New modeling from the USC Schaeffer Center for Health Policy & Economics estimates that the Alzheimer's treatment donanemab, sold as Kisunla, could extend life expectancy and time spent living independently, with the benefits flowing to patients, care partners and society more broadly. The study, led by Jack Chapel, an assistant research professor at the USC Price School of Public Policy, was published October 7 in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
The treatments target the buildup of amyloid plaques in the brain, and the researchers note that they appear to work better when started earlier in the disease course. Use has been limited so far by coverage restrictions, costs, and the difficulty of identifying and monitoring eligible patients. Alzheimer's is typically diagnosed about 3.5 years after symptoms first appear, which the authors see as a window for earlier intervention. Several blood-based biomarker tests approved by the FDA in the past year, along with digital cognitive assessments, could make earlier identification easier.
The model compared three scenarios for a group resembling participants in a pivotal Phase 3 trial: treatment during the trial, treatment starting two years earlier, and no treatment. It modeled a 29% slowing of disease progression, matching the trial result for donanemab against placebo after 18 months. Compared with no treatment, people treated during the trial were projected to live about 0.3 years longer, spend one year less with severe dementia, and gain 0.37 disability-free years and 0.63 years living in the community. These translated to a lifetime societal value of $104,900 per person, about half from improved quality of life and the rest from reduced unpaid caregiving and medical cost offsets that largely accrued to Medicaid. The estimates do not include the cost of the drug or the screening and monitoring needed to deliver it.
Starting treatment two years sooner raised the lifetime value by 32% to $138,300, and the authors report it rose to $179,400 when they also incorporated emerging evidence that earlier treatment could have a stronger slowing effect. The model also tested a conservative case in which benefits last only four years, which halved the value but still showed 15% more value from earlier treatment. The researchers additionally modeled hypothetical future drugs, estimating a treatment that halts progression completely could be worth between $530,000 and $648,300 in lifetime social value depending on when it starts.