Rintodestrant (G1T48) is a potential best-in-class oral selective estrogen receptor degrader (SERD) in development for the treatment of estrogen receptor-positive (ER+) breast cancer. Preclinical data have shown rintodestrant (G1T48) to be more potent than fulvestrant, currently the only FDA-approved SERD. Unlike fulvestrant, which is administered as an intramuscular injection, rintodestrant (G1T48) has the potential to significantly improve the patient experience with oral dosing. In 2018, we initiated a Phase 1/2a trial of rintodestrant (G1T48) in estrogen receptor-positive, HER2-negative (ER+, HER2-) breast cancer (NCT03455270). We reported the first clinical data from this trial at the European Society for Medical Oncology (ESMO) Congress 2019 in September 2019. We are planning to initiate a combination trial of rintodestrant (G1T48) and the CDK4/6 inhibitor IBRANCE® (palbociclib) in 2Q20.