Immunotherapy for head and neck cancer: latest developments and clinical potential

Sacituzumab Govitecan in Patients with Relapsed/Refractory Advanced Head and Neck Squamous Cell Carcinoma: Results from the Phase II TROPiCS-03 Basket Study

PURPOSE

Treatment options for advanced head and neck squamous cell carcinoma (HNSCC) previously treated with platinum-based chemotherapy and a PD-1 inhibitor are limited. Trophoblast cell-surface antigen 2 (Trop-2) is highly expressed in HNSCC. Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate approved for patients with certain previously treated solid tumors.

PATIENTS AND METHODS

TROPiCS-03 (NCT03964727) is an open-label, multicohort, phase II study evaluating SG in advanced solid tumors, including HNSCC. Adults with locally advanced or metastatic HNSCC that progressed following platinum-based chemotherapy and anti-PD-(L)1 therapy [given sequentially (either order) or in combination] were administered SG 10 mg/kg on days 1 and 8 of a 21-day cycle. The primary endpoint was the investigator-assessed objective response rate. Secondary endpoints included duration of response, clinical benefit rate, progression-free survival, overall survival, and safety.

RESULTS

Patients (N = 43) received a median of 3 (range, 2-9) prior anticancer regimens. The objective response rate was 16% [95% confidence interval (CI), 7%-31%], with seven confirmed partial responses. The clinical benefit rate was 28% (95% CI, 15%-44%). The median (95% CI) duration of response, progression-free survival, and overall survival were 4.2 (2.6-not reached), 4.1 (2.6-5.8), and 9.0 (7.1-10.5) months, respectively. The most common treatment-emergent adverse events (TEAE) were diarrhea (47%), nausea (47%), and neutropenia (47%). Grade ≥3 TEAE occurred in 58% of patients. Three patients died from TEAE, with one event (septic shock) considered related to SG.

CONCLUSIONS

These data demonstrate the clinical potential of Trop-2-directed therapy in managing heavily pretreated patients with advanced HNSCC.

Head and neck cancer: pathogenesis and targeted therapy

Head and neck cancer (HNC) is a highly aggressive type of tumor characterized by delayed diagnosis, recurrence, metastasis, relapse, and drug resistance. The occurrence of HNC were associated with smoking, alcohol abuse (or both), human papillomavirus infection, and complex genetic and epigenetic predisposition. Currently, surgery and radiotherapy are the standard treatments for most patients with early-stage HNC. For recurrent or metastatic (R/M) HNC, the first-line treatment is platinum-based chemotherapy combined with the antiepidermal growth factor receptor drug cetuximab, when resurgery and radiation therapy are not an option. However, curing HNC remains challenging, especially in cases with metastasis. In this review, we summarize the pathogenesis of HNC, including genetic and epigenetic changes, abnormal signaling pathways, and immune regulation mechanisms, along with all potential therapeutic strategies such as molecular targeted therapy, immunotherapy, gene therapy, epigenetic modifications, and combination therapies. Recent preclinical and clinical studies that may offer therapeutic strategies for future research on HNC are also discussed. Additionally, new targets and treatment methods, including antibody-drug conjugates, photodynamic therapy, radionuclide therapy, and mRNA vaccines, have shown promising results in clinical trials, offering new prospects for the treatment of HNC.

The HPV viral regulatory mechanism of TLRs and the related treatments for HPV-associated cancers

Infection with human papillomavirus (HPV) typically leads to cervical cancer, skin related cancers and many other tumors. HPV is mainly responsible for evading immune tumor monitoring in HPV related cancers. Toll like receptors (TLRs) are particular pattern recognition molecules. When the body is facing immune danger, it can lead to innate and direct adaptive immunity. TLR plays an important role in initiating antiviral immune responses. HPV can affect the expression level of TLR and interfere with TLR related signaling pathways, resulting in sustained viral infection and even carcinogenesis. This paper introduces the HPV virus and HPV related cancers. We discussed the present comprehension of TLR, its expression and signaling, as well as its role in HPV infection. We also provided a detailed introduction to immunotherapy methods for HPV related diseases based on TLR agonists. This will provide insights into methods that support the therapeutic method of HPV related conditions with TLR agonists.

