Eisai announced on July 13, 2026 along with Biogen that the FDA approved the supplemental approval for the weekly subcutaneous injection of lecanemab-irmb under the name Leqembi IQLIK as an initial dose for treating early Alzheimer's disease. The Alzheimer's Association declared on the same day that people with diagnosed mild cognitive impairment or early Alzheimer's disease can now choose between injection and infusion, rather than requiring treatment to begin with a biweekly infusion at a hospital or infusion center. According to FDA prescribing information, amyloid-beta pathology must be confirmed before starting treatment. The single injection with an autoinjector takes approximately 15 seconds according to the company, with the weekly dose consisting of two injections of 250 milligrams each.
What changes from earlier therapy
Previously, the subcutaneous injection was approved only as maintenance therapy. According to Eisai and Biogen, the FDA approved the subcutaneous maintenance dose in August 2025 of 360 milligrams weekly, but only after 18 months of biweekly infusion. The new decision allows treatment with the injection from the start, which goes beyond the previous requirement according to the Alzheimer's Association. Leqembi is thus the organization's first Alzheimer's medication approved for home use with an autoinjector, a device type already used for diabetes, arthritis, and severe allergies.
Supervision required, regular evaluation recommended
The FDA prescribing information requires that treatment with Leqembi IQLIK begins under guidance from a healthcare professional who must directly supervise at least two consecutive doses and determine that administration by patients or caregivers is appropriate before they take over. After that, the professional should regularly assess whether patient or caregiver administration remains appropriate. A baseline brain MRI is required beforehand, with follow-up scans at one, two, three, and six months. There is a risk of amyloid-related imaging abnormalities, or ARIA, temporary brain swelling or small hemorrhages. According to Eisai's safety data, these occurred in 21 percent of Leqembi-treated patients compared to 9 percent under placebo. Among treated patients, 16 percent were ApoE-ε4 homozygous. In this group, ARIA rates under Leqembi were 45 percent compared to 22 percent under placebo, which is why genetic testing is recommended before treatment. The FDA warns that although ARIA usually remains asymptomatic, it can be severe, life-threatening, or fatal.
Howard Fillit from the Alzheimer's Drug Discovery Foundation stated according to a statement cited by AJMC that patients and their care partners now have a meaningful choice in the mode of delivery of anti-amyloid treatment. His colleague Laura Nisenbaum told the journal NeurologyLive that a subcutaneous starting dose removes much of the infusion burden that makes long-term treatment difficult. The BrightFocus Foundation also notes that home injections, especially in the first weeks of treatment when clinic visits are most burdensome, potentially mean fewer trips to an infusion center.
What the approval doesn't yet show
The subcutaneous formulation was not tested in its own separate large phase-3 clinical trial, according to AJMC. Instead, the FDA relied on proven effectiveness of the intravenous formulation plus an open-label extension substudy showing equivalent results in amyloid reduction and overall safety profile of the injection. NeurologyLive also reports that the agency explicitly noted that the formulation was not independently tested in large outcome studies.
Comparison
A U.S. cost model cited by NeurologyLive, published in 2025 in the journal Neurology and Therapy, illustrates what costs are involved. It estimates possible societal savings from the injection compared to infusion at $72,891 to $80,925 per patient over four years.
According to the BrightFocus Foundation, eligible Medicare beneficiaries can receive coverage, while Eisai announced free treatment through its patient assistance program for eligible uninsured patients with financial hardship who meet additional program criteria.