Gemcitabine-Based Bladder Preservation in BCG-Unresponsive High-Risk NMIBC: Evidence, Limitations, and Clinical Positioning

Bacillus Calmette–Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) is a high-risk disease state for which early radical cystectomy remains the guideline-supported oncologic reference in surgically fit patients. Bladder-sparing therapy is necessary for patients ineligible for or declining cystectomy, but it is a preference-sensitive trade-off rather than an equivalent alternative: failure may permit high-grade recurrence, progression, and loss of a curative window. This targeted narrative review synthesizes the evidence for intravesical gemcitabine monotherapy, sequential gemcitabine–docetaxel, and the sustained-release gemcitabine intravesical system TAR-200/INLEXZO, updated through 4 August 2026. Because the review is not systematic and the evidence is dominated by single-arm and retrospective studies, cross-study comparisons are descriptive and establish neither superiority nor equivalence; many gemcitabine studies enrolled mixed BCG-failure cohorts that do not satisfy the contemporary definition. Gemcitabine monotherapy is active but shows declining disease control over time. Sequential gemcitabine–docetaxel has accumulated substantial multicenter observational experience, yet a 2026 retrospective comparison did not demonstrate improved high-grade recurrence-free survival over gemcitabine alone. TAR-200 achieved a centrally confirmed complete response at any time in 82.4% of patients, with a median duration of response of 25.8 months in the single-arm phase 2b SunRISe-1 study and is approved in the United States as INLEXZO for BCG-unresponsive carcinoma in situ with or without papillary tumors; no approved agent holds a papillary-only indication. Comparative patient-reported outcome evidence remains limited, and molecular markers, urinary tumor DNA and transcriptomic subtypes remain investigational rather than validated selection tools. Bladder-sparing treatment should therefore be phenotype- and label-aware, time-limited, and coupled to intensive surveillance with predefined triggers for cystectomy.