Safety and Activity of Sorafenib in Addition to Vinflunine in Post‐Platinum Metastatic Urothelial Carcinoma (Vinsor): Phase I Trial

Lessons Learned. First trial to report safety and activity of the microtubule inhibitor vinflunine plus the tyrosine kinase inhibitor sorafenib in post‐platinum metastatic urothelial cancer (mUC) patients. A recommended phase II dose was identified for the treatment combination of vinflunine plus sorafenib, with main adverse events including fatigue, febrile neutropenia, neutropenia, hypertension, and hyponatremia. An overall response rate of 41% to second‐line vinflunine plus sorafenib treatment in patients with platinum‐resistant mUC was confirmed.