Eisai moves swiftly to expand subcutaneous Leqembi label

Mere days after getting FDA approval for an injectable formulation of Alzheimer's disease therapy Leqembi that can be given at home, Eisai is looking to broaden its use.

The Japanese drugmaker has started a rolling biologics license application (BLA) for Leqembi Iqlik (lecanemab) that it hopes will make it an option for initial treatment, in addition to its approved use as a maintenance therapy.

The once-weekly subcutaneous autoinjector picked up an FDA approval late last week that clears the way for it to be an alternative to the current intravenous infusion of Leqembi, but only after patients have already been receiving the drug for 18 months.

The rolling BLA - if approved - would mean that Leqembi Iqlik could be used right from the start of therapy, allowing patients to be treated at home and doing away with the need to visit infusion clinics, potentially reducing healthcare resources associated with intravenous dosing, such as dose preparation and nurse monitoring.

The need for regular, hour-long clinic visits is one of the reasons for a slower-than-anticipated uptake of the original IV formulation Leqembi, given every two weeks, along with its relatively modest efficacy and the risk of potentially serious side effects like brain swelling and haemorrhage.

The FDA has already granted fast-track status to the rolling BLA, which is based on evaluation of subcutaneous lecanemab administration across a range of doses from substudies within the phase 3 open-label extension to CLARITY-AD, the main clinical trial supporting Leqembi's original FDA approval in 2023.

At the primary endpoint after 18 months, CLARITY-AD showed that Leqembi reduced cognitive decline by 27% compared to placebo.

In January, Eisai and partner Biogen were also granted approval by the FDA to dose the drug every four weeks during the maintenance phase, reducing the need for clinic visits.

Subcutaneous dosing could give Eisai and Biogen an edge over 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 thanks to a label that requires it to be used for a shorter period and 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 brain swelling.

In the second quarter of this year, Leqembi sales reached $160 million, while Lilly booked $49 million from Kisunla.