LAUSR

Background/Aim: Eribulin mesylate has been approved for advanced or metastatic breast cancers subjected to at least two previous chemotherapy regimens. The present multicenter, phase II, single-arm study assessed the efficacy and safety of a first-line regimen of eribulin plus trastuzumab for untreated advanced or metastatic HER2-positive breast cancer. Patients and Methods: Enrolled patients received eribulin (1.4 mg/m2 intravenously; I.V.) on days 1 and 8 of each 21-day cycle, an initial trastuzumab dose (8 mg/kg I.V.) on day 1, and 6 mg/kg of trastuzumab on day 1 of each subsequent cycle. The primary endpoint was the response rate (RR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), duration of response (DOR), and safety. Twenty-eight patients (median age: 62.5 years) received a median of 12 (range: 2–53) cycles of eribulin plus trastuzumab. Results: The RR was 53.6% [complete response (CR), 4; partial response (PR), 11] with a median PFS of 344 days. The clinical benefit rate was 64.0%. Grade 3/4 adverse events were observed in 12 (42.9%) patients. For details, neutropenia in 8 (28.6%) patients, peripheral neuropathy in 2 (7.1%) patients, interstitial pneumonia in 1 (3.6%) patient, ALT elevation in 1 (3.6%) patient, osteonecrosis of the jaw in 1 (3.6%) patient, and fatigue in 1 (3.6%) patient. The patient with osteonecrosis received denosumab, too. No symptomatic congestive heart failure was observed. Conclusion: Combination therapy of eribulin plus trastuzumab is acceptable in efficacy and safety, and a capable option for first-line advanced or recurrent HER2-positive breast cancer.