Biogen Inc. (BIIB): Leqembi subcutaneous initiation approved in Alzheimer’s disease

Research evidence excerpt

Biogen Inc. (BIIB): Leqembi subcutaneous initiation approved in Alzheimer’s disease

Goldman Sachs Biogen Inc. (BIIB)

n Subcutaneous IQLIK induction as a market and share expansion driver, due to

dosing convenience and lower barriers to initiate Leqembi treatment. Eisai has

discussed the competitive advantage of maintenance treatment as it to relates to

maintaining efficacy, and anticipates subcutaneous initiation to reduce the current

dosing advantage of Kisunla vs. IV Leqembi (Q4W vs. Q2W). On pricing, Eisai has said

it expects to follow a policy of pricing parity for IV and subcutaneous to allow

patients to switch seamlessly between the two without significant differences in

out-of-pocket costs, noting that the IV formulation is also associated with significant

infusion-related expenses. Management expects initial uptake supported by letters

of medical exception, until full reimbursement on January 1, 2027. Separately on

IQLIK maintenance, management has noted payor approval rate under insurance

coverage through medical exception process of ~85% at approximately 600

facilities.

n Ex-US, Eisai anticipates subcutaneous induction approval in Japan by 3Q26 and in

China by 1Q27. Eisai noted that Leqembi has been included in 15 commercial

insurance programs in China, while negotiations for reimbursement are ongoing in

Germany, the UK, Spain, Italy and others.

n The use of blood-based biomarker (BBB) diagnostics to mitigate barriers to

neurologist access. Eisai expects Aβ confirmatory diagnosis using blood-based

biomarkers to drive market expansion in the US, noting low economic burden, less

evasiveness and ease of access vs. PET and CSF for confirmatory testing. Per

management, the use of BBB diagnostics for confirmatory testing and triage has