Nivolumab vs investigator's choice in recurrent or metastatic squamous cell carcinoma of the head and neck: 2-year long-term survival update of CheckMate 141 with analyses by tumor PD-L1 expression

Phase 1 Study Evaluating the Association of the Cyclin-Dependent Kinase 4/6 Inhibitor Ribociclib and Cetuximab in Recurrent/Metastatic p16-Negative Squamous Cell Carcinoma of the Head and Neck

Background: The majority of human papillomavirus (HPV)-negative squamous cell carcinoma of the head and neck (SCCHN) present upregulation of the epidermal growth factor receptor (EGFR) and frequent alterations in the cyclin D1-cyclin dependent kinase (CDK) 4/6 (CDK 4/6)-retinoblastoma protein (pRb) pathway, resulting in cell cycle progression and tumor proliferation. This study investigated the combination of ribociclib, an orally highly selective inhibitor of CDK 4/6, and cetuximab in recurrent and/or metastatic (R/M) SCCHN. Methods: A phase I trial using a 3 + 3 design was performed to determine the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) of ribociclib with standard dose of weekly cetuximab in HPV-negative patients with R/M SCCHN. Ribociclib was administered orally (3 weeks on/1 week off) at dose level 1 of 400 mg daily and dose level 2 of 600 mg daily. The MTD of ribocilib was then further evaluated in an expansion cohort. Results: 10 patients were enrolled in the escalation trial. No DLTs were observed at dose level 1 (n = 3); at dose level 2, one patient was replaced due to rapid disease progression, and one patient out of six evaluable patients experienced a DLT (grade 4 thrombocytopenia >7 days). Ribociclib 600 mg daily was thus determined to be the MTD. Eleven additional patients were enrolled in the expansion cohort. Diarrhea (52%), rash (52%), fatigue (43%), nausea (33%), and mucositis (28%) were the most frequent grade 1-2 adverse events (AE). Neutropenia was the most frequent grade 3-4 AE (20%). Median progression-free survival (PFS) was 3.5 months (range 0.4-17.3 months) and median overall survival (OS) was 8.3 months (range 0.4-24.1 months). Among the 19 radiologically evaluable patients, two (10.5%) achieved a partial response and 11 (58%) had stable disease. Conclusions: The MTD of ribociclib is 600 mg daily when administered in combination with standard dose cetuximab for 3 weeks on and 1 week off. This combination was safe and showed efficacy. Further clinical trials should be conducted to evaluate the antitumor effects of this combination. Trial Information: ClinicalTrials.gov: NCT02429089; Eudract number 2014-005371-83.

Immunotherapy Approaches Beyond PD-1 Inhibition: the Future of Cellular Therapy for Head and Neck Squamous Cell Carcinoma

OPINION STATEMENT

In a span of a few years, the surprising early successes of programmed cell death 1 (PD-1) inhibitors across a vast range of tumor types have transformed our understanding of cancer immunogenicity and provided proof of principle that T cells, if manipulated, can mediate meaningful tumor regression. In head and neck cancer, only a minority of patients respond to PD-1 therapy, but these small outcomes have fueled the enthusiasm for the next generation of immunotherapy-adoptive cell therapy-which employs recent advances in genetic engineering and cell culturing methods to generate T cells with enhanced anti-tumor efficacy for infusion back into the patient. Head and neck cancer is comprised of biologically distinct cancers, HPV-positive and HPV-negative, and the clinical responses to PD-1 inhibitors in both HPV-positive and HPV-negative head and neck patients have showcased better than any other cancer type that there are distinct pathways to immunogenicity that may lend themselves to different therapeutic approaches. Thus, head and neck cancer is uniquely poised to benefit from the personalized approach of adoptive cell therapy as well as provide a valuable platform to explore contrasting T cell modalities. In this article, we will review the growing portfolio of trials of adoptive cell therapies in head and neck cancer and discuss the future directions of this emerging new field.

