Eribulin plus Pyrotinib in Trastuzumab-Resistant, HER2-Positive Advanced Breast Cancer: A Single-Arm, Multicenter Phase II Trial (EPIC Trial).

PURPOSE

This study aimed to assess the efficacy and safety of combining Eribulin with Pyrotinib in patients diagnosed with advanced HER2-positive breast cancer and exhibiting resistance to trastuzumab. This subgroup of patients typically faces a bleak clinical prognosis with limited guidance available for treatment decisions.

PATIENTS AND METHODS

Patients (N=30) with HER2-positive metastatic breast cancer, ECOG 0-1, and prior trastuzumab/taxane therapy received oral Pyrotinib 400 mg daily and intravenous Eribulin 1.4 mg/m² (days 1/8 of 21-day cycles for 6 cycles), followed by Pyrotinib until progression/intolerable toxicity. The primary endpoint was progression-free survival (PFS).

RESULTS

Between February 2021 and September 2023, 30 patients were enrolled in the study, with a median age of 57 years. All patients had previously received treatment with trastuzumab and taxanes. As of April 14, 2025, the median follow-up duration was 26 months. 18 patients experienced disease progression or death. The median progression-free survival (PFS) was 13.47 months (95% confidence interval [CI], 8.17-16.27), with a 12-month PFS rate of 61.7% (95% CI, 44.2%-86.0%). 12-month overall survival (OS) rate of 75.3% (95% CI 66.2-84.4). The objective response rate was 56.7% (17/30). The disease control rate (DCR) reached 80.0% (24/30), while the clinical benefit rate (CBR) was 73.3% (22/30). The median overall survival was not reached. Any adverse event (AE) of any grade with an incidence of more than 30% was Neutropenia (73.3%), diarrhea (70%), nausea/vomiting (66.7%), Peripheral neuropathy (63.3%), AST/ALT increased (43.3%), Anorexia (33.3%). There were no treatment-related deaths.

CONCLUSION

The combination of Eribulin and Pyrotinib emerges as a viable treatment option for HER2-positive advanced breast cancer patients who have exhibited resistance to trastuzumab. Despite advancements in anti-HER2 therapies, further research is required to address remaining challenges in this specific clinical scenario.

© 2025 Li et al.