For A4 Study-related papers and other publications, please see the A4 Study Team lists
the a4 Study Lives On
About the Study
The Anti-Amyloid Treatment in Asymptomatic Alzheimer’s (the “A4 study” for short) was a landmark clinical trial, the first of a kind, to test a specific way to prevent the memory loss associated with Alzheimer’s disease (AD). It was focused on adults who were at higher risk for developing the disease, but who had no symptoms. The purpose was to test whether an investigational drug could slow the progression of memory problems associated with brain amyloid (protein that forms plaques in the brains of people with AD). The A4 study also tested whether anti-amyloid treatment could delay the progression of AD related brain injury on imaging and other biomarkers, like blood tests. All volunteers underwent a positron emission tomography (PET) scan to determine their brain amyloid levels at screening.
The A4 study leadership teams work was extraordinary in how to ethically reach out to over 15,000 people who were unaware they could be candidates for the A4 study. A4 researchers screened more than 7,500 people and enrolled 1,169 people with pre-symptomatic Alzheimer’s disease. This stage of this disease, when amyloid protein begins to collect in the brain, but cognitive decline is not yet evident, is seen as an optimal time to intervene and slow progression. The researchers collected a wealth of information from each participant—including brain scans, blood samples, genetic information and cognitive tests—over a period of 4.5 years, and up to 8 years in the extension study.
STUDY TEAM LISTS
The A4 and LEARN Study Leadership Teams provide the list below for standardized acknowledgement of the many individuals who have contributed to the A4 and LEARN Studies (current and former). Please download the lists of the study teams below:
A4 Participants
The A4 Study wouldn’t have been possible without it’s participants and their study partners. A4 was fully enrolled with 1169 randomized participants across 67 sites in 2017. The participants were cognitively unimpaired individuals between 65 and 85 years of age with evidence of elevated amyloid plaque accumulation in the brain on screening PET. Still clinically normal but at high risk for cognitive decline.
During the placebo-controlled period, participants were coming to the clinical sites once a month for 240 weeks (over 4 and half years), for infusions and a variety of tests capturing efficacy, health outcomes, and images. Dedicated A4 participants and study partners were known to travel great distances for their visits, and some remained in the study on the open-label extension for as long as six to seven years.
Study Support
The A4 [clinical trial number NCT02008357] study was supported by a public-private-philanthropic partnership which included funding from the National Institute of Aging of the National Institutes of Health (R01 AG063689, U19AG010483 and U24AG057437), Eli Lilly (also the supplier of active medication and placebo), the Alzheimer’s Association, the Accelerating Medicines Partnership through the Foundation for the National Institutes of Health, GHR Foundation, the Davis Alzheimer Prevention Program, the Yugilbar Foundation, an anonymous foundation, and additional private donors to Brigham and Women’s Hospital, with in-kind support from Avid Radiopharmaceuticals, Cogstate, Albert Einstein College of Medicine and the Foundation for Neurologic Diseases. Data sharing work was supported by the Epstein Family Alzheimer’s Research Collaboration and Gates Ventures.
Access the study data
Data from A4, the first and largest clinical trial of pre-symptomatic Alzheimer’s disease, became widely available on July 1, 2024 to researchers studying the condition. The comprehensive dataset has already yielded key insights about Alzheimer’s disease, which affects nearly seven million people in the United States, and sharing the data opens avenues for further progress.
Brigham & Womens Press Release- A4 Study Solanezumab Results March 2023
Eli Lilly Press Release- A4 Study Solanezumab Results March 2023
Selected Slides Study Results- A4 Study Alzheimer Association International Conference July 2023
Access data from the study at a4studydata.org