The FDA has approved an Alzheimer’s drug that slowed the rate of cognitive decline in clinical trials without using an advisory committee. The high drug cost — priced at $26,000 per year, Eisai said — combined with strict restrictions on reimbursement by US government-funded health schemes will severely limit the number of patients able to access the medicine, at least for now. What is going on here?

On Friday, the US Food and Drug Administration said it had approved lecanemab under an accelerated approval process, describing the medication as “an important advancement in the ongoing fight” to treat Alzheimer’s effectively. The question is, will doctors and insurers believe it’s worth the money?

lecanemab, co-developed by Tokyo-based Eisai and US biotech Biogen, is a monoclonal antibody that reduces the buildup of sticky plaques in the brain called beta-amyloid. Phase 3 trial results published in November showed it slowed the rate of cognitive decline in early-stage Alzheimer’s patients by 27 percent compared to placebo, a moderate but statistically significant effect, say experts.

However, some physicians question whether the reduction in the rate of cognitive decline in patients is “clinically meaningful.” They have raised concerns over the safety profile of lecanemab, which can cause swelling and bleeding in the brain. At least three Alzheimer’s patients have died from brain bleeds after taking lecanemab, including two who were also taking blood-thinning medicines.

For more than 40 years, researchers have widely believed that Alzheimer’s disease symptoms are largely due to a buildup of insoluble plaques of beta-amyloid in the brain. But recent research has questioned this idea. Many people with amyloid plaques have no symptoms of dementia, and treatments aimed at slowing the buildup of plaques have shown little effect on the progress of the disease.

A study from the University of Cincinnati, OH, which appears in the Journal of Alzheimer’s Disease, suggests an alternative theory — that Alzheimer’s symptoms are caused not by an increase in insoluble amyloid plaques but by a decrease in the soluble beta-amyloid that is essential for cognitive function.

Of course, Alzheimer’s groups want this medication as they are desperate for help, but at what cost? Then there are doctors who will be prescribing this drug. I spoke to several this weekend, and they all said the same thing: “show me the data.” They are also alarmed at that this drug was approved without an advisory committee.

It’s ironic that, in an era where physicians want more data, the FDA approved this drug without an advisory committee. I would guess that they wanted to avoid the mess of the last Biogen drug approval.

Ultimately it will be up to insurers and doctors to determine if this drug works.