A phase II study evaluating axitinib in patients with unresectable, recurrent or metastatic head and neck cancer

Critical review of the current and future prospects of VEGF-TKIs in the management of squamous cell carcinoma of head and neck

As the prognosis for squamous cell carcinoma of the head and neck remains unsatisfactory when compared to other malignancies, novel therapies targeting specific biomarkers are a critical emerging area of great promise. One particular class of drugs that has been developed to impede tumor angiogenesis is vascular endothelial growth factor-tyrosine kinase inhibitors. As current data is primarily limited to preclinical and phase I/II trials, this review summarizes the current and future prospects of these agents in squamous cell carcinoma of the head and neck. In particular, the combination of these agents with immunotherapy is an exciting area that may be a promising option for patients with recurrent or metastatic disease, evidenced in recent trials such as the combination immune checkpoint inhibitors with lenvatinib and cabozantinib. In addition, the use of such combination therapy preoperatively in locally advanced disease is another area of interest.

Dissecting the functions of cancer-associated fibroblasts to therapeutically target head and neck cancer microenvironment

Head and neck cancers (HNC) are a diverse group of aggressive malignancies with high morbidity and mortality, leading to almost half-million deaths annually worldwide. A better understanding of the molecular processes governing tumor formation and progression is crucial to improve current diagnostic and prognostic tools as well as to develop more personalized treatment strategies. Tumors are highly complex and heterogeneous structures in which growth and dissemination is not only governed by the cancer cells intrinsic mechanisms, but also by the surrounding tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) emerge as predominant TME components and key players in the generation of permissive conditions that ultimately impact in tumor progression and metastatic dissemination. Although CAFs were initially considered a consequence of tumor development, it is now well established that they actively contribute to numerous cancer hallmarks i.e., tumor cell growth, migration and invasion, cancer cell stemness, angiogenesis, metabolic reprograming, inflammation, and immune system modulation. In this scenario, therapeutic strategies targeting CAF functions could potentially have a major impact in cancer therapeutics, providing avenues for new treatment options or for improving efficacy in established approaches. This review is focused on thoroughly dissecting existing evidences supporting the contribution of CAFs in HNC biology with an emphasis on current knowledge of the key molecules and pathways involved in CAF-tumor crosstalk, and their potential as novel biomarkers and/or therapeutic targets to effectively interfere the tumor-stroma crosstalk for HNC patients benefit. involved in CAF-tumor crosstalk, and their potential as novel biomarkers and/or therapeutic targets to effec- tively interfere the tumor-stroma crosstalk for HNC patients benefit.

Efficacy and safety of apatinib in patients with recurrent or metastatic head and neck squamous cell carcinoma: a retrospective multi-center study

Apatinib is a novel antiangiogenic agent that targets vascular endothelial growth factor 2. The aim of our study was to explore the efficacy and safety of apatinib in the treatment of patients with recurrence or metastasis (R/M) inoperable head and neck squamous cell carcinoma (HNSCC). This multi-center retrospective study analyzed 53 cases of recurrent or metastatic inoperable HNSCC who had progressed or recurred after undergoing standard radiotherapy, chemotherapy, and immunotherapy treated with apatinib from March 2017 to August 2021. Patients continued apatinib until the time of disease progression or onset of intolerable adverse events. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS), objective response rate (ORR), and disease control rate (DCR) and incidence of adverse events. Univariable and multivariable analyses were performed to determine prognostic factors. The main adverse events were counted, and the severity of the adverse reactions was evaluated. Fifty-three patients with recurrent or metastatic inoperable R/M HNSCC who had progressed or recurred after standard radiotherapy, chemotherapy, and immunotherapy were included. The ORR was 15.1%, and the DCR was 86.8%. The median PFS was 4.4 months (95% confidence interval [CI] 3.7-5.0 months) and the median OS was 6.6 months (95% CI 5.3-7.9 months). The number of apatinib lines was an influencing factor for both PFS and OS, and the Eastern Cooperative Oncology Group (ECOG) score, tumor differentiation, and apatinib duration were only the influencing factors for OS. Of these, only the ECOG score was an independent predictor of OS. The most common adverse reactions were hypertension (39.6%), hand-foot syndrome (32.1%), fatigue (32.1%), oral ulcers (28.3%), and nausea and vomiting (20.8%). Most adverse reactions were grade 1 or 2. Apatinib mesylate has good efficacy for recurrent/metastatic inoperable HNSCC as second-line and above-line treatment. ECOG score was an independent prognostic factors of OS in patients who were treated with apatinib. In addition, the adverse effects of apatinib mesylate were relatively mild.

