Analysis of the benefit of salvage chemotherapy after progression on nivolumab in patients with squamous cell carcinoma of the head and neck

BACKGROUND

Checkpoint inhibitor (CI) therapies have shown benefit in the treatment of locally recurrent or metastatic head and neck squamous cell carcinoma (R L/M HNSCC). Previous studies have suggested a superior benefit of salvage chemotherapy (SCT) in R/M HNSCC after progression on CI. We aimed to describe the benefit of SCT after progression on nivolumab.

PATIENTS AND METHODS

Patients were eligible if they received at least one injection of SCT in the treatment of R/M HNSCC after progression on nivolumab between 2017 and 2022. The present work was a retrospective and monocenter study. Primary endpoint was the objective response rate (ORR) on first regimen of salvage chemotherapy (SCT1). Secondary endpoints were disease-control rate (DCR), ORR on second course of SCT (ORR2), progression-free survival (PFS) on SCT1 and SCT2 (PFS2) and overall survival (OS).

RESULTS

Eighty-three patients received an SCT. The ORR on STC1 was 32%. Median progression-free survival (PFS) was 2.20 months (CI 95% 2.06-3.71). Median OS was 5.55 months (CI 95% 4.82-10.20). The ORR to the first line of treatment in the relapse setting was an independent prognostic factor for SCT1 PFS and OS.

CONCLUSION

In R/M HNSCC, SCT following nivolumab is associated with ORRs of 32%. These results are consistent with other publications that suggest a superior benefit of SCT after CI treatment, independent of the tumor outcome on previous immunotherapy.

SN-38, an active metabolite of irinotecan, enhances anti-PD-1 treatment efficacy in head and neck squamous cell carcinoma

Anti-programmed cell death 1 (anti-PD-1) therapy shows definite but modest activity in patients with advanced/metastatic head and neck squamous cell carcinoma (HNSCC). Preliminary evidence suggests that SN-38, an activated form of irinotecan that increases expression of the transcription factor FoxO3a, can suppress programmed cell death ligand-1 (PD-L1) expression in breast and ovarian tumor models. We analyzed the SN-38-mediated activation of natural killer cells in vitro and explored the efficacy of SN-38 in combination with anti-PD-1 for treatment in vivo. In vitro, SN-38 enhanced the expression of FoxO3a and reduced the expression of c-Myc and PD-L1 dose-dependently in tumor cells. Low-dose SN-38 increased interferon-γ secretion by NK cells and promoted NK cell-mediated cytotoxicity in tumor cells. In vivo studies revealed that at non-cytotoxic drug concentrations, SN-38 significantly enhanced anti-PD-1 activity in suppressing murine tumor growth. We found increased NK cell and CD8⁺ T-cell infiltration in post-treatment tumors. RNA-seq analysis indicated that SN-38 increased the enrichment of immune cells and biological function genes related to the immune responses. SN-38 is a potentially beneficial adjunct to checkpoint inhibitor therapy in HNSCC. Further studies exploring its mechanism of action and possible applications are necessary. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Immunomodulatory Therapy in Head and Neck Squamous Cell Carcinoma: Recent Advances and Clinical Prospects

The immune system plays a significant role in the development, invasion, progression, and metastasis of head and neck cancer. Over the last decade, the emergence of immunotherapy has irreversibly altered the paradigm of cancer treatment. The current treatment modalities for head and neck squamous cell carcinoma (HNSCC) include surgery, radiotherapy, and adjuvant or neoadjuvant chemotherapy which has failed to provide satisfactory clinical outcomes. To encounter this, there is a need for a novel or targeted therapy such as immunological targets along with conventional treatment strategy for optimal therapeutic outcomes. The immune system can contribute to promoting metastasis, angiogenesis, and growth by exploiting the tumor's influence on the microenvironment. Immunological targets have been found effective in recent clinical studies and have shown promising results. This review outlines the important immunological targets and the medications acting on them that have already been explored, are currently under clinical trials and are further being targeted.

