Summary
The study consists of 2 parts. Part 1 is dose escalation and will first administer
SY-5609 alone to participants with select advanced solid tumors and then in combination
with fulvestrant to participants with HR positive, HER2-negative breast cancer. Part 2 is
a dose expansion and will first administer SY-5609 in combination with gemcitabine and
then SY-5609 in combination with gemcitabine and nab-paclitaxel in participants with
pancreatic ductal adenocarcinoma (PDAC) .