Oral Tyrosine Kinase Inhibitor for Neovascular Age-Related Macular Degeneration: A Phase 1 Dose-Escalation Study

Importance An oral treatment for neovascular age-related macular degeneration would be less burdensome than repeated intravitreous injections. X-82 is an oral tyrosine kinase inhibitor active against vascular endothelial growth factor (VEGF) and platelet-derived growth factor. Objective To undertake safety testing of oral X-82 administered for the treatment of neovascular AMD. Design, Setting, and Participants Phase 1, open-label, uncontrolled, dose-escalation study at 5 US retinal clinics between November 2012 and March 2015 (Retina-Vitreous Associates Medical Group, Beverly Hills, California; Blanton Eye Institute, Houston Methodist Hospital, Retina Consultants of Houston, Houston, Texas; New England Retina Associates, Guilford, Connecticut; Elman Retina Group, Baltimore, Maryland; and Retina Research Institute of Texas, Abilene). Thirty-five participants with neovascular age-related macular degeneration, 7 of whom were treatment naive. Interventions Participants received oral X-82 for 24 weeks at 50 mg alternate days (n = 3), 50 mg daily (n = 8), 100 mg alternate days (n = 4), 100 mg daily (n = 10), 200 mg daily (n = 7), and 300 mg daily (n = 3), with intravitreous anti-VEGF therapy using predefined retreatment criteria. Every 4 weeks, participants underwent best-corrected visual acuity measurement, fundus examination, and spectral-domain optical coherence tomography. Main Outcomes and Measures The main outcome was adverse events. Other outcomes included visual acuity, central subfield retinal thickness, and number of anti-VEGF injections. Results Of the 35 participants, the mean age was 76.8 years, 16 were men and 19 were women, and 33 were white and 2 were nonwhite. Of 25 participants (71%) who completed the 24 weeks of X-82 treatment, all except 1 maintained or improved their visual acuity (mean [SD], +3.8 [9.6] letters). Fifteen participants (60%) required no anti-VEGF injections (mean, 0.68). Mean [SD] central subfield thickness reduced by -50 [97] μm, with 8 participants (all receiving at least 100 mg daily) demonstrating sustained reductions despite no anti-VEGF injections. The most common adverse events attributed to X-82 were diarrhea (n = 6), nausea (n = 5), fatigue (n = 5), and transaminase elevation (n = 4). A dose relationship to the transaminase elevations was not identified; all normalized when X-82 was discontinued. All but 1 were asymptomatic. Ten participants withdrew consent or discontinued prematurely, 6 owing to adverse events attri