Efficacy of everolimus-based therapy in advanced triple-positive breast cancer: Experience from three cancer centers in China

Background: Triple-positive breast cancer (TPBC) is highly invasive and lacks well-established treatment strategies, especially in patients with advanced stage disease. This study aimed to explore the efficacy of everolimus in patients with metastatic TPBC (mTPBC) in a multicenter real-world setting.

Methods: A total of 2518 cancer patients who received everolimus-based therapy were enrolled from three cancer institutes in China from 2014 to 2022. Their clinicopathological characteristics were collected from medical records. The indicators for the efficacy of everolimus were progression-free survival (PFS), objective response rate (ORR) and clinical benefit rate (CBR).

Results: We collected 79 HER2-enriched patients that were treated with everolimus-based therapy, 43 of whom were mTPBC. The most commonly used therapeutic combinations was everolimus plus endocrine therapy (18/43, 41.9%). Among all combinations, everolimus plus chemotherapy plus trastuzumab developed the longest PFS of 10.9 months (95% CI: 1.5-20.3). Seventeen patients (32.6%) with mTPBC received everolimus as frontline treatment (1 L/2 L/3 L, FL), and 26 patients (67.4%) as backline treatment (>3 L, BL). Among all the population, the median PFS for everolimus was 4.5 months (range: 3.0-6.0), ORR was 30.2%, and CBR was 48.8%. PFS_FL of 10.9 months was significantly longer than 4.0 months for PFS_BL (p = 0.003, HR = 0.31, 95% CI: 0.14-0.67). ORR_FL was 41.2%, showing no significance compared to ORR_BL of 23.1% (one-sided p = 0.11). CBR_FL was observed better of 76.5% versus CBR_BL of 46.2% (one-sided p = 0.026).

Conclusion: Everolimus as frontline treatment achieves clinical benefits for Chinese patients with mTPBC, which may provide some references for the management of Chinese mTPBC patients.