Practical Lessons from Amyloid Immunotherapy Trials in Alzheimer Disease

Objectives: Amyloid immunotherapy trials are central in Alzheimer disease (AD) drug development, with the potential to influence all future disease-modifying randomized controlled trials (RCTs). This study investigates practical experiences of staff and participants in immunotherapy RCTs. Setting and methods: The Clinical Trial Research Unit of the Memory Clinic at Karolinska University Hospital, Sweden is an experienced centre specialized in Alzheimer RCTs, where four active and passive phase I/II immunotherapy trials are currently ongoing. Meetings were held with staff members, who were asked to describe their experiences and suggest necessary improvements. In addition, a pilot study was conducted to investigate motivations and expectations of participants in immunotherapy RCTs. A questionnaire was sent to 20 patients, and another similar questionnaire to their caregivers. Results: The main issues emphasized by staff members concerned the critical window of opportunity for recruiting RCTs participants, the much higher level of effort required of patients and caregivers in immunotherapy RCTs compared to classical cholinesterase inhibitor RCTs, problematic informed consent procedures, and confidentiality limitations in trials with different sponsors. For patients and caregivers, the main reason for participating in RCTs was the wish to help research and other people, followed by the need for information, continuity of care, safety and support. Compared to patients, caregivers' expectations of trial results were more realistic. Conclusions: More open debates of practical experiences from different trial centres and sponsors are essential for optimizing trial designs and improving conditions for participants.