NCT07037199

Efficacy and Safety of Trastuzumab Rezetecan Followed by CDK4/6 Inhibitors and Endocrine Therapy in HR+/HER2-Low/Ultra-Low Advanced Breast Cancer

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 45 (estimated)
• Sponsor: Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University · Academic / Other
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This multicenter, prospective phase II clinical trial evaluates the efficacy and safety of sequential Trastuzumab rezetecan followed by dalpiciclib plus endocrine therapy (fulvestrant or aromatase inhibitors) in 45 patients with HR+/HER2-low/ultra-low advanced breast cancer. Enrolled patients will receive Trastuzumab rezetecan monotherapy for 6-8 cycles until clinical benefit, then transition to CDK4/6 inhibitors with endocrine therapy until disease progression or unacceptable toxicity. The primary endpoint is progression-free survival (PFS), with secondary endpoints including objective response rate (ORR), overall survival (OS), and treatment-related adverse events (TRAEs). The study will be conducted at Sun Yat-sen Memorial Hospital and collaborating centers.

Conditions

• Advanced Breast Cancer

Interventions

Type	Name	Description
DRUG	Trastuzumab rezetecan + CDK4/6 inhibitors + endocrine therapy	sequential Trastuzumab rezetecan followed by CDK4/6 inhibitors (Dalpiciclib, Abemaciclib, Ribociclib, Palbociclib) plus endocrine therapy (fulvestrant or aromatase inhibitors)

Timeline

• Start date: 2025-08-18
• Primary completion: 2028-06-30
• Completion: 2030-06-30
• First posted: 2025-06-25
• Last updated: 2025-12-31

Locations

1 site across 1 country: China