A Phase II Randomized Study of Gemcitabine and Nab-paclitaxel in Combination With S- 1/LV (GASL) or Oxaliplatin (GAP) as First-line Treatment for Metastatic Pancreatic Cancer

Gemcitabine 800mg/m2 in N/S 250ml over 30 minutes (or fixed dose rate 10 mg/m2/min) IV infusion on day 1 repeated every 14 days.

Nab-paclitaxel 125mg/m2 over 30 minutes IV infusion on day 1 repeated every 14 days, followed by Gemcitabine

"S-1 orally 60-100 mg/day day 1 to 7 on in a 2-week cycle. The dose of S-1 is defined as follows:~* BSA \< 1.25 m2: 60 mg/day~* 1.25 m2 ≤ BSA \< 1.5 m2: 80 mg/day~* BSA ≥ 1.5 m2: 100 mg/day"

leucovorin 30mg BID day 1 to 7 on in a 2-week cycle

Oxaliplatin 75mg/m2 in 250 mL of D5W over 120 minutes IV infusion on day 1 repeated every 14 days