New modeling reveals high societal value of early Alzheimer's care

New treatments that can slow the progression of Alzheimer's disease could provide significant lifetime benefits to patients and society, with even greater benefits when initiated earlier, according to new research from the USC Schaeffer Center for Health Policy & Economics.

The treatments, which target buildup of amyloid plaques in the brain, appear to be more effective when started earlier in the disease course. However, their use has been limited due to coverage restrictions, costs, and the challenges of identifying and monitoring eligible patients, among other factors.

New Schaeffer Center modeling estimates that Alzheimer's treatment donanemab (marketed as Kisunla) could extend life expectancy and time spent living independently, with value accruing to patients, care partners and society more broadly. The estimated value is increased by one-third if treatment were started two years earlier.

New therapies and diagnostic tools are making it possible to alter the course of Alzheimer's disease, but they come with considerable costs. Our research suggests that investments in early detection could help ensure that patients start treatments when they're more likely to provide the greatest benefit to patients and society."

Jack Chapel, lead author, a USC Schaeffer scholar and assistant research professor, USC Price School of Public Policy

The study was published Oct. 7 in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

Closing the diagnosis gap

Alzheimer's and related dementias will cost the United States an estimated $818 billion in 2026, and the economic impact is expected to grow as the population ages. A better understanding of the long-term benefits of Alzheimer's treatments-and how benefits may differ based on when treatment is initiated-could inform decisions on how to sustainably expand access with the greatest impact.

On average, Alzheimer's is diagnosed 3.5 years after symptoms first appear, leaving a critical opportunity for earlier intervention. Several blood-based biomarker tests approved by the FDA in the past year, as well as new digital cognitive assessments, could make it easier to identify Alzheimer's in earlier stages and connect patients to treatment.

Modeling the lifetime benefits

To project the lifetime benefits of treatment with donanemab, researchers leveraged a dynamic microsimulation model from the Schaeffer Center's U.S. Cost of Dementia Project, a federally funded effort to quantify dementia's total costs. They modeled three scenarios for a group that closely resembled participants of a pivotal Phase 3 trial: receiving treatment during the trial, starting treatment two years earlier (but still after symptoms usually emerge), and receiving no treatment. The estimates reflect the value of health and economic benefits and do not include the costs of the drug or the screening and monitoring needed to deliver it.

The researchers drew from large national health surveys and studies of dementia progression to model lifetime cognitive status with a commonly used scoring measure. For the two treatment groups, they modeled a 29% slowing of disease progression, matching the trial results for donanemab compared with a placebo after 18 months.

Treatment group: Compared with those not receiving treatment, people treated during the clinical trial were projected to live about .3 years longer and have 1 year less with severe dementia, while gaining .37 disability-free years and .63 years spent in the community.

The gains translated to a lifetime societal value of $104,900 per person. About half came from improved health-related quality of life ($52,300), followed by reductions in unpaid caregiving ($23,800) and medical cost offsets ($22,200) that largely accrued to Medicaid. On an annual basis, Medicaid costs were reduced by about $1,640, or 13%.

Earlier treatment: Starting treatment two years sooner slows cognitive decline earlier in the disease process, increasing gains across all measures and raising the lifetime value by 32% to $138,300. Earlier treatment could have an even stronger slowing effect, as emerging evidence suggests. The value rose 71% above the clinical trial group to $179,400 when incorporating these potentially larger treatment effects.

Because these treatments are so new, there is uncertainty about how long their benefits will last. In a conservative scenario where the effect lasts only four years rather than the rest of the patient's life, the lifetime value was cut in half ($49,100), but earlier treatment still produced 15% more value ($56,400).

The value of further advances

Researchers also modeled the potential lifetime benefits of future treatments that could further slow Alzheimer's progression. There is an extensive pipeline of potential Alzheimer's treatments, with more than 150 drugs undergoing clinical testing.

A hypothetical treatment that slows progression by 50% would generate an estimated lifetime social value of $208,700 to $276,700, depending on when treatment is initiated. For a treatment that completely halts progression, the estimated value more than doubles, ranging from $530,000 to $648,300.

"As therapies and diagnostic tools continue to improve, the case for finding and treating people sooner only gets stronger," Chapel said. "Every year between the first symptoms and a diagnosis is value lost for patients, their families and the public programs that ultimately pay for dementia care."