Targeting of c-MET and AXL by cabozantinib is a potential therapeutic strategy for patients with head and neck cell carcinoma

Local or metastatic relapse following surgery, radiotherapy, and cisplatin is the leading cause of death in patients with head and neck squamous cell carcinoma (HNSCC). Our study shows overexpression of c-MET and AXL in HNSCC cells and patients resistant to radiotherapy and cisplatin. We demonstrate that cabozantinib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), c-MET, and AXL, decreases migration, invasion, and proliferation and induces mitotic catastrophe and apoptotic cell death of naive and radiotherapy- and cisplatin-resistant HNSCC cells. Cabozantinib inhibits the growth and metastatic spread of experimental HNSCC in zebrafish and the growth of experimental HNSCC in mice by blocking tumor cell proliferation and angiogenesis. The efficacy of cabozantinib is also confirmed on viable sections of surgically removed specimens of human HNSCC and on a patient who relapses after five lines of treatment. These results suggest that cabozantinib is relevant for the treatment of patients with HNSCC after relapse under radiotherapy and cisplatin.

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AXL and c-MET are overexpressed in radiotherapy- and cisplatin-resistant HNSCC

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Overexpression of AXL and c-MET contributes to tumor aggressiveness and poor prognosis

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Cabozantinib has anti-tumor and anti-metastatic efficacy in mice and zebrafish models

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Cabozantinib efficacy is shown on HNSCC biopsies and in one patient after several relapses

Emerging tyrosine kinase inhibitors for head and neck cancer

INTRODUCTION

Conventional regimens for head and neck squamous cell carcinoma (HNSCC) are limited in efficacy and are associated with adverse toxicities. Food and Drug Administration (FDA) approved molecular targeting agents include the HER1 (EGFR)-directed monoclonal antibody cetuximab and the immune checkpoint inhibitors nivolumab and pembrolizumab. However, clinical benefit is only seen in roughly 15-20% of HNSCC patients treated with these agents. New molecular targeting agents are needed that either act with monotherapeutic activity against HNSCC tumors or enhance the activities of current therapies, particularly immunotherapy. Small-molecule tyrosine kinase inhibitors (TKIs) represent a viable option toward this goal.

AREAS COVERED

This review provides an update on TKIs currently under investigation in HNSCC. We focus our review on data obtained and trials underway in HNSCC, including salivary gland cancers and nasopharyngeal carcinomas, but excluding thyroid cancer and esophageal cancer.

EXPERT OPINION

While some emerging TKIs have shown clinical benefit, the positive effects have, largely, been modest. The design of clinical trials of TKIs has been hampered by a lack of understanding of biomarkers that can be used to define patient populations most likely to respond. Further preclinical and translational studies to define biomarkers of TKI response will be critically important.

Targeting Angiogenesis in Squamous Cell Carcinoma of the Head and Neck: Opportunities in the Immunotherapy Era

Simple Summary

Therapies for squamous cell carcinomas of the head and neck (SCCHN) have been rapidly evolving, initially with the inclusion of immunotherapy, but more recently with the consideration of anti-angiogenic therapies. Recent preclinical and clinical data reveal a strong correlation between vascular endothelial growth factor (VEGF) and the progression of SCCHN, with nearly 90% of these malignancies expressing VEGF. Our review article not only elaborates on the utility of anti-VEGF therapies on SCCHN but also its interaction with the immune environment. Furthermore, we detailed the current data on immunotherapies targeting SCCHN and how this could be coupled with anti-angiogenics therapies.

