A new mode of administration expands treatment options for people with early-stage Alzheimer’s. The United States Food and Drug Administration (FDA) has authorized the use of the subcutaneous formulation of Leqembi IQLIK as the initial dose of the therapy, allowing some patients to start treatment directly at home with a self-injector, either independently or with the help of a caregiver. The approval concerns the drug developed by Eisai and Biogen and represents an extension of the ways to use a therapy already available for the disease.
A NEW MODE OF ADMINISTRATION
The authorization, the two pharmaceutical companies report, concerns the subcutaneous formulation of the active ingredient lecanemab, marketed under the name Leqembi IQLIK. Until now, those starting treatment received the drug exclusively through intravenous infusions performed in hospitals or specialized centers.
With the new FDA green light, the therapy can instead be initiated using a self-injector usable at home. The approved regimen involves a weekly administration of 500 mg, divided into two injections of 250 mg each, each lasting about 15 seconds. After 18 months of treatment, it is possible to continue with a maintenance dose of 360 mg once a week. Throughout the therapeutic course, it remains possible to choose, together with the doctor, between intravenous and subcutaneous administration, switching from one mode to the other based on the patient’s needs.
WHO THE TREATMENT IS FOR
In the United States, Leqembi is indicated for adults with mild cognitive impairment (Mild Cognitive Impairment, MCI) or mild dementia due to Alzheimer’s disease, that is, in the early stages of the condition. The drug acts against beta-amyloid, the protein that forms the characteristic plaques present in the brains of people with Alzheimer’s, promoting their removal.
WHAT CLINICAL STUDIES SAY
The authorization of the subcutaneous formulation as the initial dose is based on a set of clinical studies that compared this mode of administration with the intravenous one. According to data presented to regulatory authorities, subcutaneous administration achieves drug exposure equivalent to that obtained with infusion, with clinical benefits and reduction of beta-amyloid plaques considered comparable.
The overall safety profile was also generally similar, while the most frequently observed reactions were those localized at the injection site.
The approval is also based on the results of the international phase 3 Clarity AD study, which had already demonstrated the efficacy of the intravenous formulation in patients with early Alzheimer’s. In the study, conducted on 1,795 participants, treatment with lecanemab slowed disease progression by 27% compared to placebo after 18 months, reaching the primary endpoint on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) cognitive-functional scale. The long-term extension of the study also showed that 81% of patients who continued therapy remained in the early stage of the disease even after four years of treatment.
ADVERSE REACTIONS AND MONITORING
The FDA reminds that Leqembi, like other monoclonal antibodies directed against beta-amyloid, can cause so-called amyloid-related imaging abnormalities (ARIA), which include brain edema and microhemorrhages. In most cases, these events occur in the early stages of therapy and can be asymptomatic, but severe and, rarely, fatal episodes have also been reported.
For this reason, it is recommended to perform an MRI before starting treatment and subsequent periodic checks, with particular attention during the first weeks of therapy. The risk of ARIA is higher in patients homozygous for the ApoE ε4 genetic variant, which is why the FDA recommends discussing with the patient the opportunity to perform genetic testing before starting treatment.
WHAT THE MARKET AND ANALYSTS SAY
The FDA’s decision had a positive impact on the markets, with Biogen shares recording a 4.5% rise in trading following the announcement.
According to analysts cited by Reuters, the approval of the subcutaneous formulation of Leqembi could encourage wider adoption of the treatment, thanks to greater accessibility for patients and the possibility to differentiate from competing therapies such as Eli Lilly’s Kisunla, which still requires administration via intravenous infusion. However, Citi experts have pointed out that the immediate commercial impact could be limited, considering that obstacles remain related to identifying eligible patients, diagnostic confirmation, clinical monitoring, availability of specialists, and access to reimbursements.
“A NEW ERA” FOR THERAPIES
More optimistic is Howard Fillit, co-founder and Chief Science Officer Emeritus of the Alzheimer’s Drug Discovery Foundation (ADDF), who stated: “The approval of Leqembi IQLIK for the initial dose marks a new era in Alzheimer’s treatments. For the first time, patients and caregivers have a real choice in how to receive an anti-amyloid therapy. With the expansion of therapeutic options, innovations in administration methods will play an important role in improving access to care, fostering the development of potential combination therapies, and supporting a precision medicine approach in Alzheimer’s care.”
A GLOBAL HEALTH CHALLENGE
Dementia represents one of the main health challenges related to population aging. Worldwide, it is estimated that over 55 million people live with some form of dementia, with Alzheimer’s disease being the most frequent cause.
In the United States, in 2026, it is estimated that 7.4 million people aged 65 or older will have Alzheimer’s. Furthermore, according to forecasts, 42% of those over 55 will develop some form of dementia during their lifetime, and the number of new cases is expected to double in the coming decades, reaching 1 million diagnoses per year by 2060.
Also in Italy, the phenomenon is steadily increasing: today, over 1.43 million people live with some form of dementia, but by 2050 the number could rise to about 2.2 million, equal to 4.2% of the population, with a 54% increase that would make Italy the European Union country with the highest incidence of dementia relative to the population.
