Clinical variables associated with immune checkpoint inhibitor outcomes in patients with metastatic urothelial carcinoma

BackgroundAnti-PD-1/L1 immune checkpoint inhibitors (ICI) are indicated for metastatic urothelial cancer (mUC), however, only a minority of patients will derive therapeutic benefit. Strong predictive and prognostic factors are lacking. We investigated if clinical variables were associated with ICI outcomes in mUC. MethodsWe performed a multi-center retrospective cohort study of patients with mUC who received anti-PD-1/L1 ICI for metastatic disease between 2016-2021 at 3 Canadian cancer centres. Clinical characteristics, including demographics, BMI, metastatic sites, neutrophil-to-lymphocyte ratio (NLR), objective response, and survival were abstracted from chart review. ICI treatment response was determined by investigator assessment of clinical and radiologic parameters. Fishers exact test was used to assess differences in response rates between groups. Log rank and Cox regression models were used to assess overall survival (OS). ResultsWe identified 135 patients with mUC who received anti-PD1/L1 ICI. A BMI [&ge;] 25 was significantly correlated to a higher overall response rate (ORR) to ICI (45.4% vs 16.3%, P = 0.020). After a median follow-up of 14.5 months, patients with BMI [&ge;] 30 experienced significant longer median OS 24.8 months vs. 14.4 months for 25 [&le;] BMI < 30 and 8.5 months for BMI < 25 (P = 0.012). The ORR was significantly less in the presence of bone metastasis 16% vs 41% P = 0.006, and liver metastasis 16% vs 39% P = 0.013. Conversely, the presence of metastatic lymph nodes was significantly correlated with higher ORR 40% vs 20% P = 0.032. The median OS for patients with bone metastasis was 7.3 months vs 18 months in the absence of bone metastasis (P < 0.001). Patients with liver metastasis had a median OS of 8.6 months compared to 15 months for those without liver metastasis (P = 0.006). For lung metastasis, median OS was 8.7 months compared to 17.3 months (P = 0.004). No statistical difference was shown in OS for lymph nodes metastasis, with a median of 13.5 months vs 12.7 months (P = 0.175). Patients with NLR [&ge;] 4 had a significant worse OS (8.2 months vs 17.7 months P = 0.0001). In multivariate analysis, BMI [&ge;] 30, bone metastasis and NLR [&ge;] 4 were independent prognosis factor for OS. ConclusionsOur data identified BMI and bone metastasis as novel, independent, clinical biomarkers that were strongly and independently associated with ICI response and survival in mUC. External validation of these data in a larger study and investigations into the mechanisms behind these findings are warranted.