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 ofmeasurable disease evaluable by CT scan or MRI per RECIST 1.1, able to take oralmedication without alteration

• High Grade Serous Ovarian Cancer, Fallopian Tube or Primary Peritoneal Cancer -histologically or cytologically confirmed; metastatic or unresectable; platinumresistant (defined as recurrence within 6 months of platinum containing therapy) orplatinum refractory; prior bevacizumab treatment, or ineligible or intolerant tobevacizumab, or did not receive bevacizumab based on Investigator judgement; ifgermline and/or somatic BRCA1/2 mutation, previously treated with PARP-inhibitor orineligible 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 tumoror 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 includingthe study drug