Pretreatment and on-treatment ctDNA and tissue biomarkers predict recurrence in patients with stage IIIB–D/IV melanoma treated with adjuvant immunotherapy: CheckMate 915
Georgina V. Long, Hao Tang, Keyur Desai, Sheen Wang, Michele Del Vecchio, James Larkin, Corey Ritchings, Shu‐Pang Huang, Jonathan Baden, David Balli, Han Chang, Gina Fusaro, Daniel J. Tenney, Sonia Dolfi, Jeffrey S. Weber
Abstract
PURPOSE: CheckMate 915 (NCT03068455) compared adjuvant nivolumab monotherapy versus combination nivolumab+ipilimumab in patients with resected stage III/IV melanoma. This exploratory analysis was performed to identify biomarkers that correlate with benefit from adjuvant immunotherapy. PATIENTS AND METHODS: 1,844 patients received nivolumab 480 mg every 4 weeks or nivolumab 240 mg every 2 weeks with ipilimumab 1 mg/kg every 6 weeks. Tumor and peripheral biomarkers were evaluated, including tumor-informed circulating tumor DNA (ctDNA) at postresection baseline and on-treatment, for their association with recurrence-free survival and distant metastases-free survival. RESULTS: Biomarker analyses were conducted in 60-96% of the intention-to-treat population. ctDNA positivity at baseline (seen in 16.2% of patients) and on-treatment was associated with higher risk of recurrence than ctDNA negativity (HR, 1.97; 95% CI, 1.57 to 2.46), with a high specificity (87%) and modest sensitivity (39%). ctDNA status, tumor mutational burden (TMB) status (TMB < or ≥350 mutations/tumor) and interferon gamma-RNA signature score (< or ≥median) evaluated together, as well as ctDNA status with tumor CD8 or cell programmed death ligand 1 expression, were more predictive of survival than ctDNA alone. Tumor bulk RNA-seq expression patterns identified gene expression at baseline associated with recurrence. CONCLUSIONS: This study represents the largest assessment of ctDNA and other baseline tumor and peripheral biomarkers for predicting recurrence-free survival in patients with resected melanoma receiving adjuvant immunotherapy. ctDNA alone and in combination with more established biomarkers predicted recurrence-free and distant metastasis-free survival and has potential utility for assessing and monitoring the risk of recurrence in patients with resected melanoma treated with immunotherapy in the adjuvant setting. TRIAL REGISTRATION NUMBER: NCT03068455.