Prognostic and Predictive Factors in Advanced Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease arising from the mucosa of the upper aerodigestive tract. Despite multimodality treatments approximately half of all patients with locally advanced disease relapse and the prognosis of patients with recurrent or metastatic HNSCC is dismal. The introduction of checkpoint inhibitors improved the treatment options for these patients and pembrolizumab alone or in combination with a platinum and fluorouracil is now the standard of care for first-line therapy. However, approximately only one third of unselected patients respond to this combination and the response rate to checkpoint inhibitors alone is even lower. This shows that there is an urgent need to improve prognostication and prediction of treatment benefits in patients with HNSCC. In this review, we summarize the most relevant risk factors in the field and discuss their roles and limitations. The human papilloma virus (HPV) status for patients with oropharyngeal cancer and the combined positive score are the only biomarkers consistently used in clinical routine. Other factors, such as the tumor mutational burden and the immune microenvironment have been highly studied and are promising but need validation in prospective trials.

Progression Patterns, Treatment, and Prognosis Beyond Resistance of Responders to Immunotherapy in Advanced Non-Small Cell Lung Cancer

Introduction

Immune checkpoint inhibitors (ICIs) have changed the management of non-small cell lung cancer (NSCLC). However, resistance is inevitable. The disease progression patterns, sequential treatment, and prognosis beyond ICI resistance are not completely understood.

Methods

We retrospectively analyzed stage IV NSCLC patients who underwent ICI treatment at Zhejiang Cancer Hospital between January 2016 and January 2020 and who suffered disease progression after at least stable disease on immunotherapy for more than 3 months (at least two cycles). Oligoprogression and systematic progression were defined as previous reports. The main outcome measures were progression-free survival (PFS), second PFS (PFS2), and overall survival (OS). Survival curves were plotted using the Kaplan-Meier method. The Cox proportional hazards model was used for multivariate analysis.

Results

Totally 1,014 NSCLC patients were administered immunotherapy. Of them, 208 NSCLC patients were included in this retrospective study. The estimated PFS, PFS2 and OS were 6.3 months (95% CI 5.6–7.0 months), 10.7 months (95% CI 10.1–12.7 months), and 21.4 months (95% CI 20.6–26.4 months), respectively. After resistance, 55.3% (N = 115) patients developed oligoprogression, and 44.7% (N = 93) systemic progression. For patients with systemic progression, chemotherapy (N = 35, 37.6%), best supportive care (N = 30, 32.3%), and antiangiogenic therapy alone (N = 11, 11.8%) were the major strategies. A combination of local radiotherapy (N = 38, 33.0%) with continued ICIs was the most common treatment used in oligoprogression group, followed by continued immunotherapy with antiangiogenic therapy (N = 19, 16.5%) and local radiotherapy only (N = 17, 14.9%). For patients with oligoprogression, continued immunotherapy plus local radiotherapy can lead to a significantly longer PFS2 (12.9 vs. 10.0 months; p = 0.006) and OS (26.3 vs. 18.5 months, p = 0.001). The PFS2 and OS of patients with oligoprogression were superior to those of patients with systemic progression (PFS2: 13.1 vs. 10.0 months, p = 0.001; OS: 25.8 vs. 19.1 months, p = 0.003).

Conclusions

The major progression pattern after acquired resistance from immunotherapy is oligoprogression. Local radiotherapy with continued immunotherapy beyond oligoprogression in responders was feasible and led to prolonged PFS2 and OS in advanced NSCLC patients.

