Dose/ Schedule Finding Trial of Romiplostim for Chemotherapy-Induced Thrombocytopenia (CIT) in Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Histologically or cytologically confirmed locally advanced or metastatic stage IIIB or stage IV NSCLC receiving 21-day cycles of gemcitabine/carboplatin or gemcitabine/cisplatin * Life expectancy ≥ 12 weeks at the time of screening * Thrombocytopenia as evidenced by a platelet count ≤ 50 x 10\^9/L during the qualifying cycle of chemotherapy, OR platelet count \< 100 x 10\^9/L on Day 22 of the qualifying cycle (for eligibility inclusion: ability to receive the same dose of chemotherapy on study), this criteria ensures that the patient must be dose delayed for platelet recovery * Ability to receive the same dose and schedule of chemotherapy during the first on-study treatment cycle as was given in the qualifying cycle (except Day 8 gemcitabine) * Absolute neutrophil count (ANC) ≥ 1,000/µL, hemoglobin ≥ 9.5 g/dL, and platelet count ≥ 100 x 10 \^9/L on Day 1 of the first on study chemotherapy treatment cycle * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 at the time of screening * Adequate Liver function; aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 3.0 x upper limit of normal (ULN) (except for patients with a confirmed diagnosis of Gilbert's Syndrome) * Adequate renal function; serum creatinine \< 1.5 x ULN Exclusion Criteria: * Receipt of \> 1 prior systemic chemotherapy regimen * Sepsis, disseminated coagulation or any other condition (i.e. immune \[idiopathic\] thrombocytopenic purpura \[ITP\], thrombotic thrombocytopenic purpura \[TTP\], hemolytic uremic syndrome \[HUS\]) that may exacerbate thrombocytopenia * History of unstable angina, congestive heart failure, uncontrolled hypertension (diastolic \> 100 mmHg), uncontrolled cardiac arrhythmia, or recent (within 1 year of screening ) myocardial infarction * History of arterial thrombosis (e.g., stroke or transient ischemic attack) within 1 year of screening * History of pulmonary embolism or other venous thrombosis within 1 year of screening (except for catheter-related clots) * Use of any nitrosourea or mitomycin-C within 6 weeks of screening * Have received any thrombopoietic growth factor or related substance * Have received granulocyte macrophage colony stimulating factor (GM-CSF) within the last 4 weeks prior to screening * Have received any experimental therapy within 4 weeks prior to screening * Have ever received a bone marrow or peripheral blood stem cell infusion (within 1 year of screening) * Known hypersensitivity to any recombinant E. coli-derived product.