Treatment Response of Gingival Squamous-Cell Carcinoma to Palliative Intent Immunotherapy

The use of PD-1 immune checkpoint inhibitor medications has become a common practice in the treatment of recurrent and metastatic head and neck squamous-cell carcinomas. Success in this setting has led to the investigation of their efficacy in locally advanced cases as a part of first-line therapy. In this report, we detail the treatment response to palliative intent immunotherapy of three geriatric patients with mandibular gingival squamous-cell carcinoma who decided against surgical intervention. Patient #1 was treated with pembrolizumab, a PD-1 inhibitor, and displayed complete clinical and radiologic response of the gingival mass after three months of treatment, which is ongoing at 19 months from initiation. Patients #2 and 3 are each on treatment with single-agent pembrolizumab, with partial response of their tumors, minimal side effects, and ongoing response at 9 and 5 months of treatment, respectively. Durable clinical treatment response to palliative immunotherapy, as is evident in this report, warrants further consideration and investigation in the geriatric population. With appropriate patient selection, surgery may be avoided and allow patients to prioritize quality of life over curative intent surgery.

Functional-structural sub-region graph convolutional network (FSGCN): Application to the prognosis of head and neck cancer with PET/CT imaging

BACKGROUND AND OBJECTIVE

Accurate risk stratification is crucial for enabling personalized treatment for head and neck cancer (HNC). Current PET/CT image-based prognostic methods include radiomics analysis and convolutional neural network (CNN), while extracting radiomics or deep features in grid Euclidean space has inherent limitations for risk stratification. Here, we propose a functional-structural sub-region graph convolutional network (FSGCN) for accurate risk stratification of HNC.

METHODS

This study collected 642 patients from 8 different centers in The Cancer Imaging Archive (TCIA), 507 patients from 5 centers were used for training, and 135 patients from 3 centers were used for testing. The tumor was first clustered into multiple sub-regions by using PET and CT voxel information, and radiomics features were extracted from each sub-region to characterize its functional and structural information, a graph was then constructed to format the relationship/difference among different sub-regions in non-Euclidean space for each patient, followed by a residual gated graph convolutional network, the prognostic score was finally generated to predict the progression-free survival (PFS).

RESULTS

In the testing cohort, compared with radiomics or FSGCN or clinical model alone, the model PETCT^Fea_CT^ROI + Cli that integrates FSGCN prognostic score and clinical parameter achieved the highest C-index and AUC of 0.767 (95% CI: 0.759-0.774) and 0.781 (95% CI: 0.774-0.788), respectively for PFS prediction. Besides, it also showed good prognostic performance on the secondary endpoints OS, RFS, and MFS in the testing cohort, with C-index of 0.786 (95% CI: 0.778-0.795), 0.775 (95% CI: 0.767-0.782) and 0.781 (95% CI: 0.772-0.789), respectively.

CONCLUSIONS

The proposed FSGCN can better capture the metabolic or anatomic difference/interaction among sub-regions of the whole tumor imaged with PET/CT. Extensive multi-center experiments demonstrated its capability and generalization of prognosis prediction in HNC over conventional radiomics analysis.

Current Insights and Progress in the Clinical Management of Head and Neck Cancer

Head and neck cancer (HNC), also known as the cancer that can affect the structures between the dura mater and the pleura, is the 6th most common type of cancer. This heterogeneous group of malignancies is usually treated with a combination of surgery and radio- and chemotherapy, depending on if the disease is localized or at an advanced stage. However, most HNC patients are diagnosed at an advanced stage, resulting in the death of half of these patients. Thus, the prognosis of advanced or recurrent/metastatic HNC, especially HNC squamous cell carcinoma (HNSCC), is notably poorer than the prognosis of patients diagnosed with localized HNC. This review explores the epidemiology and etiologic factors of HNC, the histopathology of this heterogeneous cancer, and the diagnosis methods and treatment approaches currently available. Moreover, special interest is given to the novel therapies used to treat HNC subtypes with worse prognosis, exploring immunotherapies and targeted/multi-targeted drugs undergoing clinical trials, as well as light-based therapies (i.e., photodynamic and photothermal therapies).

Immunotherapy in Head and Neck Cancer When, How, and Why?

