Phase I Clinical Study of Combination Therapy with Eribulin and Gemcitabine in Patients with Progressive Recurring Breast Cancer (JBCRG-18Gem)

INTERVENTION: Combined therapy of Eribulin and Gemcitabine CONDITION: Progressive Recurring Breast Cancer PRIMARY OUTCOME: MTD, DLT, RD SECONDARY OUTCOME: AE, ORR, PK INCLUSION CRITERIA: 1) Female patients who were histologically diagnosed with infiltrating breast cancer. 2) Patients with distal metastasis, unresectable local/regional recurrence, and local advanced breast cancer. 3) Patients with ECOG performance status (PS) of 0 to 1. 4) Patients with history of prior treatment with anthracycline and taxane as pre/post‐operative treatment or treatment to prevent recurrence. 5) Patients without history of prior treatment with eribulin or gemcitabine. 6) Patients in whom hematological toxicity and non‐hematological toxicity regarding DLT are all G1 or lower. 7) Patients without impaired main organ function. The values of laboratory findings within 14 days prior to registration meet all the criteria listed below. (1) neutrophil count: >=2,000/mm3 (2) platelet count: >=100,000 mm3 (3) hemoglobin: >=9.0 g/dL (4) total bilirubin: =<2.0 mg/dL (5)AST (GOT), ALT (GPT), ALP: =<3 times the upper limit of cent