Syros 5609-101 (Solid Tumors) - Clinical Trial

We are doing this study to find out if the study drug (SY-5609) is safe and to determine the highest tolerable dose of SY-5609 in participants with select, advanced solid tumors, where standard therapies no longer work or do not exist.

Solid tumors of interest

Adults with cancers for which standard curative or palliative measures do not exist or are no longer working, which include:
- Metastatic or unresectable cancers, such as: breast, ovarian, lung, colorectal, or pancreatic cancer
- Any metastatic or unresectable solid tumor histology with evidence of deregulated RB cell cycle control
- Postmenopausal women with HR-positive, HER2-negative advanced or metastatic breast cancer

If you choose to join this study, you will:
- Take the study drug (SY-5609) by mouth OR take study drug by mouth combined with receiving injections of another drug (fulvestrant)
- Provide old tumor tissue
- Have physical exams, blood and urine tests
- Have imaging scans (CT and/or MRI)
- Have heart tests (ECG)