Potential First-in-Class Inhibitor of a key Protein that modulates Wnt/β-catenin
RX-5902 is a potential first-in-class small molecule inhibitor of phosphorylated-p68, which is selectively over-expressed in cancer cells and modulates the activity of the β-catenin/Wnt pathway which is involved in cancer cell growth and proliferation, oncogene expression and in the immune response to cancer.
Phosphorylated p68, which is highly expressed in cancer cells, but not in normal cells, results in up-regulation of cancer-related genes and a subsequent proliferation of cancer cells and tumor growth. RX-5902 selectively blocks the interaction of phosphorylated p68 with beta-catenin, thereby decreasing the proliferation or growth of cancer cells in preclinical models. Apart from its direct antitumor effects, RX-5902 is immunomodulatory and multiple preclinical models suggest that RX-5902 enhances the efficacy of immunotherapy. Rexahn has evaluated RX-5902 in a Phase 1 dose escalation study in patients with a diverse range of metastatic, treatment-refractory solid tumors, including breast, ovarian, colorectal, and neuroendocrine tumors. In February 2017, Rexahn initiated a Phase 2a clinical study of RX-5902 monotherapy in patients with metastatic triple negative breast cancer (TNBC). In August 2018, we announced a collaboration with Merck to evaluate RX-5902 in combination with Keytruda® in TNBC.