Dementia experts have hailed the latest landmark in the treatment of Alzheimer’s after Eli Lilly released trial results that showed its new drug significantly slowed memory loss and cognitive decline.
The US pharmaceuticals group on Monday reported full findings of its phase 3 clinical study of donanemab at the Alzheimer’s Association International Conference in Amsterdam, showing that the antibody treatment slowed progression by about 35 per cent in the early stages of the disease.
The peer-reviewed results follow similar phase 3 findings released last November by US biotech Biogen and Japan’s Eisai for lecanemab, another antibody drug, which received full marketing approval from the US Food and Drug Administration this month under the brand name Leqembi.
Eli Lilly announced on Monday that it had submitted donanemab for FDA approval and expected a decision before the end of this year. Submissions are under way to other global regulators.
Experts on dementia called Lilly’s donanemab presentation, published in the Journal of the American Medical Association, a landmark in the field.
“The past eight months have been a real turning point, as two drugs are shown to slow down the progression of the disease after decades of work with no positive findings,” said Richard Oakley, associate director of research at UK charity the Alzheimer’s Society.
The donanemab trial involved 1,736 participants with an average age of 73 who had mild to moderate symptoms of Alzheimer’s, with half receiving intravenous infusions of the treatment and half a placebo every four weeks for 18 months. The drug slowed the progression of the disease most effectively in its earlier stages.
Both lecanemab and donanemab are based on antibodies against amyloid, one of the toxic proteins that build up in the brain as Alzheimer’s proceeds, but they worked at different stages of the process, Oakley said.
Lecanemab targets amyloid as it begins to form fibres in the brain while donanemab is active at a later stage, when the fibres have clumped together into larger accumulations of plaque. The main adverse side effect with both drugs was swelling and bleeding of the brain in a small minority of patients.
Although the clinical trial designs for the two drugs make direct comparisons difficult, there were tentative indications that donanemab might be more effective than lecanemab when administered to people in the earliest stages of Alzheimer’s, said Oakley.
It cleared amyloid plaques completely from the brain in some participants, who were then taken off the drug.
Another potential advantage for donanemab, according to Howard Fillit, chief scientist at the US-based Alzheimer’s Drug Discovery Foundation, is that patients receive infusions twice as frequently for lecanemab — every two weeks.
While Biogen and Eisai have announced a US list price of $26,500 a year for Leqembi, Lilly said it was not yet ready to set the price for its drug.
“With two drugs on the market, we can expect some competition on price,” said Fillit, “but we don’t know yet which factors will play an important role in the marketplace.”
Datamonitor Healthcare forecasts combined sales for the two products of $9bn a year by 2030 in the world’s main markets.
“This is a watershed moment but it is just a start,” said Fillit. “We must continue advancing the drug pipeline to develop the next class centred around the biology of ageing to ultimately stop Alzheimer’s in its tracks.”
He added that future therapies would be drug combinations tailored to each individual through biomarker tests.