Neoadjuvant immunotherapy in resectable head and neck cancer: oral cavity carcinoma as a potential research model

Squamous cell carcinoma of oral cavity (OCSCC) accounts for approximately 25% of cases of head and neck squamous cell carcinoma (HNSCC). Tobacco and alcohol consumption are the main risk factors for both cancers. Surgical resection, combined with adjuvant radiotherapy or radiochemotherapy in patients with high risk of relapse, is the key element in management in the initial stages. However, despite the availability of aggressive multidisciplinary treatments, advanced resectable OCSCC carries poor prognosis; only half of the patients are disease-free 5 years after the surgery. Immunotherapy based on the use of immune checkpoint inhibitors has been proven to be effective in a wide variety of tumours, including recurrent and metastatic HNSCC. These positive results resulted in investigations into its effectiveness in earlier stages of the disease with OCSCC emerging as an interesting research model because of the accessible location of the tumours. This article reviews the potential advantages of emerging immunotherapeutic agents [mainly monoclonal antibodies against programmed cell death-1 (PD-1) immune checkpoint inhibitors] as neoadjuvant treatment for OCSCC at locoregional stages as well as the ongoing clinical trials, challenges in evaluating tumour response, and possible predictive biomarkers of response with highlights regarding the role of oral microbiota as modulators of immune response. The efficacy and safety of anti-PD-1 drugs in these patients have been proven in preliminary trials. If there is a decrease in the relapse rate and an improvement in the overall survival after surgical resection in ongoing trials, preoperative immunotherapy may be established as a treatment option for patients with early stages of the disease.

Prospective development and validation of a liquid immune profile-based signature (LIPS) to predict response of patients with recurrent/metastatic cancer to immune checkpoint inhibitors

Background

The predictive power of novel biological markers for treatment response to immune checkpoint inhibitors (ICI) is still not satisfactory for the majority of patients with cancer. One should identify valid predictive markers in the peripheral blood, as this is easily available before and during treatment. The current interim analysis of patients of the ST-ICI cohort therefore focuses on the development and validation of a liquid immune profile-based signature (LIPS) to predict response of patients with metastatic cancer to ICI targeting the programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis.

Methods

A total of 104 patients were prospectively enrolled. 54 immune cell subsets were prospectively analyzed in patients’ peripheral blood by multicolor flow cytometry before treatment with ICI (pre-ICI; n=89), and after the first application of ICI (n=65). Pre-ICI, patients were randomly allocated to a training (n=56) and a validation cohort (n=33). Univariate Cox proportional hazards regression analysis and least absolute shrinkage and selection operator Cox model were used to create a predictive immune signature, which was also checked after the first ICI, to consider the dynamics of changes in the immune status.

Results

Whole blood samples were provided by 89 patients pre-ICI and by 65 patients after the first ICI. We identified a LIPS which is based on five immune cell subtypes: CD14^high monocytes, CD8+/PD-1⁺ T cells, plasmacytoid dendritic cells, neutrophils, and CD3⁺/CD56⁺/CD16⁺ natural killer (NK)T cells. The signature achieved a high accuracy (C-index 0.74 vs 0.71) for predicting overall survival (OS) benefit in both the training and the validation cohort. In both cohorts, the low-risk group had significantly longer OS than the high-risk group (HR 0.26, 95% CI 0.12 to 0.56, p=0.00025; HR 0.30, 95% CI 0.10 to 0.91, p=0.024, respectively). Regarding the whole cohort, LIPS also predicted progression-free survival (PFS). The identified LIPS was not affected by clinicopathological features with the exception of brain metastases. NKT cells and neutrophils of the LIPS can be used as dynamic predictive biomarkers for OS and PFS after first administration of the ICI.

Conclusion

Our study identified a predictive LIPS for survival of patients with cancer treated with PD-1/PD-L1 ICI, which is based on immune cell subsets in the peripheral whole blood.

Trial registration number

NCT03453892.

