Two Alzheimer Disease Therapies to Watch at CTAD 2025: Lecanemab and Sabirnetug Updates

Two programs in clinical development for Alzheimer disease will feature prominently at this year’s Clinical Trials on Alzheimer’s Disease (CTAD) meeting, December 1-4, in San Diego, with Eisai presenting new analyses on lecanemab¹ and Acumen Pharmaceuticals outlining progress on sabirnetug (ACU193) and its Enhanced Brain Delivery (EBD) platform.²

Both companies will focus on early-stage disease, with presentations spanning long-term outcomes, diagnostic timing, recruitment strategies, and methods to improve antibody penetration across the blood–brain barrier.

Updates on Lecanemab¹

Eisai will report new findings on lecanemab (Leqembi), including analyses of continued treatment and estimated time savings over 10 years derived from phase 3 data. Investigators will also describe safety and pharmacokinetics of subcutaneous initiation dosing, effects on soluble amyloid-β protofibrils, and real-world findings from ALZ-NET and an observational program in Japan.

(Note: all times are US PST)

Oral sessions include:

• Continued-treatment analyses on benefits of continued therapy over 10 years of lecanemab therapy. (December 2 at 5:05 PM and December 3 at 2:40 PM [LB12, LB21]).
• Subcutaneous initiation dosing is explored in a late-breaking symposium, Lecanemab Subcutaneous Formulation for Treatment Initiation in Early Alzheimer’s Disease: Optimizing Patient Care with a Potential New Option (December 3 at 3:10–3:50 PM).
• Real-world experience will be demonstrated in data presented from an interim analysis of a post-marketing observational study of lecanemab in Japan (December 4 at 11:40 AM)
• Mechanistic data from Clarity AD concerning soluble Aβ protofibrils will be presented as a poster (055) (December 2 at 1:40 PM).

“We continue to advance our understanding of lecanemab in both controlled clinical trials and real-world practice, and we value the opportunity to share these data with the scientific community at CTAD,” Masaki Kutsumi of Eisai said in a statement.¹

Altogether, Eisai will participate in CTAD with 8 oral presentations, 19 posters and 1 symposium covering topics including myriad outcomes from lecanemab research evaulting treatment acceptance, comparative outcomes and safety; risk factors, diagnosis and treatment in early Alzheimer disease; and biomarkers and imaging.¹

Updates from Acumen Pharmaceuticals²

Acumen Pharmaceuticals will contribute 2 presentations at CTAD focused on its phase 2 ALTITUDE-AD trial of sabirnetug and its nonclinical brain-delivery platform for sabirnetug.

Sabirnetug is a humanized monoclonal antibody (mAb) that selectively targets soluble amyloid-β oligomers (AβOs), which accumulate early, exert synaptotoxic effects, and may drive downstream neurodegeneration, according to the company. ALTITUDE -AD is evaluating the safety of the mAb infusions adminstered once every 4 weeks in slowing cogntive and functional decline vs placebo in early Alzheimer disease, Acumen stated.

The company confirmed that the phase 2 trial (NCT06335173) completed enrollment of 542 participants with early Alzheimer disease in March 2025 across the United States, Canada, the European Union, and the United Kingdom. Recruitement strategies for the global trial will be highlighted during a poster presentation (P019), December 1 at 3:00 PM and December 2, at 5:30 PM.

The Enhanced Brain Delivery program will be highlighted in a poster session on d December 4 that will describe a preclincal study evaluating the fusion of transferrin-receptor binders to sabirnetug to improve transport of the drug across the blood–brain barrier while preserving target engagement. The EBD program reflects Acumen’s July 2025 collaboration with JCR Pharmaceuticals on transferrin-receptor–targeting technology. The company stated that the goal is “to potentially improve drug delivery to the brain and potentially offer patients a more effective treatment option with an improved safety profile, to slow or prevent neurodegeneration associated with AD.”

As both reseearch programs move deeper into phase 2 and then phase 3 development, investigators at CTAD conferences of the future will have the opportunity to compare strategies for modifying early disease and addressing barriers that limit therapeutic impact—including diagnostic delay.

The Alzheimer Disease Problem in the US

Underdiagnosis continues to hinder timely intervention in treatment of Azheimer disease. In population-based studies, more than half of individuals with biomarker-defined Alzheimer pathology remain undiagnosed in clinical practice.³ In the Mayo Clinic Study of Aging, 56% of participants with amyloid-positive, biomarker-confirmed Alzheimer disease had never received an AD diagnosis in routine care.⁴ Investigators attributed the gap to limited recognition of early or atypical presentations, restricted access to biomarker testing, and variability in primary care cognitive assessment. Addressing these diagnostic delays remains central to using disease-modifying therapies effectively.⁴

References

1. Eisai to present data on lecanemab continued treatment, subcutaneous initiation dosing, and real-world experience at the 18th Clinical Trials on Alzheimer’s Disease Conference. News release. November 19, 2025. Accessed November 19, 2025. https://www.eisai.com/news/2025/news202580.html
2. Acumen Pharmaceuticals to present on recruitment strategies for phase 2 ALTITUDE-AD trial and enhanced brain delivery technology at 18th annual Clinical Trials on Alzheimer’s Disease (CTAD) Conference. News release. November 18, 2025. Accessed November 19, 2025. https://investors.acumenpharm.com/news-releases/news-release-details/acumen-pharmaceuticals-present-recruitment-strategies-phase-2
3. Amjad H, Roth DL, Sheehan OC, et al. Underdiagnosis of dementia: an observational study of patterns in diagnosis and awareness in U.S. older adults. J Gen Intern Med. 2018;33(7):1131‑1138. doi:10.1007/s11606‑018‑4377‑y
4. Roberts RO, Geda UE, Knopman DS, et al. The Mayo Clinic Study of Aging: design and samling, participation, baseline measures, and sample characteristics. Neuroepidemiology. 2008;30(1):58–69. doi: 10.1159/000115751