A new Alzheimer’s drug has been hailed as a “pivotal development” in the global fight against the disease.

Results from Phase III trials show that experimental Lecanemab drug can slow down cognitive decline among patients in the early stage of the disease.

The drug targets and clears a protein called amyloid beta that builds up in the brain – with trials suggesting the process slows decline in patients’ memory and cognition.

"Pivotal development"

This morning, the Alzheimer Society of Ireland (ASI) said it marks the most promising breakthrough in years.

“Lecanemab is the most credible treatment option for Mild Cognitive Impairment and early Alzheimer’s Disease the world has seen after decades of work,” said ASI Research and Policy Manager, Dr Laura O’Philbin.

“While the clinical benefits appear small, scientifically, this is a pivotal development and brings hope to people concerned about dementia worldwide.”

Dr O’Philbin warned that there is still a long way to go and Ireland will need “regulatory approval and developments in our health system” before the drug can be offered to patients here.

“This is a positive day, and it’s only the beginning of a better future in dementia,” she said.

Trials

The Phase III results were reported by Japanese pharmaceutical company Eisai and US Biotech firm Biogen at a conference in San Francisco overnight.

The trial, which involved 1,795 patients, found that after 18 months of treatment, the drug slowed the progress of the disease by 27%.

Experts have hailed it as proof that removing amyloid beta can slow down the progress of the disease – with future drugs expected to be even more effective.

They have warned, however, that better diagnostic facilities are needed – as the drug can only be administered in the early stages of the disease when many patients are unaware they are unwell.

Side effects

Meanwhile, more work needs to be done on the new drug's potential side effects.

Nearly 13% of patients in the lecanemab trial experienced brain swelling, with a small number also experiencing bleeding in the brain.

Five patients suffered haemorrhages and 14% suffered microhaemorrhages.

Two patients died during the trial.

It remains unclear whether lecanemab was raising the risk of bleeding, as at least one of the patients who died was also administered blood thinners after suffering a stroke.