This study is testing a new medicine called sovilnesib for women with a type of advanced ovarian cancer called high grade serous ovarian cancer (HGSOC). The study has two parts to find the best dose of sovilnesib that is safe and works well. The medicine will be given in cycles of 28 days. In Part 1, 10 patients will try different doses to see how their bodies handle the medicine (safety) and how the medicine works (efficacy). In Part 2, 20-30 more patients will try the best doses from Part 1. The researchers will stop the study if there are serious side effects or if the medicine does not seem to work. Participants must be at least 18 years old and must have certain types of ovarian cancer that have not responded well to other treatments. Patients with certain genetic conditions or other types of ovarian tumors, or those with recent heart problems cannot join.

• The study will last until the disease worsens or the medicine causes issues.
• Sovilnesib is taken as a pill and the study requires regular visits for monitoring.
• The study is focused on finding a safe and effective dose for future treatments.