Evaluation of potential biomarkers for lenvatinib plus pembrolizumab among patients with advanced endometrial cancer: results from Study 111/KEYNOTE-146

Abstract

Background: Lenvatinib plus pembrolizumab demonstrated clinically meaningful benefit in patients with previously treated advanced endometrial carcinoma in Study 111/KEYNOTE-146 (NCT02501096). In these exploratory analyses from this study, we evaluated the associations between clinical outcomes and gene expression signature scores and descriptively summarized response in biomarker subpopulations defined by tumor mutational burden (TMB) and DNA variants for individual genes of interest.

Methods: Patients with histologically confirmed metastatic endometrial carcinoma received oral lenvatinib 20 mg once daily plus intravenous pembrolizumab 200 mg every 3 weeks for 35 cycles. Archived formalin-fixed paraffin-embedded tissue was obtained from all patients. T-cell-inflamed gene expression profile (Tcell_infGEP) and 11 other gene signatures were evaluated by RNA sequencing. TMB, hotspot mutations in PIK3CA (oncogene), and deleterious mutations in PTEN and TP53 (tumor suppressor genes) were evaluated by whole-exome sequencing (WES).

Results: 93 and 79 patients were included in the RNA-sequencing-evaluable and WES-evaluable populations, respectively. No statistically significant associations were observed between any of the RNA-sequencing signature scores and objective response rate or progression-free survival. Area under the receiver operating characteristic curve values for response ranged from 0.39 to 0.54; all 95% CIs included 0.50. Responses were seen regardless of TMB (≥175 or <175 mutations/exome) and mutation status. There were no correlations between Tcell_infGEP and TMB, Tcell_infGEP and microvessel density (MVD), or MVD and TMB.

Conclusions: This analysis demonstrated efficacy for lenvatinib plus pembrolizumab regardless of biomarker status. Results from this study do not support clinical utility of the evaluated biomarkers. Further investigation of biomarkers for this regimen is warranted.

Trial registration number: NCT02501096.

Keywords: Immunotherapy; Tumor Biomarkers.

Figure 1

RNA-sequencing signature box plots by responder status for all patients. EMT, epithelial-to-mesenchymal transition; gMDSC, granulocytic myeloid-derived suppressor cell; mMDSC, monocytic myeloid-derived suppressor cell; MVD, microvessel density; Tcell_infGEP, T-cell−inflamed gene expression profile; TGF, transforming growth factor.

Figure 2

RNA-sequencing signature AUROC curves for response for all patients. For AUROC curves, 1 minus specificity (x axis) is the false-positive rate and sensitivity (y axis) is the true-positive rate. AUROC, area under the receiver operating characteristic; EMT, epithelial-to-mesenchymal transition; gMDSC, granulocytic myeloid-derived suppressor cell; mMDSC, monocytic myeloid-derived suppressor cell; MVD, microvessel density; Tcell_infGEP, T-cell−inflamed gene expression profile; TGF, transforming growth factor.

Figure 3

TMB box plots by responder status and TMB AUROC curves for response for all patients (A) and the MSS group (B). For AUROC curves, 1 minus specificity (x axis) is the false-positive rate and sensitivity (y axis) is the true-positive rate. AUROC, area under the receiver operating characteristic; MSS, microsatellite stable; TMB, tumor mutational burden.

Figure 4

Scatterplots of Tcell_infGEP versus TMB in all patients (left panel) and the MSS group (right panel) (A), Tcell_infGEP versus MVD in all patients (B), and MVD versus TMB in all patients (C). Dotted vertical/horizontal lines represent the biomarker cut-offs. MSS, microsatellite stable; MVD, microvessel density; Tcell_infGEP, T-cell−inflamed gene expression profile; TMB, tumor mutational burden.