OSE Immunotherapeutics' therapeutic candidate OSE-127 for chronic inflammatory bowel disease (IBD) showed anti-inflammatory activity in a study performed in mice and patients' samples. The study, “IL-7 receptor influences anti-TNF responsiveness and T cell gut homing in inflammatory bowel disease,” was published in the Journal of Clinical Investigation. OSE Immunotherapeutics is developing OSE-127 in collaboration with Servier. OSE-127 is a humanized monoclonal antibody targeting the interleukin-7 receptor (IL-7R). Interleukin-7 (IL-7), which can promote chronic inflammation, is a protein secreted by the immune system that binds to IL-7R and regulates T-cell (a type of immune cell) activity. Researchers found increased levels of both IL-7 and IL-7R in the inflamed colon tissues of patients with IBD who did not respond to treatments such as corticosteroids or anti-TNF therapies. In those who did not benefit from anti-TNF therapy, elevated levels of IL-7 and IL-7R also were detected in colon biopsies obtained before starting anti-TNF treatment. This suggests that IL-7 and IL-7R levels may predict the effectiveness of anti-TNF treatments, the researchers said. Laboratory studies also showed that human IL-7 was able to increase the expression of specific receptor proteins on T-cell surfaces that promote gut-homing — a mechanism that increases the T-cells' attraction to the inflamed regions in the gut. For IBD patients, an increase in T-cell gut-homing specificity means further damage and inflammation. The team used a humanized mouse model of IBD to evaluate the impact of OSE-127 treatment. A humanized mouse is a genetically modified mouse that has functioning human genes, tissues, cells, or organs. In this case, the mice expressed human T-cells.