Long-term efficacy and safety outcomes of modified (simplified) MVAC (methotrexate/vinblastine/doxorubicin/cisplatin) as frontline therapy for unresectable or metastatic urothelial cancer

Background The classic MVAC (methotrexate/vinblastine/doxorubicin/ cisplatin) regimen was the first recognized option for untreated patients with locally advanced or metastatic urothelial cancer (UC). Modifying MVAC by reducing side effects may have the potential to improve efficacy. Patients and Methods Changes to classic MVAC were provided at the authors' institution: (1) deletion of day 22 and administration of 25 mg/m² cisplatin on days 2 to 5 (modified [m]MVAC); (2) deletion of day 22 only (simplified [s]MVAC1); and (3) deletion of days 15 and 22 in a 3-week schedule (sMVAC2). A total of 4 to 6 cycles were provided. Multivariate analysis was undertaken for recognized clinical variables. Results For the period from September 1986 to May 2012, 157 patients were identified (25 with mMVAC, 72 with sMVAC1, and 60 with sMVAC2). Overall, 43.9% had a Memorial Sloan-Kettering Cancer Center score of 1 or 2, with differences across series (P =.002). Altogether, 65.8% attained a complete (19.1%) or partial response (46.7%), and 24.3% a stable disease, with no difference across regimens. After a median follow-up of 87 months (interquartile range, 37-161), median progression-free survival was 10.2 months (95% CI, 8.4-10.8), and median overall survival (OS) was 19.5 months (95% CI, 16.3-24.1). Responses were mainly seen in nodal metastases or soft tissue relapse (odds ratio, 2.48; 95% CI, 1.12-5.54). Only visceral (hazard ratio [HR], 2.42; 95% CI, 1.37-4.30) and nodal metastases/local relapse (HR, 1.70; 95% CI, 1.07-2.69) were independently associated with OS. Grade 3 or 4 toxicities were similar across regimens and were 36% neutropenia, 14% thrombocytopenia, 12% anemia, 10% mucositis, and 4% renal toxicity. Two treatment-related deaths occurred. Conclusion Simplifying MVAC may result in improved efficacy and reduced toxicity. The combined results of the original and modified MVAC regimens encourage a reappraisal of the frontline management of advanced UC.