Neoadjuvant sorafenib, gemcitabine, and cisplatin administration preceding cystectomy in patients with muscle-invasive urothelial bladder carcinoma: An open-label, single-arm, single-center, phase 2 study

BACKGROUND: Outcomes of neoadjuvant chemotherapy in patients with muscle-invasive urothelial bladder carcinoma (MIUBC) should be improved. Sorafenib was combined with gemcitabine and cisplatin chemotherapy (SGC) in an open-label, single-arm, phase 2 trial (NCT01222676).

PATIENTS AND METHODS: After transurethral resection of the bladder, T2-T4a N0 patients received four cycles of SGC followed by cystectomy. Sorafenib 400mg q12h daily, continuously, was added to standard GC chemotherapy. In a Simon's 2-stage design, the primary endpoint was the pathologic complete response (pT0), assuming H0: ≤0.20 and H1: ≥0.40, with a type I and type II error of 5% and 10%, respectively.

RESULTS: From April 2011 to June 2016, 46 patients were enrolled. Pathologic T0 response was obtained in 20 patients (43.5%, 95% CI: 28.9-58.9); pT ≤ 1 in 25 (54.3%, 95% CI: 39.0-69.1). After a median follow-up of 35 months, the median progression-free survival was not reached (NR, interquartile range: 23.6-NR), nor was median overall survival (interquartile range: 30.3-NR). Hematologic and extrahematologic grade 3 to 4 adverse events occurred in 45.6% and 26.1% of patients, respectively. In 29 samples from responders (pT ≤ 1) and nonresponders, different distribution of missense mutations involved DNA-repair genes, RAS-RAF pathway genes, chromatin-remodeling genes, and HER-family genes. ERCC1 immunohistochemical expression was associated with pT ≤ 1 response (P = 0.047). The absence of a comparator arm prevented us to quantify sorafenib contribution.

CONCLUSIONS: SGC combination was active in MIUBC, and the identified molecular features included alterations that may help personalize treatment in MIUBC with new more potent targeted agents, combined with chemotherapy.