HOUSTON, United States – The US Food and Drug Administration (FDA) on Friday approved a new drug that appears to slow the progression of Alzheimer's disease.

The FDA said Leqembi -- known chemically as lecanemab -- will be prescribed to patients with mild or early stages of the brain-deteriorating disease.

The drug is the first of its kind to convincingly show researchers that it can slow the decline in memory and thinking.

However, experts said the delay in cognitive deterioration caused by the drug will likely amount to just several months, which in some cases is a very long time for families with loved ones who suffer from Alzheimer's.

“This drug is not a cure. It doesn’t stop people from getting worse, but it does measurably slow the progression of the disease,” said Joy Snider, a neurologist at Washington University in St. Louis, in an interview with NBC. “That might mean someone could have an extra six months to a year of being able to drive.”

Medical experts said the drug comes with risks and downsides, including possible side effects like brain swelling and the need for twice-a-month infusions.

Leqembi is manufactured by Japan's Eisai and its US partner Biogen. The company said the drug will cost about $26,500 for a typical year’s worth of treatment, citing that the high price tag reflects the drug’s benefits, including improved quality of life and reduced burdens for caregivers.

The challenge in getting the drug to patients is the next hurdle, as it may be several months before Leqembi can be distributed and insurers must now decide whether and how to cover the drug's high cost.

The FDA’s approval was based on one mid-stage study in 800 people with early signs of Alzheimer’s who were still able to live independently or with minimal assistance.

Eisai also published the results of a larger 1,800-patient study that the FDA will review to confirm the drug’s benefits.

According to health experts, nearly six million Americans suffer from Alzheimer's with millions more suffering from the disease worldwide.

Alzheimer’s disease gradually attacks areas of the brain needed for memory, reasoning, communication and daily tasks. (Anadolu)