Inclusion Criteria: (For all patients unless otherwise specified)

          -  Histologically or cytologically confirmed locally advanced (stage IIIB not amenable to
             definitive multi-modality therapy including surgery) or metastatic (stage IV) EGFR
             mutant NSCLC.

          -  Patients with controlled brain metastases

          -  ECOG performance status: Phase I part: 0, 1, or 2; Phase II part: 0 or 1

          -  Presence of at least one measurable lesion according to RECIST 1.1 per investigator
             assessment

          -  Patients who are either Hepatitis B surface antigen (HBsAg) positive or hepatitis B
             virus (HBV)-DNA positive must be willing and able to take antiviral therapy 1-2 weeks
             prior to 1st dose of EGF816 treatment and continue on antiviral therapy for at least 4
             weeks after the last dose of EGF816

          -  Patients must have negative hepatitis C antibody (HCV-Ab) or positive HCV-Ab but
             undetectable level of HCV-RNA. Note: patients with detectable HCV-RNA are not eligible
             for the study.

          -  For Phase I: patients must have failed no more than 3 lines of any systemic
             antineoplastic therapy for advanced NSCLC, including EGFR-TKI

          -  For Phase II: patients must be naïve from any systemic antineoplastic therapy in the
             advanced setting. Patients who have failed no more than 1 cycle of systemic
             antineoplastic therapy in the advanced setting are allowed.

        Exclusion criteria: (For all patients unless otherwise specified)

          -  Patients with a history or presence of interstitial lung disease (ILD) or interstitial
             pneumonitis, including clinically significant radiation pneumonitis (i.e. affecting
             activities of daily living or requiring therapeutic intervention)

          -  Presence or history of another malignancy

          -  Undergone a bone marrow or solid organ transplant

          -  Known history of human immunodeficiency virus (HIV) seropositivity

          -  Patients receiving concomitant immunosuppressive agents or chronic corticosteroids use
             at the time of study entry except for control of brain metastases, topical
             applications, inhaled sprays, eye drops or local injections

          -  Patients with clinically significant, uncontrolled heart disease

          -  Any prior therapies ≤ 4 weeks prior to the first dose of study treatment

          -  Patients who are receiving treatment with medications that are known to be strong
             inhibitors or inducers of CYP3A4/5 and cannot be discontinued 1 week prior to the
             start of EGF816 treatment and for the duration of the study.

          -  Patients who have impairment of gastrointestinal (GI) function or GI disease that may
             significantly alter the absorption of EGF816

          -  Patients who are receiving treatment with any enzyme-inducing anticonvulsant that
             cannot be discontinued at least 1 week before first dose of study treatment, and for
             the duration of the study

          -  Women of child-bearing potential, defined as all women physiologically capable of
             becoming pregnant, unless they are using highly effective methods of contraception

          -  Sexually active males unless they use a condom during intercourse while taking drug
             and for 3 months after stopping treatment

        Other protocol-defined inclusion and exclusion criteria may apply.