Inclusion Criteria:

- Histologically or cytologically documented unresectable Stage III NSCLC, as defined
by American Joint Committee on Cancer/Union for International Cancer Control
(AJCC/UICC) 7th edition (2009) criteria. All histological subtypes are acceptable,
including bronchioalveolar carcinomas

- Documented stable disease or objective response, according to Response Evaluation
Criteria In Solid Tumors (RECIST) Version 1.0, after primary chemo-radiotherapy
(either sequential or concomitant) for unresected Stage III disease, within 4 weeks
(28 days) prior to enrollment

- Receipt of concomitant or sequential chemo-radiotherapy, consisting of a minimum of
two cycles of platinum-based chemotherapy and a minimum radiation dose of greater
than equal to 50 Gray. Subjects must have completed the primary thoracic
chemo-radiotherapy at least 4 weeks (28 days) and no later than 84 days prior to
enrollment. Subjects who received prophylactic brain irradiation as part of primary
chemo-radiotherapy are eligible

- Platelet count greater than or equal to 140 * 10^9 per liter, white blood cell (WBC)
greater than or equal to 2.5 * 10^9 per liter, and hemoglobin greater than or equal
to 90 gram per liter

- Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1

Additional Inclusion Criteria apply

Exclusion Criteria:

- Pre-therapies:

- Previous lung cancer specific therapy (including surgery) other than primary
chemo-radiotherapy

- Receipt of immunotherapy within 4 weeks (28 days) prior to enrollment. Note:
Subjects who have received monoclonal antibodies for imaging are acceptable

- Receipt of investigational systemic drugs (including off-label use of approved
products) within 4 weeks (28 days) prior to enrollment

- Disease status:

- Metastatic disease

- Malignant pleural effusion at initial diagnosis and/or at trial entry

- Past or current history of neoplasm other than lung carcinoma, except for
curatively treated nonmelanoma skin cancer, in situ carcinoma of the cervix or
other cancer curatively treated and with no evidence of disease for at least 5
years

- Autoimmune disease

- A recognized immunodeficiency disease including cellular immunodeficiencies,
hypogammaglobulinemia or dysgammaglobulinemia; subjects who have hereditary or
congenital immunodeficiencies

- Any preexisting medical condition requiring systemic chronic steroid or
immunosuppressive therapy (steroids for the treatment of radiation pneumonitis
are allowed)

- Known Hepatitis B and/or C

- Active infection at enrollment, including but not limited to, flu-like
infections, urinary tract infections, bronchopulmonary infections, etc

- Physiological functions:

- Clinically significant hepatic dysfunction (that is, alanine aminotransferase
[ALT] greater than 2.5 times normal upper limit [ULN]; or aspartate
aminotransferase [AST] greater than 2.5 times ULN; or bilirubin greater than or
equal to 1.5 * ULN)

- Clinically significant renal dysfunction (that is, serum creatinine greater than
or equal to 1.5 * ULN)

- Clinically significant cardiac disease, for example, New York Heart Association
(NYHA) Classes III-IV; uncontrolled angina, uncontrolled arrhythmia or
uncontrolled hypertension, myocardial infarction in the previous 6 months as
confirmed by an electrocardiogram (ECG)

- Splenectomy

- Infectious process that in the opinion of the investigator could compromise the
subject's ability to mount an immune response

Additional Exclusion Criteria apply