Intensity-Modulated Reirradiation Therapy With Nivolumab in Recurrent or Second Primary Head and Neck Squamous Cell Carcinoma: A Nonrandomized Controlled Trial.

Importance: Intensity-modulated radiation therapy (IMRT) reirradiation of nonmetastatic recurrent or second primary head and neck squamous cell carcinoma (HNSCC) results in poor progression-free survival (PFS) and overall survival (OS). Objective: To investigate the tolerability, PFS, OS, and patient-reported outcomes with nivolumab (approved standard of care for patients with HNSCC) during and after IMRT reirradiation. Design, Setting, and Participants: In this multicenter nonrandomized phase 2 single-arm trial, the treatment outcomes of patients with recurrent or second primary HNSCC who satisfied recursive partitioning analysis class 1 and 2 definitions were evaluated. Between July 11, 2018, and August 12, 2021, 62 patients were consented and screened. Data were evaluated between June and December 2023. Intervention: Sixty- to 66-Gy IMRT in 30 to 33 daily fractions over 6 to 6.5 weeks with nivolumab, 240 mg, intravenously 2 weeks prior and every 2 weeks for 5 cycles during IMRT, then nivolumab, 480 mg, intravenously every 4 weeks for a total nivolumab duration of 52 weeks. Main Outcomes and Measures: The primary end point was PFS. Secondary end points included OS, incidence, and types of toxic effects, including long-term treatment-related toxic effects, patient-reported outcomes, and correlatives of tissue and blood biomarkers. Results: A total of 62 patients were screened, and 51 were evaluable (median [range] age was 62 [56-67] years; 42 [82%] were male; 6 [12%] had p16+ disease; 38 [75%] had salvage surgery; and 36 [71%.] had neck dissection). With a median follow-up of 24.5 months (95% CI, 19.0-25.0), the estimated 1-year PFS was 61.7% (95% CI, 49.2%-77.4%), rejecting the null hypothesis of 1-year PFS rate of less than 43.8% with 1-arm log-rank test P = .002 within a 1-year timeframe. The most common treatment-related grade 3 or higher adverse event (6 [12%]) was lymphopenia with 2 patients (4%) and 1 patient each (2%) exhibiting colitis, diarrhea, myositis, nausea, mucositis, and myasthenia gravis. Functional Assessment of Cancer Therapy-General and Functional Assessment of Cancer Therapy-Head and Neck Questionnaire quality of life scores remained stable and consistent across all time points. A hypothesis-generating trend favoring worsening PFS and OS in patients with an increase in blood PD1+, KI67+, and CD4+ T cells was observed. Conclusions and Relevance: This multicenter nonrandomized phase 2 trial of IMRT reirradiation therapy and nivolumab suggested a promising improvement in PFS over historical controls. The treatment was well tolerated and deserves further evaluation. Trial Registration: ClinicalTrials.gov Identifier: NCT03521570.

Intestinal tuft cell immune privilege enables norovirus persistence.

The persistent murine norovirus strain MNVCR6 is a model for human norovirus and enteric viral persistence. MNVCR6 causes chronic infection by directly infecting intestinal tuft cells, rare chemosensory epithelial cells. Although MNVCR6 induces functional MNV-specific CD8+ T cells, these lymphocytes fail to clear infection. To examine how tuft cells promote immune escape, we interrogated tuft cell interactions with CD8+ T cells by adoptively transferring JEDI (just EGFP death inducing) CD8+ T cells into Gfi1b-GFP tuft cell reporter mice. Unexpectedly, some intestinal tuft cells partially resisted JEDI CD8+ T cell-mediated killing-unlike Lgr5+ intestinal stem cells and extraintestinal tuft cells-despite seemingly normal antigen presentation. When targeting intestinal tuft cells, JEDI CD8+ T cells predominantly adopted a T resident memory phenotype with decreased effector and cytotoxic capacity, enabling tuft cell survival. JEDI CD8+ T cells neither cleared nor prevented MNVCR6 infection in the colon, the site of viral persistence, despite targeting a virus-independent antigen. Ultimately, we show that intestinal tuft cells are relatively resistant to CD8+ T cells independent of norovirus infection, representing an immune-privileged niche that can be leveraged by enteric microbes.

High-throughput mRNA sequencing of human placenta shows sex differences across gestation.

