Background: Vinflunine (VFL) is a microtubule inhibitor approved by EMA as treatment after platinum progression in metastatic UC. We evaluated whether maintenance VFL delays progression after response to CT. Methods: Patients (pts) with measurable disease, locally recurrent/metastatic UC and adequate organ function with radiological response or stabilization after 4-6 cycles (cy) of a cisplatin/gemcitabine chemotherapy (carboplatin allowed after cy 4) were randomized (R) 1:1 to receive VFL 320 or 280mg/m² (in case of PS1, age ≥ 75 years, prior pelvic radiotherapy (RT) or CrCl < 60ml/min) every 21 days vs best supportive care (BSC), until disease progression. Primary endpoint was progression free survival (PFS). With a median PFS considered unacceptable for the experimental arm of 4 months (m) (p0) and acceptable 6.5m (p1). 78 eligible were required for an α-error of 0.05 (one-tailed test) and a 0.1 β-error. Results: 88 pts from 21 institutions of SOGUG were R between 04/2012-01/2015. Forty five in the VFL arm and 43 in the BSC arm. 1 pt was not treated. 1 of 87 treated pts was not eligible due to an excess of time between the last dose of cisplatin and the start of VFL. At the beginning of treatment: median age 64 years [42-83]; PS1 50%; Hb < 10g/dl 8%; liver metastasis 21%. Pts in the VFL arm received a median of 6 cy per patient [1–43]. 10 pts (22.2%) continue in treatment in VFL arm. Most common G3/4AEs (%pts) in VFL arm were constipation (13.6), neutropenia (15.9), fatigue (15.9), and 1 febrile neutropenia (2.3). After a median of 12.2 m of follow-up [0.5-41.4], 59% of pts have progressed and 43% of pts have died in the VFL arm; 81% and 62% pts respectively in the BSC arm. The median PFS was of 6.5 m (1.3-11.7) in the VFL arm and 4.6 m (3.1-6) the BSC arm; HR 0.56 (IC95%; 0.34-0.93, p = 0.024). After progression, 34% of pts received treatment at VFL arm and 60% of pts at BSC arm. Conclusions: Maintenance VFL in patients with disease control after first line cisplatin-based chemotherapy significantly reduces 44% the risk of progression with an acceptable tolerability profile. Trial is maturing to assess the impact of maintenance VFL in survival. Clinical trial information: NCT01529411