Abstract
Gemcitabine and cisplatin chemotherapy (GC regimen) represents a standard treatment for advanced urothelial carcinoma. We performed an open-label, single-arm, non-randomised, phase 2 trial evaluating the addition of sunitinib to standard GC chemotherapy (SGC regimen). Overall, 63 treatment-naïve participants were recruited and received up to six 21-d cycles of cisplatin 70 mg/m2 (intravenously [IV], day 1) and gemcitabine 1000 mg/m2 (IV, days 1 and 8) combined with sunitinib 37.5 mg (orally, days 2-15). Following review of toxicity after the first six patients, the sunitinib dose was reduced to 25 mg for all patients. Overall response rate was 64%, with response noted in 37 of 58 patients. At 6 mo, 30 of 58 assessable patients (52%; 90% confidence interval [CI], 40-63%) were progression free. Median overall survival was 12 mo (95% CI, 9-15) and was heavily influenced by Bajorin prognostic group. Grade 3-4 toxicities were predominantly haematologic and limited the deliverability of the triple SGC regimen. The trial did not meet its prespecified primary end point of >60% patients progression free at 6 mo. Cumulative myelosuppression led to treatment delays of gemcitabine and cisplatin and dose reduction and/or withdrawal of sunitinib in the majority of cases. The triple-drug combination was not well tolerated. Phase 3 evaluation of the triple SGC regimen in advanced transitional cell carcinoma is not recommended. PATIENT SUMMARY: The addition of sunitinib to standard cisplatin and gemcitabine chemotherapy was poorly tolerated and did not improve outcomes in advanced urothelial carcinoma. Treatment delivery was limited by myelotoxicity.