Efficacy and toxicity of antibody-drug conjugates (ADCs) in the treatment of metastatic urothelial cancer (mUC): A systematic review.

Abstract

e16536 Background: mUC is an aggressive disease with limited overall survival. Recently, immunotherapy with checkpoint inhibitors (ICI) has dramatically improved outcomes but with limited response rates and overall survival. ADC were designed with the intent to deliver potent cytotoxic drugs selectively to antigen-expressing tumor cells by linking cytotoxins to mAbs and have emerged as a new option of treatment with promising results. We aimed to realize a systematic review of efficacy, treatment-related AEs (trAEs) and impact on quality of life of ADC in mUC. Methods: A systematic review of the literature has been performed in January 2022 using Pubmed and Embase database according to the Preferred Reported Items for Systematic Reviews and Meta-analyses (PRISMA) statement. After excluding review, duplicate and non-relevant articles, 10 clinical trials were included in the analysis. The search method involved querying for the terms bladder carcinoma or urothelial carcinoma with any of the following: enfortumab vedotin (EV), sacituzumab govitecan (SG), antibody-drug conjugate. Only prospective clinical trials were included. Results: The systematic review yielded 1103 records using MEDLINE (741 records) and EMBASE (362 records). Ultimately, 9 phase 1, 2 or 3 clinical trials with 1355 patients were selected for inclusion and 4 drugs were identified: Enfortumab vedotin (EV), sacituzumab govitecan (SG), an anti-HER2 compound (RC48-ADC), and an anti- SLITRK6 drug (ASG-15ME). Efficacy outcomes are presented in table 1. Phase 2 trials have reported promising response rates in mUC and one randomized phase 3 trial showed the superiority of EV vedotin over CT after failure to platinum-based CT and ICI with improvement in overall survival. TRAEs of any grade occurred in more than 90% of patients in phase 2 or 3 trials, with high rates of discontinuation (table 2). TRAEs of special interest related to EV were rash, neuropathy, and hyperglycemia. SG is associated with diarrhea and hematologic toxicity. Data from phase 2 and 3 trials of EV suggest no impact on quality of life and an improvement in some parameters. Conclusions: ACDs represent a very promising new option for the treatment of mUC. A phase 3 trial confirmed the superiority of EV over CT after platinum and IO failure. A high incidence of potential adverse events was observed in phase 2 and 3 trials, including rash, neutropenia, hematologic toxicity, and neuropathy. Practitioners’ oncologists should be aware of potential adverse events and optimal management. Quality of life is preserved during the treatment with EV.