PROJECT SUMMARY The absence of safe and effective strategies for the management of ocular pain is motivating the development of a novel topical drug suitable for patient self-administration. Conventional local anesthetics, such as proparacaine, inhibit voltage-gated Na+ ion channels (NaV) and are highly effective for the management of ocular pain in acute, in-office settings. However, these agents are short acting and toxic to the corneal surface, which prevents their use beyond a few administrations. SiteOne Therapeutics has discovered a chemical series of novel, exquisitely selective inhibitors of human NaV1.7, a subtype implicated in the transmission of pain signals by human genetics. These compounds exhibit excellent analgesic effects when administered systemically. Topical ocular administration is well tolerated and leads to good intraocular exposure. The goal of this phase II grant is to fund preclinical studies including candidate selection, formulation development, and early IND-enabling studies.