Inclusion Criteria:

          -  Patients of either gender, aged from 18 years older to 70.

          -  Histologically or cytologically confirmed metastatic, or unresectable locally
             advanced, recurrent NSCLC.

          -  At least one measurable disease by CT or MRI, according to RECIST Version 1.1.

          -  Documented evidence of any activating EGFR mutation in the tumor tissue.

          -  Have undergone or are able to undergo a biopsy of either primary or metastatic tumor
             tissue within 28 days of dosing of Avitinib, and have tissue available to send to
             central lab for further genetic profiling especially the status of T790M.

          -  Life expectancy of at least 3 months.

          -  ECOG performance status of 0 to 1.

          -  Adequate hematological and physiological functions of heart, lung, liver, and kidney
             according to definitions given in Appendix D.

          -  Disease progression under at least one treatment with current marketed EGFR TKI
             therapy for at least 30 days (e.g. Erlotinib, or Gefitinib, or Afatinib) with
             intervening treatment after most recent EGFR TKI therapy. The washout period for an
             EGFR TKI (Erlotinib, or Gefitinib) is at a minimum of 7 days. The washout period for
             an irreversible EGFR inhibitor (Afatinib) and chemotherapy is at a minimum of 14 days.

          -  Any toxicity related to prior EGFR inhibitor treatment must have resolved to Grade 1
             or less.

          -  NSCLC patients with asymptomatic brain metastasis or drug-controllable brain
             metastasis.

          -  Signed consent on an Independent Ethics Committee-approved Informed Consent Form prior
             to any study-specific evaluation.

        Exclusion Criteria:

          -  No pathology confirmation

          -  History of interstitial lung disease related to prior EGFR inhibitor therapy.

          -  Symptomatic brain metastases or uncontrollable or unstable brain metastasis.

          -  Positive to HCV or HIV antibody.

          -  Treatment with prohibited medications (e.g., concurrent anticancer therapy including
             other chemotherapy, radiation, hormonal, or immunotherapy) ≤14 days prior to treatment
             with Avitinb.

          -  Clinically significant abnormal 12-lead ECG, QT interval corrected using Fridericia's
             method (QTcF) >450 msec (males) or >470 msec (females).

          -  Family history of long QT syndrome.

          -  Treatment with any Category 1 and 2 drugs (See:https://www.crediblemeds.org/ or
             www.qtdrug.org).

          -  Presence of any serious or unstable concomitant systemic disorder incompatible with
             the clinical study (e.g., substance abuse, uncontrolled psychiatric condition,
             uncontrolled intercurrent illness including active infection, arterial thrombosis, and
             symptomatic pulmonary embolism).

          -  Any other reasons for the investigator to consider the patient should not participate
             in the study.