ESDR093 - Tear fluid dupilumab levels of patients with moderate-to-severe atopic dermatitis and ocular surface disease

Ocular surface disease (OSD) is a common adverse event in dupilumab-treated patients with atopic dermatitis (AD). The pathomechanism remains unclear. At present, no data are available on dupilumab levels in the eyes of these patients. The aim of this study is to measure dupilumab levels in tear fluid after 4 and 28 weeks of dupilumab treatment. This prospective study included dupilumab-treated moderate-to-severe AD patients. Patients were seen by a dermatologist and an ophthalmologist at the start of dupilumab, and after 4 and 28 weeks of dupilumab treatment. Tear fluid was collected using the standard Schirmer’s test, and was stored at -80 °C. Schirmer’s strips were eluted, and the tear fluids of both eyes were combined. Serum samples were also obtained after 4 and 28 weeks of dupilumab treatment. Dupilumab levels were measured in tear fluid and serum using liquid chromatography with tandem mass spectrometry. A total of 48 dupilumab-treated AD patients were included. Based on the severity of OSD at week 4 of dupilumab treatment, patients with moderate-to-severe OSD had slightly higher dupilumab levels in their tear fluid compared to patients with no or mild OSD (median 0.25 mg/L (interquartile range (IQR) 0.19-0.61) vs. 0.22 mg/L (IQR 0.13-0.55), p=0.353). This difference reached significance after 28 weeks of dupilumab treatment (median 0.55 mg/L (IQR 0.35-1.31) in moderate-to-severe OSD vs. 0.29 mg/L (IQR 0.16-0.60) in no or mild OSD, p=0.021). No significance difference was found in serum dupilumab levels at week 28 of dupilumab treatment between patients with no or mild OSD and patients with moderate-to-severe OSD. In conclusion, higher dupilumab levels in tear fluid were found in patients with moderate-to-severe OSD during dupilumab treatment compared to patients with no or mild OSD. Further research is needed to investigate the implications of these increased levels of dupilumab.