American pharmaceutical company Eli Lilly announced the encouraging results from clinical trials of the new Alzheimer’s drug donanemab in a press release. According to the company, the drug can slow cognitive decline in patients by 35%. Data is considered preliminary before publication in a peer-reviewed journal.
The study was conducted on 1,182 people with early signs of Alzheimer’s disease who also had beta-amyloid protein clusters in their brains. These microscopic aggregates are thought to be the cause of memory impairment in Alzheimer’s disease.
Half of the participants received 700 mg of donanemab intravenously three times four weeks apart, followed by 1400 mg of donanemab every four weeks. The other half of the participants received a placebo.
The number of beta-amyloid clusters in the brain was decreased in 72% of patients receiving Donanemab. Compared to the placebo group, the development of cognitive impairment was slowed by approximately 35% in all patients who completed the full course of treatment.
Additionally, after one year, nearly half of the participants showed no signs of progressing to dementia. For comparison: only 29% did not improve in the placebo group.
Further analysis was performed on 552 additional patients with high levels of tau (a small protein commonly used as a marker of Alzheimer’s disease progression and severity) in their brains. Combining the experimental data, the scientists calculated that cognitive decline slowed by 22%.
The test also showed that the drug had side effects – cerebral edema and micro-bleeding in the brain, including fatal ones.
Donanemab is not the first drug to target amyloid. Two other drugs that work using a similar mechanism have been approved for use in recent years. The new drug differs from them in that it only binds to harmful forms of beta-amyloid, excluding those necessary for brain function.