Phase II Clinical Trial of First-line Eribulin Plus Trastuzumab for Advanced or Recurrent HER2-positive Breast Cancer.

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.

Establishment of a microplate-formatted cell-based immunoassay for rapid analysis of nucleotide excision repair ability in human primary cells.

DNA photolesions induced by UV, cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct (6-4PP), are repaired by nucleotide excision repair (NER) in human cells. Various immunoassays using monoclonal antibodies specific for the photolesions have been developed and widely used for the analysis of cellular NER activity. In this study, we have newly developed a microplate-formatted cell-based immunoassay, based on indirect immunofluorescence staining with lesion-specific antibodies combined with an infrared imaging system. Using this assay, we show the repair kinetics of CPD and 6-4PP in various fibroblasts from newborn and adult donors with no age-related difference. Furthermore, epidermal keratinocytes and melanocytes exhibit comparable NER activity, and calcium ion-induced differentiation of keratinocytes has no significant impacts on their NER activity. We also evaluated the effects of a proteasome inhibitor, MG132, and a histone deacetylase inhibitor, sodium butyrate, on NER efficiency using this assay. All these results suggest that the new assay is highly useful for the rapid and quantitative analysis of NER activity in various primary cells with limited growth activity and is applicable to a screening system for drugs affecting NER efficiency.