Gemcitabine as first-line therapy for high-grade non-muscle invasive bladder cancer: results from a tertiary center in the contemporary BCG-shortage era

Background: To evaluate the safety profile and efficacy of intravesical gemcitabine as first-line adjuvant therapy for non-muscle invasive bladder cancer (NMIBC) in the setting of ongoing Bacillus Calmette-Guérin (BCG) shortage. Methods: We performed an institutional, retrospective review of patients treated with intravesical gemcitabine induction and maintenance therapy from March 2019 to October 2021. Patients with intermediate or high-risk NMIBC who were BCG-naïve or experienced a high-grade (HG) recurrence after 12 months since the last dose of BCG were included in the analysis. The primary endpoint was complete response (CR) rate at the 3-month visit. Secondary endpoints were recurrence-free survival (RFS) and assessment of adverse events. Results: A total of 33 patients were included. All had HG disease and 28 (84.8%) were BCG-naive. The median follow-up was 21.4 months (range, 4.1-39.4). Tumor stages were cTa in 39.4%, cT1 in 54.5%, and cTis in 6.1% of patients. Most patients (90.9%) were in the AUA high-risk category. The 3-month CR was 84.8%. Among patients who achieved CR with adequate follow-up, 86.9% (20/23) remained disease-free at 6 months. The 6-month and 12-month RFS were 87.2% and 76.5%, respectively. The estimated median RFS was not reached. Approximately 78.8% of patients were able to complete full induction. Common adverse events (incidence ≥10%) included dysuria and fatigue/myalgia. Conclusions: Intravesical gemcitabine for intermediate and high-risk NMIBC in areas where BCG supply is limited was safe and feasible at short-term follow-up. Larger prospective studies are needed to better ascertain the oncologic efficacy of gemcitabine.