This study is an extension of a previous study identified as NCT06079190. Entry into this extension study occurs after completing the treatment period in that previous study.

Before starting, informed consent must be provided. If there is difficulty providing consent independently, a legally authorized representative may provide consent on behalf of the participant, and the participant must provide agreement according to local regulations.

A study partner is required for participation. This is an adult who has regular contact with the participant for at least 8 hours per week in person. The study partner must be able to provide accurate information about cognitive and functional abilities and must sign a consent form.

The same study partner from the previous study should continue in this extension study whenever possible. If the original study partner cannot continue, a replacement study partner meeting the same requirements must be available.

Female participants must not be pregnant or breastfeeding. Those who can become pregnant must use highly effective birth control methods starting at least 14 days before the first dose and continuing until at least 12 weeks after the last dose. A negative pregnancy test is required within 24 hours before the first dose.

Male participants must agree not to donate sperm during the study. If engaging in sexual intercourse with a woman who can become pregnant, a condom must be used, and the female partner must use an additional highly effective birth control method.

The study medication is GSK4527226, which is given as a solution for infusion. This means the medication is delivered directly into a vein through an intravenous line.

This is an open-label study, meaning both the participant and the medical team know which treatment is being given.

The study evaluates the long-term safety and effectiveness of GSK4527226 in participants with early Alzheimer’s disease. Alzheimer’s disease is a condition that affects memory and thinking abilities.

Specific dosage, frequency, and duration of the medication administration are determined according to the study protocol and individual participant needs.

Throughout the study, safety will be monitored by tracking any adverse events. An adverse event is any unwanted medical occurrence or symptom that happens during the study.

Special attention will be given to serious adverse events, which are medical problems that require hospitalization, are life-threatening, or result in significant disability.

Adverse events of special interest will also be monitored. These are specific types of side effects that are particularly important to track for this medication.

The study will specifically monitor for ARIAs, which stands for amyloid-related imaging abnormalities. These are changes that can be seen on brain scans and may include swelling or small areas of bleeding in the brain.

The severity of any ARIAs that occur will be assessed and recorded.

Various assessments will be performed to measure changes in thinking abilities and daily functioning from the beginning of this extension study.

The CDR-SB (Clinical Dementia Rating – Sum of Boxes) will be used to assess overall dementia severity and functioning in different areas.

The ADAS-Cog14 (Alzheimer’s Disease Assessment Scale – Cognitive Subscale with 14 items) will measure cognitive abilities including memory, language, and other thinking skills.

The MMSE (Mini-Mental State Examination) will assess general cognitive function through questions and tasks.

The ADCS-ADL-MCI (Alzheimer’s Disease Cooperative Study – Activities of Daily Living scale for Mild Cognitive Impairment) will evaluate the ability to perform everyday activities.

The iADRS (Integrated Alzheimer’s Disease Rating Scale) combines measures of cognition and daily function.

The ADCOMS (Alzheimer’s Disease Composite Score) is a combined measure that tracks disease progression.

The study partner will need to be present at specific visits to provide input for some of these assessments.

The study is expected to begin enrollment in December 2025.

The estimated completion date for the study is November 2028.

The exact duration of individual participation will depend on when enrollment occurs and the specific study protocol requirements.

Regular visits will be scheduled throughout the study period for medication administration, safety monitoring, and assessments.