This is a phase I, open-label, multicenter study to evaluate safety, tolerability, pharmacokinetics, and efficacy of single and multiple doses of oral administration of HS-10352 in patients with locally advanced or metastatic breast cancer with hormone receptor (HR) positive and epidermal growth factor receptor 2 (HER2) negative who have progressed following prior therapy. There is a dose-escalation study, which is designed to evaluate the safety, tolerability, and pharmacokinetics of single dose and multiple doses of HS-10352 given once every day (QD). An alternative dosing schedule of twice every day (BID) may be investigated if the drug clearance of HS-10352 is faster than anticipated.~All patients will be carefully followed for adverse events during the study treatment and for 28 days after the last dose of study drug. Subjects of this study will be permitted to continue therapy with assessments for progression once every 8 weeks, if the product is well tolerated and the subject has stable disease or better. As the disease progresses, survival follow-up is recommended bimonthly.
HS-10352 is a highly potent and selective small molecule inhibitor of phosphoinositide 3-kinase (p110α). In preclinical studies, it demonstrated strong activity against PI3K p110α in vitro and in vivo, and inhibited tumor cell growth. The first-in-human trial is conducted to assess the maximum tolerated dose (MTD) and dose limiting toxicity (DLT), to evaluate the pharmacokinetics, safety and preliminary anti-tumor activity of HS-10352 at single dose and multiple doses.