Neoadjuvant immunotherapy with nivolumab and ipilimumab induces major pathological responses in patients with head and neck squamous cell carcinoma

Abstract

Surgery for locoregionally advanced head and neck squamous cell carcinoma (HNSCC) results in 30‒50% five-year overall survival. In IMCISION (NCT03003637), a non-randomized phase Ib/IIa trial, 32 HNSCC patients are treated with 2 doses (in weeks 1 and 3) of immune checkpoint blockade (ICB) using nivolumab (NIVO MONO, n = 6, phase Ib arm A) or nivolumab plus a single dose of ipilimumab (COMBO, n = 26, 6 in phase Ib arm B, and 20 in phase IIa) prior to surgery. Primary endpoints are feasibility to resect no later than week 6 (phase Ib) and primary tumor pathological response (phase IIa). Surgery is not delayed or suspended for any patient in phase Ib, meeting the primary endpoint. Grade 3‒4 immune-related adverse events are seen in 2 of 6 (33%) NIVO MONO and 10 of 26 (38%) total COMBO patients. Pathological response, defined as the %-change in primary tumor viable tumor cell percentage from baseline biopsy to on-treatment resection, is evaluable in 17/20 phase IIa patients and 29/32 total trial patients (6/6 NIVO MONO, 23/26 COMBO). We observe a major pathological response (MPR, 90‒100% response) in 35% of patients after COMBO ICB, both in phase IIa (6/17) and in the whole trial (8/23), meeting the phase IIa primary endpoint threshold of 10%. NIVO MONO's MPR rate is 17% (1/6). None of the MPR patients develop recurrent HSNCC during 24.0 months median postsurgical follow-up. FDG-PET-based total lesion glycolysis identifies MPR patients prior to surgery. A baseline AID/APOBEC-associated mutational profile and an on-treatment decrease in hypoxia RNA signature are observed in MPR patients. Our data indicate that neoadjuvant COMBO ICB is feasible and encouragingly efficacious in HNSCC.

Fig. 1. IMCISION trial design, pathological response waterfall plot, time-to-progression survival analysis, FDG-PET response evaluation, PD-L1 CPS, and tumor-infiltrating CD3⁺CD8⁺ T-cells.

a IMCISION phase Ib/IIa study design. Patients with primary or recurrent HNSCC, with an indication for major (salvage) head and neck surgery, were included in IMCISION. Patients underwent baseline primary tumor biopsy and several imaging studies. Phase Ib consisted of 12 patients (6 treated with nivolumab in arm A as a safety run-in, 6 with nivolumab + ipilimumab in arm B), phase IIa of 20 patients (all nivolumab + ipilimumab). Imaging was repeated in week 4, shortly prior to surgery. b Percentage pathological response (PR) at the primary tumor site from baseline biopsy to on-treatment surgical specimen in patients treated with nivolumab (17% MPR, left) and nivolumab + ipilimumab (35% MPR, right). The two dotted horizontal lines (at 50 and 90% PR) divide patients into three categories: 90–100% PR (major pathological response, MPR, green), 50‒89% partial PR (PPR, yellow), and <50% or no PR (NPR, red). Three patients did not undergo surgery and are marked not evaluable (‘ne’). Upper bars mark baseline clinical lymph node status and patients included with recurrent disease after previous (chemo / bio) radiotherapy (‘salvaged’). Source data are provided as a Source Data file. c Clinical photography (upper panels), H&E-stained tumor sections (middle panels, scale bars measure 500 μm) and FDG-PET images (lower panels) of pt39 with a cT3N0 carcinoma of the left tongue border at baseline (left) and on-treatment, shortly prior to surgery (right). This patient achieved an MPR. The clinically evident reduction in tumor bulk is reflected on the H&E slide by the presence of keratinous debris (KD) and surrounding multinucleated giant cells (arrows). FDG-PET obtained shortly prior to surgery shows resolution of tracer accumulation at the tongue border. d Kaplan–Meier estimate of the time to progression of the 29 IMCISION patients, classified according to neoadjuvant treatment and primary tumor PR, and of 114 non-IMCISION patients from a comparable historical cohort that underwent major (salvage) surgery without neoadjuvant treatment. Comparisons are made using a two-sided log-rank test. None of the patients with an MPR upon neoadjuvant ICB (either NIVO or COMBO) suffered recurrent disease after 24.0 months median follow-up. e Waterfall plot showing the percentage change in primary tumor total lesion glycolysis (TLG) from baseline to on-treatment as measured by FDG-PET, stratified by PR. Black bars represent the TLG change in 2 patients without an evaluable pathological response (‘PR NE’). One of the ‘PR NE’ patients was pt21, who had a TLG decrease and an evident clinical response (see Supplementary Fig. 2). An exact P-value was calculated using a two-sided Wilcoxon rank-sum test. Source data are provided as a Source Data file. f Baseline PD-L1 combined positive score (CPS) of primary tumors per PR category assessed per immunohistochemistry. An exact P-value was calculated using a two-sided Wilcoxon rank-sum test. N = all 32 baseline primary tumor samples (10 MPR, 2 PPR, 20 NPR). Source data are provided as a Source Data file. g Baseline intratumoral infiltration of CD3 + CD8 + T-cells assessed per digital analysis of multiplex-stained slides. An exact P-value was calculated using a two-sided Wilcoxon rank-sum test. N = 31 baseline primary tumor samples (10 MPR, 1 PPR, 20 NPR). Source data are provided as a Source Data file. For f and g, boxplots represent the median and 25th and 75th percentile, the whiskers extend from the hinge to the minimal and maximal data point but no further than 1.5× IQR. For translational research purposes, the three patients that did not undergo surgery were included for CPS and CD3 + CD8 + T-cell assessment and categorized according to their clinical ICB response: 1 as likely MPR and 2 as likely NPR.