Synergies Radiotherapy-Immunotherapy in Head and Neck Cancers. A New Concept for Radiotherapy Target Volumes-"Immunological Dose Painting"

The combination of immune checkpoint inhibitors and definitive radiotherapy is investigated for the multimodal treatment of cisplatin non-eligible locally advanced head and neck cancers (HNC). In the case of recurrent and metastatic HNC, immunotherapy has shown benefit over the EXTREME protocol, being already considered the standard treatment. One of the biggest challenges of multimodal treatment is to establish the optimal therapy sequence so that the synergistic effect is maximal. Thus, superior results were obtained for the administration of anti-CTLA4 immunotherapy followed by hypofractionated radiotherapy, but the anti-PD-L1 therapy demonstrates the maximum potential of radio-sensitization of the tumor in case of concurrent administration. The synergistic effect of radiotherapy–immunotherapy (RT–IT) has been demonstrated in clinical practice, with an overall response rate of about 18% for HNC. Given the demonstrated potential of radiotherapy to activate the immune system through already known mechanisms, it is necessary to identify biomarkers that direct the “nonresponders” of immunotherapy towards a synergistic RT–IT stimulation strategy. Stimulation of the immune system by irradiation can convert “nonresponder” to “responder”. With the development of modern techniques, re-irradiation is becoming an increasingly common option for patients who have previously been treated with higher doses of radiation. In this context, radiotherapy in combination with immunotherapy, both in the advanced local stage and in recurrent/metastatic of HNC radiotherapy, could evolve from the “first level” of knowledge (i.e., ballistic precision, dose conformity and homogeneity) to “level two” of “biological dose painting” (in which the concept of tumor heterogeneity and radio-resistance supports the need for doses escalation based on biological criteria), and finally to the “third level“ ofthe new concept of “immunological dose painting”. The peculiarity of this concept is that the radiotherapy target volumes and tumoricidal dose can be completely reevaluated, taking into account the immune-modulatory effect of irradiation. In this case, the tumor target volume can include even the tumor microenvironment or a partial volume of the primary tumor or metastasis, not all the gross and microscopic disease. Tumoricidal biologically equivalent dose (BED) may be completely different from the currently estimated values, radiotherapy treating the tumor in this case indirectly by boosting the immune response. Thus, the clinical target volume (CTV) can be replaced with a new immunological-clinical target volume (ICTV) for patients who benefit from the RT–IT association (Image 1).

Emerging immune checkpoint inhibitors for the treatment of head and neck cancers

Introduction: The benefits of immune checkpoint inhibitors (ICIs) in recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) have been demonstrated through multiple studies to improve overall survival (OS) with decreased side effects when compared to the standard of care (SOC) treatment regimens in place for decades, leading to the approval of two ICIs, nivolumab and pembrolizumab. There has been a subsequent influx in the development of novel immunotherapy agents for the treatment of HNSCC. Areas covered: Data for anti-programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) and anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4) antibodies in treatment of R/M HNSCC will be reviewed. Emerging immune checkpoint inhibitors as well as combined therapies in HNSCC will be discussed. The role of predictive biomarkers, HPV-status, PD-L1 expression, and challenges related to treating patients with ICIs will be summarized. Expert opinion: A shift toward ICIs as SOC for the treatment of R/M HNSCC will continue as emerging immune checkpoints and combination therapies are evaluated. Response rates are variable in this patient population underlying the importance of identifying predictive biomarkers to aid in patient selection for ICI treatment.

Review of emerging biomarkers in head and neck squamous cell carcinoma in the era of immunotherapy and targeted therapy

BACKGROUND

Biomarkers in head and neck squamous cell carcinoma (HNSCC) emerge rapidly in recent years, especially for new targeted therapies and immunotherapies.

METHODS

Recent, relevant peer-reviewed evidence were critically reviewed and summarized.

RESULTS

This review article briefly introduces essential biomarker concepts, including purposes and classifications (predictive, prognostic, and diagnostic markers), and the phases of biomarker development. We summarize current biomarkers in order of clinical utility; p16 and human papillomavirus status remain the most important and validated biomarkers in HNSCC. The rationale for biomarker study design continues to evolve with technological advances, especially whole-exome or whole-genomic sequencing. Noninvasive body fluid and liquid biopsy biomarkers appear to hold strong potential for development as tools for early cancer detection, cancer diagnosis, monitoring of disease recurrence, and outcome prediction. In light of discrepancies among different technologies, standardized approaches are needed.

