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After 39 Leqembi Infusions, a Blood Test Shows No Alzheimer's Pathology
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Sean Terwilliger completed 39 infusions of lecanemab (Leqembi, the amyloid-targeting drug) over 18 months, took the p-tau217 blood test that measures the tau-protein ratio tied to Alzheimer's pathology, and his result came back below the disease threshold. His neurologist called it a meaningful positive finding. Terwilliger declined maintenance dosing, citing Eli Lilly's Kisunla data showing no meaningful added benefit from continuing, and now faces a strange consequence: his amyloid levels are too low to qualify for the clinical trials he wants to join. He's treating it as remission, not a cure, and plans to retest at least twice a year and re-enroll when levels climb back up.
Full analysis
After 18 months and 39 infusions of Leqembi (lecanemab, a drug that targets amyloid plaques in the brain), Sean Terwilliger took the p-tau217 blood test — a recently released blood marker test that measures the ratio of tau proteins associated with Alzheimer's — and the result showed he no longer meets the pathology threshold for the disease. His neurologist agreed this was a meaningful positive result. Terwilliger chose not to continue to a maintenance dose of Leqembi, reasoning from data on a similar drug (Kisunla, made by Eli Lilly) that showed maintenance dosing produced no meaningful additional benefit. The unexpected consequence: his amyloid levels are now too low to qualify for the clinical trials he wants to join. He plans to repeat the p-tau217 blood test at least twice a year and expects to re-enter trials when levels rise again, describing his current state as remission rather than a cure.
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