Immunosuppressive monocytes are enriched in hepatocellular carcinoma patients with liver dysfunction in a phase II trial of combination sorafenib and nivolumab [scRNA-Seq]
Background and aims: Immune checkpoint inhibition (ICI) and anti-angiogenic therapies are active in hepatocellular carcinoma (HCC), although patients with impaired hepatic function have worse outcomes.   Methods: We conducted a multi-center, open-label clinical trial to assess the safety and efficacy of the multikinase inhibitor, sorafenib, combined with nivolumab, in patients with advanced or unresectable HCC and varying liver function. In Part 1, we investigated the primary endpoint of the maximum-tolerated dose (MTD) of the combination in patients with Child-Pugh A or B7 HCC. In Part 2, we enrolled patients with Child-Pugh B HCC with the primary endpoint of grade >/=3 treatment-related adverse events (TRAE) incidence. Secondary and exploratory endpoints included immunologic biomarkers.   Results: Overall, 25 patients were consented and 16 eligible patients enrolled. In Part 1, dose-limiting toxicity occurred in 1 of 6 patients in Dose Level -1, and 2 of 5 patients in Dose Level 1; Dose Level -1 was determined to be the MTD. In total, 69% of patients experienced a Grade >/=3 TRAE, with similar distribution for patients with Child-Pugh A and B liver function (70%, 95% CI: 0.35, 0.93 vs 66.7%, 95% CI: 0.22, 0.96). The objective response rate was 6%. We found that patients with Child-Pugh B harbored more circulating suppressive monocytes at baseline.  Conclusions: While the combination of sorafenib and nivolumab demonstrated acceptable safety at the MTD in both Child-Pugh subgroups, the objective response rate was below the pre-specified threshold to be declared worthy of further exploration. A distinct immune cell profile in Child-Pugh B patients warrants further exploration to better define mechanisms of resistance and potential therapeutic targets in this population with unmet clinical need. Overall design: Tumor samples were collected from patients undergoing standard-of-care resections. Samples were digested in RPMI containing Collagenase I & II (0.1 mg/ml, Sigma Aldrich) and DNAse I, minced, and digested for one hour using the GentleMACS system (Miltenyi Biotec). Isolation of live and CD45+ cells was performed using MACS LS columns (Miltenyi Biotec). The samples were then used immediately for single cell RNA sequencing. Droplet-based single cell RNA sequencing (scRNAseq) was performed using the 10x Genomics 5' Reagent Kits version 1, according to manufacturer instructions. All sequencing was performed on an Illumina NovaSeq S4 sequencer with paired end 200 base pair read length and 25,000 reads per droplet for gene expression.