AriBio, a clinical-stage biopharmaceutical company developing novel therapies for neurodegenerative diseases, has revealed the interim results from its ongoing Phase 2a clinical trial of AR1005 in patients with dementia with Lewy bodies. The findings were presented at the Alzheimer’s Association International Conference 2026 in London.
AR1005 is an investigational oral fixed-dose combination of lamotrigine, which inhibits voltage-gated sodium channels and decreases excessive excitatory neurotransmission, and rivastigmine, an approved treatment for cognitive symptoms.
The Phase 2 trial is assessing whether targeting neuronal hyperexcitability with this combination can mitigate cognitive and neuropsychiatric symptoms in patients with DLB. The study is being conducted at Severance Hospital in Korea and is expected to enrol 60 patients; the interim analysis included data from 31 participants.
At week 20, AR1005 demonstrated a 1.15-point treatment difference in the Mayo Fluctuations Scale (MFS) in favour of AR1005 compared with placebo.
MFS evaluates cognitive fluctuations, a characteristic and clinically significant symptom of DLB, with lower scores indicating less severe symptoms.
Quantitative electroencephalography (qEEG) supported this finding: AR1005 exhibited lower theta-to-beta ratios (TBR), a measure associated with EEG slowing in DLB. The treatment difference was -3.34 globally, with similar findings in the central and occipital regions.
The interim analysis also found a 0.46-point treatment difference in favour of AR1005 on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) at week 20; however, the difference was not statistically significant. Additionally, favourable numerical trends were observed on the Korean Mini-Mental State Examination (K-MMSE) and the Caregiver-Administered Neuropsychiatric Inventory (CGA-NPI). The complete efficacy and safety profile will be assessed after the study is completed.
Professor Byoung-Seok Ye of the Department of Neurology, Severance Hospital, the principal investigator of the study, said, “Dementia with Lewy bodies is associated with a range of symptoms, including cognitive decline, cognitive fluctuations, visual hallucinations, and parkinsonism, while available treatment options remain limited. The findings from this interim analysis provide early clinical data supporting further evaluation of AR1005, particularly in relation to cognitive fluctuations and quantitative EEG measures.”
Fred Kim, managing director at AriBio, said, “These interim findings strengthen our conviction in targeting neuronal hyperexcitability in DLB. We have begun preparing for a pre-IND meeting with the FDA and will use the complete dataset to define the design and endpoints of a global Phase 2/3 program, with the goal of bringing a new treatment option to patients and families living with DLB.”
The findings are based on an interim analysis conducted before enrollment was completed. Final efficacy and safety results will be assessed after all 60 participants have completed the study.
