TEQ103

TEQ103 (formerly SERA2, also known as ErSO-TFPy) is a first-in-class small molecule selective estrogen receptor activator (SERA) being developed for the treatment of estrogen receptor alpha (ERα) positive breast cancer. The compound was originally developed through a collaboration between University of Illinois researchers and Systems Oncology, with Oncoteq obtaining a worldwide exclusive license in November 2023. TEQ103 works through a novel mechanism by binding with high affinity to ERα and hyperactivating the anticipatory unfolded protein response (aUPR) in cancer cells. This hyperactivation pushes the normally protective stress-response pathway into overdrive to selectively induce apoptosis in ER-expressing cancer cells while sparing healthy cells. In preclinical studies, TEQ103 demonstrated the ability to induce complete regression of large breast tumors in mouse models, including those resistant to current standard-of-care treatments such as selective estrogen receptor degraders (SERDs) and CDK4/6 inhibitors.