MSU42011

MSU42011 is a potent and selective small molecule agonist of the retinoid X receptor (RXR). Developed based on structure-activity relationship (SAR) studies to improve upon the therapeutic profile of bexarotene, MSU42011 has demonstrated efficacy in preclinical murine models of HER2-positive breast cancer, triple-negative breast cancer (TNBC), and lung cancer. Its mechanism involves modulating the tumor microenvironment by reducing the expression of immunosuppressive molecules such as CD206 and PD-L1 in myeloid cells (including monocytes and tumor-associated macrophages) and increasing the recruitment and activation of CD8+ T cells. MSU42011 has shown synergistic effects when combined with anti-PD1 immunotherapy, potentially expanding the therapeutic window for patients with solid tumors that do not typically benefit from checkpoint inhibitors.