New Alzheimer’s drug shows promise, but don’t celebrate yet

Photo: vestque via Flickr

Photo: vestque via Flickr

A recent announcement by drugmaker Eli Lilly that its drug donanemab slowed the progression of Alzheimer’s by nearly one-third is giving many patients, caregivers and providers reason for optimism. But let’s not do a happy dance quite yet.

I don’t want to diminish anyone’s hope, especially the estimated 6 million Americans living with Alzheimer’s disease and their caregivers. But it’s prudent to remember that other drug companies have shown promising initial results for Alzheimer’s drugs, only to find that larger-scale Phase 3 trials didn’t pan out, as Gina Kolata of The New York Times notes.

“Pharmaceutical companies have spent billions of dollars testing anti-amyloid drugs to no avail, leading many experts to believe that the hypothesis is wrong — or that the only way to treat Alzheimer’s is to start very early before there are any clinical signs of disease,” she wrote.

Donanemab specifically targeted the protein beta-amyloid in early symptomatic Alzheimer’s disease and helped clear it from the brain, which Lilly believes can be a viable means to slow cognitive decline. According to a company press release on the TRAILBLAZER-ALZ study, a randomized, placebo-controlled, double-blind, multi-center Phase 2 trial with 272 participants, the drug met the primary endpoints in Alzheimer’s Disease Rating Scale (iADRS), slowing decline by 32% relative to placebo, which was statistically significant.

However, “the drug missed most of the secondary trial goals, including one watched by experts,” Business Insider reported.

More detailed data, published in the March 13 online edition of The New England Journal of Medicine, shows mixed results, according to this story in BioPharma Dive. “Newly disclosed, however, is a detailed accounting of how the drug performed on several important secondary measures, on several of which donanemab didn’t show a clear-cut difference,” reporter Jonathan Gardner wrote.

On one key scale, known as CDR-SB, those taking Donanemab didn’t do all that much better than volunteers taking a placebo at the end of the 76-week investigation; differences were more apparent between the groups at 36 and 52 weeks. Yet, as Deborah Brauser reported in Medscape, “the donanemab group did show an 85-centiloid greater reduction in amyloid plaque level at 76 weeks, as shown on PET, compared with the placebo group.”

As Ronald Petersen, who directs Mayo’s Alzheimer’s Disease Research Center, told The Advisory Board, “These data are fine to rationalize doing the larger study, but these data are too preliminary to conclude any clinical benefit or efficacy.”

The company is continuing to study the drug in a second, 500-patient trial, according to CNBC. More extensive, international Phase 3 studies will be needed before Lilly can apply for FDA approval.

While any progress on Alzheimer’s Disease is good news, journalists should be cautious when reporting on these drug trials and their potential. There have been too many instances of hopes being dashed when once-promising treatments turn out to be a bust.

Journalists: while we await results of more drug trials and treatments, how are those with Alzheimer’s and their caregivers coping during the pandemic? What local services and supports are available to help families? It’s been challenging to get an accurate assessment of how people with Alzheimer’s in nursing homes are faring — now that visiting restrictions have eased in many states, are we getting a more accurate picture?

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