Patients are administered with sequential and maintenance icotinib plus chemotherapy. Gemcitabine 1000mg/m2 iv d1 and d8, cisplatin 75mg/m2 iv d1, icotinib 125 mg is administered orally three times per day at d 8-21, every 3 weeks for a cycle. After receiving a maximum of 4-cycle treatment, non-progressive patients continue to receive icotinib as maintenance treatment until disease progression or intolerable toxicity.

Gemcitabine 1000mg/m2 iv d1 and d8, cisplatin 75mg/m2 iv d1. After receiving a maximum of 4-cycle treatment, non-progressive patients continue to receive icotinib (125 mg three times per day) as maintenance treatment until disease progression or intolerable toxicity.

Patients are administered with sequential and maintenance icotinib plus chemotherapy. Gemcitabine 1000mg/m2 iv d1 and d8, cisplatin 75mg/m2 iv d1, sequential icotinib 125 mg is administered orally three times per day at d 8-21, every 3 weeks for a cycle. After receiving a maximum of 4-cycle treatment, non-progressive patients continue to receive maintenance icotinib until disease progression or intolerable toxicity.

A duration from randomization date to disease progression(as defined by RECIST) or death. If a participant are known to have progressed, the time to progression is defined as the time from the date of randomization to the date of progression. Otherwise, a participant will be censored at the last date they are known not to be progressed.

Overall Survival is assessed via calculation of the time to death due to any cause. If a participant is known to have died, the time to death is defined as the time from the date of randomization to the date of death. Otherwise, a participant will be censored at the last date they are known to be alive.