Inclusion criteria:

          -  Aged 18 years or older

          -  Pathologically confirmed of advanced and/or metastatic stage IIIb/IV non-small cell
             carcinoma of lung

          -  Activating EGFR mutation (exon 19 deletion, L858R, G719X, L861X)

          -  Presence of EGFR activating mutation and absence of EGFR T790M in the tumour
             associated with the latest disease progression. Only applicable in Part B

          -  Must have adequate fresh or archival tumour tissue at the late disease progression
             immediately prior to the study entry

          -  Part A: Progression of disease (RECIST 1.1) while on continuous treatment with single
             EGFR TKI or for histology other than adenocarcinoma and without prior EGFR TKI
             treatment: progression of disease (RECIST v1.1) on platinum-based chemotherapy. Part
             B: Progression of disease (RECIST v1.1) while on continuous treatment with single
             agent of the second generation irreversible EGFR TKI (e.g. afatinib or dacomitinib)

          -  No intervening systemic therapy between cessation of EGFR TKI and study treatment

          -  Patient must have measurable disease per RECIST 1.1 presented after tumour biopsy for
             the late disease progression

          -  Eastern Cooperative Oncology Group (ECOG) performance score 0 or 1

          -  Life expectancy of >= 3 months

          -  Fasting plasma glucose < 8.9 mmol/L (< 160mg/dL) and HbA1C < 8%

          -  Adequate organ function

          -  Recovered from any previous therapy related toxicity to <= Grade 1 at study entry
             (except for stable sensory neuropathy <= Grade 2 and alopecia)

          -  Written informed consent that is consistent with ICH-GCP guidelines and local
             regulations

          -  No known potentially targetable mutation other than IGF signaling pathway or EGFR or
             no available treatment for potentially targetable mutation

        Exclusion criteria:

          -  Part A only: For patient who has been treated with afatinib: last treatment at reduced
             dose below the assigned dose level

          -  Patient whose disease progressed on insufficient dose of EGFR TKI immediately prior to
             study in the opinion of the investigator

          -  More than 2 prior EGFR TKI treatment regimens for Part B

          -  Chemotherapy, biological therapy or investigational agents (except EGFR TKIs) within 4
             weeks

          -  Use of previous EGFR TKIs except afatinib within 3 days

          -  Radiotherapy within 4 weeks prior to the start of study treatment

          -  Active brain or subdural metastases

          -  Meningeal carcinomatosis.

          -  Major surgery (as judged by the investigator) within 4 weeks

          -  Known hypersensitivity to afatinib, monoclonal antibody

          -  Prior severe infusion-related reaction to a monoclonal antibody

          -  History or presence of clinically relevant cardiovascular abnormalities

          -  Female patients of childbearing potential (see Section 4.2.2.3) and male who are able
             to father a child

          -  Any history of or concomitant condition that, in the opinion of the investigator not
             to comply with the study or interfere with the evaluation of the efficacy and safety
             of the test drug

          -  Previous or concomitant malignancies at other sites, except effectively treated
             non-melanoma skin cancers, carcinoma in situ of the cervix, ductal carcinoma in situ
             or effectively treated malignancy that has been in remission for more than 3 years and
             is considered to be cured.

          -  Disease that is considered by the investigator to be rapidly progressing or life
             threatening such as extensive symptomatic visceral disease including hepatic
             involvement and pulmonary lymphangitic spread of tumour (subjects who are intended for
             urgent chemotherapy)

          -  Requiring treatment with any of the prohibited concomitant medications

          -  Known pre-existing interstitial lung disease (ILD)

          -  Any history or presence of poorly controlled gastrointestinal disorders that could
             affect the absorption of the study drug

          -  Active hepatitis B infection active hepatitis C infection and/or known HIV carrier.

          -  Previous treatment with agents targeting the insulin like growth factor (IGF)
             signalling pathway.

          -  Previous treatment with EGFR TKI which cannot be documented as either reversible or
             irreversible (Part B only)

          -  Part B only: Prior treatment with third generation irreversible EGFR TKI (e.g. AZD9291
             or CO-1686)