Background: Vinflunine is a novel microtubule inhibitor currently approved by EMA as treatment after platinum progression, in metastasic bladder cancer. It is distinguished from the other vinca-alkaloids because it binds relatively weakly to tubulin, suggesting an improved tolerance profile as a result of less neuropathy. Based on the fact that no cumulative toxicity is expected and the results reported in second-line, we aim to test the role of vinflunine in first line therapy, as maintenance treatment for patients who obtain clinical benefit after platinum. Methods: This is a multicenter, randomized, open label, proof-of-concept study that will be performed in 20 institutions members of the Spanish Oncology Genitourinary Group (SOGUG). Subjects will be randomized in a 1:1 ratio to receive vinflunine 320 mg/m2 every 21 days plus BSC vs BSC alone until disease progression. Vinflunine dose will be 280mg/m2 for patients with PS=1, age ≥ 75 years, prior pelvic radiotherapy or creatinine clearance Cr <60ml/min. Stratification factors are: 1) Scheduled dose at randomization (320 vs 280mg/m2) 2) Liver metastasis (Y/N). Main inclusion criteria are: Subjects ≥18 and< 80 years of age with histological diagnosis of transitional cell carcinoma of the urothelial tract and measurable disease with radiological response or stabilization after 6 cycles of a platinum containing doublet for metastasic/advanced disease. Primary objective will be progression free survival (PFS), considering as clinically relevant 6 months in experimental arm. To guarantee an overall type-1 α error (one side) no greater than 0.05 and a type II (β) error 0.1 for the primary endpoint of PFS, a sample size of 86 patients allocated in a 1:1 ratio is planned. Recruitment is scheduled to start by February 2012. A pharmacogenomic translational study will also be conducted.