FDA approves Leqembi Iqlik subcutaneous injection as starting dose for early Alzheimer’s disease

The U.S. Food and Drug Administration approved Leqembi Iqlik (lecanemab-irmb) subcutaneous injection as a once-weekly starting dose for early Alzheimer’s disease on July 13, 2026, officials said. The approval allows adults with mild cognitive impairment or mild dementia due to Alzheimer’s to initiate treatment at home using two 250 mg subcutaneous injections, providing an alternative to the original bi-weekly intravenous regimen.

The approval expands Leqembi’s U.S. labeling to allow initiation of therapy using a subcutaneous injection as an alternative to the original biweekly intravenous (IV) starting regimen, according to the FDA and Eisai officials. The newly approved starting dose regimen for Leqembi Iqlik is 500 milligrams once weekly, delivered as two 250 mg subcutaneous injections administered in approximately 15 seconds each, records show. The subcutaneous autoinjector formulation is designed for at-home administration by patients or their care partners following appropriate training, Eisai representatives said.

In the Phase 3 CLARITY AD trial, lecanemab demonstrated a 27% reduction in clinical decline measured by the Clinical Dementia Rating–Sum of Boxes (CDR-SB) over 18 months compared to placebo.

The FDA granted Priority Review to the supplemental Biologics License Application (sBLA) for the weekly starting dose, with a Prescription Drug User Fee Act (PDUFA) action date of May 24, 2026, before granting approval on July 13, 2026, according to agency records. This approval complements the prior FDA approval of Leqembi Iqlik 360 mg weekly subcutaneous maintenance dosing in August 2025, which allowed patients to continue therapy either by IV infusion every four weeks or weekly subcutaneous injections after an 18-month initiation period, Eisai and Biogen confirmed.

Clinical data supporting the approval include a comprehensive package evaluating subcutaneous administration of lecanemab across multiple studies and dosing regimens, officials said. The overall approval program is based on the Phase 3 CLARITY AD trial, in which lecanemab demonstrated a 27% reduction in clinical decline measured by the Clinical Dementia Rating–Sum of Boxes (CDR-SB) over 18 months compared to placebo. A secondary endpoint, the Alzheimer’s Disease Cooperative Study–Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS-MCI-ADL), showed a 37% statistically significant benefit versus placebo, according to Eisai and Biogen.

Data presented by the companies indicate that transitioning to weekly Leqembi Iqlik after 18 months of IV initiation maintains clinical and biomarker benefits comparable to continued IV dosing. The FDA had previously converted Leqembi’s accelerated approval to traditional approval after confirmation of clinical benefit, establishing the drug’s efficacy for Alzheimer’s disease treatment, agency sources said.

The safety profile of the subcutaneous formulation is similar to intravenous infusion, with no new major safety signals identified, Eisai reported. Injection-related reactions are primarily localized and include erythema, induration, swelling, heat, pain, pruritus, rash, ecchymosis, nodules, and hematoma, most commonly occurring at the first dose. Less frequent systemic reactions such as headache, chills, fever, and fatigue are generally mild to moderate. Prescribers are advised to monitor for recurrent or delayed localized reactions during ongoing weekly administration. Both IV and subcutaneous regimens retain class-typical risks related to amyloid-related imaging abnormalities (ARIA), with specific ARIA data for the subcutaneous starter dose encompassed within the broader clinical safety package referenced in the approval.

Leqembi is indicated in the United States for adults with mild cognitive impairment or mild dementia due to Alzheimer’s disease, collectively referred to as early Alzheimer’s disease in company communications and labeling. Eisai and Biogen emphasized that the drug is intended for adult patients only, with no pediatric use included in the indication or clinical development. The Alzheimer’s Association, based in Chicago, welcomed the FDA’s approval on July 13, 2026, noting that Leqembi Iqlik is the first monoclonal antibody that clears amyloid beta for early Alzheimer’s disease to be approved for subcutaneous administration using an autoinjector, a status now encompassing both maintenance and starter dosing.

Eisai’s partner BioArctic reported that the company plans to launch the Leqembi Iqlik starting dose in the U.S. in late August 2026, following the FDA approval. The maintenance-dose formulation was launched on October 6, 2025, after the August 29, 2025 FDA approval, according to Eisai. Company communications stress that the subcutaneous autoinjector option may increase convenience and flexibility for patients and care partners by providing an at-home weekly injection alternative to infusion-center IV therapy, potentially reducing logistical burdens associated with regular IV infusions.

With the new starting-dose approval, Leqembi now supports a fully integrated IV and subcutaneous treatment pathway, enabling initiation and continuation of therapy either by infusion or autoinjector, with the option to switch between routes over time. This integrated approach aims to provide patients with early Alzheimer’s disease greater flexibility in managing their treatment regimen.