Treatment options for recurrent high-risk non-muscle-invasive bladder cancer (HR NMIBC) and muscle-invasive bladder cancer (MIBC) are limited, highlighting a need for clinically effective, accessible, and better-tolerated alternatives. In this review we examine the clinical development program of TAR-200, a novel targeted releasing system designed to provide sustained intravesical delivery of gemcitabine to address the needs of patients with NMIBC and of those with MIBC. We describe the concept and design of TAR-200 and the clinical development of this gemcitabine intravesical system in the SunRISe portfolio of studies. This includes 3 phase I studies evaluating the safety and initial tumor activity of TAR-200 and 5 phase II/III studies assessing the efficacy and safety of TAR-200, with or without systemic cetrelimab, as a treatment option for patients with HR NMIBC (bacillus Calmette-Guérin naive [papillary and carcinoma in situ] and MIBC (neoadjuvant and patients ineligible for or refusing radical cystectomy). Pharmacokinetics demonstrate intravesical gemcitabine delivery via TAR-200 over a prolonged period without detectable plasma levels. Phase I studies showed that TAR-200 is well tolerated, with preliminary antitumor activity in intermediate-risk NMIBC and MIBC. Preliminary data from the phase IIb SunRISe-1 study demonstrate that TAR-200 monotherapy is safe and effective in patients with bacillus Calmette-Guérin-unresponsive high-risk NMIBC. TAR-200 represents an innovative approach to the local treatment of bladder cancer., Competing Interests: Declaration of competing interest Siamak Daneshmand has received grants/research funding and travel support from Photocure; consulting/advisory fees from Photocure, Pacific Edge, Ferring, Bristol Myers Squibb, Janssen, Johnson & Johnson, Protara, Urogen, Pfizer, CG Oncology, Vesica Health, and ImmunityBio; and has stock/other ownership interests in Taris. Ashish M. Kamat has served as a consultant for Abbott Molecular, Arquer, ArTara, Asieris, Astra Zeneca, BioClin Therapeutics, Biological Dynamics, Bristol Myers Squibb, Cepheid, Cold Genesys, Eisai, Engene, Ferring, FerGene, Imagin, Incyte DSMB, Janssen, MDxHealth, Medac, Merck, Pfizer, Photocure, ProTara, Roviant, Seattle Genetics, Sessen Bio, Theralase, TMC Innovation, US Biotest, and Urogen; and has contracted research with Adolor, Bristol Myers Squibb, FerGene, FKD Industries, Heat Biologics, Merck, Photocure, and SWOG/NIH and patents with CyPRIT (Cytokine Predictors of Response to Intravesical Therapy) Joint with UT MD Anderson Cancer Center. Neal D. Shore has received grants/research funding from AbbVie, Advantagene, Amgen, Aragon Pharmaceuticals, Astellas, AstraZeneca, Bayer, Boston Scientific, Bristol Myers Squibb, CG Oncology, Clovis Oncology, Dendreon, DisperSol, Endocyte, Exact Imaging, Exelixis, Ferring, FKD Therapies, Forma Therapeutics, Foundation Medicine, Genentech, Guardant Health, InVitae, Istari Oncology, Janssen, Jiansu Yahong Meditech, MDxHealth, Medivation, Merck, MT Group, Myovant Sciences, Myriad, Novartis, Nymox, OncoCellMDx, ORIC Pharmaceuticals, Pacific Edge, Palette Life Sciences, Plexxikon, Pfizer, Point Biopharma, Propella Therapeutics, RhoVac, Sanofi, Seattle Genetics, Sesen Bio, Steba Biotech, Theralase, Tolmar, Urogen, Urotronic, US Biotest, Vaxiion, Veru, and Zenflow; consulting/advisory fees from AbbVie, Amgen, Astellas, AstraZeneca, Bayer, Boston Scientific, Bristol Myers Squibb, CG Oncology, Clarity Pharmaceuticals, Clovis Oncology, Dendreon, Exact Imaging, FerGene, Ferring, Foundation Medicine, Genesis Cancer Care, Genzyme, InVitae, Janssen, Lantheus, Lilly, MDxHealth, Medivation, Myovant Sciences, Myriad Genetics, Nymox, Pacific Edge