A Phase 2 Trial of ALN-APP in Patients With Cerebral Amyloid Angiopathy

To be considered for this study, you would generally need to be an adult. If you have the more common type of CAA, called sporadic CAA, you need to be 50 years old or older and have a diagnosis of probable CAA based on specific medical guidelines.

If you have a less common type of CAA, known as Dutch-type CAA, you need to be 30 years old or older and have a specific gene change (E693Q amyloid precursor protein mutation) that causes this condition.

There are also some reasons why you wouldn't be able to join. For example, if you have moderate or severe Alzheimer's disease, or significant memory and thinking problems not related to CAA. You also can't have had a recent brain bleed within the last three months, or have certain liver or kidney problems. If you've recently been part of another medical trial or had treatment with certain antibodies targeting amyloid protein, you also wouldn't be able to participate. The study team will check all these details carefully.

If you decide to take part in this study, the first step is a 'screening' process to make sure you meet all the requirements. This involves various health checks. After screening, you would be involved in the study for up to 50 months, which is about four years.

For the first 24 months, you would receive either the study medicine (ALN-APP) or a placebo (a dummy treatment, like a sugar pill). You wouldn't know which one you are getting, and neither would your doctor – this is called a 'double-blind' period. After these two years, there's an optional extra period of 18 months where everyone who continues would know they are receiving ALN-APP (this is called 'open-label'). Throughout the study, you'll have regular visits for check-ups, assessments, and follow-up appointments to monitor your health and how the treatment is affecting you.