• Incidence of dysphagia (CTCAE grade 2 or greater) from start of treatment through week 16. [ Time Frame: Start of treatment through week 16 ] [ Designated as safety issue: Yes ]
  

• Maximum severity of dysphagia from start of treatment through week 16. [ Time Frame: Start of treatment through week 16 ] [ Designated as safety issue: No ]
  
• Incidence of severe dysphagia (CTCAE grade 3 or greater) from start of treatment through week 16. [ Time Frame: Start of treatment through week 16 ] [ Designated as safety issue: No ]
  
• Unplanned breaks in radiotherapy (including discontinuations of radiotherapy) from start of treatment through week 7. [ Time Frame: Start of treatment through week 7 ] [ Designated as safety issue: No ]
  
• Patient-reported outcomes- average swallowing index score from start of treatment through week 12. [ Time Frame: Start of treatment through week 12 ] [ Designated as safety issue: No ]
  
• Opioid analgesic use, hospitalization, PEG/NG tube use, TPN use, IV hydration use, and infections, from start of treatment through week 16. [ Time Frame: Start of treatment through week 16 ] [ Designated as safety issue: No ]
  
• Incidence of chronic dysphagia (CTCAE grade 2 or greater) at month 6 [ Time Frame: Six months from start of treatment ] [ Designated as safety issue: Yes ]
  
• Incidence of pneumonitis at months 6 through 12 [ Time Frame: Six to twelve months from start of treatment ] [ Designated as safety issue: Yes ]
  
• Disease progression, incidence of second primary tumors, other malignancies, and survival (at least once yearly for life) [ Time Frame: During a subject's lifetime from start of treatment ] [ Designated as safety issue: Yes ]
  
• Duration of dysphagia (CTCAE grade 2 or greater) from start of treatment through week 16. [ Time Frame: Start of treatment through week 16 ] [ Designated as safety issue: No ]
  

Inclusion Criteria:

• Patients with a histologically or cytologically proven diagnosis of NSCLC
• Unresectable (locally advanced) stage IIIa or IIIb disease
• Initial RT field of treatment to encompass greater than or equal to 30% of the esophagus
• Life expectancy greater than or equal to 6 months
• Estimated weight loss less than or equal to 10% in the 3 months before study randomization
• Measurable disease
• 18 years of age or older
• ECOG performance status of 0 - 2
• Hemoglobin (hgb) greater than or equal to 10 g/dL without transfusional support or growth factor use in the 4 weeks before study randomization
• Absolute neutrophil count (ANC) greater than or equal to 1.5 x 10^9/L without growth factor use in the 2 weeks before study randomization
• Platelet count greater than or equal to 100 x 10^9/L
• Serum bilirubin less than or equal to 1.5 x institutional upper limit of normal (ULN)
• Serum creatinine less than or equal to 2.0 mg/dL (Note: Subjects with a serum creatinine greater than or equal to 1.4 and less than or equal to 2.0 mg/dL must demonstrate a 24-hour urinary creatinine clearance greater than or equal to 50 mL/min)
• Females of childbearing potential: negative serum or urine pregnancy test
• Subject must give written informed consent before participating in any study-specific procedure, randomization, or receiving investigational product.
• Subjects with reproductive capability must agree to practice adequate contraception methods.

Exclusion Criteria:

• Metastatic disease (M1)/stage 4 NSCLC
• Pleural or pericardial effusion greater than 100ml in volume as documented by appropriate imaging (PET, CT scan or ultrasound). If an effusion greater than 100ml is documented by cytology to be free from malignancy and the investigator feels the subject is capable of receiving CT/ RT for their primary disease/ NSCLC, the investigator should discuss the patient with the study physician at Amgen. Effusions smaller than 100ml would be acceptable, unless the investigator suspects that the effusion is malignant, in which case the effusions should be evaluated by cytology. Sponsor approval must be obtained before subject is randomized.
• Plan to remove the tumor surgically before completing the protocol CT/RT course
• Shielding of any part of the esophagus during RT (including posterior spinal cord shielding)
• Prior chemotherapy, radiotherapy, or surgery for NSCLC
• Prior invasive malignancy during the past 3 years other than non-melanomatous skin cancer. Note: Subjects with prior surgically-cured malignancies [eg, stage I breast cancer or prostate cancer, in-situ carcinoma of the cervix, etc] are not excluded; however, sponsor approval must be obtained before subject is randomized.
• Presence or history of dysphagia or conditions predisposing to dysphagia (eg, uncontrolled gastroesophageal reflux disease [GERD], dyspepsia, etc)
• History of pancreatitis
• Four weeks or less since completion of treatment using an investigational product/device in another clinical study or presence of any unresolved toxicity from previous treatment
• Previous treatment on this study or with a fibroblast growth factor
• Known to be sero-positive for human immunodeficiency virus (HIV), hepatitis C virus (HCV), or hepatitis B virus (HBV)
• Pregnant or breastfeeding women
• Known sensitivity to E coli derived products
• Compromised ability of the subject to give written informed consent and/or to comply with study procedures
• Refusal to sign an informed consent form to participate in this study, and sign the hospital information release form, if applicable
• Unwilling or unable to complete the PRO questionnaires
• Psychological, social, familial, or geographical reasons that would prevent regular follow-up