Abstract

Despite the lack of approved anti-angiogenic therapies in squamous cell carcinoma of the head and neck (SCCHN), preclinical and more recent clinical evidence support the role of targeting the vascular endothelial growth factor (VEGF) in this disease. Targeting VEGF has gained even greater interest following the recent evidence supporting the role of immunotherapy in the management of advanced SCCHN. Preclinical evidence strongly suggests that VEGF plays a role in promoting the growth and progression of SCCHN, and clinical evidence exists as to the value of combining this strategy with immunotherapeutic agents. Close to 90% of SCCHNs express VEGF, which has been correlated with a worse clinical prognosis and an increased resistance to chemotherapeutic agents. As immunotherapy is currently at the forefront of the management of advanced SCCHN, revisiting the rationale for targeting angiogenesis in this disease has become an even more attractive proposition.

Current and Emerging Molecular Therapies for Head and Neck Squamous Cell Carcinoma

Head and neck cancer affects nearly 750,000 patients, with more than 300,000 deaths annually. Advances in first line surgical treatment have improved survival rates marginally particularly in developed countries, however survival rates for aggressive locally advanced head and neck cancer are still poor. Recurrent and metastatic disease remains a significant problem for patients and the health system. As our knowledge of the genomic landscape of the head and neck cancers continues to expand, there are promising developments occurring in molecular therapies available for advanced or recalcitrant disease. The concept of precision medicine is underpinned by our ability to accurately sequence tumour samples to best understand individual patient genomic variations and to tailor targeted therapy for them based on such molecular profiling. Not only is their purported response to therapy a factor of their genomic variation, but so is their inclusion in biomarker-driven personalised medicine therapeutic trials. With the ever-expanding number of molecular druggable targets explored through advances in next generation sequencing, the number of clinical trials assessing these targets has significantly increased over recent years. Although some trials are focussed on first-line therapeutic approaches, a greater majority are focussed on locally advanced, recurrent or metastatic disease. Similarly, although single agent monotherapy has been found effective in some cases, it is the combination of drugs targeting different signalling pathways that seem to be more beneficial to patients. This paper outlines current and emerging molecular therapies for head and neck cancer, and updates readers on outcomes of the most pertinent clinical trials in this area while also summarising ongoing efforts to bring more molecular therapies into clinical practice.

Angiogenesis Inhibitors for Head and Neck Squamous Cell Carcinoma Treatment: Is There Still Hope?

Background

Head and neck squamous cell carcinoma (HNSCC) carries poor survival outcomes despite recent progress in cancer treatment in general. Angiogenesis is crucial for tumour survival and progression. Therefore, several agents targeting the pathways that mediate angiogenesis have been developed. We conducted a systematic review to summarise the current clinical trial data examining angiogenesis inhibitors in HNSCC.

Methods

We carried out a literature search on three angiogenesis inhibitor categories—bevacizumab, tyrosine kinase inhibitors and endostatin—from Ovid MEDLINE, Cochrane Library, Scopus and ClinicalTrials.gov database.

Results

Here, we analysed 38 clinical trials, total of 1670 patients, investigating 12 angiogenesis inhibitors. All trials were in phase I or II, except one study in phase III on bevacizumab. Angiogenesis inhibitors were used as mono- and combination therapies together with radio-, chemo-, targeted- or immunotherapy. Among 12 angiogenesis inhibitors, bevacizumab was the most studied drug, included in 13 trials. Although bevacizumab appeared effective in various combinations, it associated with high toxicity levels. Endostatin and lenvatinib were well-tolerated and their anticancer effects appeared promising.

Conclusions

Most studies did not show benefit of angiogenesis inhibitors in HNSCC treatment. Additionally, angiogenesis inhibitors were associated with considerable toxicity. However, some results appear encouraging, suggesting that further investigations of angiogenesis inhibitors, particularly in combination therapies, for HNSCC patients are warranted.

