Efficacy and safety of pembrolizumab for older patients with chemoresistant urothelial carcinoma assessed using propensity score matching

Background: We used real-world and large-scale data to assess the clinical efficacy and safety of pembrolizumab in older patients with advanced urothelial carcinoma (UC). Methods: A total of 608 patients who received pembrolizumab for the treatment of chemoresistant UC were retrospectively analyzed. All patients were histologically diagnosed with pure UC. Using propensity score matching (PSM) (ECOG performance status, site of metastasis, hemoglobin level and neutrophil-to-lymphocyte ratio, 1:1 matching), the overall survival (OS) and adverse events (AEs) of patients <75 and ≥75 years old were compared. Results: The median follow-up (IQR) period was 16.1 (9.9–20.5) months. After PSM, there were 215 patients each in the aged <75 years and aged ≥75-year-old groups. The median OS of all patients was estimated to be 10.4 months (95% confidence interval [CI] = 8.8–12.1). After PSM, the median OS was 7.8 months (95% CI = 5.2–10.4) in the <75-year-old group and 10.4 months (95% CI = 7.3–13.5) in the ≥75-year-old group (P = 0.186). Any-grade AEs were more frequently reported in the ≥75-year-old group in comparison to the age <75-year-old group (55.3% vs. 41.9%, P = 0.007), whereas there was no significant difference between the two groups in the incidence of grade ≥3 AEs (10.2% vs. 12.6%, P = 0.544). The objective response rate, defined as complete remission or a partial response, was 22.8% in the <75-year-old group and 25.1% in the ≥75-year-old group (P = 0.651). Conclusions: The present study demonstrates that age does not affect the efficacy and safety of pembrolizumab treatment for advanced chemoresistant UC. Pembrolizumab treatment should not be avoided based on chronological age; however, close monitoring for the development of treatment-related AE should be considered for older patients.