Non-murine models to investigate tumor-immune interactions in head and neck cancer

The immune response has important roles in the biology of solid tumors, including oncogenesis, tumor growth, invasion and metastasis, and response to treatment. Improved understanding of tumor-immune system interactions has provided promising therapeutic options that are based on the rescue and enhancement of the anti-tumoral host response. Immune-based treatments have been approved for clinical use in various types of cancer, including head and neck cancer (HNC); other strategies involving combination therapies are currently in development. These novel therapies were developed based on knowledge derived from in vitro, in silico, and in vivo pre-clinical studies. However, clinical trials seldom replicate the efficacy observed in pre-clinical animal studies. This lack of correlation between pre-clinical studies and clinical trials may be related to limitations of the models used; which highlights the relevance of considering immune-related aspects of different pre-clinical models. Murine models are the most frequently used pre-clinical models of HNC and are discussed elsewhere. Non-murine models have characteristics that offer unique opportunities for the study of HNC etiology, therapeutic strategies, and tumor-immune system interactions. The current review focuses on immune-related aspects of non-murine models, including dog, cat, pig, zebrafish, and frog, that could be used to investigate tumor-immune interactions in HNC.

Rationale for Combining Radiotherapy and Immune Checkpoint Inhibition for Patients With Hypoxic Tumors

In order to compensate for the increased oxygen consumption in growing tumors, tumors need angiogenesis and vasculogenesis to increase the supply. Insufficiency in this process or in the microcirculation leads to hypoxic tumor areas with a significantly reduced pO2, which in turn leads to alterations in the biology of cancer cells as well as in the tumor microenvironment. Cancer cells develop more aggressive phenotypes, stem cell features and are more prone to metastasis formation and migration. In addition, intratumoral hypoxia confers therapy resistance, specifically radioresistance. Reactive oxygen species are crucial in fixing DNA breaks after ionizing radiation. Thus, hypoxic tumor cells show a two- to threefold increase in radioresistance. The microenvironment is enriched with chemokines (e.g., SDF-1) and growth factors (e.g., TGFβ) additionally reducing radiosensitivity. During recent years hypoxia has also been identified as a major factor for immune suppression in the tumor microenvironment. Hypoxic tumors show increased numbers of myeloid derived suppressor cells (MDSCs) as well as regulatory T cells (Tregs) and decreased infiltration and activation of cytotoxic T cells. The combination of radiotherapy with immune checkpoint inhibition is on the rise in the treatment of metastatic cancer patients, but is also tested in multiple curative treatment settings. There is a strong rationale for synergistic effects, such as increased T cell infiltration in irradiated tumors and mitigation of radiation-induced immunosuppressive mechanisms such as PD-L1 upregulation by immune checkpoint inhibition. Given the worse prognosis of patients with hypoxic tumors due to local therapy resistance but also increased rate of distant metastases and the strong immune suppression induced by hypoxia, we hypothesize that the subgroup of patients with hypoxic tumors might be of special interest for combining immune checkpoint inhibition with radiotherapy.

Differences of tumor-recruiting myeloid cells in murine squamous cell carcinoma influence the efficacy of immunotherapy combined with a TLR7 agonist and PD-L1 blockade

OBJECTIVES

The immune status of the tumor microenvironment has a marked impact on clinical outcomes. Here we examined the immune environments of tumor-infiltrating leukocytes (TILes) in two murine models of squamous cell carcinoma and compared the effects of immunotherapeutic agents, including a TLR7 agonist and an immune checkpoint inhibitor, and a chemotherapeutic agent, gemcitabine, in these models.

MATERIALS AND METHODS

TILes from NR-S1- and SCCVII-grafted mice were analyzed by flow cytometry. NR-S1-inoculated mice received resiquimod (a synthetic TLR7 agonist), an anti-PD-L1 antibody, or both, and tumor growth and TILs were examined. Gemcitabine was administered to deplete CD11b⁺ cells.

