Module 2A
tumor
DISEASE, TUMOR, BREAST CANCER
A single-arm, ascending-dose study was conducted in 2 cohorts to explore the recommended dose of samuraciclib and fulvestrant in HR+/HER2− advanced breast cancer patients who had previously received, and become resistant to, a CDK4/6 inhibitor. Female patients with histologically confirmed diagnosis of breast cancer, evidence of metastatic or locally advanced disease, and documented ER+ and/or PgR+ and HER2- tumor status treated with an AI in combination with a CDK4/6i before study entry were eligible. In each cohort the dose of fulvestrant was 500 mg every 28 ± 2 days, with an additional 500 mg dose given 14 ± 2 days after the first dose. Cohort 1 tested samuraciclib 240 mg OD continuous dosing. If the DLT stopping criteria were not met, Cohort 2 commenced enrollment at the Module 1A MTD. Patients underwent regular safety monitoring and 8-week scans reported using RECIST V1.1