. “Hopefully that will lead to more drugs being tested in very early stage disease, and that would lead to more significant breakthroughs.”

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