SINGAPORE - Patients with Alzheimer’s disease – the most common cause of dementia – may soon get a new drug that can slow progression of the disease, a recent study has found.

Speaking to media on Tuesday, visiting consultant in the Department of Psychological Medicine at the National University Hospital (NUH) Christopher Chen said disease progression for patients who were given the drug known as lecanemab was found to be at least six months behind those who received a placebo after 18 months of treatment.

The Phase 3 trial of the antibody drug involved nearly 1,800 participants aged 50 to 90 with early stages of Alzheimer’s disease. They included 13 patients from NUH, the only centre in South-east Asia that participated in the study. Associate Professor Chen, who is also director of the Memory, Ageing and Cognition Centre at NUHS, co-wrote the study.

One in 10 people here above 60 are affected by Alzheimer’s disease, which has no effective treatment.

In the trial, lecanemab was found to be capable of interfering with the formation of amyloid plaques that collect between neurons and disrupt cell function. Amyloid is a naturally occurring protein in the brain that can clump together to form plaques.

Patients who took the experimental drug had a slower level of cognitive and functional decline and experienced a greater reduction in amyloid formation than people who did not, said Prof Chen, who noted it was the first study of an anti-amyloid treatment to show convincing results.

In 2021, the United States Food and Drug Administration controversially approved another anti-amyloid drug, aducanumab, despite several doctors calling for clear evidence of cognitive benefit.

In the study of lecanemab, 14 per cent of patients who took the drug experienced microbleeding in the brain compared with 7.7 per cent of patients who did not.

Mild swelling in the brain was also seen in 12.6 per cent of patients who took lecanemab, compared with 1.7 per cent of those who did not.

However, Prof Chen said these imaging abnormalities disappeared as treatment continued.

He added: “Many of these imaging abnormalities were also asymptomatic and very mild.”

On Nov 29, findings from the study were published in The New England Journal of Medicine and presented at the 15th Clinical Trials On Alzheimer’s Disease conference in San Francisco.

Caregivers of dementia patients who participated in the study said they were hopeful that the drug could help prolong the lucidity of their loved ones.

Madam Norhaini, a 70-year-old retiree who worked in sales and declined to give her full name, noted that her husband has become less moody and more social after the trial.

The couple first noticed his condition when Mr Jaffar, 67, a former delivery driver with mild cognitive impairment who declined to give his full name, started forgetting conversations after half an hour and would re-arrange the contents of his drawer every day.

Said Madam Norhaini, who noted that her husband is more jovial and even irons his clothes himself now: “Apart from fever on one night after the first infusion, I can see so much change.”

Meanwhile, Mr Puar Teck Kiang, 79, hoped an effective drug would become available for his 72-year-old wife, who has stopped taking part in her favourite hobby of line-dancing and no longer leaves her home since the first signs of dementia emerged in 2019.

Three months ago, he hired a professional caregiver to help his wife bathe after she began resisting taking showers.

Said the retired business department head, who used to travel frequently with his wife: “As a caregiver, I feel depressed and frustrated for her. I love my wife more now because I know she’s facing a death sentence, so I’m trying very hard to persuade the hospital to give her medication because she has no other hope.”

The drug is currently awaiting approval from the FDA, with the United Kingdom and Europe to follow, said Prof Chen.

Currently, NUH is also recruiting for participants aged 55 to 80 for another trial evaluating the effectiveness in earlier stages of Alzheimer’s disease, including anyone who has amyloid in their brain, he added.

An editorial in The Lancet medical journal on Dec 3 said that while lecanemab was shown to reduce cognitive decline by 27 per cent, its effect may not be clinically meaningful, and it remained to be seen if the drug would be a game changer. It also noted there may be concerns about its safety in patients taking blood-thinning drugs.