Alterations in DNA Damage Response and Repair Genes as Potential Marker of Clinical Benefit From PD-1/PD-L1 Blockade in Advanced Urothelial Cancers

Abstract

Purpose Alterations in DNA damage response and repair (DDR) genes are associated with increased mutation load and improved clinical outcomes in platinum-treated metastatic urothelial carcinoma. We examined the relationship between DDR alterations and response to PD-1/PD-L1 blockade. Methods Detailed demographic, treatment response, and long-term outcome data were collected on patients with metastatic urothelial carcinoma treated with atezolizumab or nivolumab who had targeted exon sequencing performed on pre-immunotherapy tumor specimens. Presence of DDR alterations was correlated with best objective response per Response Evaluation Criteria in Solid Tumors (RECIST) and progression-free and overall survival. Results Sixty patients with urothelial cancer enrolled in prospective trials of anti-PD-1/PD-L1 antibodies met inclusion criteria. Any DDR and known or likely deleterious DDR mutations were identified in 28 (47%) and 15 (25%) patients, respectively. The presence of any DDR alteration was associated with a higher response rate (67.9% v 18.8%; P < .001). A higher response rate was observed in patients whose tumors harbored known or likely deleterious DDR alterations (80%) compared with DDR alterations of unknown significance (54%) and in those whose tumors were wild-type for DDR genes (19%; P < .001). The correlation remained significant in multivariable analysis that included presence of visceral metastases. DDR alterations also were associated with longer progression-free and overall survival. Conclusion DDR alterations are independently associated with response to PD-1/PD-L1 blockade in patients with metastatic urothelial carcinoma. These observations warrant additional study, including prospective validation and exploration of the interaction between tumor DDR alteration and other tumor/host biomarkers of immunotherapy response.

Trial registration: ClinicalTrials.gov NCT02553642 NCT01928394 NCT02108652.

Figures

Fig 1.

Flow diagram of the study. CPI, checkpoint inhibitor; MSK-IMPACT, Memorial Sloan Kettering Integrated Molecular Profiling of Actionable Cancer Targets.

Fig 2.

Waterfall plot of observed best responses from anti-PD-1/PD-L1 checkpoint inhibitors. DDR, DNA damage response and repair.

Fig 3.

(A) Progression-free survival by DNA damage response and repair (DDR) alteration status. (B) Overall survival by DDR alteration status. delDDRmt, deleterious DDR alterations; DDRmt, nondeleterious DDR alterations; DDRwt, nondetectable DDR gene alterations; NR, not reached.