ATR-107

ATR-107 is a fully human monoclonal antibody that targets the interleukin 21 receptor (IL21R). It was developed as an immunomodulatory agent, primarily for autoimmune and inflammatory diseases such as Crohn's disease. ATR-107 acts by binding to IL21R, thereby blocking the activity of interleukin 21 (IL-21), a cytokine involved in regulating immune cell function. This blockade inhibits downstream signaling pathways, including STAT3 phosphorylation in T cells and B cells, which are implicated in autoimmune pathogenesis. The drug demonstrated prolonged pharmacodynamic effects with sustained IL21R occupancy but was associated with high immunogenicity—over 75% of subjects developed anti-drug antibodies after single-dose administration. Development was discontinued due to these immunogenicity concerns and related adverse events[1][2][4][6].

Other names

Anti-interleukin 21 receptor antibodyAnti-interleukin21 receptor antibodyAnti-interleukin-21 receptor antibodyAnti-IL21R antibodyAnti-IL-21R antibodyAnti-IL 21R antibody