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Imagine receiving a diagnosis of mild cognitive decline linked to Alzheimer’s disease. In such cases, your physician may recommend newer therapies like lecanemab or donanemab, both of which have demonstrated effectiveness in clinical studies by removing amyloid plaques from the brain, a key indicator of Alzheimer’s.

However, both treatments require significant time for biweekly or monthly infusions and come with serious risks, including life-threatening brain swelling or bleeding. Additionally, treatment costs can be exorbitant; even those with Medicare may face co-pays that run into thousands of dollars annually despite coverage.

But, are the potential disadvantages justifiable? Dr. Sarah Hartz, a psychiatry professor at Washington University in St. Louis, believes many patients may answer affirmatively if they were aware of the potential for prolonging their independent living. Her recent research estimated how long individuals could maintain daily activities without help after starting treatment with lecanemab (branded as Leqembi) or donanemab (marketed as Kisunla).

“Patients are often curious about how long they can continue driving, managing their finances, cooking meals, and dressing themselves,” Hartz noted.

The study posits that the duration of independent living can range from eight to 39 additional months, depending on the level of cognitive impairment present at the time of medication initiation.

“We recommend patients not to regard these figures as definitive; they are merely estimates influenced by individual circumstances and stages of cognitive decline,” Hartz cautioned. “Instead, these figures should guide discussions with healthcare providers to evaluate whether the treatment is suitable for them.”

Clear communication about disease progression is vital for both healthcare providers and patients, according to neurologist Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Boca Raton, Florida, who did not partake in the study.

“It’s essential to remember that these are not miraculous solutions,” Isaacson added. “The goal is to slow deterioration—individuals may decline over two years instead of three, for example.”

The study, recently published in the journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions, analyzed data from Washington University involving 282 patients who had not previously received medication for Alzheimer’s.

“We examined four key activities: can the person settle bills, drive, handle their own schedule and medications, and prepare meals?” Hartz explained. “Loss of independent living was defined as requiring assistance with at least three of these functions.”

The study utilized the time untreated patients spent living independently to create a decline timeline, which was then compared to results observed in lecanemab and donanemab clinical trial participants.

For those experiencing mild cognitive decline, typical symptoms may include forgetfulness and difficulties in conversation, which suggested the potential for roughly 29 months of independent living without treatment.

Estimates indicated that taking donanemab could extend independent living by eight months, while lecanemab might provide an additional ten months. Although these extensions might seem modest, they can hold significant value for some individuals, Hartz observed.

“While these medications come with a high price tag, when compared to the costs associated with residential care or nursing homes, they might appear more reasonable,” she stated.

Individuals with mild cognitive symptoms—like repetitive questioning or disorientation—who already reside in a care facility are also eager to understand when they might need additional, pricier support, Hartz added.

At this point in the disease progression, researchers estimated that donanemab could provide an additional 19 months of independence in self-care tasks like dressing, eating, and bathing, while lecanemab could extend this period by 26 months.

“I want to emphasize that the aim of this study was not to promote or dissuade the use of these medications,” Hartz clarified. “The objective is to provide context on the effects of these treatments to assist individuals in making informed decisions for themselves and their loved ones.”

However, the methodology employed in the study assumed that variations in dementia scores are linear and can be equated with time, a premise that has yet to be confirmed, noted Dr. Alberto Espay, a neurology professor at the University of Cincinnati and director of the Gardner Family Center for Parkinson’s Disease and Movement Disorders.

“Further, ‘extension of independence’ refers to a statistically longer duration in the same state before further decline, not an actual improvement,” Espay stressed in an email. “This differentiation is crucial as patients cannot be assured of recovery if they undergo treatment.”

Instead, he remarked, patients must “hope that their deteriorative process will be slower with treatment” while also fearing potential side effects like swelling or bleeding in the brain.

Following the FDA’s expedited approval of lecanemab and subsequently of donanemab, some medical professionals questioned whether the slight benefits observed in clinical trials justified the associated risks.

Randomized controlled clinical trials demonstrated that individuals using lecanemab experienced a 27% slower decline over 18 months than those who were not treated, marking a difference of half a point on a standard dementia progression scale.

Patients with mild cognitive decline who received donanemab reported a 35% lower risk of cognitive progression over one and a half years compared to those given a placebo.

Nevertheless, the side effects can be severe. Lecanemab has been linked to allergic reactions, confusion, dizziness, palpitations, muscle and joint pain, seizures, severe headaches, and flu-like symptoms, among others.

Reports indicate six deaths occurred among lecanemab users, with 2.8% of trial participants experiencing ARIA-E, or amyloid-related imaging abnormalities, which involve brain swelling and bleeding, as reported by clinicians at Northwestern University’s Feinberg School of Medicine. None of the placebo group had such reactions.

In the clinical trial for donanemab, 2.9% of participants experienced a serious ARIA-E side effect, and three patients died, according to the Alzheimer’s Society. Nearly 13% encountered various serious side effects during the study.

Patients must undergo regular brain scans to monitor for bleeding and swelling while being closely followed by their healthcare providers. Due to an increased risk of ARIA-E, both medications are administered cautiously, especially in individuals with two copies of the APOE-4 gene, a known genetic risk factor for Alzheimer’s.

Experts emphasize the urgent need for effective Alzheimer’s treatments as the number of diagnosed individuals is expected to rise to nearly 14 million by 2060, according to projections from the US Centers for Disease Control and Prevention. As of 2023, an estimated 6.7 million Americans aged 65 and older are living with Alzheimer’s disease.

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