Fig. 2. RNA and whole-exome sequencing.

a Baseline and on-treatment epithelial to mesenchymal transition (EMT), T-cell, IFNγ, endothelial cell, and tumor hypoxia expression signatures per pathologic response (PR) category assessed by RNA sequencing (RNAseq). Exact P-values were calculated using a two-sided Wilcoxon rank-sum test. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR), on-treatment N = 30 primary tumor samples (10 MPR, 1 PPR, 19 NPR). Source data are provided as a Source Data file. b Change in hypoxia gene expression in paired baseline and on-treatment primary tumor samples. An exact P-value was calculated using a two-sided Wilcoxon signed rank test. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR), on-treatment N = 30 primary tumor samples (10 MPR, 1 PPR, 19 NPR). Source data are provided as a Source Data file. c Change in the percentage of tumor cells that express hypoxia-inducible factor 1α (HIF-1α) in paired baseline and on-treatment primary tumors, measured by immunohistochemistry. Two MPR patients without analyzable, residual tumor after ICB are included with value ‘0%’. An exact P-value was calculated using a two-sided Wilcoxon signed rank test. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR), on-treatment N = 30 primary tumor samples (10 MPR, 1 PPR, 19 NPR). Source data are provided as a Source Data file. d HIF-1α-stained primary tumor slides of a patient with primary tumor MPR at baseline (top) and on-treatment (bottom). Black bars measure 200 μm. e Microvessel density (MVD) in available pre- and on-treatment primary tumor samples. Comparisons between pre- and on-treatment samples of the same patient are made using a two-sided Wilcoxon signed rank test. The comparison between the median MVD of on-treatment MPR and NPR samples is made using a two-sided Wilcoxon rank-sum test. All P-values are exact. Baseline N = 29 (9 MPR, 1 PPR, 19 NPR), on-treatment N = 29 (10 MPR, 0 PPR, 19 NPR). Source data are provided as a Source Data file. f Change in PD-1, PD-L1, LAG-3, and CTLA-4 signature expression in baseline and corresponding on-treatment primary tumor samples per PR category. An exact P-value was calculated using a two-sided Wilcoxon signed rank test. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR), on-treatment N = 30 primary tumor samples (10 MPR, 1 PPR, 19 NPR). Source data are provided as a Source Data file. g Oncoplot showing mutations as assessed by whole-exome sequencing (WES) of baseline primary tumor samples. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR); a column represents a patient. Top bar chart represents tumor mutational burden (TMB). Percentages listed right represent the proportion of samples harboring a mutation in the gene listed left. Bottom bars show PR, salvage status and ICB regimen. Source data are provided as a Source Data file. h Top plot: number of COSMIC signature 2 (AID / APOBEC)-associated mutations per PR category. Right plot: total TMB per ICB response category. The dot plot shows ICB response and the contribution of AID / APOBEC-associated mutations to the TMB per individual sample. Exact P-values were calculated using a two-sided Wilcoxon rank-sum test. Baseline N = all 32 primary tumor samples (10 MPR, 2 PPR, 20 NPR). Source data are provided as a Source Data file. For translational purposes, the three patients that did not undergo surgery were categorized according to their clinical ICB response in this figure: 1 as likely MPR and 2 likely NPR. For a and h, boxplots represent the median and 25th and 75th percentile, the whiskers extend from the hinge to the minimal and maximal data point but no further than 1.5× IQR.