INTRODUCTION: Fetal sex affects fetal and maternal health outcomes in pregnancy, but this connection remains poorly understood. As the placenta is the route of fetomaternal communication and derives from the fetal genome, placental gene expression sex differences may explain these outcomes. OBJECTIVES: We utilized next generation sequencing to study the normal human placenta in both sexes in first and third trimester to generate a normative transcriptome based on sex and gestation. STUDY DESIGN: We analyzed 124 first trimester (T1, 59 female and 65 male) and 43 third trimester (T3, 18 female and 25 male) samples for sex differences within each trimester and sex-specific gestational differences. RESULTS: Placenta shows more significant sexual dimorphism in T1, with 94 T1 and 26 T3 differentially expressed genes (DEGs). The sex chromosomes contributed 60.6% of DEGs in T1 and 80.8% of DEGs in T3, excluding X/Y pseudoautosomal regions. There were 6 DEGs from the pseudoautosomal regions, only significant in T1 and all upregulated in males. The distribution of DEGs on the X chromosome suggests genes on Xp (the short arm) may be particularly important in placental sex differences. Dosage compensation analysis of X/Y homolog genes shows expression is primarily contributed by the X chromosome. In sex-specific analyses of first versus third trimester, there were 2815 DEGs common to both sexes upregulated in T1, and 3263 common DEGs upregulated in T3. There were 7 female-exclusive DEGs upregulated in T1, 15 female-exclusive DEGs upregulated in T3, 10 male-exclusive DEGs upregulated in T1, and 20 male-exclusive DEGs upregulated in T3. DISCUSSION: This is the largest cohort of placentas across gestation from healthy pregnancies defining the normative sex dimorphic gene expression and sex common, sex specific and sex exclusive gene expression across gestation. The first trimester has the most sexually dimorphic transcripts, and the majority were upregulated in females compared to males in both trimesters. The short arm of the X chromosome and the pseudoautosomal region is particularly critical in defining sex differences in the first trimester placenta. As pregnancy is a dynamic state, sex specific DEGs across gestation may contribute to sex dimorphic changes in overall outcomes.

Dietary resistant starch supplementation increases gut luminal deoxycholic acid abundance in mice.

Bile acids (BA) are among the most abundant metabolites produced by the gut microbiome. Primary BAs produced in the liver are converted by gut bacterial 7-α-dehydroxylation into secondary BAs, which can differentially regulate host health via signaling based on their varying affinity for BA receptors. Despite the importance of secondary BAs in host health, the regulation of 7-α-dehydroxylation and the role of diet in modulating this process is incompletely defined. Understanding this process could lead to dietary guidelines that beneficially shift BA metabolism. Dietary fiber regulates gut microbial composition and metabolite production. We tested the hypothesis that feeding mice a diet rich in a fermentable dietary fiber, resistant starch (RS), would alter gut bacterial BA metabolism. Male and female wild-type mice were fed a diet supplemented with RS or an isocaloric control diet (IC). Metabolic parameters were similar between groups. RS supplementation increased gut luminal deoxycholic acid (DCA) abundance. However, gut luminal cholic acid (CA) abundance, the substrate for 7-α-dehydroxylation in DCA production, was unaltered by RS. Further, RS supplementation did not change the mRNA expression of hepatic BA producing enzymes or ileal BA transporters. Metagenomic assessment of gut bacterial composition revealed no change in the relative abundance of bacteria known to perform 7-α-dehydroxylation. P. ginsenosidimutans and P. multiformis were positively correlated with gut luminal DCA abundance and increased in response to RS supplementation. These data demonstrate that RS supplementation enriches gut luminal DCA abundance without increasing the relative abundance of bacteria known to perform 7-α-dehydroxylation.

High-throughput mRNA-seq atlas of human placenta shows vast transcriptome remodeling from first to third trimester†.

