ERBB2 and Keratoconjunctivitis sicca: Currently, no ADCs with AS269 or duocarmycin payloads are approved for clinical use in the US; however, ARX788 and trastuzumab duocarmazine—ADCs with AS269 and duocarmycin payloads, respectively—are in clinical development for locally advanced or metastatic solid tumors.40,49,50 In a phase I study (N = 69) of patients with HER2-positive metastatic breast cancer, ocular AEs with ARX788 included corneal epitheliopathy (46%; 4% with grade ≥3), blurred vision (22%; 3% with grade ≥3), and xerophthalmia (22%; all grades 1-2) (Table 3), which were all reversible.