Inclusion Criteria:

          -  Provision of signed and dated, written informed consent prior to any treatment
             protocol-specific procedures

          -  Patients aged at least 18 years

          -  Locally advanced or metastatic EGFRm NSCLC, not amenable to curative surgery or
             radiotherapy with confirmation of the presence of the T790M mutation

          -  Two lines of prior therapy including at least one EGFR TKI

          -  World Health Organization (WHO) performance status 0-2.

          -  Females of child-bearing potential must use adequate contraceptive measures, not be
             breast-feeding and have negative pregnancy test prior to start of dosing.

          -  Males patients should be willing to use barrier contraception.

        Exclusion Criteria:

          -  Previous treatment with AZD9291

          -  Patients currently receiving (or unable to stop use at least 1 week prior to receiving
             the first dose of AZD9291) any treatment known to be potent inhibitors or inducers of
             CYP3A4

          -  Any evidence of severe or uncontrolled systemic diseases, including uncontrolled
             hypertension, active bleeding diatheses, or significantly impaired bone marrow reserve
             or organ function, including hepatic and renal impairment, which in the clinician's
             opinion would significantly alter the risk/benefit balance, or active infection
             including hepatitis B, hepatitis C and human immunodeficiency virus (HIV).

          -  Patients with symptomatic CNS metastases who are neurologically unstable

          -  Past medical history of ILD, drug-induced ILD, radiation pneumonitis requiring steroid
             treatment, or any evidence of clinically active ILD

          -  Any of the following cardiac criteria:

               1. Mean resting corrected QT interval (QTc using Fredericia's formula) > 470 msec

               2. Any clinically important abnormalities in rhythm, conduction or morphology of
                  resting ECG (e.g., complete left bundle branch block, third degree heart block,
                  second degree heart block)

               3. Any factors that increase the risk of QTc prolongation or risk of arrhythmic
                  events such as heart failure, hypokalemia, congenital long QT syndrome, family
                  history of long QT syndrome or unexplained sudden death under 40 years of age in
                  first degree relatives or any concomitant medication known to prolong the QT
                  interval

          -  Any unresolved toxicity from prior therapy Common Terminology Criteria for Adverse
             Events (CTCAE) > grade 3 at the time of starting treatment in the access program

          -  History of hypersensitivity to AZD9291 (or drugs with a similar chemical structure or
             class to AZD9291) or any excipients of these agents

          -  Males and females of reproductive potential who are not using an effective method of
             birth control and females who are pregnant or breastfeeding or have a positive (urine
             or serum) pregnancy test prior to access program entry