CONCLUSION

Biomarkers from cancer tissue or blood in HNSCC could direct new anticancer therapies.

Management of recurrent and metastatic oral cavity cancer: Raising the bar a step higher

In recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M-SCCHN), the armamentarium of systemic anti-cancer modalities continues to grow in parallel with innovations in and better integration of local approaches. The backbone of cytotoxic chemotherapy remains cisplatin with 5-fluorouracil or a taxane. In contrast to cisplatin, the tumoricidal activity of carboplatin monotherapy is debatable. Adding the epidermal growth factor receptor (EGFR) inhibitor cetuximab to a platinum/5-fluorouracil doublet (the so-called EXTREME regimen) produced a statistically but also clinically significant improvement of survival and became thus the standard first-line palliative treatment in adequately fit patients. Interestingly, three large randomized trials (EXTREME, SPECTRUM, and ZALUTE) evaluating different anti-EGFR monoclonal antibodies (cetuximab, panitumumab, and zalutumumab, respectively) demonstrated preferential anti-tumour efficacy in patients with primary cancer in the oral cavity. Modern immunotherapy with immunomodulating antibodies, dubbed immune checkpoint inhibitors, such as anti-programmed cell death protein-1 (anti-PD-1) inhibitors nivolumab and pembrolizumab, showed unprecedented activity in one first-line (KEYNOTE-048) and several second-line trials (CheckMate-141, KEYNOTE-012, KEYNOTE-055, and KEYNOTE-040). In a minority of also heavily-pretreated patients, these agents generate long-lasting responses without the typical chemotherapy-related toxicity, however, at a price of a low overall response rate, rare but potentially life-threatening immune-related adverse events, the risk of hyperprogression, and high costs. In oligometastatic disease, emerging data indicate long-term benefit with locally ablative techniques including metastasectomy and stereotactic radiotherapy of pulmonary but also hepatic and other distant lesions. In the frame of highly-individualized cancer care, a particularly intriguing approach is a combination of systemic and local therapies.

Immunotherapies and Future Combination Strategies for Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is often diagnosed at an advanced stage and has a dismal prognosis. Nearly 10 years after the approval of cetuximab, anti-PD1/PD-L1 checkpoint inhibitors are the first drugs that have shown any survival benefit for the treatment on platinum-refractory recurrent/metastatic (R/M) HNSCC. Furthermore, checkpoint inhibitors are better tolerated than chemotherapy. The state of the art in the treatment of R/M HNSCC is changing, thanks to improved results for checkpoint inhibitors. Results for these treatments are also awaited in curative settings and for locally advanced HNSCC. Unfortunately, the response rate of immunotherapy is low. Therefore, the identification of predictive biomarkers of response and resistance to anti-PD1/PD-L1 is a key point for better selecting patients that would benefit the most from immunotherapy. Furthermore, the combination of checkpoint inhibitors with various agents is being currently evaluated to improve the response rate, prolong response duration, and even increase the chances for a cure. In this review, we summarize the most important results regarding immune targeting agents for HNSCC, predictive biomarkers for resistance to immune therapies, and future perspectives.

A review and validation of overall survival extrapolation in health technology assessments of cancer immunotherapy by the National Institute for Health and Care Excellence: how did the initial best estimate compare to trial data subsequently made available?

BACKGROUND

Validation of overall survival (OS) extrapolations of immune-checkpoint inhibitors (ICIs) during the National Institute for Health and Care Excellence (NICE) Single Technology Assessment (STA) process is limited due to data still maturing at the time of submission. Inaccurate extrapolation may lead to inappropriate decision-making. The availability of more mature trial data facilitates a retrospective analysis of the plausibility and validity of initial extrapolations. This study compares these extrapolations to subsequently available longer-term data.

METHODS

A systematic search of completed NICE appraisals of ICIs from March 2000 to December 2017 was performed. A targeted search was also undertaken to procure published OS data from the pivotal clinical trials for each identified STA made available post-submission to NICE. Initial Kaplan-Meier curves and associated extrapolations from NICE documentation were extracted to compare the accuracy of OS projections versus the most mature data.

