The primary objectives of this study are to evaluate the safety and tolerability of CS-7017 administered orally twice a day in combination with erlotinib, and to assess the pharmacokinetics of CS-7017 in combination with erlotinib.

Inclusion Criteria:

• Histologically or cytologically confirmed unresectable locally advanced or metastatic (stage IIIb or IV) Non-small Cell Lung Cancer (NSCLC)
• Recurrent disease (either no response to treatment or subsequent relapse after an objective response) that has progressed after first-line platinum based therapy
• Male or female ≥ 18 years of age
• Anticipation of more than 3 months survival
• Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤ 1
• Adequate organ and bone marrow function

Exclusion Criteria:

• Prior Tyrosine Kinase Inhibitor (TKI) therapy
• Anticipation of need for a major surgical procedure or radiation therapy during the study
• Remaining influence of previous therapies such as radiotherapy, surgery, immunotherapy within 4 weeks prior to start of study treatment
• Treatment with anticancer medication within 4 weeks before study treatment, currently enrolled in another investigational drug study, or enrolled in another investigational drug study within 4 weeks of start of treatment
• History of any of the following events within 6 months prior to start of study treatment: myocardial infarction, severe/unstable angina pectoris, coronary/peripheral artery bypass graft, New York Heart Association (NYHA) class ≥I Congestive Heart Failure (CHF), cerebrovascular accident or cerebral infarction, pulmonary embolism, deep vein thrombosis, or other clinically significant thromboembolic event; clinically significant pulmonary disease (eg, severe Chronic-Obstructive Pulmonary Disease (COPD) or asthma)
• Severe edema, ascites fluid, pericardial or pleural effusion or pericardial involvement with the tumor within 6 months prior to start of study treatment, or which require steroid therapy/ diuretic therapy
• Subjects with brain metastasis (defined as untreated, symptomatic or requiring steroids or anticonvulsant medications to control associated symptoms)
• Subjects with clinically significant active infection which requires antibiotic therapy, or who are hepatitis B surface antigen (HBsAg)-, hepatitis C virus (HCV)- or human immunodeficiency virus (HIV)-positive or receiving antiretroviral therapy
• Subjects with malabsorption syndrome, chronic diarrhea (lasting over 4 weeks), inflammatory bowel disease, or partial bowel obstruction
• Diabetes mellitus requiring insulin, or a history of poor serum glucose control with the use of non-insulin diabetes medications
• Treatment with Thiazolidinedione(TZDs) within 4 weeks prior to start of study treatment
• History of a second malignancy, with the exception of in situ cervical cancer or adequately treated basal cell or squamous cell carcinoma of the skin
• Poorly-controlled blood pressure as judged by the Investigator

De-identified individual participant data (IPD) and applicable supporting clinical trial documents may be available upon request at https://vivli.org/. In cases where clinical trial data and supporting documents are provided pursuant to our company policies and procedures, Daiichi Sankyo will continue to protect the privacy of our clinical trial participants. Details on data sharing criteria and the procedure for requesting access can be found at this web address: https://vivli.org/ourmember/daiichi-sankyo/

Studies for which the medicine and indication have received European Union (EU) and United States (US), and/or Japan (JP) marketing approval on or after 01 January 2014 or by the US or EU or JP Health Authorities when regulatory submissions in all regions are not planned and after the primary study results have been accepted for publication.

Formal request from qualified scientific and medical researchers on IPD and clinical study documents from clinical trials supporting products submitted and licensed in the United States, the European Union and/or Japan from 01 January 2014 and beyond for the purpose of conducting legitimate research. This must be consistent with the principle of safeguarding study participants' privacy and consistent with provision of informed consent.

Baseline characteristics are reported for participants in the Safety Analysis Set.

Treatment-emergent adverse event data were collected from after the first dose up to 30 days after the last dose, up to approximately 1.5 years in the Safety Analysis Set.

Adverse events (AEs) were defined as any untoward, unfavorable, unintended medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. All-cause mortality includes all deaths that occurred during the study and within 30 days after the last dose of study drug.