Systematic Review Registration

PROSPERO (https://www.crd.york.ac.uk/prospero/), identifier CRD42020157144.

Potential of substituted quinazolines to interact with multiple targets in the treatment of cancer

The efficacy of quinazoline-based antiglioma agents has been attributed to their effects on microtubule dynamics.1,2 The design, synthesis and biological evaluation of quinazolines as potent inhibitors of multiple intracellular targets, including microtubules and multiple RTKs, is described. In addition to the known ability of quinazolines 1 and 2 to cause microtubule depolymerization, they were found to be low nanomolar inhibitors of EGFR, VEGFR-2 and PDGFR-β. Low nanomolar inhibition of EGFR was observed for 1-3 and 9-10. Compounds 1 and 4 inhibited VEGFR-2 kinase with activity better than or equal to that of sunitinib. In addition, compounds 1 and 2 had similar potency to sunitinib in the CAM angiogenesis assay. Multitarget activities of compounds in the present study demonstrates that the quinazolines can affect multiple pathways and could lead to these agents having antitumor potential caused by their activity against multiple targets.

Efficacy of axitinib in metastatic head and neck cancer with novel radiographic response criteria

BACKGROUND

There are limited treatment options for unresectable recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Vascular endothelial growth factor is of significant interest for targeted therapy in R/M HNSCC because of its central role in tumorigenesis and immunosuppression. Axitinib is a potent inhibitor of vascular endothelial growth factor receptor (VEGFR) 1 , VEGFR2, VEGFR3, platelet-derived growth factor receptor, as well as c-kit and offers such an approach.

METHODS

This article reports the results of a phase 2 trial evaluating axitinib in R/M HNSCC according to the Choi criteria for radiographic response assessment. The primary endpoint of this trial was 6-month overall survival.

RESULTS

Twenty-nine patients were enrolled, and 28 were evaluable for a response. Patients were heavily pretreated with 61% having had at least 1 previous systemic treatment in the metastatic setting (range, 0-5). The median overall survival of 9.8 months and the 6-month overall survival rate of 70% met the protocol-defined criteria for clinical efficacy. The best overall response rate was 42%. Correlative analyses demonstrated that PI3K signaling pathway alterations were associated with an increased response to therapy (75% vs 17%). A marked response to therapy was seen in a subgroup of patients who were treated with an immune checkpoint inhibitor after progression on axitinib.

CONCLUSIONS

Treatment with axitinib is associated with improved survival in patients with heavily pretreated head and neck cancer, and PI3K pathway alterations may serve as a biomarker for response. Further investigation is warranted to evaluate axitinib in biomarker-selected populations, especially in combination with immune checkpoint inhibitor therapy.

LAY SUMMARY

Metastatic head and neck squamous cancer is an incurable disease with limited treatment options and a poor prognosis. This study is the first to demonstrate that the targeted oral drug axitinib improves survival in patients with heavily pretreated metastatic head and neck cancer. Furthermore, patients whose tumors have specific mutations derive the greatest benefit from therapy. The investigation of axitinib alone or in combination with immunotherapy in a genomic biomarker-selected population is warranted.

Molecular targeted therapy: novel therapeutic approach for head and neck cancer

Cancer is a major public health burden worldwide, affecting millions of people each year. One of the major hallmarks of cancer is rapid growth and progression by evasion of host immune responses. Tumor resistance to conventional anticancer drugs by several mechanisms, such as drug inactivation, efflux pumps and enhanced toxicity to normal cells decreases their clinical efficacy. These limitations resulted in the development of new targeted agents, such as monoclonal antibodies and small molecule inhibitors that have high tumor specificity. This paper discusses the therapeutic applications of novel molecular targeted agents and immunotherapy as an alternative treatment option for head and neck cancers, as well as provides insight into future therapeutic approaches for advanced head and neck cancers.

