Treatment landscape

Disease-modifying therapies

Two anti-amyloid monoclonal antibodies are FDA-approved for early symptomatic Alzheimer's disease with confirmed amyloid pathology:

• Lecanemab (Leqembi) — biweekly IV infusion, with a subcutaneous formulation submitted to regulators.
• Donanemab (Kisunla) — every-four-week IV infusion, with a finite-duration treatment paradigm tied to amyloid clearance.

Both demonstrated clinically meaningful but modest slowing of decline in pivotal trials. Both require APOE genotyping and serial MRI surveillance for amyloid-related imaging abnormalities (ARIA). Both are covered by Medicare under a coverage-with-evidence-development framework that requires registry participation.

Symptomatic therapies

Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and the NMDA receptor antagonist memantine remain in routine clinical use. They do not modify the underlying disease course, but they can produce modest symptomatic benefit in subgroups of patients. Their role alongside anti-amyloid therapy is generally additive.

What defines access

Access to disease-modifying therapy is constrained more by infrastructure than by approval status. The defining bottlenecks are:

• Infusion-chair capacity for biweekly or monthly administration.
• MRI scanner throughput for ARIA surveillance.
• Specialist supply — cognitive neurologists qualified to confirm eligibility, manage ARIA, and conduct counselling.

For a fuller analysis, see our Insight on why the anti-amyloid rollout is rate-limited by infrastructure, and our reference snapshot of disease-modifying therapies.

What is changing

The most consequential near-term changes to the treatment landscape are subcutaneous formulations of both leading antibodies, ongoing GLP-1 receptor agonist trials in Alzheimer's, and APOE4-stratified labeling discussions. None of these would change the underlying mechanism category — they would change the delivery format, the patient population, and the precision of eligibility.