75 mg/m2, IV, every 21 days for 4 cycles (1-4) or 75 mg/m2, IV, every 21 days for 4 cycles with optional continuation for 2 additional cycles until disease progression or unacceptable toxicity

250 mg, administered orally once daily beginning at Cycle 5 until disease progression or unacceptable toxicity

The duration of a complete response (CR; the disappearance of all target lesions) or partial response (PR; at least a 30% decrease in the sum of the longest diameter of target lesions) was defined as the time from first objective status assessment of CR or PR to the first time of progression or death as a result of any cause. A responder is a patient exhibiting a best overall study response of CR or PR.

Overall survival is the duration from enrollment to death. For patients who are alive, overall survival is censored at the last contact. Median overall survival could not be estimated as most participants were living at the end of the study. 25 participants from each treatment group were censored. In place of this outcome measure, the percentage of participants who died during the study are provided in the Post-Hoc Analysis Outcome Measure: Percentage of Participants Who Died During the Study.

Total of all reporting groups

Classifies patients according to their functional impairment. Scores range from 0 (Fully Active) to 5 (Death). 0 - Fully Active. 1 - Ambulatory, Restricted Strenuous Activity. 2 - Ambulatory, No Work Activities. 3 - Partially Confined to Bed, Limited Self Care. 4 - Completely Disabled.

Stage means how big the tumor is and how far it has spread. Stages range from 0 (not spread) to IV (spread throughout the body). Stage 0 - the cancer has not spread beyond the inner lining of the lung. Stage I - the cancer is small and hasn't spread to the lymph nodes. Stage II - the cancer has spread to some lymph nodes near the original tumor. Stage III - the cancer has spread to nearby tissue or spread to far away lymph nodes. Stage IV - the cancer has spread to other organs of the body such as the other lung, brain, or liver.

Pemetrexed 500 milligrams per meters squared (mg/m2) plus cisplatin 75 mg/m2 administered by intravenous (IV) infusion once every 3 weeks for 4 cycles without progression followed by pemetrexed 500 mg/m2 administered by IV infusion (with optional cisplatin 75 mg/m2 for up to 2 additional cycles) until disease progression or unacceptable toxicity.

Response using Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Complete Response=disappearance of all target lesions; Partial Response=30% decrease in sum of longest diameter of target lesions; Progressive Disease=20% increase in sum of longest diameter of target lesions; Stable Disease=small changes not meeting above criteria. Responder is a participant exhibiting a best overall study response of CR or PR.

Qualified for Response population includes all treated patients with measurable disease prior first dose of study therapy.

The duration of a complete response (CR; the disappearance of all target lesions) or partial response (PR; at least a 30% decrease in the sum of the longest diameter of target lesions) was defined as the time from first objective status assessment of CR or PR to the first time of progression or death as a result of any cause. A responder is a patient exhibiting a best overall study response of CR or PR.

Qualified for Response population includes all treated patients with measurable disease prior first dose of study therapy. Patients were censored for this analysis (2 pemetrexed/cisplatin/gefitinib and 2 pemetrexed/cisplatin).

This outcome measure takes the place of the outcome measure for Overall Survival, which could not be reported since the median value could not be calculated.

Randomized and treated population includes all randomized patients. Patients are analyzed according to the treatment they actually received (ITT population). 25 participants from each treatment group were censored.

Overall survival is the duration from enrollment to death. For patients who are alive, overall survival is censored at the last contact. Median overall survival could not be estimated as most participants were living at the end of the study. 25 participants from each treatment group were censored. In place of this outcome measure, the percentage of participants who died during the study are provided in the Post-Hoc Analysis Outcome Measure: Percentage of Participants Who Died During the Study.

Randomized and treated population includes all randomized patients. Patients are analyzed according to the treatment they actually received (ITT population). Median overall survival could not be estimated as most participants were living at the end of the study.

Pemetrexed 500 milligrams per meters squared (mg/m2) plus cisplatin 75 mg/m2 administered by intravenous (IV) infusion once every 3 weeks for 4 cycles without progression followed by pemetrexed 500 mg/m2 administered by IV infusion (with optional cisplatin 75 mg/m2 for up to 2 additional cycles) until disease progression or unacceptable toxicity.