AriBio said Monday that the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) has formally approved POLARIS-AD, a global phase 3 clinical trial of AR1001, an oral treatment for Alzheimer's disease.

AriBio plans to initiate the phase 3 trial in the U.K. before the end of the first quarter of 2024. The U.K. will be the third country where AriBio conducts the POLARIS-AD global clinical trial, following the U.S. and Korea in 2022.

The POLARIS-AD study will enroll 1,250 patients (about 600 in the U.S., 150 in Korea, 100 in China, and 400 in the U.K. and seven EU countries). Phase 3 protocols have also been submitted to China and the European Union.

POLARIS-AD is a 52-week, double-blind, randomized, placebo-controlled, multicenter phase 3 trial to evaluate the efficacy and safety of AR1001 in patients with early Alzheimer's disease. Various cognitive and functional assessments will be used to evaluate the efficacy and safety of AR1001 in improving cognitive function and slowing the progression of Alzheimer's.

The primary endpoints include changes in CDR-SB (Clinical Dementia Rating Scale-Sum of Boxes), ADAS-Cog13 (Alzheimer's Disease Assessment Scale-Cognitive Subscale), A-iADL (Amsterdam-Institutionalized Activities of Daily Living Questionnaire), GDS (Geriatric Depression Scale), MMSE (Mini-Mental State Examination), and changes in cerebrospinal fluid (CSF) and plasma biomarkers, as approved by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA).

"The U.K. MHRA approval of phase 3 trial is an important milestone for AR1001, allowing patients to take AR1001 for the first time in Europe," AriBio CEO Choung Jai-jun said.

David Greeley, chief medical officer of AriBio’s U.S. office, said, "Many European researchers have already shown interest in the PDE-5 mechanism and sent inquiries to participate in the trial. We look forward to a rapid and successful global phase 3 trial for AR1001.”