Response-Adaptive Surgical Timing in Neoadjuvant Immunotherapy Demonstrates Enhanced Pathologic Treatment Response in Head and Neck Squamous Cell Carcinoma

Abstract

Purpose: We evaluated whether indoleamine 2,3-dioxygenase (IDO1) inhibitor (IDOi) BMS986205 + PD-1 inhibitor nivolumab enhanced T-cell activity and augmented immune-mediated antitumor responses in untreated, resectable head and neck squamous cell carcinoma (HNSCC). We employed response-adaptive surgical timing to identify responders to immunotherapy and enhance their response.

Patients and methods: Patients with HNSCC were 3:1 randomized to receive nivolumab with or without BMS986205 orally daily (NCT03854032). In the combination arm, BMS986205 was initiated 7 days prior to nivolumab. Patients were stratified by human papillomavirus (HPV) status. Response-adaptive surgical timing involved response assessment by radiographic criteria 4 weeks after treatment with nivolumab in both arms. Nonresponders underwent surgical resection, whereas responders received 4 more weeks of randomized therapy before surgery. Biomarker analysis utilized pathologic treatment response (pTR) and RNA sequencing.

Results: Forty-two patients were enrolled, and the addition of IDOi to nivolumab did not result in greater rate of radiographic response (P = 0.909). Treatment was well tolerated, with only 2 (5%) patients experiencing grade 3 immune-related adverse events. The addition of IDOi augmented rates of pTR in patients with high baseline IDO1 RNA expression (P < 0.05). Response-adaptive surgical timing demonstrated reliability in differentiating pathologic responders versus nonresponders (P = 0.009). A pretreatment NK cell signature, PD-L1 status, and IFN-γ expression in the HPV- cohort correlated with response. The HPV+ cohort found B-cell and cancer-associated fibroblast signatures predictive of response/nonresponse.

Conclusions: Response-adaptive surgical timing enhanced treatment response. IDOi BMS986205 augmented pTR in patients with high IDO1 expression in baseline samples, indicating a need for identifying and targeting resistant nodes to immunotherapy. HPV status-dependent signatures predicting response to immunotherapy in HNSCC warrant further study.

Figure 1.. Trial schematic and waterfall plots of pathologic treatment response and radiographic response rates.

A: Trial Schematic. B: Pictorial depiction of patients included and excluded for radiographic and pathologic analyses. C and D: Degree of pathologic treatment response (pTR) at the primary tumor site (C) and overall pTR (combined analysis of both primary tumor and lymph nodes [when applicable]) (D). E: Per RECIST criteria, degree of overall radiographic response (combined analysis of both primary tumor and lymph nodes [when applicable]).

Figure 2.. Differences in the TME of HPV^– and HPV⁺ HNSCCs.

A: Transcriptional profiles of TJU HNSCC and TCGA HNSCC (n = 588) cohorts with color-coding for HPV status. B: Tumor subsites for HPV⁺ and HPV^– TJU HNSCC samples. C: Cell type deconvolution landscape of TJU HNSCC cohort. Each sample is represented by a bar composed of major cell types predicted to be enriched in its tumor microenvironment (TME). The gray color shows tumor tissue plus all other unpredicted cell types. D-H: Percentages of various cell types that are differentially enriched in the TME of HPV⁺ and HPV^– samples (total n = 655). *p < 0.05**p < 0.01, ***p < 0.001.

Figure 3.. PDL1, PDL2, and interferon pathway as biomarkers of response to Immune Checkpoint Inhibition in HPV- HNSCC.

A: Volcano plot representing differential expression analysis comparing baseline samples of responders and non-responders in the HPV^– HNSCC samples (n = 17, 8 responders and 9 non-responders). Each gene is shown as a dot; the X axis shows log(Fold Change) of expression levels compared to non-responders; the Y axis shows −10log(False Discovery Rate). Statistically significant genes (FDR < 0.1) are colored blue. B-E: Comparison of PDL2 expression (B), IFNG signature score (C), PDL1 expression (D), and tumor mutational burden (TMB) (n=14 as three patients were excluded from whole exome sequencing due to <20% viable tumor cells in their sample)(E) values between baseline samples of responders (R) and non-responders (NR) in HPV^– samples (n = 17, except for TMB analysis n = 14 due to strict sample quality filtration for mutation calling). - ns, *p < 0.05, **p < 0.01, ***p < 0.001.

Figure 4.. Cellular biomarkers of response to nivolumab.

A: Heatmap of TME deconvolution (median-scaled) representing major cell types in HPV^– HNSCC baseline samples (n = 17). Populations that significantly differ between responders and non-responders are marked by stars. B-D: CD8+ T cells (B), NK cells (C), and macrophages (D) content compared between baseline and post-treatment samples of responders (R) and non-responders (NR) in the HPV^– HNSCC cohort (n = 34). E: Heatmap of ​​​TME-associated expressional signature scores in baseline samples ​(n = 34) and segregated based on TME classification ​(Immune-enriched fibrotic, immune-enriched non-fibrotic, fibrotic and immune desert) demonstrating the immune-desert TME as associated with non-response.

Figure 5:. Bulk RNAseq analysis in HPV-positive patients.

A: Schematic of B-cell maturation from pro-B to more mature B-Cell and downstream second messengers with post- vs pre-treatment GSEA at equivalent stages of maturation. Venn diagrams of non-responder (NR) and responder (R) leading edge genes of Pro-B (right top) and Second Messenger (right bottom) gene sets to identify genes unique to responders are displayed. STRING 12.0 was performed with the unique leading-edge genes in responders. Nodes of different colors demonstrate an enrichment with their associated FDRs. Genes associated with significant enrichment: cell cycle (teal) in the Pro-B gene set; antigen activates B cell receptor (red), FCGR dependent phagocytosis (blue), and intracellular signaling (green) in the second messenger gene set. B: GSEA of NR and R of the CAF2 gene set, post-treatment. Unique leading-edge genes of the NR and R CAF2 gene set were determined by using a Venn diagram. Leading edge genes were then analyzed by using STRING. CAF2 NR demonstrated enrichment of IL-4 and IL-13 signaling (red), and integrated stress response signaling (blue). In contrast, CAF2 Rs were enriched for collagen-containing extracellular matrix (green).