Inclusion Criteria:

- Histologically or cytologically confirmed stage IIIB or IV NSCLC.

- Recurrent disease (either no response to treatment or subsequent relapse after an
objective response) that has progressed after first line therapy.

- Measurable disease.

- ≥ 18 years of age.

- ECOG performance status of 0 or 1.

- Adequate organ and bone marrow function.

- Agreement to use effective contraception while on treatment and for at least 6 months
after end of treatment.

Exclusion Criteria:

- Treatment with anticancer therapy, antibody based therapy, retinoid therapy, or
hormonal therapy within 4 weeks before study treatment.

- Left ventricular ejection fraction (LVEF) < 45%.

- Therapeutic radiation or major surgery within 4 weeks before study treatment or
palliative radiation therapy within 2 weeks before study drug treatment.

- Previous use of EGFR-targeted regimen, anti-HER2, anti-HER3, or anti-HER4 therapy.

- More than 2 prior chemotherapy regimens for NSCLC (Phase 2 subjects only).

- Uncontrolled infection requiring IV antibiotics, antivirals, or antifungals, known
human immunodeficiency virus (HIV) infection, or active hepatitis B or C infection at
time of screening.

- Clinically active brain metastases.