RESULTS

More than 50% of TILes from NR-S1- and SCCVII-inoculated mice were CD11b⁺Gr-1⁺ cells. A major fraction of NR-S1 CD11b⁺ cells was Ly6G^highLy6C^low-negaF4/80^- tumor-associated neutrophils (TANs) and the majority of SCCVII CD11b⁺ cells were Ly6G^lowLy6C^-F4/80⁺ tumor-associated macrophages. NR-S1 TANs did not express MHC class II and CD86, but did express reactive oxygen species and PD-L1. Resiquimod, alone and in combination with an anti-PD-L1 antibody, did not regress NR-S1 tumors, but the combination increased the CD8/regulatory T cell-ratio, and IFN-γ and PD-1 expression in CD8⁺ TILes. Pre-administration of low-dose gemcitabine prior to the combination treatment suppressed the progression of NR-S1 tumors.

CONCLUSIONS

NR-S1 tumors with abundant recruitment of TANs were resistant to treatments with a TLR7 agonist, alone and in combination with PD-1 blockade, and required an additional gemcitabine treatment. The phenotype and status of tumor-infiltrating CD11b⁺ myeloid cells may influence the efficacy of immunotherapeutic agents.

The effects of checkpoint inhibition on head and neck squamous cell carcinoma: A systematic review

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent malignancy worldwide. Immunotherapy with checkpoint inhibitors such as anti-CTLA-4 anti-PD-l and anti-PD-L1 has shown promising results in treating patients with recurrent/metastatic HNSCC. We aimed to systematically review the literature on immunotherapy with checkpoint inhibitors as treatment for advanced HNSCC.

METHODS

PubMed, EMBASE, Google Scholar, and the Cochrane Library were systematically searched with the purpose of identifying all studies addressing the effects of checkpoint inhibitors as treatment for HNSCC in human clinical trials. We assessed effects of the treatment with checkpoint inhibitors on overall survival (OS), progression-free survival (PFS), HPV-status, PD-L1-status, and adverse events.

RESULTS

We identified eight studies (n = 1431 patients) with an OS ranging from 7.5 to 14.9 months in PD-1 checkpoint inhibition. Two studies (n = 541 patients) observed a significantly (p = 0.01) and (p = 0.007) longer OS with checkpoint inhibition compared to standard-treatment, platinum-based chemotherapy (7.5 versus 5.1 months and 14.9 months versus 10.7 months). Two studies (n = 411 patients) found an increased OS associated with PD-L1-postive patients compared to PD-L1-negative patients. The eight studies have heterogenous design with only three being randomized.

CONCLUSION

Few clinical trials have investigated the treatment with checkpoint inhibition for HNSCC. Solely, two randomized studies comprising 240 patients treated with nivolumab (anti-PD-L) and 301 patients treated with pembrolizumab (anti-PD-L) showed a significantly prolonged survival in patients with recurrent/metastatic HNSCC compared with standard-treatment. There is a further need for randomized clinical trials investigating a putative role of checkpoint inhibition in the treatment of advanced HNSCC.

CD147 mediates transforming growth factor-β1-induced epithelial-mesenchymal transition and cell invasion in squamous cell carcinoma of the tongue

Epithelial-mesenchymal transition (EMT) is a physiological process in which epithelial cells attain the motile and invasive characteristics of mesenchymal cells, which results in the development of increased migratory and invasive cell behavior, serving as a vital mechanism of cancer progression. Hence, controlling the EMT for cancer treatment, including head and neck squamous cell carcinoma (HNSCC), is imperative. Among EMT-associated factors, transforming growth factor-β (TGF-β) is a well-established potent inducer. Recent research has revealed that CD147, a member of the immunoglobulin superfamily, promotes the EMT. However, the role of CD147 in the EMT and the following tumorigenicity in HNSCC has not been completely elucidated. This study aims to investigate the role of CD147 in the EMT and related tumorigenicity in HNSCC. The present study used two HNSCC cell lines, SAS and FaDu, for in vitro studies. In HNSCC cells, TGF-β1 induced spindle-shaped morphological changes, and western blot analysis revealed that TGF-β1 induced changes in EMT markers, downregulation of vimentin, and upregulation of E-cadherin, yet increased CD147. In addition, TGF-β1 increased cell migration in HNSCC cells. However, a TGF-β1-induced alteration in EMT makers was attenuated with CD147 silencing by small interfering RNA (siRNA) in SAS cells. In addition, the TGF-β1-induced cell invasion of SAS was attenuated with CD147 silencing. In conclusion, the present study suggests that CD147 mediates TGF-β1-induced EMT and tumorigenicity in HNSCC. Hence, CD147 may serve as a vital therapeutic target in HNSCC.

