Inclusion Criteria

Inclusion criteria:

1. Diagnosis of advanced stage NSCLC squamous histology.

2. Platinum-based doublet chemotherapy as 1st line treatment of Stage IIIB/IV NSCLC.

3. Eligible to receive 2nd line therapy in the opinion of the investigator.

4. Measurable disease according to RECIST 1.1.

5. Adequate Performance Status.

6. Availability of tumour tissue material for correlative studies. Archived tumour
tissue is acceptable.

7. Adequate organ function.

8. Age = 18 years and above.

9. Written informed consent that is consistent with ICH-GCP guidelines.

Exclusion criteria:

1. Prior treatment with EGFR directed small molecules or antibodies.

2. Radiotherapy within 4 weeks prior to randomization.

3. Active brain metastases .

4. Any other current malignancy or malignancy diagnosed within the past three (3) years
(other than basal-cell carcinoma of the skin, in situ cervical cancer, in situ
prostate cancer).

5. Known pre-existing interstitial lung disease.

6. Significant or recent acute gastrointestinal disorders with diarrhoea as a major
symptom

7. Any other concomitant serious illness or organ system dysfunction which in the
opinion of the investigator would either compromise patient safety or interfere with
the evaluation of the safety of the test drug.

8. Women of child-bearing potential and men who are able to father a child, unwilling to
be abstinent or use adequate contraception prior to study entry, for the duration of
study participation and for at least 2 months after treatment has ended.

9. Female patients of childbearing potential (see Section 4.2.3.3) who:

1. are nursing or

2. are pregnant or

3. are not using an acceptable method of birth control, or do not plan to continue
using this method throughout the study and/or do not agree to submit to
pregnancy testing required by this protocol.

10. Active hepatitis B infection (defined as presence of Hep B DNA), active hepatitis C
infection (defined as presence of Hep C RNA) and/or known HIV carrier.

11. Known or suspected active drug or alcohol abuse in the opinion of the investigator.

12. Any contraindications for therapy with afatinib or erlotinib.

13. Known hypersensitivity to erlotinib, afatinib or the excipients of any of the trial
drugs.

14. Major surgery within 4 weeks of starting study treatment.

15. Prior participation in an afatinib clinical study, even if not assigned to afatinib.

16. Use of any investigational drug within 4 weeks of randomisation (unless a longer time
period is required by local regulations or by the guidelines for the investigational
product).

17. Patients without Progression of their lung cancer.