Erlotinib has demonstrated efficacy as a single agent in patients with NSCLC and the addition of erlotinib to chemotherapy has not achieved better results in the general population.

However, several preclinical and phase I studies have shown that a sequential treatment of erlotinib and chemotherapy could avoid a possible negative interaction between both drugs when administrated concomitantly, and therefore, it could improve the benefit of the combination therapy.

This study will investigate if the intermittent treatment of a chemotherapy drug, such as docetaxel, with erlotinib could achieve a clinical benefit.

Inclusion Criteria:

• Written informed consent.
• Age >= 18 years.
• Histologically or cytologically documented inoperable, locally advanced (stage IIIb with malignant pleural or pericardial effusion) or metastatic (Stage IV) NSCLC.
• Patients who have failed only one prior chemotherapy to treat the advanced disease and candidates to receive a second line treatment.
• ECOG PS 0-2.
• Adequate hematological function: hemoglobin => 9 g/dl; neutrophils count => 1.5 x 10(9)/l; platelet count => 100 x 10(9)/l.
• Adequate liver function: Bilirubin <= 1,5 x ULN; AST and ALT <= x 3 ULN when no hepatic metastases or <=5 x ULN if hepatic metastases; Alkaline phosphatase <=5 x UNL except that there is hepatic metastases.
• Adequate renal function: Calculated creatinine clearance => 40 mL/min (Cockroft y Gault) or serum creatinine <= 1.5 x ULN .
• Patient able to meet the requirements of the study and accessible for correct follow-up.
• Oral swallowing capability.

Exclusion Criteria:

• Previous treated with more than one chemotherapeutic treatment for NSCLC
• Concomitant treatment with another drug under investigation.
• Pregnancy or lactation. Fertile women must provide a negative result of pregnancy test (in serum or urine) within 7 days prior to study treatment start. In addition, they must use an effective method of contraception (oral contraceptives, intrauterine device, barrier methods of contraception, together with spermicidal jelly or surgical sterilization) during the study.
• Evidence of other disease, metabolic or neurological dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates use of an investigational drug or patient at high risk from treatment complications.
• Contraindication for the use of erlotinib or docetaxel.