Overcoming Resistance to Combination Radiation-Immunotherapy: A Focus on Contributing Pathways Within the Tumor Microenvironment

Radiation therapy has been used for many years to treat tumors based on its DNA-damage-mediated ability to kill cells. More recently, RT has been shown to exert beneficial modulatory effects on immune responses, such as triggering immunogenic cell death, enhancing antigen presentation, and activating cytotoxic T cells. Consequently, combining radiation therapy with immunotherapy represents an important area of research. Thus far, immune-checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have been the focus of many research studies and clinical trials. The available data suggest that such immunotherapies are enhanced when combined with radiation therapy. However, treatment resistance, intrinsic or acquired, is still prevalent. Various theories as to how to enhance these combination therapies to overcome treatment resistance have been proposed. In this review, we focus on the principles surrounding radiation therapy's positive and negative effects on the tumor microenvironment. We explore mechanisms underlying radiation therapy's synergistic and antagonistic effects on immune responses and provide a base of knowledge for radio-immunology combination therapies to overcome treatment resistance. We provide evidence for targeting regulatory T cells, tumor-associated macrophages, and cancer-associated fibroblasts in combination radio-immunotherapies to improve cancer treatment.

Characteristics and impact of programmed death-ligand 1 expression, CD8+ tumor-infiltrating lymphocytes, and p16 status in head and neck squamous cell carcinoma

BACKGROUND

No predictive biomarker of immune checkpoint inhibitors in head and neck squamous cell carcinoma (HNSCC) has been well established. The impact of programmed death-ligand 1 (PD-L1) expression, CD8+ tumor-infiltrating lymphocytes (TILs), and p16 status in HNSCC is unclear and may vary according to ethnicity.

METHODS

HNSCC patients treated between 2007 and 2013 were reviewed. Archival tissues were retrieved for PD-L1, CD8+ TILs, and p16 analyses. PD-L1 expression was evaluated by using the validated SP142 assay on the VENTANA platform. CD8+ TILs were defined by using semiquantitative scoring.

RESULTS

A total of 203 patients were analyzed. PD-L1 expression was observed in 80% of patients and was significantly associated with older age (P < 0.001). A high CD8+ TIL score (≥ 6) was significantly associated with never-smoking (P = 0.020), oral cavity cancer (P < 0.001), and stage M0 at presentation (P = 0.025). The p16 status was positive in 12% of patients. Patients with a high TIL score had a significantly longer OS (P = 0.032). Patients with PD-L1 expression of 1-49% and ≥ 50% were associated with a significantly shorter OS compared with those with PD-L1 < 1% (P = 0.027 and P = 0.011, respectively). Multivariate analysis showed that PD-L1 ≥ 50% was significantly associated with a poor OS. (HR 2.98 [95% CI 1.2-7.39]; P = 0.019.) CONCLUSIONS: A high prevalence of PD-L1 expression was observed in HNSCC using the validated SP142 assay. PD-L1 expression was associated with older age, while highly PD-L1 expression (≥ 50%) was an independent prognostic factor for poor OS in anti-PD1/PD-L1 untreated HNSCC patients.

Pembrolizumab versus methotrexate, docetaxel, or cetuximab for recurrent or metastatic head-and-neck squamous cell carcinoma (KEYNOTE-040): a randomised, open-label, phase 3 study

BACKGROUND

There are few effective treatment options for patients with recurrent or metastatic head-and-neck squamous cell carcinoma. Pembrolizumab showed antitumour activity and manageable toxicity in early-phase trials. We aimed to compare the efficacy and safety of pembrolizumab versus standard-of-care therapy for the treatment of head-and-neck squamous cell carcinoma.