Biotechnology, Peerview, Pfizer, Phosphorus, Photocure, Propella Therapeutics, Sanofi, Sema4, Sesen Bio, Specialty Networks, Telix Pharmaceuticals, Tempus, Tolmar, Urogen, and Vaxiion; and honoraria/speaker fees from Astellas, AstraZeneca, Bayer, Clovis Oncology, Dendreon, Foundation Medicine, Guardant Health, Janssen, Merck, and Pfizer. Joshua J. Meeks has received honoraria from Astellas Pharma, AstraZeneca, Imvax, Incyte, Janssen, Merck, Pfirzer, Prokarium, Urogen Pharma; research funding from Epizyme and Merck Sharp & Dohme; has patents, royalties, or other intellectual property (institutional) : NMIBC classifier, TCGA classifier; and has a relationship (undefined) with Olympus. Matthew D. Galsky has served as a consultant for Abbvie Inc, Alligator, Astellas Pharma, AstraZeneca, Basilea, Bicycle, Bristol Myers Squibb, Curis, Dracen, Dragonfly, EMD Serono, FujiFilm Holdings America Corporation, Genentech, Gilead Sciences, GlaxoSmithKline, Incyte Corp, Janssen Biotech, Merck, Numab, Pfizer, Rappta Therapeutics, Seattle Genetics, and Veracyte. Joseph M. Jacob has received consulting or advisory fees from Janssen, Photocure, Urogen, and Verity Pharmaceuticals. Michiel S. van der Heijden has served as a consultant (paid to institution) for Astellas Pharma, AstraZeneca, Bristol Myers Squibb, Janssen, MSD Oncology, Pfizer, Roche, and Seagen; and has received institutional research funding from 4SC, AstraZeneca, Bristol Myers Squibb, and Roche. Stephen B. Williams has no disclosures to report. Thomas Powles has received consulting fees from Astellas, AstraZeneca, Bristol Myers Squibb, Eisai, Exelixis, Incyte, Ipsen, Johnson & Johnson, Mash Up Ltd, Merck Serono, MSD, Novartis, Pfizer, Roche, and Seattle Genetics; grant support from Astellas, AstraZeneca, Bristol Myers Squibb, Eisai, Exelixis, Ipsen, Johnson & Johnson, Merck Serono, MSD, Novartis, Pfizer, Seattle Genetics, and Roche; and support for attending meetings and/or travel from AstraZeneca, Ipsen, MSD, Pfizer, and Roche. Sam S. Chang has served as a consultant for ImmunityBio, Janssen, Merck, Pfizer, and Uro Urogen; Vanderbilt University Medical Center is a trial site for TAR-200. James W. F. Catto has received honoraria from AstraZeneca, Bristol Myers Squibb, and Roche; consultant fees from AstraZeneca, Bristol Myers Squibb, Ferring, Gilead Sciences, Ipsen, Janssen, QED Therapeutics, Photocure, Roche, and Steba Biotech; and institutional grants from Roche; has participated in a data safety monitoring board or advisory board for Bristol Myers Squibb; and is an unpaid trustee for Fight Bladder Cancer UK and Weston Park Cancer Charity. Sarah P. Psutka has had a consulting or advisory role with Janssen, Medtronic, and Merck; and has received honoraria from AstraZeneca. Félix Guerrero-Ramos has received grants/research funding from Combat Medical; consulting/advisory fees from AstraZeneca, Bristol Myers Squibb, Combat Medical, and Janssen; honoraria/speaker fees from Combat Medical, Janssen, and Pfizer; and travel support from Ipsen and Pfizer. Evanguelos Xylinas has received grants/research funding from Ferring; and consulting/advisory fees from Boston Scientific, Ipsen, Janssen Oncology, MSD, Astellas, AstraZeneca, and Bristol Myers Squibb. Makito Miyake has no disclosures to report. Giuseppe Simone has no disclosures to report. Karen Daniel, Hussein Sweiti, and Christopher Cutie are employees of Janssen Research & Development and may have stock/stock options with Johnson & Johnson. Andrea Necchi has served as a consultant or advisor for Astellas, AstraZeneca, Bayer, Bristol Myers Squibb, Incyte, Janssen, Merck, Pfizer, and Roche; and has received institutional grant support from Bristol Myers Squibb, Gilead Sciences, and Merck., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)