Alzheimer’s drug donanemab lowers risk of dementia

A “powerful and meaningful” drug is offering new hope in the battle against Alzheimer’s disease — with scientists hailing it as a “huge opportunity” for patients suffering from early onset dementia.

The groundbreaking medication donanemab, developed by Eli Lilly, had a successful clinical trial and is expected to be approved by the Food and Drug Administration this fall.

People who took donanemab had a 40% lower risk of progressing from mild cognitive impairment to mild dementia, or from mild to moderate dementia.

If approved, donanemab would be the third Alzheimer’s drug to enter the market in recent months, following Leqembi and Aduhelm.

This is “just the opening chapter in a new era of molecular therapies for Alzheimer’s disease,” Dr. Gil Rabinovici, director of the University of California San Francisco’s Memory and Aging Center, wrote in an editorial for JAMA.

“This will be a very important and meaningful drug,” said Dr. Daniel Skovronsky, chief scientific and medical officer at Lilly, as quoted in Fierce Biotech.

“[T]here’s a huge opportunity here for patients,” Skovronsky added.

Like Leqembi and Aduhelm, donanemab is a monoclonal antibody that attacks plaque in the brain, which is made up of a protein called amyloid.

Amyloid plaques lead to the spread of another protein called tau. Both amyloid and tau proteins lead to the development of Alzheimer’s disease.

The donanemab trial also found that the drug slowed cognitive decline by 35% compared with a placebo in people with low to intermediate levels of tau protein in the brain.

Donanemab, in fact, was shown to be even better at removing amyloid plaques than Aduhelm or Leqembi.

And while Leqembi is meant to be taken for longer periods of time, patients taking donanemab can have a fixed-duration dosing schedule, meaning in some instances they can take it and stop.

“I expect that many patients will be able to stop dosing even as soon as 12 months,” Skovronsky said.

He added, “That’s a big difference than being prescribed a drug that you might have to take the rest of your life. And I think that could be exciting and important for patients.”

Despite the excitement, these new Alzheimer’s drugs have limitations and risks, experts noted.

Donanemab and the other new drugs have been linked to brain swelling and bleeding. Three people in the clinical trial of donanemab died from these side effects.

The risk of brain swelling and bleeding were higher among people with the APOE4 gene, which is related to an increased risk for Alzheimer’s.

Additionally, people with more advanced cases of Alzheimer’s disease showed little to no benefit compared to those who took a placebo.

Therefore, donanemab could be restricted to people with low to intermediate levels of tau proteins, which indicates mild disease.

Nonetheless, Skovronsky and other medical experts are optimistic that the FDA’s approval will come soon.

“Every day that goes by, there are some patients who pass through this early stage of Alzheimer’s disease and become more advanced and they won’t benefit from treatment,” Skovronsky said in an interview with CNBC. “That’s a very pressing sense of urgency.”