Core Viewpoint - Alzheimer's disease (AD) is a severe neurodegenerative disorder with significant impacts on individuals and society, yet drug development has faced numerous failures despite substantial investments from major pharmaceutical companies [2][3]. Drug Development and FDA Approvals - In June 2021, the FDA accelerated the approval of Aducanumab, developed by Eisai and Biogen, marking the first new drug for Alzheimer's since 2003, although its approval was controversial due to associated risks like ARIA (Amyloid-related Imaging Abnormalities) [3][6]. - Following Aducanumab, the FDA approved two additional antibody drugs targeting Aβ: Donanemab by Eli Lilly and Lecanemab by Eisai and Biogen, both of which also present ARIA-related side effects [3][6]. Denali Therapeutics' Research - Denali Therapeutics published a study in August 2025 on a new antibody transport carrier, ATV cisLALA, which utilizes transferrin receptor (TfR) to enhance brain delivery of anti-Aβ antibodies while mitigating ARIA risks [4][9]. - The ATV cisLALA carrier shows improved distribution in brain tissue compared to traditional Aβ antibodies, which tend to accumulate around blood vessels, potentially triggering inflammatory responses and ARIA [9][11]. Mechanism of Action - Traditional Aβ antibodies enter the brain through cerebrospinal fluid and perivascular spaces, where amyloid deposits are located, leading to inflammation and ARIA. In contrast, the ATV carrier enhances delivery through capillaries, reducing ARIA side effects [11][12]. - Denali's TfR-based approach is not limited to Aβ; the company is also developing therapies targeting tau protein using the same delivery mechanism, aiming to address two key toxic proteins in Alzheimer's simultaneously [11].