RESULTS

The review identified 11 STAs, of which 10 provided OS data upon submission to NICE. The extrapolations undertaken considered parametric or piecewise survival models. Additional data cut-offs provided a mean of 18 months of OS beyond the end of the original data. Initial extrapolations typically under-estimated OS from the most mature data cut-off by 0.4-2.7%, depending on the choice of assessment method and use of the manufacturer- or ERG-preferred extrapolation.

CONCLUSION

Long-term extrapolation of OS is required for NICE STAs based on initial immature OS data. The results of this study demonstrate that the initial OS extrapolations employed by manufacturers and ERGs generally predicted OS reasonably well when compared to more mature data (when available), although on average they appeared to underestimate OS. This review and validation shows that, while the choice of OS extrapolation is uncertain, the methods adopted are generally aligned with later-published follow-up data and appear appropriate for informing HTA decisions.

Durable intracranial and extracranial response to nivolumab with appearance of secondary resistance in a heavily pretreated patient with head and neck cancer

BACKGROUND

Recently, nivolumab was approved in the second-line setting of squamous cell cancer of the head and neck (SCCHN). The benefits of PD-(L)1 inhibitors in PD-L1(-) tumors are unclear, and no reports exist on the activity of these agents in brain metastases from SCCHN. Little is known regarding the mechanisms underlying acquired resistance to PD-(L)1 inhibition.

METHODS

A patient with PD-L1(-) metastatic SCCHN progressing to cetuximab-based chemotherapy received third-line nivolumab. T cell infiltration and mRNA expression of immune-related genes were compared in prenivolumab and postnivolumab biopsies from a progressing tumor lesion.

RESULTS

An exceptional local and systemic response was achieved, including complete devitalization of brain metastases that lasted for more than a year. Increased T cell infiltration and upregulation of genes related to T cell exhaustion and resistance to PD-1 inhibition were found.

CONCLUSION

Durable responses to PD-(L)1 inhibitors may be observed in biomarker-negative SCCHN. Mechanisms of resistance should be studied.

Unexpected response with palliative conventional therapy in head and neck squamous cell carcinoma after anti-programmed death-1 progression

BACKGROUND

The application of anti-programmed death-1 (PD-1) therapies for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) has found promising results. It is the first "second-line therapy" in this setting to impact on prognosis. The studies demonstrated overall response rates in the range of 20%. Therefore, HNSCC showed 60%-80% progression at first evaluation with better overall survival, suggesting regained efficacy of treatments given thereafter.

METHODS

We report three clinical cases treated with anti-PD-1 after platinum-based chemotherapy.

RESULTS

Our case reports achieved an unforeseen response to conventional therapies supporting the hypothesis of restored responses to conventional therapies after immunotherapy.

CONCLUSIONS

We believe that the inhibition of the PD-1/PD-ligand 1 checkpoint may synergize with both chemotherapy or radiotherapy through immunologic interplay, reversing the HNSCC-induced immune suppression.

Patterns of Response and Progression to Immunotherapy

Patterns of response and progression to immunotherapy may differ from those observed with drugs such as chemotherapy and molecularly targeted agents. Specifically, some patients experience a response after progression that is retrospectively named pseudoprogression. This phenomenon of pseudoprogression, first reported in patients with melanoma who were treated with ipilimumab, has led to the development of immune-specific related response criteria, such as irRC (immune-related response criteria), irRECIST (immune-related RECIST), and iRECIST (immunotherapy RECIST) that allow continued treatment beyond progression. However, the rate of pseudoprogression has never exceeded 10% of patients across tumor types. Conversely, rapid progressions after immunotherapy, called hyperprogressions, were reported by three different teams in 9% to 29% of patients treated with immunotherapy. Because of the absence of control arms in these studies, it remains to be determined whether these rapid progressions reflect a detrimental effect of immunotherapy in these patients. Finally, preliminary data suggest that immunotherapy might also affect response to subsequent standard therapies. In total, given the rarity of pseudoprogressions across tumor types and the recent description of hyperprogressions, classic RECIST remains a reasonable and rational method to assess response to immunotherapy. Continuation of treatment beyond progression should be proposed only in carefully selected patients whose clinical conditions have improved and who have not experienced severe toxicities. Although there is an urgent need to identify predictive biomarkers of efficacy to immunotherapy, there is an equally urgent need to identify predictive factors of progression or possibly hyperprogression.