An update on angiogenesis targeting in head and neck squamous cell carcinoma

Angiogenesis is an integral aspect of the growth and proliferation of solid tumors, including head and neck squamous cell carcinoma (HNSCC), and has potential implications in prognosis and treatment of both localized and recurrent/metastatic HNSCC. Therefore, there has been a significant interest in utilizing anti-angiogenic agents either alone or in combination with currently approved and emerging therapies. A phase III randomized trial (E1305) of chemotherapy with or without bevacizumab in the first-line treatment of recurrent/metastatic HNSCC showed an increased response rate and longer progression-free survival but fell short in demonstrating a statistically significant improved survival with bevacizumab. Moreover, toxicity, especially bleeding, was increased. Nevertheless, the study of other anti-angiogenic agents and novel combinations with other therapies, including immunotherapy, remains of interest. Several clinical trials are currently underway.

Target therapies in recurrent or metastatic head and neck cancer: state of the art and novel perspectives. A systematic review

Recurrent or metastatic head and neck squamous-cell carcinomas (R/M HNSCC) are a group of cancers with a very poor prognosis. Many clinical trials testing novel target therapies in this setting are currently ongoing. We performed a systematic review focusing our attention on all clinical trials, ongoing or already published, concerning the use of novel drugs for treatment of R/M HNSCC. We found that the research of novel molecules effective in treatment of R/M HNSCC has been intense during last decade, and nowadays it is still very active. Unfortunately, the results in this setting have been, overall, disappointing: until now, only cetuximab and, recently, nivolumab and pembrolizumab received authorization for treatment of R/M HNSCC. Nevertheless, the promising results showed by some novel drugs may lead to continue the research in this field, with the aim of producing more evidence and finding new therapeutic indication.

Investigational multitargeted kinase inhibitors in development for head and neck neoplasms

INTRODUCTION

Despite advances in treatment, head and neck squamous cell carcinoma (HNSCC) survival rates remain stagnant. Current treatment is associated with significant toxicities and includes chemotherapy, radiation, surgery, and few targeted treatments. Targeted treatments, epidermal growth factor receptor (EGFR)-targeted agent, cetuximab, and immune checkpoint inhibitors, pembrolizumab and nivolumab, show improved toxicity profiles and modestly improved survival in select patients. An urgent need remains to identify novel targeted treatments for single-agent or combined therapy use.

AREAS COVERED

Multitargeted kinase inhibitors are small molecule inhibitors with limited toxicity. This review will focus on early-stage investigations of multitargeted tyrosine kinase inhibitors (m-TKIs) (those that target at least two tyrosine kinases) for HNSCC. Preclinical and early trials investigating m-TKIs for various disease settings of HNSCC will be evaluated for efficacy, identification of significant biomarkers and potential for combination therapy.

EXPERT OPINION

Few single agent m-TKIs have demonstrated efficacy in unselected HNSCC populations. The most promising clinical results have been obtained when m-TKIs are tested in combination with other therapies, including immunotherapy, or in mutation-defined subgroups of patients. The future success of m-TKIs will rely on identification, in preclinical models and clinical trials, of predictive biomarkers of response and mechanisms of innate and acquired resistance.

Beyond EGFR Targeting in SCCHN: Angiogenesis, PI3K, and Other Molecular Targets

Although the molecular landscape of squamous cell carcinoma of the head and neck (SCCHN) has been largely deciphered, only one targeted therapy has been approved to date without any molecular selection, namely cetuximab. Cetuximab is a monoclonal antibody targeting EGFR. It has been shown to improve overall survival in the locally advanced setting in combination with radiotherapy and the recurrent and/or metastatic setting in combination with a platinum compound and 5FU. Beside EGFR targeting agents, antiangiogenic agents have been shown to produce antitumor activity but were associated with substantial toxicity. Buparlisib that targets PI3K was also shown to improve survival in combination with paclitaxel in an unselected patient population. Several other targeted therapies have been developed in SCCHN, most of time in all comers, potentially explaining the limited efficacy reported with them. The recent emergence of clinical trials of targeted therapies in enriched patient populations and precision medicine trials such as umbrella trials might boost the clinical development of targeted therapy in SCCHN.