METHODS

We did a randomised, open-label, phase 3 study at 97 medical centres in 20 countries. Patients with head-and-neck squamous cell carcinoma that progressed during or after platinum-containing treatment for recurrent or metastatic disease (or both), or whose disease recurred or progressed within 3-6 months of previous multimodal therapy containing platinum for locally advanced disease, were randomly assigned (1:1) in blocks of four per stratum with an interactive voice-response and integrated web-response system to receive pembrolizumab 200 mg every 3 weeks intravenously or investigator's choice of standard doses of methotrexate, docetaxel, or cetuximab intravenously (standard-of-care group). The primary endpoint was overall survival in the intention-to-treat population. Safety was analysed in the as-treated population. This trial is registered with ClinicalTrials.gov, number NCT02252042, and is no longer enrolling patients.

FINDINGS

Between Dec 24, 2014, and May 13, 2016, 247 patients were randomly allocated to pembrolizumab and 248 were randomly allocated to standard of care. As of May 15, 2017, 181 (73%) of 247 patients in the pembrolizumab group and 207 (83%) of 248 patients in the standard-of-care group had died. Median overall survival in the intention-to-treat population was 8·4 months (95% CI 6·4-9·4) with pembrolizumab and 6·9 months (5·9-8·0) with standard of care (hazard ratio 0·80, 0·65-0·98; nominal p=0·0161). Fewer patients treated with pembrolizumab than with standard of care had grade 3 or worse treatment-related adverse events (33 [13%] of 246 vs 85 [36%] of 234). The most common treatment-related adverse event was hypothyroidism with pembrolizumab (in 33 [13%] patients) and fatigue with standard of care (in 43 [18%]). Treatment-related death occurred in four patients treated with pembrolizumab (unspecified cause, large intestine perforation, malignant neoplasm progression, and Stevens-Johnson syndrome) and two patients treated with standard of care (malignant neoplasm progression and pneumonia).

INTERPRETATION

The clinically meaningful prolongation of overall survival and favourable safety profile of pembrolizumab in patients with recurrent or metastatic head and neck squamous cell carcinoma support the further evaluation of pembrolizumab as a monotherapy and as part of combination therapy in earlier stages of disease.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co.

Immune biomarkers of response to immune-checkpoint inhibitors in head and neck squamous cell carcinoma

Anti-programmed cell death protein 1 (PD-1) agents have become the standard of care for platinum-refractory recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) and are currently being evaluated in various disease settings. However, despite the gain in overall survival seen in some of the clinical trials, the majority of patients display primary resistance and do not benefit from these agents. Taking into consideration the potentially severe immune-related toxicities and their high cost, the search for predictive biomarkers of response is crucial. Besides Programmed death ligand-1 (PD-L1) expression, other biomarkers such as immune infiltration, tumor mutational burden or immune-gene expression profiling have been explored, but none of them has been validated in this disease. Among these, the microbiota has recently garnered tremendous interest since it has proven to influence the efficacy of PD-1 blockade in some tumor types. With the accumulating evidence on the effect of the microbiota in HNSCC tumorigenesis and progression, the study of its potential role as a predictive immune biomarker is warranted. This review examines the available evidence on emerging immune predictive biomarkers of response to anti-PD-1/PD-L1 therapy in HNSCC, introducing the microbiota and its potential use as a predictive immune biomarker in this disease.

L’immunothérapie dans les cancers ORL

IMMUNOTHERAPY IN HEAD AND NECK CANCERS

Immunotherapy wave has also touched head and neck cancer. In recurrent or metastatic disease, checkpoint inhibitors (anti PD-1/PD-L1) are approved in 2^nd line with a clear benefit on overall survival and quality of life. Multiple clinical studies are in progress in both palliative and curative intent, combined or not with other checkpoint inhibitor (anti-CTLA4) or other standard therapies (radiotherapy, chemotherapy). It is essential to define which patients will benefit from immunotherapy, according to robust biomarkers, in order to increase risk benefit balance by decreasing side effects and selecting those who respond the most. Here we present an overview of immunotherapy in 2018 in head and neck squamous cell cancer.

