This study is a Phase I, first-in-human, open-label dose-escalation study of AC699, an orally bioavailable estrogen receptor degrader, given as a single agent.
This clinical trial is evaluating a drug called AC699 in participants with estrogen receptor positive/human epidermal growth factor 2 negative (ER+/HER2-) locally advanced or metastatic breast cancer. The main goals of this study are to:~Identify the recommended dose of AC699 that can be given safely to participants~Evaluate the safety profile of AC699~Evaluate the pharmacokinetics of AC699~Evaluate the effectiveness of AC699