US Alzheimer's Disease Launch Readiness

Two anti-amyloid antibodies, lecanemab (Leqembi, Eisai/Biogen, full approval July 2023) and donanemab (Kisunla, Eli Lilly, full approval July 2024), are already in market, each reimbursed under Medicare Part B only through CMS's National Coverage Determination 200.3 Coverage with Evidence Development. That registry, which requires the prescribing clinician to enroll every patient in a CMS-approved nationwide data-collection program, is the structural gate a new entrant inherits before writing a single script, not a negotiable term. Amyloid confirmation, historically PET (long limited by Medicare to once per lifetime) or CSF, plus mandatory serial-MRI ARIA monitoring, compounds the site-infrastructure bar; a new agent's advantage can only come from making registry enrollment and monitoring operationally lighter than what the two incumbents already require.

ICER's April 2023 final evidence report found lecanemab's benefits not adequately demonstrated at its $26,500 list price and set a health-benefit price benchmark of $8,900 to $21,500 a year, a verdict ICER reached even more harshly against aducanumab in 2021 (a $3,000 to $8,400 benchmark against a $56,000 list); Biogen discontinued aducanumab in 2024. A new entrant's launch price is therefore not a free variable: pricing materially above the $8,900-$21,500 band risks the same above-value verdict that has already ended one anti-amyloid launch and constrained a second's uptake. Donanemab's roughly $32,000 list, partly defended by its flexible-duration dosing that lets treatment stop once amyloid clears, is the one precedent for holding a premium against this benchmark.

The FDA's May 2025 clearance of the first blood test for AD amyloid, the Lumipulse G plasma pTau217/Aβ42 ratio (Fujirebio), is the single structural change since the two incumbents launched: 91.7% positive and 97.3% negative concordance against amyloid PET or CSF, for symptomatic patients aged 55 and older. Replacing a PET scan or lumbar puncture with a blood draw materially expands the capacity to confirm the amyloid-positive fraction of the 7.2 million Americans with Alzheimer's dementia and the 22% of seniors with mild cognitive impairment. A new entrant that builds its identification pathway around blood-based confirmation, rather than the PET-constrained referral pattern the incumbents launched into, reaches the diagnosed pool faster than either predecessor did at launch.

This assessment synthesises three independently verified research angles into one pre-launch view: competitive standard-of-care positioning, target-population epidemiology and diagnostic pathway, and anticipated payer posture. Every factual claim traces to a primary source: FDA approval records, peer-reviewed trial publications, CMS coverage documentation, and ICER evidence reports.

Alzheimer's Disease sources: FDA Drugs@FDA, NEJM CLARITY AD and JAMA TRAILBLAZER-ALZ 2 primary publications, CMS NCD 200.3 Coverage with Evidence Development documentation, ICER Final Evidence Reports on lecanemab (2023) and aducanumab (2021), the FDA clearance of the Lumipulse G plasma pTau217/Aβ42 ratio (May 2025), and Alzheimer's Association 2025 Facts and Figures.