Sequential intravesical valrubicin and docetaxel for the treatment of nonmuscle invasive bladder cancer.

Abstract

496 Background: Intravesical gemcitabine-docetaxel (Gem/Doce) has emerged as an efficacious and well-tolerated therapy for NMIBC. At first cytoscopic evaluation, success rate for BCG failures is 75-80% with 60% of responders remaining disease free at 24 months. Success rates are even higher for BCG naïve patients with close to 90% disease free at 3 months, and 93% of responders HG disease free at 24 months. There is an unmet need for effective bladder-sparing regimens for Gem/Doce failures. FDA-approved agents in this setting have poor long-term efficacy; Valrubicin has an 8% 24-month disease free rate, and recently approved Pembrolizumab has less than 20% complete response at 1 year. Based on poor efficacy of alternatives, we evaluated sequential intravesical valrubicin-docetaxel (Val/Doce) as a rescue therapy for NMIBC. Methods: We retrospectively identified all patients with NMIBC who were treated with Val/Doce between April 2013 and June 2021. Patients were included with intent to receive 6 weekly intravesical instillations of sequential 800 mg valrubicin and 37.5 mg docetaxel after complete TURBT. Monthly maintenance of 2 years was initiated if disease free at 3-month cytoscopic evaluation. The primary outcome was recurrence-free survival (RFS). Progression events included the development of muscle invasive or metastatic disease as well as any cystectomy. Survival was assessed using the Kaplan-Meier method and log rank test, indexed from start of Val/Doce induction. Surveillance was performed according to AUA guidelines. Results: The final cohort included 75 patients with median follow-up of 21 months. Of these patients, 12 were treated with Val/Doce for low-grade Ta disease, with 60% disease free at 2 years and no subsequent HG occurrences. The remaining 63 patients had high-grade disease of which 86% were BCG failures and 89% were Gem/Doce unresponsive. The 2 year RFS for high-grade patients was 39%. CIS was present in 56% of the cohort. RFS was similar for those with and without CIS. Progression occurred in 12 of the patients with high-grade disease. Of note, 10 underwent cystectomy and 2 died of metastatic bladder cancer, yielding a bladder cancer specific death rate of 3%. Overall and cystectomy-free survival was 88 and 85% at 24 months, respectively. The most commonly reported side effects were bladder spasms (24%), urinary frequency (13%), and dysuria (11%). There were 3 patients who could not tolerant a full induction course. Conclusions: Sequential intravesical valrubicin-docetaxel will rescue a substantial portion of patients with HG NMIBC failing Gem/Doce or BCG. Thus, the regimen allows a high proportion of patients ( > 80%) to retain their bladders with an acceptable ( < 20%) progression rate without succumbing to bladder cancer-related death ( < 5%).[Table: see text]