Real-world outcomes of CDK4/6 inhibitors plus hormone therapy for HR+/HER2- advanced breast cancer

A Real-world Study on the Treatment of HR+/HER2- Advanced Breast Cancer Patients With CDK4/6 Inhibitors and Treatment Options After Drug Resistance.

This project will see if different CDK4/6 inhibitors combined with endocrine therapy lead to different outcomes and what treatments patients receive next for adults with HR+/HER2- advanced breast cancer treated at Tianjin Medical University Cancer Hospital.

Quick facts

• Study type: Observational
• Enrollment: 245 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Tianjin Medical University Cancer Institute and Hospital (other)
• Locations: 1 site (Tianjin)
• Trial ID: NCT07407439 on ClinicalTrials.gov

What this trial studies

This single-center real-world study will collect clinical and case data from patients with HR+/HER2- advanced breast cancer treated with CDK4/6 inhibitors plus endocrine therapy between March 2022 and March 2025. Researchers will compare efficacy and safety across different CDK4/6 agents (including palbociclib, abemaciclib, ribociclib, and dalpiciclib) when given with endocrine therapy. The study will summarize subsequent treatment choices after progression and develop a predictive model to forecast response to post‑CDK4/6 therapies. Selected patients may provide tumor or blood samples for genomic and transcriptomic analyses to support translational research on resistance mechanisms.

Who should consider this trial

Good fit: Adults (≥18) with HR+/HER2- advanced breast cancer treated at Tianjin Medical University Cancer Institute and Hospital from March 2022 to March 2025 who received a CDK4/6 inhibitor plus endocrine therapy for at least one cycle and have complete medical records.

Not a fit: Patients with incomplete medical records, those who only received CDK4/6 inhibitor monotherapy, or those who received CDK4/6 inhibitors only as neoadjuvant or postoperative adjuvant intensification will be excluded and thus will not benefit from this analysis.

Why it matters

Potential benefit: If successful, the results could help doctors and patients choose the most appropriate CDK4/6 drug and the best next treatments after progression for HR+/HER2- advanced breast cancer in Chinese clinical practice.

How similar studies have performed: Randomized trials have shown that CDK4/6 inhibitors improve outcomes in HR+/HER2- advanced breast cancer, but direct real-world head-to-head comparisons and post-progression predictive models remain relatively limited.

Eligibility criteria

Inclusion Criteria:

1. Age ≥ 18 years old;
2. Patients diagnosed with HR+/HER2- (as defined by the ASCO/CAP guidelines) advanced breast cancer who were treated in our hospital from March 2022 to March 2025;
3. Received CDK4/6 inhibitors (including but not limited to the four currently marketed ones: palbociclib, abemaciclib, ribociclib, and dalpiciclib) as advanced-stage treatment for at least one cycle;
4. Have complete medical history records, including demographic information, pathological reports, treatment records, laboratory test results, and imaging examination reports, etc.

Exclusion Criteria:

1. Incomplete medical history data.
2. Only received CDK4/6 inhibitors monotherapy.
3. Received CDK4/6 inhibitors as neoadjuvant/postoperative adjuvant intensification therapy.

Where this trial is running

Tianjin

• Tianjin Medical University Cancer Insititute and Hospital — Tianjin, China (RECRUITING)

Study contacts

• Study coordinator: Yehui Shi, MD

Conditions: Breast Cancer, Palbociclib, Abemaciclib, Ribociclib, Dalcetrapib, CDK4/6 inhibitors, CDK4/6 inhibitors resistance, HR+/HER2- breast cancer