Partial tumor irradiation plus pembrolizumab in treating large advanced solid tumor metastases

Mark C Korpics; Benjamin E Onderdonk; Rebekah E Dadey; Jared H Hara; Lilit Karapetyan; Yuanyuan Zha; Theodore G Karrison; Adam C Olson; Gini F Fleming; Ralph R Weichselbaum; Riyue Bao; Steven J Chmura; Jason J Luke

doi:10.1172/JCI162260

Partial tumor irradiation plus pembrolizumab in treating large advanced solid tumor metastases

J Clin Invest. 2023 May 15;133(10):e162260. doi: 10.1172/JCI162260.

Authors

Affiliations

¹ Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, USA.
² UPMC Hillman Cancer Center and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
³ Department of Cutaneous Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA.
⁴ Human Immunological Monitoring Core, Biological Sciences Division.
⁵ Department of Public Health Sciences.
⁶ Department of Medicine, Section of Hematology/Oncology, and.
⁷ Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois, USA.

Abstract

BACKGROUNDWe previously demonstrated the safety of stereotactic body radiotherapy followed by pembrolizumab (SBRT+P) in patients with advanced solid tumors. This phase I clinical trial was expanded to study the safety of partial tumor irradiation (partial-Rx). We assessed irradiated local failure (LF) and clinical outcomes with correlations to biomarkers including CD8+ T cell radiomics score (RS) and circulating cytokines.METHODSPatients received SBRT to 2-4 metastases and pembrolizumab for up to 7 days after SBRT. Tumors measuring up to 65 cc received the full radiation dose (complete-Rx), whereas tumors measuring more than 65 cc received partial-Rx. Landmark analysis was used to assess the relationship between tumor response and overall survival (OS). Multivariable analysis was performed for RS and circulating cytokines.RESULTSIn the combined (expansion plus original) cohort, 97 patients (219 metastases) were analyzed and received SBRT+P. Forty-six (47%) patients received at least 1 partial-Rx treatment. There were 7 (7.2%)dose-limiting toxicities (DLTs). 1-year LF was 7.6% overall, and 13.3% and 5.4% for partial-Rx and complete-Rx tumors, respectively (HR 2.32, 95% CI 0.90-5.97, P = 0.08). The overall, unirradiated, and irradiated objective response rates were 22%, 12%, and 34%, respectively. Irradiated tumor response to SBRT+P was associated with prolonged OS; 1-year OS was 71% (responders), 42% (mixed-responders), and 0% (nonresponders) (P < 0.01). High-RS was significantly associated with improved LF, progression-free survival (PFS), and OS. Elevated circulating IL-8 was independently associated with inferior PFS and OS.CONCLUSIONSBRT+P is safe in patients with large, advanced solid tumors. Additional studies are warranted to assess noninferiority of complete versus partial irradiation of tumors in the setting of immunotherapy.TRIAL REGISTRATIONClinicaltrials.gov NCT02608385FUNDINGMerck Investigator Studies Program; Hillman Fellows for Innovative Cancer Research Program; NIH grants UM1CA186690-06, P50CA254865-01A1, P30CA047904-32, and R01DE031729-01A1.

Keywords: Cancer; Clinical Trials; Immunotherapy; Oncology; Radiation therapy.

Publication types

Clinical Trial, Phase I
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Antibodies, Monoclonal, Humanized / adverse effects
Cytokines
Humans
Neoplasms* / drug therapy
Neoplasms* / radiotherapy
Radiosurgery* / adverse effects

Substances

Antibodies, Monoclonal, Humanized
Cytokines
pembrolizumab

Associated data

ClinicalTrials.gov/NCT02608385

Grants and funding

Merck Investigator Studies Program supported drug supply and grant funding for the study as an initial award to Dr. Luke and subsequently to Dr. Chmura