Optimizing treatments for recurrent or metastatic head and neck squamous cell carcinoma

INTRODUCTION

The majority of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) will recur. The treatment of patients with recurrent/metastatic (R/M HNSCC) is rapidly evolving. Areas covered: This article will comprehensively review the current systemic treatment of R/M HNSCC. Expert commentary: For the time being, the EXTREME regimen (cetuximab in combination with platinum and 5-fluorouracil) still remains standard of care in previously untreated R/M HNSCC patients who are candidates for combination chemotherapy. Single agents with well documented activity in HNSCC include methotrexate, cisplatin, 5-FU, docetaxel, and paclitaxel. The anti-PD-1 monoclonal antibody nivolumab can be considered the current standard of care in patients with R/M HNSCC progressing after platinum-based therapy based on the results of CheckMate 141 showing a survival benefit over standard of care drugs, such as single agent weekly cetuximab, methotrexate, or docetaxel. Multiple randomized phase III trials comparing anti-PD(L)-antibodies either as single agent or in combination with chemotherapy or an anti-CTLA-4 with the EXTREME as fist line treatment are ongoing or planned. The outcome of these trials might change the current treatment paradigm in previously untreated R/M HNSCC. Immunotherapeutic agents under active investigation include Toll-like receptor 8 agonists and inhibitors of IDO1.

Application of molecular targeted therapies in the treatment of head and neck squamous cell carcinoma

Despite the development of standard therapies, including surgery, radiotherapy and chemotherapy, survival rates for head and neck squamous cell carcinoma (HNSCC) have not changed significantly over the past three decades. Complete recovery is achieved in <50% of patients. The treatment of advanced HNSCC frequently requires multimodality therapy and involves significant toxicity. The promising, novel treatment option for patients with HNSCC is molecular-targeted therapies. The best known targeted therapies include: Epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab, panitumumab, zalutumumab and nimotuzumab), EGFR tyrosine kinase inhibitors (gefitinib, erlotinib, lapatinib, afatinib and dacomitinib), vascular endothelial growth factor (VEGF) inhibitor (bevacizumab) or vascular endothelial growth factor receptor (VEGFR) inhibitors (sorafenib, sunitinib and vandetanib) and inhibitors of phosphatidylinositol 3-kinase/serine/threonine-specific protein kinase/mammalian target of rapamycin. There are also various inhibitors of other pathways and targets, which are promising and require evaluation in further studies.

Efficacy, Safety, and Pharmacokinetics of Axitinib in Nasopharyngeal Carcinoma: A Preclinical and Phase II Correlative Study

Purpose: We hypothesized that axitinib is active with an improved safety profile in nasopharyngeal carcinoma (NPC).Experimental Design: We evaluated axitinib in preclinical models of NPC and studied its efficacy in a phase II clinical trial in recurrent or metastatic NPC patients who progressed after at least one line of prior platinum-based chemotherapy. We excluded patients with local recurrence or vascular invasion. Axitinib was started at 5 mg twice daily in continuous 4-week cycles. Primary endpoint was clinical benefit rate (CBR), defined as the percentage of patients achieving complete response, partial response, or stable disease by RECIST criteria for more than 3 months.Results: We recruited 40 patients, who received a median of 3 lines of prior chemotherapy. Axitinib was administered for a mean of 5.6 cycles, with 16 patients (40%) receiving ≥6 cycles. Of 37 patients evaluable for response, CBR was 78.4% (95% CI, 65.6%-91.2%) at 3 months and 43.2% (30.4%-56.1%) at 6 months. Grade 3/4 toxicities were uncommon, including hypertension (8%), diarrhea (5%), weight loss (5%), and pain (5%). All hemorrhagic events were grade 1 (15%) or grade 2 (3%). Elevated diastolic blood pressure during the first 3 months of axitinib treatment was significantly associated with improved overall survival (HR, 0.29; 95% CI, 0.13-0.64, P = 0.0012). Patient-reported fatigue symptom was associated with hypothyroidism (P = 0.039). Axitinib PK parameters (C_max and AUC_(0-t)) were significantly correlated with tumor response, toxicity, and serum thyroid-stimulating hormone changes.Conclusions: Axitinib achieved durable disease control with a favorable safety profile in heavily pretreated NPC patients. Clin Cancer Res; 24(5); 1030-7. ©2018 AACR.