Head and neck cancer (HNC) is one of the most common cancers worldwide. Alcohol and tobacco consumption, besides viral infections, are the main risk factors associated with this cancer. When diagnosed in advanced stages, HNC patients present a higher probability of recurrence or metastasising. The complexity of therapeutic options and post-treatment surveillance is associated with poor prognosis and reduced overall survival (OS). This review aims to explore immunotherapy (immune checkpoint inhibitors (ICI), therapeutic vaccines, and oncolytic viruses) in HNC patients’ treatment, and to explore when, how, and why patients can benefit from it. The monotherapy with ICI or in combination with chemotherapy (QT) shows the most promising results. Compared to standard therapy, ICI are able to increase OS and patients’ quality of life. QT in combination with ICI demonstrates significant response rates and considerable long-term clinical benefits. However, the toxicity associated with this approach is still a hurdle to overcome. In parallel, the therapeutic vaccines directed to the Human Papilloma Virus are also efficient in increasing the antitumour response, inducing cellular and humoral immunity. Although these results demonstrate clinical benefits compared to standard therapy, it is also important to unravel the resistance mechanisms in order to predict the clinical benefit of immunotherapy.

Combined Association of Tumoral PD-L1 Expression and Pretreatment Presence of Epstein-Barr Virus DNA With Risk Stratification and Prognosis of Patients With Nasopharyngeal Carcinoma

Background

Little is known about whether the combination of tumor programmed death-ligand 1 (PD-L1) expression and pretreatment EBV DNA status can help stratify nasopharyngeal carcinoma (NPC) patients by risk of metastasis or predict prognosis.

Methods

PD-L1 expression was assessed using immunohistochemical staining of 78 non-keratinizing NPC patients with clinical data. Survival outcomes and independent prognostic factors were identified.

Results

Seventy-eight patients were included, high PD-L1 expression was observed in 25 of 43 patients (58%) with metastasis, while it was observed only in 7 of 35 patients (20%) without metastasis. Multivariate analyses showed that progression-free survival (PFS) was independently predicted by tumoral PD-L1 expression and pretreatment EBV DNA status. When combining, 93.75% patients with high PD-L1 and EBV infection developed distant metastasis, and those patients were associated with worse PFS.

Conclusions

Both PD-L1 expression and pretreatment EBV DNA are closely related to metastasis and prognosis of NPC patients. Their combination can facilitate risk stratification and prognosis prediction, which may improve disease treatment and management.

New Scenarios in Pharmacological Treatments of Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent types of cancer with a lethal outcome in half of the diagnosed cases. Mostly, HNSCC develops in the oral cavity, and its development is associated with tobacco and areca nut/betel quid usage, alcohol consumption, and HPV infection. Oral squamous cell carcinoma, as other head and neck cancers, presents a high degree of intratumor heterogeneity, which makes their treatment difficult, and directly correlates with drug resistance. Since the classical treatments for HNSCC oftentimes do not resolve the clinical picture, there is great need for novel therapeutic approaches, models for drug testing, and new drug delivery systems.

The Wnt-Driven Mll1 Epigenome Regulates Salivary Gland and Head and Neck Cancer

We identified a regulatory system that acts downstream of Wnt/β-catenin signaling in salivary gland and head and neck carcinomas. We show in a mouse tumor model of K14-Cre-induced Wnt/β-catenin gain-of-function and Bmpr1a loss-of-function mutations that tumor-propagating cells exhibit increased Mll1 activity and genome-wide increased H3K4 tri-methylation at promoters. Null mutations of Mll1 in tumor mice and in xenotransplanted human head and neck tumors resulted in loss of self-renewal of tumor-propagating cells and in block of tumor formation but did not alter normal tissue homeostasis. CRISPR/Cas9 mutagenesis and pharmacological interference of Mll1 at sequences that inhibit essential protein-protein interactions or the SET enzyme active site also blocked the self-renewal of mouse and human tumor-propagating cells. Our work provides strong genetic evidence for a crucial role of Mll1 in solid tumors. Moreover, inhibitors targeting specific Mll1 interactions might offer additional directions for therapies to treat these aggressive tumors.

