A panel that advises the Food and Drug Administration agreed that a new drug to treat Alzheimer’s disease was beneficial for slowing cognitive decline, paving the way for full regulatory approval next month.

Earlier this year, the drug, known as lecanemab, was granted partial, or accelerated, approval, but that restricted it to people who could pay $26,500 a year or were enrolled in a clinical trial. Under its current status, it is not available under the public health programs Medicare and Medicaid.

According to the Alzheimer’s Association, 6.5 million Americans are living with the disease, the most common cause of dementia, that shows up initially as problems with memory, language and thinking.

Alzheimer’s and other dementias will cost the US $345bn this year, according to the organization. By 2050, when the number of Alzheimer’s patients is projected to reach 11 million, and the cost of care is projected to rise to $1tn annually.

According to studies, people with mild cognitive impairment or mild Alzheimer’s dementia showed a 27% slower decline in cognitive abilities using lecanemab, which can remove sticky amyloid plaques from the brain, compared with those receiving a placebo.

Full FDA approval would make lecanemab, under the brand name Leqembi, the first drug to modify the course of the disease, not simply treat its symptoms.

The studies have also revealed some serious side-effects for some patients, including brain swelling and bleeding or microhemorrhages.

The Centers for Medicare & Medicaid Services said earlier this month it will cover the drug for patients who agreed to enroll in a national registry that collects “evidence about how these drugs work in the real world”.

But that registry has yet to be created, and the Alzheimer’s Association argues that the step will make it harder for patients to access treatment. “We continue to believe that registry as a condition of coverage is an unnecessary barrier,” the group said in a statement.

Analysts anticipate that with full FDA approval, Leqembi could exceed $1bn in sales in 2026 and reaching $5.7bn by 2030.

The Alzheimer’s Association CEO, Joanne Pike, urged approval and expanded patient access “without barriers”. “We are in full agreement with the FDA Advisory Committee that Leqembi provides clinical benefit and that this benefit outweighs the risks,” she told Reuters.