Safotibant

Safotibant (INN) also known by the research code LF22-0542 is a non-peptide bradykinin B₁ antagonist. It displayed binding Ki values of 0.35 and 6.5 nM at cloned human and mouse B₁ receptors, respectively, while having no affinity for either human, mouse, or rat B₂ receptors at concentrations up to 10 μM. This means that LF22-0542 is at least 4000 times selective for the B₁ receptor over the B₂ receptor. Systemic administration of LF22-0542 inhibited acute pain induced by acetic acid, formalin, and a hot plate. It also reversed acute inflammatory pain induced by carrageenan, and persistent inflammatory pain induced by CFA. In a neuropathic pain model, LF22-0542 reversed the thermal hyperalgesia, but not the mechanical hyperalgesia.