LSZ102

LSZ102 is an orally bioavailable, nonsteroidal selective estrogen receptor degrader (SERD) developed for the treatment of estrogen receptor alpha (ERα)-positive breast cancer. It was designed to overcome limitations of earlier SERDs like fulvestrant by providing improved oral bioavailability and potent anti-estrogenic activity. In preclinical and early clinical studies, LSZ102 demonstrated the ability to degrade ERα protein and inhibit proliferation in ER-positive breast cancer models. Clinical trials evaluated its use as a single agent and in combination with other targeted therapies such as ribociclib (a CDK4/6 inhibitor) or alpelisib (a PI3K inhibitor) in patients with advanced or metastatic ER-positive breast cancer who had progressed after prior endocrine therapy. The drug showed manageable safety profiles but limited efficacy as monotherapy; some preliminary activity was observed in combination regimens[1][2][3][4][5][6]. Development was discontinued after Phase I/Ib trials[2][8].