The placenta, composed of chorionic villi, changes dramatically across gestation. Understanding differences in ongoing pregnancies are essential to identify the role of chorionic villi at specific times in gestation and develop biomarkers and prognostic indicators of maternal-fetal health. The normative mRNA profile is established using next-generation sequencing of 124 first trimester and 43 third trimester human placentas from ongoing healthy pregnancies. Stably expressed genes (SEGs) not different between trimesters and with low variability are identified. Differential expression analysis of first versus third trimester adjusted for fetal sex is performed, followed by a subanalysis with 23 matched pregnancies to control for subject variability using the same genetic and environmental background. Placenta expresses 14,979 polyadenylated genes above sequencing noise (transcripts per million > 0.66), with 10.7% SEGs across gestation. Differentially expressed genes (DEGs) account for 86.7% of genes in the full cohort [false discovery rate (FDR) < 0.05]. Fold changes highly correlate between the full cohort and subanalysis (Pearson = 0.98). At stricter thresholds (FDR < 0.001, fold change > 1.5), there remains 50.1% DEGs (3353 upregulated in first and 4155 upregulated in third trimester). This is the largest mRNA atlas of healthy human placenta across gestation, controlling for genetic and environmental factors, demonstrating substantial changes from first to third trimester in chorionic villi. Specific differences and SEGs may be used to understand the specific role of the chorionic villi throughout gestation and develop first trimester biomarkers of placental health that transpire across gestation, which can be used for future development of biomarkers for maternal-fetal health.

Core Needle Biopsies as an Alternative Source for Ex Vivo Expanded TIL for Adoptive Cell Therapy in Triple-Negative Breast Cancer.

Adoptive transfer of ex vivo expanded tumor-infiltrating lymphocytes (TILs) have produced long-term response in metastatic cancers. TILs have traditionally been expanded from surgically resected specimens. Ultrasound-guided core needle biopsy (CNB) is an alternative method that avoids the morbidity of surgery and have added benefits which may include patients not amenable to surgery as well as the potential to produce TILs from multiple lesions in the same patient. We assessed the ability to produce and expand TILs from primary triple-negative breast cancer tumors from CNB (n=7) and demonstrate comparable expansion, phenotype and cytokine secretion after phorbol myristate acetate-ionomycin stimulation to TILs expanded from surgery (n=6). T cell Receptor clonality and diversity were also comparable between the two cohorts throughout the TIL culture. CNB is a safe and feasible method to obtain tumor tissue for TIL generation in patients with triple-negative breast cancer.

Naturally occurring canine laminopathy leading to a dilated and fibrosing cardiomyopathy in the Nova Scotia Duck Tolling Retriever.

Dilated cardiomyopathy (DCM) is characterized by decreased systolic function and dilation of one or both ventricles, often leading to heart failure or sudden death. Two 10-month-old sibling Nova Scotia Duck Tolling Retrievers (NSDTR) died acutely with evidence of dilated cardiomyopathy with myocardial fibrosis. Association analysis using two cases and 35 controls identified three candidate regions homozygous in the two cases. Whole genome sequencing identified a frameshift deletion in the LMNA gene (NC_049228.1:g.41688530del, NP_001274080:p.(Asp576ThrfsTer124)). Three retrospectively identified NSDTRs with sudden death before 2 years of age and severe myocardial fibrosis were also homozygous for the deletion. One 5 year old with sudden death and myocardial fibrosis was heterozygous for the deletion. This variant was not identified in 722 dogs of other breeds, nor was it identified to be homozygous in 784 NSDTR. LMNA codes for lamin A/C proteins, which are type V intermediate filaments that provide structural support to the nuclear membrane. In humans, LMNA variants can cause DCM with sudden death as well as diseases of striated muscles, lipodystrophy, neuropathies, and accelerated aging disorders. This frameshift deletion is predicted to affect processing of prelamin A into lamin A. Pedigree analysis in the NSDTR and functional evaluation of heterozygotes is consistent with a predominantly recessive mode of inheritance and possibly low penetrance in heterozygotes in contrast to people, where most pathogenic LMNA variants are dominantly inherited.

Ab initio study of the electronic states of V3Si in momentum space.

The electronic properties of V3Si are reported using the full-potential linearized augmented plane wave method. The electronic properties in the momentum space such as one and two dimensional electron momentum densities and the Fermi surface are presented. The momentum densities are compared with available experimental data. The one-dimensional electron momentum density i.e. the Compton profile is found to be in excellent agreement with the experiment. Anisotropy in the directional Compton profile corroborates the crystalline effects. The dimensions of the Fermi-surfaces are well captured by the 2D electron momentum density. The chemical bonding in this metallic compound is studied by means of the electron localization function and reciprocal form factor which suggest dominance of metallic bonding.

A nationwide analysis of salvage surgery for laryngeal cancer in the elderly.

