Anlotinib-containing regimens in HR+ advanced breast cancer after prior CDK4/6 inhibitor progression

This retrospective study (NCT06734533, registered in ClinicalTrials.gov on November 3, 2024) evaluated the efficacy and safety of anlotinib-containing regimens in patients with HR + /HER2- advanced breast cancer who have progressed on prior CDK4/6 inhibitor therapy. From January 2020 to March 2025, 80 patients were included. With a median follow-up of 9.2 months, the median progression-free survival was 6.4 months (95% CI, 5.2-7.1). Age ≥ 60 years and bone metastasis were identified as poor predictors of PFS, whereas prior treatment with CDK4/6 inhibitor for ≥ 6 months was a favorable predictor. The objective response rate and disease control rate were 30.0% (95% CI, 19.6-42.1) and 87.1% (95% CI, 77.3-93.1), respectively. Grade 3-4 adverse events were observed in 10 patients (12.5%), with the most common being neutropenia (3.8%) and aspartate aminotransferase increased (3.8%). Given the retrospective design and potential confounding of this analysis, these findings should be interpreted with caution. Anlotinib-containing regimens showed potential clinical activity in this patient population and warrant further evaluation.