Donanemab introduces a finite-duration treatment model
Donanemab's protocol allows treatment cessation once amyloid plaque clearance is confirmed — a meaningfully different model from indefinite biologic dosing.
Treatment may be a course rather than a chronic commitment. The downstream economics differ accordingly.
Donanemab (Kisunla) was approved with a treatment paradigm distinct from lecanemab: patients can stop infusions once amyloid PET demonstrates plaque clearance below a defined threshold. In trial populations, a substantial proportion reached that threshold within roughly a year.
Three implications are worth watching:
- Patient experience. A defined endpoint changes the conversation about whether to start treatment.
- Health-system planning. Forecasting infusion capacity is harder when treatment duration is variable and patient-specific.
- Long-term durability. What happens after plaque clears — and whether plaque returns over years — remains an open empirical question.
The donanemab model is not necessarily better than lecanemab's continuous dosing; the trade-offs include higher reported ARIA rates and a different infusion schedule. But the option to stop is a structural change in how the field thinks about anti-amyloid therapy.
Key sources
- FDA prescribing information — Kisunla (donanemab)
- TRAILBLAZER-ALZ 2 primary publication and amyloid-clearance subgroup analyses
- Eli Lilly TRAILBLAZER-ALZ program disclosures