Targeting VEGFR and FGFR in head and neck squamous cell carcinoma in vitro

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease characterized by a tumor microenvironment (TME) that overexpresses vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), which can lead to neovascularization, tumor growth and metastasis. Therapeutic strategies inhibiting these signaling pathways might lead to innovative HNSCC treatments. Five HNSCC cell lines were characterized based on VEGFR1-3 and FGFR1-4 expression by sqRT-PCR and treated with three different tyrosine kinase inhibitors (TKIs) (nintedanib, dovitinib and pazopanib), all of which are effective against VEGFR and FGFR family members. Crystal violet assays were performed to analyze the effect of the treatments on cell growth (viability). Additionally, VEGFR1-3 and FGFR1-4 expression data were retrieved from The Cancer Genome Atlas (TCGA), and statistical analyses were performed to investigate the receptor expression level in the different cell lines and the efficacy of the single-agent treatments. A correlation analysis was performed to quantify the degree of relationship between receptor expression and drug efficacy. With the exception of VEGFR2, the targeted receptors were expressed at different levels in all of the cell lines. The cell lines exhibited concentration-dependent responses with cell line-specific differences toward two of the three TKIs (nintedanib and dovitinib). Notably, all of the cell lines were resistant to pazopanib. TKIs have potential as therapeutic agents for HNSCC. Cell line-specific differences were observed in our in vitro experiments. The observed pazopanib resistance could be explained by receptor expression. Further investigation is required to determine TKI efficacy in HNSCC.

Immunotherapy for Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma has been found to be an immunosuppressive malignancy, with many defects in the host immune system contributing to the progression of disease. A greater understanding of these defects has lead to the identification and investigation of new therapeutic strategies, targeting immune system dysfunction in an effort to improve the outcomes of this disease. This article provides a brief review of the knowledge regarding the immune defects present in head and neck cancer, as well as a review of the current therapeutic strategies being investigated for use.

A phase II trial of the BCL-2 homolog domain 3 mimetic AT-101 in combination with docetaxel for recurrent, locally advanced, or metastatic head and neck cancer

BACKGROUND

AT-101 is a BCL-2 Homolog domain 3 mimetic previously demonstrated to have tumoricidal effects in advanced solid organ malignancies. Given the evidence of activity in xenograft models, treatment with AT-101 in combination with docetaxel is a therapeutic doublet of interest in metastatic head and neck squamous cell carcinoma.

PATIENTS AND METHODS

Patients included in this trial had unresectable, recurrent, or distantly metastatic head and neck squamous cell carcinoma (R/M HNSCC) not amenable to curative radiation or surgery. This was an open label randomized, phase II trial in which patients were administered AT-101 in addition to docetaxel. The three treatment arms were docetaxel, docetaxel plus pulse dose AT-101, and docetaxel plus metronomic dose AT-101. The primary endpoint of this trial was overall response rate.

RESULTS

Thirty-five patients were registered and 32 were evaluable for treatment response. Doublet therapy with AT-101 and docetaxel was well tolerated with only 2 patients discontinuing therapy due to treatment related toxicities. The overall response rate was 11 % (4 partial responses) with a clinical benefit rate of 74 %. Median progression free survival was 4.3 months (range: 0.7-13.7) and overall survival was 5.5 months (range: 0.4-24). No significant differences were noted between dosing strategies.

CONCLUSION

Although met with a favorable toxicity profile, the addition of AT-101 to docetaxel in R/M HNSCC does not appear to demonstrate evidence of efficacy.