All enrolled patients will be randomized to PG2 or Placebo arm and will receive the cisplatin-based chemotherapy treatment (Cisplatin 75mg/m2 and Docetaxel 60mg/m2 on Day1) during the first three 21-day chemo-cycles. Chemo regimen modification is allowable, as usual, in case of disease progression or unacceptable toxicity (see Section 6). After randomization, each patient will be administered with PG2 or placebo for 4 days in the 1st week, 3 days in the 2nd week and 3 days in the 3rd week of each chemo-cycle for 3 cycles (Dosing Schedule in Section 6). Total 10 doses will be given in each cycle.