Dose-at-home Leqembi for Alzheimer's cleared in US

Eisai and Biogen have won FDA approval for a subcutaneous injection version of Leqembi that could help accelerate uptake of the Alzheimer's disease therapy.

The green light for Leqembi Iqlik (lecanemab) means it can be used as an alternative to infusions during the maintenance phase of treatment with the anti-amyloid therapy, and patients will still need to receive the drug via intravenous infusion for the first 18 months.

Thereafter, they will be able to continue treatment with a once-weekly injection that can be administered at home rather, than in an infusion clinic.

At the moment, Leqembi is administered intravenously at clinics every two weeks, although, in January Eisai and Biogen were also granted approval by the FDA to dose the drug every four weeks during the maintenance phase, reducing the need for hour-long clinic visits.

Now, after the 18-month timepoint is reached, there will be a choice between monthly infusions in clinic or subcutaneous injections once a week, said Biogen. Leqembi Iqlik is due to be launched on 6th October.

The new format could give Eisai and Biogen an edge in the marketplace against Eli Lilly's Kisunla (donanemab), currently their only rival in the anti-amyloid Alzheimer's treatment category, which has been gaining ground in the market.

Physicians have already been drawn to using Kisunla because its label calls for it to be used only until amyloid plaques are cleared from the brain, while Eisai and Biogen's label calls for continuous treatment, as well as a once-monthly dosing schedule that requires fewer clinic visits.

In July, Lilly also claimed FDA approval for a modified dosing schedule for Kisunla that reduces the risk of an amyloid-related side effect (ARIA-E, a form of brain swelling) and could also make it more appealing to prescribers.

At the same time, the FDA has just recommended additional monitoring for patients taking Leqembi, specifically more MRI scans to look for ARIA-E, which could also lend Kisunla an edge.

The approval of Leqembi Iqlik could help Eisai and Biogen fight back at a time when – after a sluggish start – both Alzheimer's therapies show signs of gathering sales momentum.

In July, Biogen said that global sales of the drug in the second quarter of 2025 rose fourfold over the same period of 2024, reaching $160 million, a result that beat analyst expectations and which the company said resulted in part from improved rates of blood tests to diagnose Alzheimer's.

Meanwhile, Lilly recorded Kisunla sales of $21 million in the first quarter, rising to $49 million in the second, narrowing the gap with its first-to-market rival.