OX40 (CD134) is a co-stimulatory, trans-membrane molecule of the tumor necrosis factor-receptor superfamily expressed by activated CD4+ and CD8+ T cells. Engagement of OX40 by OX40-ligand expressed by antigen presenting cells (APC) enhances CD4+ and CD8+ cell proliferation, stimulates cytokine production and promotes survival of antigen-specific memory T cells. Based on this background, OX40 targeted immunotherapy treatments are being tested in patients with advanced cancers. A previous study, based on the analysis of 72 patients with CRC, suggests that OX40 expression by colorectal cancer infiltrating cells correlates with favorable prognosis. This information could be of potentially high clinical relevance since it might contribute to the definition of a constellation of markers allowing a more precise identification of patients with colorectal cancer who might benefit from current therapies, while sparing unnecessary treatment to others. Furthermore, patients potentially taking advantage of OX40 targeted immunotherapy might also be characterized.
Weixler B, Cremonesi E, Sorge R, et al. OX40 expression enhances the prognostic significance of CD8 positive lymphocyte infiltration in colorectal cancer. Oncotarget. 2015;6(35):37588-37599.