Phase 1 Study of Fusilev® to Prevent or Reduce Mucositis in Patients With Non-Small Cell Lung Cancer Receiving Folotyn®

Inclusion Criteria: * At least 18 years of age * Relapsed or Refractory Non Small Cell Lung Cancer (NSCLC) after at least one line of therapy * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 * Histologically or cytologically confirmed Stage III B/IV NSCLC * Adequate hematological, hepatic, and renal function * Available during the first 8 weeks of the study treatment period to visit the clinic for oral Mucositis assessments on scheduled days Exclusion Criteria: * Active concurrent malignancy. If there is a history of prior malignancies other than those exceptions listed above, the patient must be disease-free for at least 5 years * Congestive heart failure * Uncontrolled hypertension * Known human immunodeficiency virus (HIV)-positive diagnosis * Previous exposure to Pralatrexate * Pregnant or breast-feeding women * Major surgery within 14 days of enrollment * Active uncontrolled infection, underlying medical condition, or other serious illness that would impair the ability of the patient to receive protocol treatment * Symptomatic central nervous system (CNS) metastases or lesions for which treatment is required. Patients who received prophylactic CNS treatment are eligible