Immunologic Correlates of Pathologic Complete Response to Preoperative Immunotherapy in Hepatocellular Carcinoma

Abstract

In hepatocellular carcinoma (HCC), surgical resection is associated with high recurrence rate, and no effective adjuvant therapy currently exists. We initiated a pilot randomized trial of perioperative immunotherapy with nivolumab and ipilimumab for resectable HCC. Here, we provide an illustrative report of a case that achieved a complete response and report immunologic correlates of this complete pathologic response to perioperative immunotherapy. Clinical response was correlated with an increase in CD8⁺ T-cell infiltration, with an increase in two effector T-cell clusters. This study is ongoing, and the final results may contribute to a paradigm shift in the perioperative treatment of HCC, leading to the incorporation of immunotherapy in the curative setting.

Figure 1.

Pre- and posttreatment CT scans of the responding patient. Arterial phase CT scans taken pretreatment (A) and posttreatment (B) after one dose of nivolumab plus ipilimumab, followed by one dose of single-agent nivolumab. The tumors initially showed arterial enhancement consistent with HCC but lost this enhancement after treatment.

Figure 2.

Clinical trial schema and IHC analysis showing favorable immune infiltration posttreatment in the responder. A, Clinical trial NCT03222076 arm A schema indicating when samples were collected. The dose of nivolumab (indicated in red) was not given due to hepatotoxicity. Time points for blood and tumor tissue collection and the assays performed are indicated by red and blue arrows. q2w, every 2 weeks; q6w, every 6 weeks; q12w, every 12 weeks. B and C, IHC analysis of pre- and posttreatment hepatic tissues from the HCC patient. B, IHC analysis of total T cells (CD3⁺), CD8⁺ T cells, CD45RO-expressing cells, granzyme B (Gr-B)-expressing cells, FoxP3-expressing cells (regulatory T cells), and PD-L1-expressing immune cells (PD-L1 Imm). Mean density + SD is shown for five different regions in the liver at each timepoint. C, Representative IHC images of CD3⁺ and CD8⁺ T cells pre- and posttreatment (after resection) from one representative region is shown at a maginification of 20×.

Figure 3.

Mass cytometry (CyTOF) analysis of tissues and blood from the responder. Phenograph analysis was performed to determine the frequencies of each cluster in the total CD45⁺ population. A, tSNE plot showing the different clusters identified within each cell subpopulation. Clusters 5, 12 (CD8⁺ T-cell effectors), and 8 (regulatory T cell) are shown. NK, natural killer. B, Heatmap showing marker expression and frequencies of the different clusters identified. Clusters 5, 12, and 8 are marked by red boxes. C, Frequency of activated CD8⁺ T cells (cluster 5) for pre- and posttreatment tumor tissue, pre- and posttreatment nontumoral liver (normal liver), and pre- and posttreatment PBMCs at various time points as indicated. D, Frequency of activated CD8⁺ T cells (cluster 12) for pre- and posttreatment tissue, pre- and posttreatment nontumoral liver, and pre- and posttreatment PBMCs at various time points as indicated. E, Frequency of CD4⁺ Tregs (cluster 8) for pre- and posttreatment tissue, pre- and posttreatment nontumoral liver, and pre- and posttreatment PBMCs at various time points as indicated. F, Effector CD8⁺ T-cell/Treg ratio pre- and posttreatment in tumors and nontumoral liver samples.