This phase II, multicenter, open-label, randomized controlled trial (FACET study) evaluates the efficacy and safety of fulvestaciclib, a novel oral CDK4/6 inhibitor, combined with anti-HER2 dual blockade (trastuzumab and pertuzumab, HP) and endocrine therapy (ET) in hormone receptor-positive (HR+) and HER2-positive advanced breast cancer (ABC). Patients with HR+/HER2+ ABC without prior systemic therapy for advanced disease are randomized in a 1:1:1 ratio into three arms, stratified by visceral metastasis status (yes vs. no) and metastatic type (de novo vs. recurrent). Arm A: After 4-8 cycles of induction chemotherapy (taxane) plus HP, patients receive fulvestaciclib + HP + ET as maintenance therapy. Arm B: After 4-8 cycles of induction chemotherapy (taxane) plus HP, patients receive HP + ET alone (without fulvestaciclib) as maintenance therapy. Arm C (exploratory): Patients receive upfront fulvestaciclib + HP + ET as first-line therapy without induction chemotherapy (chemo-free). For premenopausal/perimenopausal patients, ovarian function suppression (OFS) is added in all arms. Treatment continues until disease progression, unacceptable toxicity, withdrawal of consent, or death. The primary endpoint is investigator-assessed progression-free survival (PFS) comparing Arm A versus Arm B. Secondary endpoints include PFS (Arm A vs. Arm C), overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), duration of response (DoR), cumulative incidence of central nervous system (CNS) metastases, safety, and patient-reported outcomes (PROs).
Age range
18 Years
Sex
ALL
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Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Progression-Free Survival (PFS) Assessed by Investigator
Timeframe: From randomization to first documented progression per RECIST 1.1 or death, assessed every 6 weeks for 12 weeks then every 12 weeks until progression, up to 6 years.