FLT3 Ligand Immunotherapy and Stereotactic Radiotherapy for Advanced Non-small Cell Lung Cancer

Inclusion Criteria:

* AJCC stage 3 or 4 histologically proven NSCLC not amenable to curative therapy
* Age \>= 18 years
* Prior treatment with at least one standard chemotherapy regimen or targeted agent prior to enrollment
* Radiological assessment within 21 days prior to study entry demonstrating measurable disease that includes at least one pulmonary lesion . 1 cm in greatest dimension that would be amenable to SBRT and at least one measurable lesion that would be outside of the SBRT treatment fields
* History/physical examination within 30 days prior to registration
* ECOG performance status 0-2
* Signed, written informed consent

Exclusion Criteria:

* Less than 21 days between registration and the last receipt of chemotherapy, biotherapy, immunotherapy, radiotherapy (excluding palliative radiotherapy), or major surgery. Prior receipt of immunomodulatory therapy (eg: nivolumab) is permitted, as long as there has been a 21 day washout period following the most recent treatment.
* Untreated central nervous system metastases. Patients with a history of brain metastases must have had no CNS-directed therapy within the past 60 days and radiological assessment within 30 days of study entry demonstrating a lack of progressive CNS disease
* Ongoing or recent (within 21 days prior to study entry) use of high dose oral corticosteroids (.2 mg of dexamethasone daily or equivalent). Intranasal and/or inhaled corticosteroid use is permitted.
* Any unresolved CTCAE grade \>2 toxicity from previous anti-cancer therapy. Patients with irreversible toxicity that is not reasonably expected to be exacerbated by study therapy (eg, hearing loss)may be enrolled after discussion with the principal investigators.
* History of allogeneic organ transplant or autoimmune disease
* Active malignancy, other than NSCLC, for which systemic therapy is indicated. History of adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, asymptomatic prostate cancer without known metastatic disease and with no requirement for therapy asides from hormonal therapy, adequately treated stage 1 or 2 cancer currently in complete remission, or any other cancer that has been in complete remission for \>= 5 years is permitted.
* Uncontrolled intercurrent illness including, but not limited to, symptomatic congestive heart failure, unstable angina pectoris, uncontrolled cardiac arrhythmia, or psychiatric illness/social situation that would limit compliance with study requirements as judged by the treating physicians
* The following laboratory results, within 10 days of first study drug administration:

* Hemoglobin . 9.0 g/dL, Absolute neutrophil count . 1.5 x 109/L, Platelet count . 100 x 109/L
* Serum creatinine . 1.5 x ULN and creatinine clearance (by Cockcroft-Gault formula) \< 60 mL/min
* Women of child bearing potential: positive pregnancy test (serum)