BACKGROUND: We aim to describe outcomes of elderly patients undergoing salvage surgery for laryngeal cancer and to characterize the interplay of age with various other factors in this growing population. METHODS: Using the National Cancer Database, we identified cases of salvage laryngectomy in patients who failed chemoradiation. An age cutoff of 70 years was used to separate subjects into two groups. Various factors were compared. RESULTS: Of the 825 patients included, 166 (20.1%) were elderly. Elderly patients had worse overall survival (p = 0.001), higher 30-day and 90-day mortality (p = 0.006, p < 0.001), and a longer length of stay (LOS) (p = 0.015). LOS over 1 week was associated with worse survival (p = 0.032). CONCLUSION: Elderly patients had worse overall perioperative survival than their younger counterparts. LOS and 30-day readmissions were associated with higher risk of mortality in this group. We provide a contemporary set of relevant information for head and neck cancer providers to consider in this growing population.

Correction: Ab initio study of the electronic states of V3Si in momentum space.

[This corrects the article DOI: 10.1039/D3RA04535H.].

ScRNA-seq defines dynamic T-cell subsets in longitudinal colon and peripheral blood samples in immune checkpoint inhibitor-induced colitis.

Immune checkpoint inhibitors (ICIs) are increasingly being used to manage multiple tumor types. Unfortunately, immune-related adverse events affect up to 60% of recipients, often leading to treatment discontinuation in settings where few alternative cancer therapies may be available. Checkpoint inhibitor induced colitis (ICI-colitis) is a common toxicity for which the underlying mechanisms are poorly defined. To better understand the changing colon-specific and peripheral immune environments over the course of progression and treatment of colitis, we collected blood and colon tissue from a patient with Merkel cell carcinoma who developed colitis on treatment with pembrolizumab. We performed single-cell RNA sequencing and T-cell receptor sequencing on samples collected before, during and after pembrolizumab and after various interventions to mitigate toxicity. We report T-cells populations defined by cytotoxicity, memory, and proliferation markers at various stages of colitis. We show preferential depletion of CD8+ T cells with biologic therapy and nominate both circulating and colon-resident T-cell subsets as potential drivers of inflammation and response to immune suppression. Our findings highlight the need for further exploration of the colon immune environment and rationalize future studies evaluating biologics for ICI-colitis, including in the context of ICI re-challenge.

IL-7R licenses a population of epigenetically poised memory CD8+ T cells with superior antitumor efficacy that are critical for melanoma memory.

Recurrence of advanced melanoma after therapy is a major risk factor for reduced survival, and treatment options are limited. Antitumor immune memory plays a critical role in preventing melanoma recurrence and memory T cells could be a potent cell-based therapy, but the identity, and functional properties of the required immune cells are incompletely understood. Here, we show that an IL-7Rhi tumor-specific CD8+ population is critical for antitumor memory and can be epigenetically augmented to drive powerful antitumor immune responses. Using a model of functional antimelanoma memory, we found that high IL-7R expression selectively marks a CD8+ population in lymphoid organs that plays critical roles in maintaining tumor remission after immunotherapy or surgical resection. This population has intrinsic cytotoxic activity, lacks markers of exhaustion and has superior antitumor efficacy. IL-7Rhi cells have a functionally poised epigenetic landscape regulated by DNA methylation, which can be augmented by hypomethylating agents to confer improved survival and complete melanoma clearance in naive mice. Importantly, greater than 95% of tumor-specific T cells in draining lymph nodes after therapy express high levels of IL-7R. This overlap between IL-7Rhi and antigen-specific T cells allows for enrichment of a potent functional CD8+ population without determining antigen-specificity, which we demonstrate in a melanoma model without a known antigen. We identify that IL-7R expression in human melanoma is an independent prognostic factor of improved survival. These findings advance our basic understanding of antitumor memory and suggest a cell-based therapy using high IL-7R expression to enrich for a lymph node population with superior antitumor activity that can be augmented by hypomethylating agents.

High-throughput mRNA-seq atlas of human placenta shows vast transcriptome remodeling from first to third trimester.

