Definition

An orally bioavailable small molecule agent that targets retinoid X receptor alpha (RXR-alpha; RXRA) variant, with potential antineoplastic activity. Upon oral administration, RXR-alpha variant-targeting agent NM6603 selectively targets and binds to RXR-alpha variants and inhibits transforming growth factor-beta (TGFb)-mediated signaling pathway. This abrogates TGF-beta-mediated immunosuppression in the tumor microenvironment (TME), increases cytotoxic T-lymphocyte (CTL) activities, and inhibits tumor cell proliferation in susceptible tumor cells. RXR-alpha, a transcription factor that plays an important role in the regulation of the expression of multiple genes, is often modified in various types of tumor cells.