Eisai to Present Lecanemab SC Formulation and Etalanetug Tau Data at AAIC 2026

Eisai announced today that it will present 52 abstracts spanning its Alzheimer's disease (AD) portfolio at the Alzheimer's Association International Conference (AAIC) 2026, to be held July 12–15 in London and online.¹ The package represents one of the most comprehensive AD data disclosures of the year and encompasses real-world evidence for lecanemab (brand name Leqembi), emerging data on the subcutaneous formulation, and phase 2 findings for etalanetug (E2814), the company's investigational anti-MTBR tau antibody — a program that reflects the broader evolution of large-molecule medicines toward multi-target therapeutic strategies.

Can Leqembi be administered at home? First real-world SC data to be presented at AAIC

The centerpiece of Eisai's AAIC program is a Developing Topics Session on the subcutaneous formulation of Leqembi, scheduled for July 12.¹ The session will feature clinical trial data alongside real-world patient experience with SC administration, including safety profiling, patient-reported outcomes, and practical use considerations for AD treatment centers.

Of particular interest is a presentation reporting the first real-world findings of at-home subcutaneous Leqembi administration — a meaningful development for a therapy that, in its IV formulation, requires patients to travel to infusion centers every two or four weeks. Patient, care partner, and HCP evaluation of the Leqembi autoinjector has shown high rates of satisfaction and ease of use in interim pilot data,² supporting the case for home administration. A companion presentation from the INITIATE-SC study, a multicenter real-world investigation of SC Leqembi initiation, will add further context on how the route-of-administration shift is playing out in clinical practice.¹

The FDA approved Eisai's BLA for the subcutaneous maintenance formulation (Lequembi IQLIK) in August 2025. A supplemental BLA for initiation treatment via the subcutaneous route was accepted in January 2026 and granted Priority Review, with a PDUFA action date of August 24, 2026.³

What does three years of real-world Leqembi use look like? LEADER data updated at AAIC

A Featured Research Session on July 14 will present updated findings from LEADER, a comprehensive multi-center retrospective study evaluating real-world Leqembi use across diverse US clinical settings three years post-approval.¹ Highlights include outcomes stratified by APOE ε4 status, sex, race, and ethnicity; real-world experience with once-monthly maintenance dosing; and physician and patient satisfaction with maintenance therapy.

The LEADER dataset is emerging as a critical evidence base for Leqembi commercial positioning, addressing questions around long-term durability, real-world safety, and whether the benefits demonstrated in the pivotal Clarity AD trial⁴ translate across a broader patient population. Real-world studies to date have supported meaningful clinical response in MCI and mild AD populations, though ARIA monitoring and APOE ε4 carrier management remain active areas of clinical consideration.⁵,⁶

Can targeting both amyloid and tau improve Alzheimer's outcomes? etalanetug phase 2 data in focus

Eisai will also present phase 2 data for etalanetug, an anti-microtubule-binding region (MTBR) tau antibody co-developed with University College London and designed to inhibit intraneuronal propagation of tau seeds.¹ Etalanetug is being investigated as an add-on to Leqembi background therapy — a combination strategy reflecting the emerging consensus that simultaneous targeting of both amyloid and tau pathology may be necessary for meaningful disease modification.⁷

Two oral presentations in a Featured Research Session on July 13 will cover baseline imaging characteristics of participants in the Phase 2 Study 202 trial, and the relationship between etalanetug and tau tangle-specific plasma biomarker eMTBR-tau243 in dominantly inherited AD (DIAD).¹ The Tau NexGen trial (NCT04660955), evaluating etalanetug in combination with Leqembi in DIAD, is ongoing under the DIAN-TU consortium at Washington University School of Medicine. Etalanetug received FDA Fast Track designation in September 2025.¹

Additional poster presentations will characterize etalanetug's mechanism, including macrophage uptake of tau monomer and aggregate via Fcγ receptors, and a novel CSF eMTBR-tau243 immunoassay for detecting AD tau pathology.¹

What else Is Eisai presenting at AAIC 2026?

