A Clinical Trial to Evaluate AL002 in Participants with Alzheimer's Disease
Research type
Research Study
Full title
A MULTICENTER, LONG-TERM EXTENSION STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND EFFICACY OF AL002 IN PARTICIPANTS WITH ALZHEIMER'S DISEASE
IRAS ID
1006808
Contact name
Janel Boyce-Rustay
Contact email
Sponsor organisation
Alector, Inc.
Eudract number
2022-002987-57
Clinicaltrials.gov Identifier
Research summary
Summary of Research
This is a Phase 2, randomized, parallel-group, long-term extension (LTE), dose-blind, multicentre study to evaluate the long-term safety and efficacy of AL002 [referred to as investigational medicinal product (IMP) in this AL002-LTE study] in participants with Alzheimer’s disease (AD). The study is a multicentre, global trial that will enrol participants who completed the planned treatment period in AL002-2 (parent study). This study is sponsored by Alector Inc. and the purpose of this study to see how safe and effective the experimental drug, AL002 is when given intravenously (IV) to participants with early AD.AD is a degenerative brain disease and one of the most common causes of dementia. Over half a million people in the UK have dementia related to AD, which causes progressive memory loss and issues with cognitive function such as language, spatial awareness, organisation and concentration, as well as changes in mood. There is currently no effective treatment for AD.
AD is thought to be caused by the build-up of proteins in the brain, which clump together to form plaques (made up of amyloid protein) and tangles (made up of tau protein). The immune system plays an important role in clearing these proteins, but this becomes less effective with age. The study drug, AL002, binds to and stimulates cells in the immune system called microglia to help clear these proteins. This is the second clinical study using AL002; the first study in health volunteers and participants with Alzheimer's Disease indicated that the drug is safe and well tolerated.
Dose Blind means that the participants, study doctor, and all of the study team members and the Sponsor who are actively involved in the day-to-day activities of the study, will not know patient's dose assignment.
Dose Assignment means that if patients received AL002 during the AL002-2 study, they will remain at the same dose. If they received placebo during the AL002-2 study, they will receive AL002 in the LTE study.Summary of Results
A Multicenter, Long-term Extension Study to Evaluate Safety, Tolerability, and Efficacy of AL002 In Participants With Alzheimer’s Disease
What was this study about?
Alzheimer’s Disease (AD) is a common cause of dementia. The cause of AD is, however, not currently known, and there is a need for better treatments for patients with AD.
What was the goal of this study?
The goal of this study was to determine if long-term treatment with an investigational study drug, AL002, provided benefits to the patients and was well tolerated. The term “investigational” means the study drug is not yet approved by health authorities to treat AD.
How was the study done?
This study started in January 2023 and ended in February 2025. Ten countries signed up to participate in this study.
This study was an additional period where patients who had completed the previous Phase 2 study could continue to receive AL002. A Phase 2 study is a type of study in which a new treatment is tested in a significant number of people who have the disease being studied. In that study, some patients had received a placebo (a dummy substance that did not contain any medicine). If a patient had received AL002 in the previous study, they continued to receive AL002 at the same dose in this study. If a patient had received placebo in the previous study, they started this study on a lower dose of AL002 and increased their dose slowly to the highest dose. The patients and doctors knew that all patients were receiving AL002 but did not know what dose of AL002 they had received in the prior study, nor what dose they were receiving in this study. The researchers did this to make sure the study results were not influenced.
Three different doses of AL002 were studied: 15, 40, or 60 mg/kg. AL002 was administered by a doctor by slow infusion into a vein every 4 weeks.
There were requirements to meet to take part in this study. These included things that patients needed to have (inclusion criteria) or not have (exclusion criteria). Below is a simplified list of these requirements:
• The patient had to have completed the treatment period in a previous study with AL002, known as Study AL002-2.
• The patient had to have a person available who saw them frequently (at least 10 hours a week) and was able to go on study visits with them. This person had to be able to provide information on any changes in the patient’s ability to understand and perform daily activities.
• The patient had to be capable of completing all the assessments performed during the study.
• Pregnant or breastfeeding females were not allowed to take part in this study.
To determine if AL002 was safe, study doctors recorded all adverse events that happened during the study. An adverse event is any medical event occurring during the study, even if not related to the treatment. Side effects that study doctors think might be related to study treatment are called “adverse reactions”. A serious adverse reaction means the adverse reaction either led to patient death or was considered life-threatening by the doctor or caused hospitalization, or was debilitating, or was otherwise considered medically important by the doctor.
What were the results of this study?
A total of 197 patients enrolled, 101 were female and 96 were male. Their ages ranged from 53 to 87 years old.
Three patients each experienced one serious adverse reaction while taking AL002. The serious adverse reactions were cerebral infarction (a type of stroke), anaphylactic reaction (a severe allergic reaction), and ARIA-H. ARIA stands for amyloid-related imaging abnormality and is an abnormal difference sometimes seen on a brain scan of a patient with AD using a technique called magnetic resonance imaging. In cases of ARIA-H, small bleeds (or hemorrhages) are seen in the brain. The cerebral infarction was considered a medically important event by the patient’s doctor. The anaphylactic reaction was considered life-threatening, and both the anaphylactic reaction and ARIA-H resulted in the patients being hospitalized. All the serious adverse reactions resolved and all the patients recovered.
Most non-serious adverse reactions experienced by patients were mild and most types of reaction were reported by no more than 5 patients.
This study was stopped early by the Sponsor after reviewing the results of Study AL002-2 which showed that AL002 was well tolerated but did not provide benefit as a treatment for AD. Although this study was stopped early, the results may be informative to other studies. No further studies with AL002 are currently planned.
Where can I learn more about this study?
For more details, visit:
• European Clinical Trials Register - https://euclinicaltrials.eu/ctis-public/view/2023-506872-29-00
• US Clinical Trials Register - https://clinicaltrials.gov/study/NCT05744401
The sponsor was Alector, Inc.: 131 Oyster Point Boulevard, Suite 600, South San Francisco, CA 94080, USA.REC name
London - Chelsea Research Ethics Committee
REC reference
23/LO/0446
Date of REC Opinion
7 Jun 2023
REC opinion
Further Information Favourable Opinion