li Lilly’s experimental drug donanemab slowed the progression of Alzheimer’s disease by 60% in patients in the early stages of the brain-wasting disease.

In a breakthrough study, a new drug has demonstrated a nearly twofold increase in the deceleration of cognitive decline for patients compared to the overall treatment group, results reported in May.

These results, however, were found to be less impressive in older, later-stage patients, and those exhibiting higher levels of tau, a protein associated with Alzheimer’s progression.

Anne White, president of neuroscience at Lilly, which produced the drug Donanemab, stated that these findings emphasise the importance of early detection and diagnosis in altering the course of Alzheimer’s.

“Earlier detection and diagnosis can really change the trajectory of this disease,” White said, reported Reuters.

However, the study also revealed that Donanemab, like similar drugs, may result in brain swelling in over 40% of patients genetically predisposed to Alzheimer’s. Prior reports indicated that 24% of the overall Donanemab treatment group experienced brain swelling.

Additionally, the study found that brain bleeding occurred in 31% of the Donanemab group and around 14% of the placebo group. Three trial patients’ deaths were reported to be linked to the treatment.

Study investigator Dr. Liana Apostolova, a professor in Alzheimer’s Disease research at Indiana University School of Medicine, acknowledged the serious nature of these side effects but noted they were typically manageable through MRI monitoring or discontinuation of the drug.

“These side effects should not be taken lightly,” Apostolova said, indicating a need for “very stringent MRI safety screening while we treat these patients.”

Donanemab, similar to Eisai and Biogen’s recently approved Leqembi, is an intravenous antibody engineered to remove beta-amyloid protein deposits from the brains of Alzheimer’s patients.

According to Lilly, even for patients who discontinued the drug after significant reductions in their amyloid deposits, Donanemab’s treatment effect continued to rise relative to the placebo over the 18-month trial period.

White highlighted that even after an average of seven drug-free months at the end of the trial, patients continued to benefit. She added that these findings endorse the concept that Donanemab treatment can cease once amyloid is eradicated from the brain.

Dr. Liz Coulthard, associate professor in dementia neurology at the University of Bristol, also spoke positively of the future prospects.

“Over the next year or two we may well be able to offer patients a choice of treatments that slow down progression of Alzheimer’s disease,” she said. “Some patients did not worsen significantly during the trial and on average progression of disease was slowed 4.4-7.5 months over 18 months.”

In May, Lilly reported that the study had achieved all its goals, demonstrating that donanemab slowed cognitive decline by 29% compared to a placebo in 1,182 people with mild cognitive impairment or mild dementia who had brain deposits of beta amyloid and tau.

For high tau patients, donanemab was shown to slow disease progression by about 17%, while the benefit was 35% for those with low-to-intermediate tau levels.

The comprehensive study results were unveiled at the Alzheimer’s Association International Conference in Amsterdam and published in the Journal of the American Medical Association (JAMA).

Eli Lilly anticipates a decision on the approval of Donanemab by the US Food and Drug Administration (FDA) by the end of this year. The company also mentioned that submissions to other global regulators are ongoing, and most will be finalised by year-end.

Earlier this month, the FDA granted standard approval to Leqembi, the first Alzheimer’s disease-modifying treatment to reach that milestone, facilitating more widespread insurance coverage.

Both Leqembi and Donanemab are currently being studied in extensive trials to assess their impact on delaying the onset of Alzheimer’s symptoms.

Despite the promising news, Lilly shares, which reached a record high near $469 in June, fell by half a percentage point to $447.28 in early trading on the New York Stock Exchange.