Efficacy of Carboplatin/Paclitaxel-Based Radiochemotherapy in Locally Advanced Squamous Cell Carcinoma of Head and Neck

BACKGROUND

Cisplatin-based chemotherapy (CTX) is commonly used concurrently with radiotherapy for head and neck cancer. The value of CTX regimens other than cisplatin for locally advanced squamous cell carcinoma of head and neck (LASCCHN) has not been well established. Here we compare the outcome of patients treated with different platinum-based chemotherapy regimens.

METHODS

Medical records from 104 patients with LASCCHN treated with radiochemotherapy (RCTX) between February 2013 and August 2016 were analyzed.

RESULTS

All patients were treated with intensity-modulated radiation therapy (51 definitive, 53 postoperative). The median total dose was 66.6 Gy and the median fraction dose was 1.8 Gy. 81 (78%) patients were administered cisplatin CTX, 23 (22%) patients received carboplatin and paclitaxel (CarboTaxol). The rate of recurrence was 38% in patients treated with cisplatin and 30% in CarboTaxol-treated patients (p = 0.6). Regarding the CTX regimens, event-free survival (EFS) was 37 versus 30 months (p = 0.6) and overall survival (OS) was 35 versus 28 months (p = 0.5) in cisplatin group versus CarboTaxol group, respectively. Significantly higher grade 3/4 acute toxicity in terms of dysphagia was observed following cisplatin-based RCTX (p = 0.002). In multivariable analysis, females and patients with early primary tumors (T1-2) have longer EFS and OS, regardless the CTX regimen.

CONCLUSIONS

Primary or adjuvant RCXT with CarboTaxol is a safe and effective treatment alternative for LASCCHN patients with contraindication to cisplatin-based RCTX.

The Synergistic Effect of Immune Checkpoint Blockade and Radiotherapy in Recurrent/Metastatic Sinonasal Cancer

Treatment options for recurrent/metastatic sinonasal cancer (RMSNC) patients are limited. We present two cases with RMSNC treated with a combination of immune checkpoint blockade and hypo-fractionated stereotactic radiotherapy (HSRT). 

Case 1 presented with RMSNC three months after the primary treatment. The patient progressed under first-line chemotherapy and pembrolizumab was offered. The disease progressed after the sixth cycle. We performed reirradiation with HSRT to the primary site. Case 2 presented with local recurrence eight years after the primary treatment for maxillary sinus cancer. He refused surgery and chemotherapy and was offered nivolumab treatment. After two doses, we performed reirradiation with HSRT.

Case 1 showed regression at both the local and the metastatic sites after radiotherapy. The second patient’s symptoms resolved completely three months after radiotherapy.

The HSRT and immune checkpoint blockade combination is a promising treatment option for patients with RMSNC.

Oral cancers: Current status

Oral cancer is a global disease. Despite a well elucidated tumour progression model, these cancers present late. Attempts at early detection by way of adjunctive diagnostic technologies and screening have not lived up to expectations in spite initial promise. Surgery is the mainstay of treatment. Treatment intensification by way of adjuvant radiation/chemo radiation is warranted for those with high risk features. Recent studies have explored intensification in those with intermediate risk factors in an attempt to improve outcomes. There has been generation of recent robust evidence that has influenced the need and extent of neck dissection. Neoadjuvant chemotherapy (NACT) may have a potential role in organ preservation and borderline resectable oral cancers. Recurrent tumours should be offered surgery whenever feasible while the addition of biological agents to chemotherapy gives best results in the palliative settings.

Cancer vaccines

Attempts to generate an anticancer immune response in vivo in patients with cancer have taken several forms. Although to date there have been relatively few published studies describing the effects of the approach in hematologic malignancy, that circumstance is expected to change rapidly during the next few years. In solid tumors, it is not known which, if any, of the approaches being explored will be able to produce responses of sufficient effectiveness and duration to be of general clinical value. Despite the documented increase in survival of patients developing an immune response to tumor immunization, no randomized clinical trial has been entirely convincing. As knowledge of the molecular basis of the immune response and of the immune defenses used by cancer cells improves, it is reasonable to expect to see increasing benefits from tumor vaccines, which are likely to complement, long before they replace, conventional therapies.