What does it do?
Lecanemab is a drug that is injected bi-weekly to those suffering from early Alzheimer’s.
The antibody treatment, created by Japanese and US pharmaceutical giants Eisai and Biogen, combats the build-up of plaque in the brain, which is thought to be behind Alzheimer’s.
What did trials show?
The Phase III trial of lecanemab evaluated the drug’s ability to reduce cognitive and functional decline among 1,795 patients with early Alzheimer’s.
Half of participants were given 10mg/kg of the drug bi-weekly, while the others were given a placebo drug.
Researchers measured participants’ memory, judgment, problem solving and judgement before they started taking the drug or placebo and again 18 months later.
Results showed that those given lecanemab saw their mental condition decline 27 per cent less than those given the dummy treatment.
The lecanemab group also experienced a slower build up of amyloid levels in the brain, scans showed.
Is the drug dangerous?
As well as promising results, clinical trials also flagged safety concerns.
Brain swelling and micro hemorrhages were spotted among 21.3 per cent in the lecanemab group and 9.3 per cent in the placebo group.
The pharma giants said the figures fall within an expected range.
And one patient in the US reportedly died while taking lecanemab during clinical trials, after suffering a brain bleed.
However, Eisai and Biogen noted that all available safety information shows the therapy is not linked with an increased risk of death.
How close is it to being rolled out?
The drugmakers are seeking approval for lecanemab from the US Food and Drug Administration, with a decision expected in early January.
The companies say they will also submit their findings to regulators in Japan and Europe to by April 2023.
However, watchdogs will then need to assess whether the drug is safe and effective before making a decision, so it is unclear when the treatment could be rolled out.
How is it different to similar drug Aduhelm?
Both Aduhelm and lecanemab — which are both made by Eisai and Biogen — are antibodies designed to remove amyloid deposits.
However, lecanemab targets amyloid that has not yet clumped together, while Aduhelm removed amyloid plaques that built up in the brain.
Aduhelm’s approval was a rare bright spot for Alzheimer’s patients, but critics have warned about the underwhelming results of the drug and highlighted its risks.