A Phase I/II Study of VLS-1488 in Subjects With Advanced 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 Dose Escalation: No available therapeutic options to provide clinically meaningful benefits in the following tumor types: High Grade Serous Ovarian Cancer, Squamous Non -Small Cell Lung Cancer, Triple Negative Breast Cancer, Gastric Adenocarcinoma (not EBV+), Colorectal, Esophageal Squamous Cell Carcinoma, Esophageal Adenocarcinoma, Gastroesophageal Junction, Bladder (transitional cell), Head and Neck Squamous Cell Carcinomas (not nasopharynx, sinonasal or lip), Ovarian Carcinosarcoma, CN-high Endometrial/Uterine Dose Expansion: Must have been previously treated with several lines of standard of care treatment specified in the protocol in the following tumor types: High Grade Serous Ovarian Cancer, Squamous Non-Small Cell Lung Cancer, Triple Negative Breast Cancer, Gastric Adenocarcinoma (not EBV+), Colorectal, Esophageal Squamous Cell Carcinoma, Esophageal Adenocarcinoma, Head and Neck Squamous Cell Carcinomas (not nasopharynx, sinonasal or lip), CN-high Endometrial/Uterine Key Exclusion Criteria: MSI-H, dMMR, POLE gene hotspot mutated, or known hypermutator phenotype Previously received KIF18A inhibitor Current CNS metastases or leptomeningeal disease Cardiac parameters: MI or stroke ≤ 1 year, unstable angina/PE/DVT/CABG ≤ 6 months, NYHA Class ≥ II, LVEF < 50% Inability to comply with concomitant medication restrictions with respect to strong inhibitors and inducers of CYP3A, and clinical inhibitors of MDR1 (P-gp) and BCRP Any clinically significant ascites or pleural effusions at time of enrollment, or any therapeutic paracentesis or thoracentesis within 28 days of planned first dose of study drug Bowel obstruction or GI perforation within 6 months of planned first dose of study drug