HDAC inhibitor tucidinostat and metronomic capecitabine plus endocrine therapy for HR-positive HER2-negative advanced breast cancer after CDK4/6 inhibitors: SYSUCC-020 phase 2 trial
A new drug combination modestly extended survival in advanced breast cancer patients whose tumors stopped responding to earlier treatments, with genetic markers suggesting who benefits most.
This Phase 2 trial demonstrates that tucidinostat combined with metronomic capecitabine and endocrine therapy is feasible and active in HR+/HER2- advanced breast cancer post-CDK4/6 inhibitor failure, achieving 25.8% ORR with exploratory biomarker evidence that baseline TP53 status and circulating tumor cell counts predict PFS. While median PFS of 5.39 months is modest, the trial provides biomarker data for patient selection and establishes proof-of-concept for HDAC inhibitor combinations in the post-CDK4/6i setting.
What the study was
- Study design
- Simon two-stage Phase 2 trial (NCT05411380)
- Population
- HR+/HER2- advanced breast cancer patients after CDK4/6 inhibitor progression
- Sample size
- 66
- Category
- Treatment Innovation
- Maturity
- Exploratory
- Journal
- Signal Transduction and Targeted Therapy
Why it surfaced
Phase 2 data for novel HDAC inhibitor combination post-CDK4/6i; ctDNA/CTC biomarker data valuable for patient selection in future trials.
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