A Study of Sovilnesib in Subjects With Ovarian Cancer

Key Inclusion Criteria: * All Parts: Age ≥ 18 years, ECOG Performance Status ≤ 1, at least 1 site of measurable disease evaluable by CT scan or MRI per RECIST 1.1, able to take oral medication without alteration * High Grade Serous Ovarian Cancer, Fallopian Tube or Primary Peritoneal Cancer - histologically or cytologically confirmed; metastatic or unresectable; platinum resistant (defined as recurrence within 6 months of platinum containing therapy) or platinum refractory; prior bevacizumab treatment, or ineligible or intolerant to bevacizumab, or did not receive bevacizumab based on Investigator judgement; if germline and/or somatic BRCA1/2 mutation, previously treated with PARP-inhibitor or ineligible or intolerant. Key Exclusion Criteria: * MSI-H, dMMR, POLE gene hotspot mutated, or known hypermutator phenotype * Endometrioid, clear cell, mucinous, sarcomatoid, low-grade/borderline ovarian tumor or mixed tumors containing any of the above histologies * Previously received KIF18A inhibitor * Current CNS metastases or leptomeningeal disease * Cardiac parameters: MI or stroke ≤ 6 months, unstable angina/PE/DVT/CABG ≤ 6 months, NYHA Class ≥ II, LVEF \< 50% * Any gastrointestinal condition (e.g. malabsorption syndrome, surgical anastomosis, short bowel syndrome) that might affect the absorption of oral medications including the study drug