Study of Neuroinflammation in Multiple Sclerosis by PET-MRI Imaging Using the Radiotracer ([18F]-DPA-714) : a Multicentre Cohort Study (INFLANET)

Overview

The Service Hospitalier Frédéric-Joliot (SHFJ) and Paris Brain Institute (ICM) groups have identified \[18F\]-DPA-714 as a promising second-generation TSPO tracer, a macromolecule overexpressed in neuroinflammatory conditions, for PET imaging. They have also developed a non-invasive quantification methodology, enabling the generation of individual neuroinflammation maps in MS patients. Recent findings from \[18F\]-DPA-714 PET imaging in MS patients revealed that most of the white matter lesions contained a smoldering component, even when considered inactive on MRI, and that their neuroinflammatory profiles were associated with longitudinal disability worsening. The Inflanet project aims to leverage a unique consortium comprising French radiochemists, radiopharmacists, nuclear medicine/neuroimaging experts, and MS neurologists to establish the first national network dedicated to \[18F\]-DPA-714 PET imaging in MS, so far limited to monocentric studies. The objectives of the INFLANET project are (1) to conduct the first multicenter study assessing neuroinflammation in patients with active MS using \[18F\]DPA-714 PET tracer, and (2) to establish a methodology suitable for the quantification of multicenter PET data obtained with \[18F\]DPA-714. The INFLANET initiative aims to disseminate TSPO PET within the French MS research community, thereby opening the unique perspective of future large-scale, multicenter studies. These endeavors are expected to enhance our capacity to predict diseases, stratify patients, and assess new therapeutic interventions.

INFLANET is a multicentric, prospective, non-randomized, non-blinded, interventional study.The study will include a total of 41 participants, with 18 individuals diagnosed with multiple sclerosis (MS) distributed across three sites (6 patients per site: Paris, Lyon, Rennes). Additionally, there will be 23 healthy volunteers (HV), with 20 HV allocated to the Lyon and Rennes sites (10 HV per site) and 3 HV for the Paris site. The study involves several clinical visits, with two visits for patients (Screening V0 and Baseline V1), two visits for 20 healthy volunteers (Screening V0 and Baseline V1), and three visits for three healthy volunteers (Screening V0, Baseline V1 - Test, and V1' - Retest, in Paris site). Various evaluations are integrated into the study, including neurological assessments at the screening visit, neuropsychological assessments at the baseline visit, 18F-DPA714 PET-MR or PET + MRI (n=1 for 20 HV and 18 subjetcs with MS; n=2 for 3 HV) at V1 and V1', and blood sampling at the screening visit to confirm TSPO eligibility. The PET-MR procedure involves TSPO PET using \[18F\]-DPA-714 in conjunction with 3T MRI for both MS patients and healthy volunteers. Gadoteric acid is administered for MS patients only as part of the imaging.