Stop taking Alzheimer’s medication

The European Medicines Agency (EMA) has declined to approve the drug lecanemab for the treatment of Alzheimer’s disease. The decision was based on an assessment of the risks associated with the drug, in particular amyloid-associated imaging abnormalities (ARIA), which can cause inflammation and bleeding in the brain in some patients.

Although lecanemab showed a 27% reduction in cognitive decline in clinical trials, the European Medicines Agency concluded that these benefits did not outweigh the risks of serious side effects, including major brain bleeding, especially in patients with the APOE4 gene variant, which is common among those with Alzheimer’s disease.

The decision has sparked controversy and dismay in the scientific and medical community, with some experts believing that the EMA should have provided clearer guidance on what constitutes clinically significant benefit in the treatment of Alzheimer’s disease. However, there is also recognition of the need to continue research and development of safer and more effective treatments for this devastating disease.

In particular, the agency’s expert panel recommended against granting marketing authorisation to Leqembi, the brand name for Lecanemab. The committee considers that the observed effect on delaying cognitive decline does not outweigh the risk of serious side effects associated with the medicine, in particular the frequent occurrence of amyloid-related imaging abnormalities (ARIA), which include swelling and bleeding in the brain.

Two years ago, the first results of lecanemab were greeted with euphoria, because it was the first drug in decades to offer some benefit to patients with Alzheimer’s, a disease that currently has no cure and whose causes are unclear. The disease affects 50 million people and their families worldwide.

The drug targets amyloid, a protein that builds up in the brain and may have some effect on the progression of the disease. Early results showed that the antibody reduced cognitive decline by 27%, according to a clinical trial of 1,700 patients across several countries. The effect was so modest that patients or caregivers were unable to notice it. Added to the results were several cases of encephalitis, bleeding and at least two deaths.

The FDA initially granted emergency use authorization for the drug, then gave it full approval in July. In November 2022, a study showed that the drug shrank patients’ brains, but the reasons were unclear. Despite this, the manufacturers decided to move forward with approving the antibody.

All eyes are now on whether the European Commission will agree with the US agency’s decision on the drug, which is being developed by Eisai and Biogen. The European Committee for Medicinal Products for Human Use ultimately recommended against approval of the drug due to its potential adverse effects.

Monoclonal antibodies are among the most expensive drugs in the world. Aducanumab — an antibody similar to lecanemab that Biogen developed for Alzheimer’s but failed — costs $56,000 per patient.

One of the big challenges for lecanemab and other similar drugs, such as donanemab, which reduces cognitive decline by 35% and is still being evaluated, is that the first signs of dementia must be detected very early and the drug must be taken for life to have clear results. This creates challenges and costs in diagnosis and treatment that few health systems can afford.

Other experts echoed this sentiment, albeit with apparent dismay. “I am disappointed by the decision not to license lecanemab for the treatment of Alzheimer’s disease,” John Hardy, a neuroscientist at University College London, told SMC.

“The question of whether the unequivocal statistical benefit of a treatment is worth the risk of serious, if rare, side effects is always difficult with any treatment, and in this case the EMA and the FDA came to different conclusions when presented with similar data. I’m sure we’ll now see wealthy people with early-onset Alzheimer’s traveling to the US or other countries for treatment.”

“I think this decision will be reconsidered as US and other physicians gather real-world data with lecanemab and donanemab,” he added.