Cost-effectiveness Analysis of Nivolumab for Treatment of Platinum-Resistant Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck

Background

The CheckMate 141 trial found that nivolumab improved survival for patients with recurrent or metastatic head and neck cancer (HNC). Despite the improved survival, nivolumab is much more expensive than standard therapies. This study assesses the cost-effectiveness of nivolumab for the treatment of HNC.

Methods

We constructed a Markov model to simulate treatment with nivolumab or standard single-agent therapy for patients with recurrent or metastatic platinum-refractory HNC. Transition probabilities, including disease progression, survival, and probability of toxicity, were derived from clinical trial data, while costs (in 2017 US dollars) and health utilities were estimated from the literature. Incremental cost-effectiveness ratios (ICERs), expressed as dollar per quality-adjusted life-year (QALY), were calculated, with values of less than $100 000/QALY considered cost-effective from a health care payer perspective. We conducted one-way and probabilistic sensitivity analyses to assess model uncertainty.

Results

Our base case model found that treatment with nivolumab increased overall cost by $117 800 and improved effectiveness by 0.400 QALYs compared with standard therapy, leading to an ICER of $294 400/QALY. The model was most sensitive to the cost of nivolumab, though nivolumab only became cost-effective if the cost per cycle decreased from $13 432 to $3931. The model was not particularly sensitive to assumptions about survival. If one assumed that all patients alive at the end of the CheckMate 141 trial were cured of their disease, nivolumab was still not cost-effective (ICER $244 600/QALY).

Conclusion

While nivolumab improves overall survival, at its current cost it would not be considered a cost-effective treatment option for patients with HNC.

The Role of Immunotherapy and Radiation Therapy in Tumor Chemosensitivity in Advanced Head and Neck Cancer

BACKGROUND Cancer is the second leading cause of death internationally, resulting in millions of deaths each year. While treatment in the past has heavily relied on surgery and radiotherapy, chemotherapy and immunotherapy are being increasingly utilized depending on disease presentation. CASE REPORT A 56-year-old male presented to the Emergency Department with a 3-week history of a rapidly enlarging left supraclavicular neck mass. Computed tomography scan revealed a 12×13 cm mass extending from the angle of the mandible to the supraclavicular area. A biopsy confirmed advanced stage squamous cell carcinoma of the head and neck. The patient was started on a chemotherapy regimen of docetaxel, cisplatin, and 5-fluorouracil (TCF). The tumor progressed through chemotherapy, which was switched to cetuximab; however, this therapy was discontinued after an anaphylactic reaction. Palliative radiation treatment was begun along with pembrolizumab. Pembrolizumab was continued, and after 9 cycles, the patient's cancer was almost in complete remission. Three months later, disease progression was once again noted with pembrolizumab treatment, which was subsequently discontinued. The patient was started on paclitaxel and carboplatin chemotherapy regimen as a last resort, despite failure of prior TCF treatment, and the patient responded, this time with complete remission in 4 months. CONCLUSIONS This case demonstrates a unique outcome in which a patient who previously was resistant to chemotherapy, later responded to chemotherapy after a trial of radiation therapy and immunotherapy. Immunotherapy may have a synergistic effect with radiation therapy and play a role in tumor sensitivity to chemotherapy in head and neck cancer treatment.

Engineering Vaccines to Reprogram Immunity against Head and Neck Cancer

The recent Food and Drug Administration's approval of monoclonal antibodies targeting immune checkpoint receptors (ICRs) for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) offers exciting promise to improve patient outcome and reduce morbidities. A favorable response to ICR blockade relies on an extensive collection of preexisting tumor-specific T cells in the tumor microenvironment (TME). ICR blockade reinvigorates exhausted CD8+ T cells and enhances immune killing. However, resistance to ICR blockade is observed in about 85% of patients with HNSCC, therefore highlighting the importance of characterizing the mechanisms underlying HNSCC immune escape and exploring combinatorial strategies to sensitize hypoimmunogenic cold HNSCC to ICR inhibition. Cancer vaccines are designed to bypass the cold TME and directly deliver cancer antigens to antigen-presenting cells (APCs); these vaccines epitomize a priming strategy to synergize with ICR inhibitors. Cancer cells are ineffective antigen presenters, and poor APC infiltration as well as the M2-like polarization in the TME further dampens antigen uptake and processing, both of which render ineffective innate and adaptive immune detection. Cancer vaccines directly activate APC and expand the tumor-specific T-cell repertoire. In addition, cancer vaccines often contain an adjuvant, which further improves APC function, promotes epitope spreading, and augments host intrinsic antitumor immunity. Thus, the vaccine-induced immune priming generates a pool of effectors whose function can be enhanced by ICR inhibitors. In this review, we summarize the major HNSCC immune evasion strategies, the ongoing effort toward improving HNSCC vaccines, and the current challenges limiting the efficacy of cancer vaccines.