Immunotherapy beyond progression in advanced renal cell carcinoma: a case report and review of the literature

Immunotherapy is associated with different response patterns compared with chemotherapy and targeted therapy, including delayed response and stabilization after progression (pseudoprogression). According to new immuno-based response criteria, immunotherapy can be continued after radiological progression when a clinical benefit is observed. We report a case of an advanced renal cell carcinoma patient treated with nivolumab, who developed clinical benefit and delayed radiological response after initial progression. We performed a review of the literature on immunotherapy beyond progression in advanced solid tumors. 12 clinical trials were identified and showed that selected patients have subsequent response and survival benefit receiving immunotherapy beyond progression. Future studies are needed to optimize timing and duration of immunotherapy and to define patient selection criteria for treatment beyond progression.

Immune Checkpoint Inhibition in Head and Neck Cancer

Head and Neck Squamous Cell Carcinoma (HNSCC) is the 6th most common cancer globally and commonly presents with locally advanced disease, which has a recurrence rate of around 50% despite aggressive multi-modality treatment involving surgery, radiotherapy and chemotherapy or EGFR inhibition where appropriate. As understanding of the underlying cancer biology and the complex interactions within the tumor microenvironment improves, there is gathering interest in and evidence for the role of immunomodulating agents in the management of HNSCC. Immune checkpoint inhibitors, which aim to hinder the inhibitory interaction between programmed cell death protein 1 (PD-1) and its ligand PD-L1, have demonstrated durable improvements in patient outcomes in advanced / metastatic HNSCC, with both pembrolizumab and nivolumab being granted FDA approval in 2016. There are numerous ongoing clinical trials exploring the role of checkpoint inhibitors both as single agents and in combination, administered with established treatment modalities such as chemotherapy and radiotherapy, as well as alongside other novel immune modulators. These trials are not limited to advanced / metastatic HNSCC, but also to the neo-adjuvant or adjuvant settings. As studies complete and more results become available, the role immunotherapy agents will have within the treatment strategies for HNSCC may change, with increasing biomarker selection resulting in personalized therapy aiming to further improve patient outcomes.

Immunotherapy in Head and Neck Squamous Cell Cancer

Prognosis in relapsed metastatic head and neck squamous cell cancer (RM-HNSCC) is dismal. Platinum based chemotherapy in combination with Cetuximab is used in first-line setting, while no further validated options are available at progression. Immunotherapy has produced durable clinical benefit in some patients with RM-HNSCC although the premises are several patients are nonresponders. Studies are ongoing to determine predictive factors and the ideal setting/combination of novel immunotherapies. In this paper, we discuss the past and present of immunotherapy in head and neck cancer and provide an up-to-date information regarding the potential ways to improve immunotherapy outcomes in HNSCC.

Nivolumab in recurrent/metastatic head and neck cancers

Head and neck cancer is an immunosuppressive disease, with a high proportion expressing PD-L1. Until recently, options were lacking in second line. Prognosis is poor especially for patients who progress during chemotherapy with survival often inferior to 6 months. Nivolumab is the only anti-PD-1 agent to prolong survival in the second-line setting and is now the standard option since the CheckMate-141 trial. Treatment is generally well tolerated, patients seem to have a better quality of life when compared with chemotherapy. Markers of efficacy are lacking even if some data are emerging. Different combinations of immunotherapy are ongoing. Hyperprogression is a phenomenon associated with poor outcome and might be the consequence of anti-PD-1 treatment but this is yet to be proven.