Exploratory Study of Low-Dose Whole-Brain Radiation Therapy With HeLaXON 1X in Patients With Mild Alzheimer's Disease Dementia (LDRT-AD-03)

This randomized, sham-controlled, exploratory clinical trial will evaluate the efficacy and safety of HeLaXON, an investigational low-dose radiation therapy device, in patients with mild Alzheimer's disease dementia. A total of 30 participants will be randomly assigned in a 1:1 ratio to receive either low-dose whole-brain radiation therapy or a sham procedure using the same device. Participants in the treatment group will receive 0.04 Gy per session twice weekly for 3 weeks, for a total of 6 sessions and a cumulative dose of 0.24 Gy. Participants in the sham group will undergo the same device procedures without radiation delivery. Participants and outcome assessors will remain blinded to treatment assignment. Changes in cognitive function, dementia severity, daily functioning, and amyloid burden will be evaluated at 6 and 12 months after treatment. Safety will be assessed throughout the study. Exploratory blood biomarkers, including plasma Aβ42/40 ratio, p-tau217, and Aβ oligomer, will also be evaluated.

• Change From Baseline in Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB) Score
• Change From Baseline in Alzheimer's Disease Assessment Scale-Korea-Cognitive Subscale-13 (ADAS-K-Cog-13) Score
• Change From Baseline in Korean Mini-Mental Status Examination-2 (K-MMSE-2) Score
• Change From Baseline in Korean Instrumental Activities of Daily Living (K-iADL) Score

1. Study completion expected

   30 Dec 2028

2. Primary completion expected

   31 Mar 2028

3. Expected to start

   26 Oct 2026

4. Registered

   7 Oct 2026