Background: The placenta, composed of chorionic villi, changes dramatically across gestation. Understanding differences in ongoing pregnancies are essential to identify the role of chorionic villi at specific times in gestation and develop biomarkers and prognostic indicators of maternal- fetal health. Methods: The normative mRNA profile is established using next-generation sequencing of 124 first trimester and 43 third trimester human placentas from ongoing healthy pregnancies. Stably expressed genes not different between trimesters and with low variability are identified. Differential expression analysis of first versus third trimester adjusted for fetal sex is performed, followed by a subanalysis with 23 matched pregnancies to control for subject variability using the same genetic and environmental background. Results: Placenta expresses 14,979 mRNAs above sequencing noise (TPM>0.66), with 1,545 stably expressed genes across gestation. Differentially expressed genes account for 86.7% of genes in the full cohort (FDR<0.05). Fold changes highly correlate between the full cohort and subanalysis (Pearson = 0.98). At stricter thresholds (FDR<0.001, fold change>1.5), there are 6,941 differentially expressed protein coding genes (3,206 upregulated in first and 3,735 upregulated in third trimester). Conclusion: This is the largest mRNA atlas of healthy human placenta across gestation, controlling for genetic and environmental factors, demonstrating substantial changes from first to third trimester in chorionic villi. Specific differences and stably expressed genes may be used to understand the specific role of the chorionic villi throughout gestation and develop first trimester biomarkers of placental health that transpire across gestation, which can be used for future development of biomarkers in maternal-fetal disease.

T follicular helper cells in cancer, tertiary lymphoid structures, and beyond.

With the emergence and success of checkpoint blockade immunotherapy, immuno-oncology has primarily focused on CD8 T cells, whose cytotoxic programs directly target tumor cells. However, the limited response rate of current immunotherapy regimens has prompted investigation into other types of tumor-infiltrating immune cells, such as CD4 T cells and B cells, and how they interact with CD8 T cells in a coordinated network. Recent studies have demonstrated the potential therapeutic benefits of CD4 T follicular helper (TFH) cells and B cells in cancer, highlighting the important role of their crosstalk and interactions with other immune cell components in the tumor microenvironment. These interactions also occur in tumor-associated tertiary lymphoid structures (TLS), which resemble secondary lymphoid organs (SLOs) with orchestrated vascular, chemokine, and cellular infrastructures that support the developmental pathways of functional immune cells. In this review, we discuss recent breakthroughs on TFH biology and T cell-B cell interactions in tumor immunology, and their potential as novel therapeutic targets to advance cancer treatment.

PD-1 maintains CD8 T cell tolerance towards cutaneous neoantigens.

The peripheral T cell repertoire of healthy individuals contains self-reactive T cells1,2. Checkpoint receptors such as PD-1 are thought to enable the induction of peripheral tolerance by deletion or anergy of self-reactive CD8 T cells3-10. However, this model is challenged by the high frequency of immune-related adverse events in patients with cancer who have been treated with checkpoint inhibitors11. Here we developed a mouse model in which skin-specific expression of T cell antigens in the epidermis caused local infiltration of antigen-specific CD8 T cells with an effector gene-expression profile. In this setting, PD-1 enabled the maintenance of skin tolerance by preventing tissue-infiltrating antigen-specific effector CD8 T cells from (1) acquiring a fully functional, pathogenic differentiation state, (2) secreting significant amounts of effector molecules, and (3) gaining access to epidermal antigen-expressing cells. In the absence of PD-1, epidermal antigen-expressing cells were eliminated by antigen-specific CD8 T cells, resulting in local pathology. Transcriptomic analysis of skin biopsies from two patients with cutaneous lichenoid immune-related adverse events showed the presence of clonally expanded effector CD8 T cells in both lesional and non-lesional skin. Thus, our data support a model of peripheral T cell tolerance in which PD-1 allows antigen-specific effector CD8 T cells to co-exist with antigen-expressing cells in tissues without immunopathology.

Latent Coronary Plaque Morphology From Computed Tomography Angiography, Molecular Disease Activity on Positron Emission Tomography, and Clinical Outcomes.

