Using GENFI participant engagement to inform observational research and clinical trials.

Background: It is vital that we include the views of individuals with frontotemporal dementia (FTD) and their families in the design of clinical trials. This study aims to establish what types of trials and treatments individuals with familial FTD would like to participate in. Methods: 135 participants from the GENFI cohort of at‐risk genetic FTD family members (34% of whom were known mutation carriers) completed a structured online questionnaire about clinical trials via Qualtrics. There was a total of 27 questions with a mix of multiple choice and free text questions. Topics included willingness to participate, understanding about likely proximity to symptom onset, and willingness to undertake different methods of therapeutic drug delivery including gene therapies. Results: 54% of individuals were definitely willing to participate in clinical trials with 39% stating it would depend on what the specific trial involved. Only 6% said they would not take part in a trial. The presence of a placebo group was a factor in trial participation with 31% stating they would decline to take part if there was a chance they did not receive the active drug. In light of a recent study suggesting plasma neurofilament light chain (NfL) may be a marker of proximity to symptom onset, we asked people if they would be willing to find out their NfL level as part of the trial, and 85% said they would. Most individuals said they would be willing to have IV infusions or lumbar punctures as part of the trial, although this did depend on the frequency with which they were required. For trials where drug administration would require more invasive measures, e.g. injections directly into the cisterna magna or the brain itself, only about 50% of people said they would be willing to take part. Lastly, if participation in a gene therapy trial precluded an individual from participating in future studies, only 30% said they would definitely consider being involved. Conclusions: Observational studies and clinical trials are designed to make a difference to people's lives, and it is important to consider patients and family members throughout the development pipeline of treatments. [ABSTRACT FROM AUTHOR]