Viral Modulation of TLRs and Cytokines and the Related Immunotherapies for HPV-Associated Cancers

The modulation of the host innate immune system is a well-established carcinogenesis feature of several tumors, including human papillomavirus- (HPV-) related cancers. This virus is able to interrupt the initial events of the immune response, including the expression of Toll-like receptors (TLRs), cytokines, and inflammation. Both TLRs and cytokines play a central role in HPV recognition, cell maturation and differentiation as well as immune signalling. Therefore, the imbalance of this sensitive control of the immune response is a key factor for developing immunotherapies, which strengthen the host immune system to accomplish an efficient defence against HPV and HPV-infected cells. Based on this, the review is aimed at exposing the HPV immune evasion mechanisms involving TLRs and cytokines and at discussing existing and potential immunotherapeutic TLR- and cytokine-related tools.

Therapy Testing in a Spheroid-based 3D Cell Culture Model for Head and Neck Squamous Cell Carcinoma

Current treatment options for advanced and recurrent head and neck squamous cell carcinoma (HNSCC) enclose radiation and chemo-radiation approaches with or without surgery. While platinum-based chemotherapy regimens currently represent the gold standard in terms of efficacy and are given in the vast majority of cases, new chemotherapy regimens, namely immunotherapy are emerging. However, the response rates and therapy resistance mechanisms for either chemo regimen are hard to predict and remain insufficiently understood. Broad variations of chemo and radiation resistance mechanisms are known to date. This study describes the development of a standardized, high-throughput in vitro assay to assess HNSCC cell line's response to various therapy regimens, and hopefully on primary cells from individual patients as a future tool for personalized tumor therapy. The assay is designed to being integrated into the quality-controlled standard algorithm for HNSCC patients at our tertiary care center; however, this will be subject of future studies. Technical feasibility looks promising for primary cells from tumor biopsies from actual patients. Specimens are then transferred into the laboratory. Biopsies are mechanically separated followed by enzymatic digestion. Cells are then cultured in ultra-low adhesion cell culture vials that promote the reproducible, standardized and spontaneous formation of three-dimensional, spheroid-shaped cell conglomerates. Spheroids are then ready to be exposed to chemo-radiation protocols and immunotherapy protocols as needed. The final cell viability and spheroid size are indicators of therapy susceptibility and therefore could be drawn into consideration in future to assess the patients' likely therapy response. This model could be a valuable, cost-efficient tool towards personalized therapy for head and neck cancer.

Advances in T-cell checkpoint immunotherapy for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) has been found to be a complex group of malignancies characterized by their profound immunosuppression and high aggressiveness. In most cases of advanced HNSCC, treatment fails to obtain total cancer cure. Efforts are needed to develop new therapeutic approaches to improve HNSCC outcomes. In this light, T-cells "immune checkpoint" has attracted much attention in cancer immunotherapy. It has been broadly accepted that inhibitory T-cell immune checkpoints contribute to tumor immune escape through negative immune regulatory signals (cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4], programmed cell death 1 [PD-1], B7-H3, and B7-H4, etc). Current data suggest that PD-1 and CTLA-4 receptors can inhibit T-cell receptors and T-cell proliferation. Blockade of PD-1/PD-L1 and/or CTLA-4/CD28 pathways has shown promising tumor outcomes in clinical trials for advanced solid tumors like melanoma, renal cell cancer, and non-small cell lung cancer. The present review attempts to explore what is known about PD-1/PD-L1 and CTLA-4/CD28 pathways with a focus on HNSCC. We further discuss how these pathways can be manipulated with therapeutic intent.