Optimization of dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin therapy for Japanese patients with urothelial carcinoma

Background: Dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) regimen has been established as a systemic chemotherapy for patients with urothelial carcinoma. However, it is rarely used in Japan owing to the challenges associated with managing the related adverse events. This study aimed to optimize the dd-MVAC protocol for Japanese patients. Methods: Criteria were developed to adjust the doses of anticancer drugs used in dd-MVAC. In this regimen, the initial cycle of methotrexate and cisplatin was administered at 75% of the full dose. Patients who did not experience significant toxicities during the first cycle subsequently received the full dose starting from the second cycle. Additionally, the doses of methotrexate and cisplatin were adjusted according to the Cockcroft-Gault creatinine clearance. Based on these criteria, patients with urothelial carcinoma underwent dd-MVAC between August 2018 and May 2023, and all patients were scheduled to undergo six cycles. Results: A total of 86 patients received dd-MVAC, with 36, 15, and 35 patients receiving it as neoadjuvant, adjuvant, and salvage chemotherapy, respectively. Fifty-nine patients (68.6%) completed the six scheduled cycles. Grade ≥ 3 toxicities of Common Terminology Criteria for Adverse Events were observed in 76 (88.4%) patients; however, most were manageable. In the neoadjuvant cohort, the pathological complete response rate was 52.2% among patients with clinical N0 lower tract urothelial carcinoma. High levels of alkaline phosphatase at the initiation of treatment were correlated with failure to complete six cycles of dd-MVAC. Conclusion: Adjusting the dd-MVAC regimen based on renal function and significant adverse events may result in a high completion rate of scheduled treatments in Japanese patients with urothelial carcinoma.