Metabolic activity by 18 F–FDG-PET/CT is predictive of early response after nivolumab in previously treated NSCLC

Abstract

Background

Nivolumab, an anti-programmed death-1 (PD-1) antibody, is administered in patients with previously treated non-small cell lung cancer. However, little is known about the established biomarker predicting the efficacy of nivolumab. Here, we conducted a preliminary study to investigate whether ¹⁸F–FDG-PET/CT could predict the therapeutic response of nivolumab at the early phase.

Methods

Twenty-four patients were enrolled in this study. ¹⁸F–FDG-PET/CT was carried out before and 1 month after nivolumab therapy. SUV_max, metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were calculated. Immunohistochemical analysis of PD-L1 expression and tumour-infiltrating lymphocytes was conducted.

Results

Among all patients, a partial metabolic response to nivolumab was observed in 29% on SUV_max, 25% on MTV, and 33% on TLG, whereas seven (29%) patients achieved a partial response (PR) based on RECIST v1.1. The predictive probability of PR (100% vs. 29%, p = 0.021) and progressive disease (100% vs. 22.2%, p = 0.002) at 1 month after nivolumab initiation was significantly higher in ¹⁸F–FDG on PET/CT than in CT scans. Multivariate analysis confirmed that ¹⁸F–FDG uptake after administration of nivolumab was an independent prognostic factor. PD-L1 expression and nivolumab plasma concentration could not precisely predict the early therapeutic efficacy of nivolumab.

Conclusion

Metabolic response by ¹⁸F–FDG was effective in predicting efficacy and survival at 1 month after nivolumab treatment.

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