The AAIC program also includes presentations on the AHEAD 3-45 trial (NCT04468659) in preclinical AD, exploring Leqembi’s potential in amyloid-positive cognitively normal individuals, and an expanding body of blood-based biomarker work supporting earlier and less invasive diagnostic pathways.¹ Leqembi is currently approved in 53 countries and regions. An Eisai-sponsored symposium on early intervention in AD is scheduled for July 14.

"We are sharing a broad and robust data set at AAIC spanning the Alzheimer's disease continuum, multiple therapeutic targets, and modes of administration, underscoring our commitment to advancing care for this complex disease."
— Lynn D. Kramer, MD, FAAN, Chief Clinical Officer, Deep Human Biology Learning, Eisai¹

References

1. Eisai to Showcase Alzheimer's Disease Portfolio with More Than 50 Presentations at the Alzheimer's Association International Conference 2026 (AAIC). (2026 Jun 29). PR Newswire. https://www.prnewswire.com/news-releases/eisai-to-showcase-alzheimers-disease-portfolio-with-more-than-50-presentations-at-the-alzheimers-association-international-conference-2026-aaic-302813154.html
2. Jamison K, Zullig L, Turner RS, Jones D. (2025 Dec 23). Patient, care partner, and health care professional opinion of the lecanemab autoinjector for subcutaneous delivery in early Alzheimer's disease patients. Alzheimers Dement. https://pmc.ncbi.nlm.nih.gov/articles/PMC12726169/
3. Mirasol, F. (2026 May 8). Eisai, Biogen Receive Extended FDA Review for Lecanemab Subcutaneous Starting Dose. BioPharm International. https://www.biopharminternational.com/view/eisai-biogen-receive-extended-fda-review-for-lecanemab-subcutaneous-starting-dose
4. van Dyck CH, Swanson CJ, Aisen P, et al. (2022 Nov 29). Lecanemab in early Alzheimer's disease. N Engl J Med. https://www.nejm.org/doi/full/10.1056/NEJMoa2212948
5. Honig LS, Sabbagh MN, van Dyck CH, et al. (2024 May 10). Updated safety results from phase 3 lecanemab study in early Alzheimer's disease. Alzheimers Res Ther. https://pubmed.ncbi.nlm.nih.gov/38730496/
6. Bregman, N., Nathan, T., Shir, D., Omer, N., Levy, M. H., David, A. B., Aizenstien, O., Lotan, E., Alcalay, Y., Awad, A. A., Gadoth, A., Ash, E., & Shiner, T. (2025 May 28).Lecanemab in clinical practice: real-world outcomes in early Alzheimer's disease. Alzheimers Res Ther. https://pubmed.ncbi.nlm.nih.gov/40437535/
7. Benzinger T, Charil A, Gordon B, et al. (2025 Dec 1). Baseline imaging characteristics of participants in the Phase II/III DIAN-TU-001 Tau NexGen trial for dominantly inherited Alzheimer's disease. Alzheimers Dement. https://europepmc.org/article/pmc/pmc12739784
8. A Study to Confirm Safety and Efficacy of Lecanemab in Participants With Early Alzheimer's Disease (Clarity AD). ClinicalTrials.gov. NCT03887455. https://clinicaltrials.gov/study/NCT03887455
9. AHEAD 3-45 Study: A Study to Evaluate Efficacy and Safety of Treatment With Lecanemab in Participants With Preclinical Alzheimer's Disease. ClinicalTrials.gov. NCT04468659. https://clinicaltrials.gov/study/NCT04468659
10. A Study to Assess Safety and Target Engagement of E2814 in Participants With Mild to Moderate Cognitive Impairment Due to Dominantly Inherited Alzheimer's Disease. ClinicalTrials.gov. NCT04971733. https://clinicaltrials.gov/study/NCT04971733