The Food and Drug Administration on July 13, 2026 approved a new starting dosage regimen for the subcutaneous form of Leqembi (lecanemab-irmb), allowing patients with early Alzheimer's disease to begin treatment entirely at home, through a once-weekly self- or caregiver-administered injection, without first attending an intravenous infusion visit. The agency's notice calls it the first at-home starting dose ever approved for an Alzheimer's treatment.
The change closes a gap left by an earlier milestone. Leqembi was first approved in 2023 as an IV-only infusion given every two weeks; in August 2025 the FDA cleared a weekly subcutaneous autoinjector, Leqembi Iqlik, but only for patients who had already completed 18 months of IV dosing. The newly approved regimen, 500 milligrams once a week delivered as two 250 milligram injections, lets patients skip the infusion-center phase altogether and start on the autoinjector from day one, with the option to switch between IV and subcutaneous dosing at any point.
The FDA based the approval on sub-studies within the long-term extension of the Clarity AD trial, the same placebo-controlled study that supported Leqembi's original approval, comparing once-weekly subcutaneous dosing with the established biweekly IV regimen. Eisai and Biogen, the drug's co-developers, say the subcutaneous route produced drug exposure equivalent to IV infusion and that rates of amyloid-related imaging abnormalities, the swelling or bleeding on brain scans that is Leqembi's main safety risk, did not differ by route of administration. No separate large efficacy trial tested the at-home starting dose on its own; the approval rests on this exposure-matching data rather than new outcome results.
At-home injection does not remove the need for clinical monitoring. Under the newly revised prescribing information, patients must still have a baseline brain MRI before starting treatment and further scans after one, two, three and six months to check for those imaging abnormalities, and the drug continues to carry a boxed warning for that risk. Eisai and Biogen say the product will be distributed through specialty pharmacies, with U.S. launch of the at-home starting dose planned for late August 2026.