A Study of Eribulin With Gemcitabine in Patients With Advanced Liposarcoma or Leiomyosarcoma

Inclusion Criteria: 1. Histologically confirmed advanced liposarcoma or leiomyosarcoma with 1-2 prior chemotherapy including anthracycline (unless contraindicated) 2. ECOG performance status of 0-2 3. Measurable or evaluable disease (RECIST 1.1.) 4. Adequate laboratory findings * Hb ≥ 9.0 g/dL * Absolute neutrophil count ≥ 1000 /µL * Platelet ≥ 75,000/ µL * Total Bilirubin: ≤ 1.5 × UNL (upper normal limit) (≤ 2 × UNL in patients with liver metastasis) * Serum Creatinine: ≤1.5 X upper limit of normal (ULN) OR ≥ Creatinine Clearance 60 mL/min (Cockcroft-Gault) for patients with creatinine levels \> 1.5 X institutional ULN * AST(SGOT)/ALT(SGPT): ≤ 3.0 × UNL or ≤ 5.0 × UNL (in patients with liver metastasis) * Alkaline Phosphatase : ≤ 3.0 × UNL or ≤ 5.0 × UNL (in patients with liver or bone metastasis) * Prothrombin time and partial thromboplastin time : ≤1.5 X ULN 5. Female patient of childbearing potential has a negative serum or urine pregnancy test within 72 hours prior Exclusion Criteria: 1. More than 3 prior cytotoxic agents 2. Patient who has had chemotherapy, radiotherapy, or biological therapy within 2 weeks prior to entering the study 3. Uncontrolled or active CNS metastasis and/or carcinomatous meningitis 4. Patient has known hypersensitivity to the components of study drugs or its analogs. 5. Patient is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the study. 6. Long QT Syndrome ≥480 ms 7. peripheral neuropathy ≥2 with previous treatment 8. unstable cardiovascular disease 9. Symptomatic interstitial lung disease (ILD) or presence of ILD on chest X-ray