Changes in Real-World Outcomes in Patients with Metastatic Renal Cell Carcinoma from the Molecular-Targeted Therapy Era to the Immune Checkpoint Inhibitor Era

Background Knowledge of changes in the outcome in patients with metastatic renal cell carcinoma from the molecular-targeted therapy era to the immune checkpoint inhibitor (ICI) era remains limited in the real-world setting. Objectives We aimed to clarify outcome changes from the previous molecular-targeted therapy era to the current ICI era in patients with metastatic renal cell carcinoma using multi-institution real-world data. Methods We retrospectively evaluated 415 patients with metastatic renal cell carcinoma who received first-line systemic therapy at five Japanese institutions between January 2008 and August 2021. We divided the patients into two groups based on the treatment era: molecular-targeted therapy era (January 2008-August 2018) and ICI era (September 2018-August 2021). According to the era, progression-free survival, overall survival, and objective response rate from first-line systemic therapy were compared. Results Overall, 304 (73.3%) and 111 (26.7%) patients were categorized into the molecular-targeted therapy and ICI eras, respectively. The proportion of patients without prior nephrectomy (p = 0.0030) or those with low Karnofsky Performance Status scores [<= 70] (p = 0.0258) were significantly higher in the ICI era group. The patients in the ICI era group had significantly longer overall survival (median: not reached vs 23.2 months, p = 0.0001) and a higher objective response rate (47.8% vs 24.7%, p < 0.0001) than those in the molecular-targeted therapy era group, and progression-free survival tended to be longer in the ICI era group (median: 13.3 vs 8.75 months, p = 0.0579). Multivariate analysis further showed that the treatment era (ICI vs molecular-targeted therapy) was an independent factor for overall survival and objective response (both, p < 0.0001). Conclusions The present multi-institution real-world data showed the improved outcome of previously untreated patients with metastatic renal cell carcinoma in the ICI era group compared with that in the molecular-targeted therapy era group. These findings strongly encourage the use of ICI-based treatment for patients with metastatic renal cell carcinoma in the real-world setting. Further studies with extended follow-up periods are needed to confirm our findings.