BBO-10203 + trastuzumab

**BBO-10203 + trastuzumab** is an investigational combination therapy consisting of BBO-10203, a first-in-class orally bioavailable small molecule that covalently binds the RAS-binding domain of phosphoinositide 3-kinase alpha (PI3Kα), preventing its activation by RAS proteins (HRAS, NRAS, KRAS), and trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER2). This combination is being developed for the treatment of advanced HER2-positive breast cancer and other HER2-positive solid tumors. BBO-10203 inhibits RAS-mediated PI3Kα signaling, suppresses tumor cell pAKT signaling, and blocks cancer cell growth, with preclinical data indicating that it does not induce hyperglycemia—a common side effect of other PI3Kα inhibitors. Trastuzumab targets and blocks HER2-driven signaling and is an established agent in HER2-positive cancers. The combination aims to exploit dual pathway blockade for enhanced antitumor efficacy, particularly in tumors with HER2 amplification or overexpression[3][4][6].