Atopic dermatitis
The efficacy of OMZ in AD has been evaluated in many case series/reports160 and was formally evaluated in three small clinical trials. A recent randomized clinical trial (RCT) in 62 pediatric AD patients showed efficacy of OMZ in reducing AD severity and improving quality of life 161. Two previous controlled studies (NCT00822783 and NCT01678092) did not show an overall efficacy of OMZ on the clinical course of AD patients after 16 or 24 weeks of treatment compared with AD patients in placebo groups, despite some effects on IgE levels, FcεRI expression levels, and pro- and anti-inflammatory cytokine levels110,162. Accordingly, LGZ did not show efficacy in a RCT including 22 patients163. Another anti-IgE approach with the anti-CεmX mAb FB825 targeting membrane IgE on B cells is currently under investigation (NCT04413942). In clinical practice, a subgroup of AD patients does benefit from anti-IgE treatment, as shown in case reports and smaller case series 164-167, which implies that IgE plays an important role in the pathophysiology of AD in these patients. The efficacy of OMZ in AD patients with IgE AAb has not been investigated so far. Interestingly, one study showed that patients with a filaggrin mutation were unresponsive to omalizumab treatment, suggesting that the presence of primary skin barrier deficiency may likely be a factor for non-response165.