The Journal of Clinical Investigation (JCI)Partial Tumor Irradiation plus Pembrolizumab in Treating Large Advanced Solid Tumor Metastases

This study presents findings from a Phase I clinical trial examining the use of Stereotactic Body Radiotherapy (SBRT) combined with pembrolizumab (P) in treating advanced solid tumors, with a focus on the safety and effectiveness of partial tumor irradiation. The trial involved 97 patients, 47% of whom received at least one partial radiation treatment. The overall one-year local failure (LF) rate was 7.6%, and the results suggest an association between tumor response to SBRT+P and improved overall survival (OS), particularly for irradiated tumors.

The trial also explored the role of biomarkers, finding that a high Radiomics Score (RS), based largely on CD8+ T cell levels, was linked to better LF, progression-free survival (PFS), and OS. Conversely, increased levels of circulating cytokine IL-8 were associated with worse PFS and OS. The study concluded that SBRT+P is safe for patients with large, advanced solid tumors and recommended further research to compare the effectiveness of complete versus partial tumor irradiation in the context of immunotherapy.