SBRT Combined With Pembrolizumab Improves Survival in Metastatic Urothelial Carcinoma

Combining pembrolizumab with radiotherapy significantly enhances overall survival (OS) in patients with metastatic urothelial carcinoma (mUC) who have progressed after platinum-based chemotherapy, according to results from the ARON-2 real-world study published in Scientific Reports.

“The ARON-2 study (NCT05290038) was designed to globally share real-world data on the efficacy of pembrolizumab in patients who had recurred or progressed after platinum-based chemotherapy,” wrote Mimma Rizzo, Medical Oncology Unit, Azienda Ospedaliero Universitaria Consorziale Policlinico Di Bari, Piazza Giulio Cesare in Bari, Italy, and coauthors. “In this sub-analysis, we evaluated the impact of palliative or stereotactic radiation therapy in this population,” they added.

In the retrospective study of 837 patients with mUC, the researchers found that those receiving SBRT alongside pembrolizumab had a significantly longer median OS of 16 months, compared with 6.8 months for those who received conventional radiotherapy (CRT) and 10.2 months for those who did not receive radiotherapy. SBRT also improved the 1-year OS rate, with 61% of patients surviving at one year, compared with 34% in the CRT group and 47% in the no-radiotherapy group. A higher progression-free survival rate was also in the SBRT group, with 48% of patients experiencing disease-free survival at one year.

SBRT was associated with better outcomes in patients with lower urinary tract carcinoma (LTUC) and lymph node metastases. Among LTUC patients, those treated with SBRT had a median OS of 15.8 months, compared with 7.1 months for CRT-treated patients. In patients with lymph node metastases, the median OS reached 30 months with SBRT, a significant improvement over CRT (14.6 months) and no radiotherapy (10 months).

“Our study showed that the use of SBRT may play a role in a subset of patients to increase the control of the disease and maybe increase the overall survival,” concluded the study authors.

Reference

Rizzo M, Soares A, Grande E, et al. Radiotherapy plus pembrolizumab for advanced urothelial carcinoma: results from the ARON-2 real-world study. Sci Rep. 2024;14(1):19802. doi:10.1038/s41598-024-70182-3