Overview
- Analyses presented at the Alzheimer’s Association International Conference in July 2026 report that weekly 500 mg autoinjector dosing produced drug exposures and biomarker and clinical effects similar to the established biweekly 10 mg/kg intravenous regimen.
- The FDA has approved a 360 mg subcutaneous maintenance dose and is reviewing a 500 mg subcutaneous initiation dose with a PDUFA decision set for August 24, 2026.
- Company-substudy safety data showed far fewer systemic infusion reactions after subcutaneous injection (under 2%) compared with intravenous infusion (about 26%) and reported ARIA‑hemorrhage rates of 2.9% for the 500 mg group and 2% for the 360 mg group over short follow-up periods.
- Patient surveys and human factors studies found strong preference for the autoinjector, citing 10–15 second home injections that are less invasive than hour-long IV infusions and that many patients and care partners can be trained to self-administer.
- These results come from Eisai-sponsored substudies, modeling and small real-world samples with limited follow-up, so independent confirmation, continued MRI safety monitoring for ARIA, and systems to ensure adherence will be important as use shifts away from infusion centers.