BACKGROUND: Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography and radiomics-based precision coronary plaque phenotyping derived from coronary computed tomography angiography may enhance risk stratification in patients with coronary artery disease. We sought to investigate whether the prognostic information provided by these 2 approaches is complementary in the prediction of myocardial infarction. METHODS: Patients with known coronary artery disease underwent coronary 18F-sodium fluoride positron emission tomography and coronary computed tomography angiography on a hybrid positron emission tomography/computed tomography scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity. We performed quantitative plaque analysis of coronary computed tomography angiography datasets and extracted 1103 radiomic features for each plaque. Using weighted correlation network analysis, we derived latent morphological features of coronary lesions which were aggregated to patient-level radiomics nomograms to predict myocardial infarction. RESULTS: Among 260 patients with established coronary artery disease (age, 65±9 years; 83% men), 179 (69%) participants showed increased coronary 18F-NaF activity (coronary microcalcification activity>0). Over 53 (40-59) months of follow-up, 18 patients had a myocardial infarction. Using weighted correlation network analysis, we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns in an unsupervised fashion. Following adjustments for calcified, noncalcified, and low-density noncalcified plaque volumes and 18F-NaF coronary microcalcification activity, 4 radiomic features remained independent predictors of myocardial infarction (hazard ratio, 1.46 [95% CI, 1.03-2.08]; P=0.03; hazard ratio, 1.62 [95% CI, 1.04-2.54]; P=0.02; hazard ratio, 1.49 [95% CI, 1.07-2.06]; P=0.01; and hazard ratio, 1.50 (95% CI, 1.05-2.13); P=0.02). CONCLUSIONS: In patients with established coronary artery disease, latent coronary plaque morphological features, quantitative plaque volumes, and disease activity on 18F-sodium fluoride positron emission tomography are additive predictors of myocardial infarction.

Utilizing Dynamic Risk Stratification in Patients With Tall Cell Variant Papillary Thyroid Cancer.

OBJECTIVES: Tall cell variant (TCV) papillary thyroid cancer (PTC) is a subtype of PTC associated with aggressive tumor behavior, advanced stage, and higher rates of recurrence and mortality. The present study aimed to test an established dynamic risk stratification tool in the TCV population, with the goal of better predicting the postoperative course of these patients. STUDY DESIGN: Retrospective chart review. METHODS: A total of 94 patients with TCV who underwent total thyroidectomy with radioactive iodine ablation were retrospectively reviewed from 1998 through 2020. Biochemical, structural, and overall response to treatment was determined for each patient, based on postoperative thyroglobulin levels and imaging findings. Primary outcomes were locoregional and distant recurrence, presence of disease at final follow-up, need for additional intervention, and disease-specific mortality. RESULTS: Patients with TCV who were stratified as having an excellent overall response to treatment had lower rates of locoregional recurrence than indeterminate, biochemical incomplete, and structural incomplete responses (2.0%, 33.3%, 55.0%, and 85.7% at 5 years respectively, p < 0.001). The same was true for distant recurrence as well (2.0%, 9.0%, 35.1%, and 42.9%, p < 0.001). An excellent response was also associated with lower rates of presence of disease at final follow-up, need for additional intervention, and disease-specific mortality. CONCLUSIONS: Although TCV is an aggressive subtype associated with worse clinical outcomes than classical PTC, patients with an excellent overall response to treatment have significantly improved outcomes when compared to indeterminate, biochemical incomplete, and structural incomplete responses. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:2430-2438, 2023.

Current State and Future Directions of EGFR-Directed Therapy in Head and Neck Cancer.

OPINION STATEMENT: Epidermal growth factor receptor (EGFR) is commonly overexpressed in many head and neck squamous cell carcinomas (HNSCC). With the success of EGFR inhibition in other cancer types, there was optimism for efficacy in HNSCC. Unfortunately, the clinical outcomes of EGFR-directed therapy have not provided overwhelming benefit. In the curative-intent setting, cisplatin has proven superior over cetuximab, an EGFR monoclonal antibody, in multiple large trials, and cisplatin should continue to be the treatment of choice when administered with definitive or adjuvant radiation. For cisplatin-ineligible patients, we prefer carboplatin-based treatment over cetuximab. We reserve cetuximab for a small group of patients who are eligible for radiation and systemic treatment but have contraindications to any platinum therapy. The role of EGFR inhibitors in the recurrent/metastatic setting is more robust. Although supplanted by immunotherapy as front-line treatment, cetuximab remains a meaningful second-line option for patients who have progressed on immune checkpoint inhibitors. Overall, EGFR-directed therapies have been of modest value in the treatment of both locally advanced and metastatic HNSCC. The future of EGFR-directed therapies will likely develop from exploring combination therapies, especially with immunotherapy. Early evidence suggests synergistic effects allowing for a more robust immune response, which holds promise for novel regimens in the treatment of HNSCC.