A Study of Samuraciclib in Combination With Fulvestrant in Metastatic or Locally Advanced Breast Cancer in Adult Participants

Objective Response Rate (ORR)

ORR defined as the proportion of participants who achieved a best overall Response (BOR) of CR or PR per RECIST Version 1.1 from randomization until disease progression, or death due to any cause.

Time frame: Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

Duration of Response (DOR)

DOR defined as the time from the date of first documentation of objective tumor response (CR or PR) to the earliest documented disease progression per RECIST version 1.1, or death due to any cause.

Time frame: Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

Progression Free Survival (PFS)

PFS defined as the time from the date of randomization to the earliest documented disease progression per RECIST version 1.1, or death due to any cause.

Time frame: Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

Incidence and severity of adverse events (AEs) as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0

Safety will be assessed by monitoring adverse events and clinically relevant changes in vital signs and clinical laboratory results.