Diquafosol Tetrasodium (INS365) Ophthalmic Solution is Not Absorbed Systemically in Patients with Dry Eye

Abstract

Abstract: : Purpose: Diquafosol tetrasodium (INS365) ophthalmic solution has been shown to be effective for the treatment of dry eye. Animal studies have suggested that diquafosol is rapidly broken down on the surface of the eye and should not be systemically absorbed. The purpose of the study was to determine if diquafosol is absorbed after topical dosing in patients with dry eye. Methods: Twenty-five patients enrolled in a 6 month phase 3 efficacy study comparing 1.0% and 2.0% diquafosol with placebo had blood collected at multiple time points during the study. Eighteen subjects had a blood sample collected 2-15 minutes post dose on days 1, 84 and 168. Seven subjects had blood samples collected at 15 and 60 minutes post dosing on 2 separate days approximately 5-6 months into the study. Blood samples were analyzed using an LCMS-MS assay (limit of quantitation for diquafosol = 2 ng/ml), which also measured the endogenous metabolites UTP, UDP and UMP. Results: Of the 25 subjects enrolled, 7 received placebo, 10 received diquafosol 1.0% and 8 received 2.0% diquafosol. Diquafosol was not detectable in any blood sample. Nearly half the samples had detectable quantities of UTP and the other endogenous metabolites; however, the levels were comparable between the subjects receiving placebo and the subjects receiving diquafosol. Conclusions: There is no detectable systemic exposure of diquafosol tetrasodium (INS365) ophthalmic solution after ocular administration.

Keywords: clinical (human) or epidemiologic studies: tre • cornea: tears/tear film/dry eye • metabolism