Paquinimod is a S100A9 inhibitor preventing S100A9 binding to TLR-4. Paquinimod reduces pathology in experimental collagenase-induced osteoarthritis. Paquinimod treatment of collagenase-induced OA (CIOA) resulted in significantly reduced synovial thickening (57%), osteophyte size at the medial femur (66%) and cruciate ligaments (67%) and cartilage damage at the medial tibia (47%) and femur (75%; n=7, untreated n=6). Paquinimod reduces leukocyte recruitment during sterile inflammation. Paquinimod also reduced priming of proinflammatory effector CD4(+) T cells.
