Reduction of PK11195 uptake observed in multiple sclerosis lesions after natalizumab initiation.

Objective: The objective of this study is to longitudinally analyze the uptake of [C]PK11195-PET in multiple sclerosis patients after 3 and 6 months of natalizumab treatment.

Methods: Eighteen MS patients, starting treatment with monocloncal anti-VLA-4, were enrolled in a longitudinal PK-PET study. PK uptake was quantified by volume of distribution (VT) calculation using image-derived input function at baseline, 3 and 6 months.