Grapiprant

Grapiprant (CJ-023423) is an orally available, a potent and selective EP4 receptor antagonist that exhibits significant inhibitory effects on paw swelling, inflammatory biomarkers, synovial inflammation and bone destruction in AIA rats. Grapiprant is highly selective for the human EP4 receptor over other human prostanoid receptor subtypes. It also inhibits PGE2-evoked elevation in intracellular cAMP at the human and rat EP4 receptors with pA2 of 8.3 and 8.2 nM, respectively. In vivo, oral administration of grapiprant significantly reduces thermal hyperalgesia induced by intraplantar injection of PGE2 (ED50 = 12.8 mg/kg). It is also effective in models of acute and chronic inflammatory pain. Grapiprant significantly reduces mechanical hyperalgesia in the carrageenan model. Furthermore, it significantly reverses complete Freund′s adjuvant-induced chronic inflammatory pain response. It produces antihyperalgesic effects in animal models of inflammatory pain. Grapiprant is approved and widely used for treatment of osteoarthritis related pain in dogs. Grapiprant is classify as a non-cyclooxygenase inhibiting non-steroidal anti-inflammatory drug (NSAID).