Phase II study of gefitinib adaptive dose escalation to skin toxicity in recurrent or metastatic squamous cell carcinoma of the head and neck

Therapeutic drug monitoring of oral targeted antineoplastic drugs

PURPOSE

This review provides an overview of the current challenges in oral targeted antineoplastic drug (OAD) dosing and outlines the unexploited value of therapeutic drug monitoring (TDM). Factors influencing the pharmacokinetic exposure in OAD therapy are depicted together with an overview of different TDM approaches. Finally, current evidence for TDM for all approved OADs is reviewed.

METHODS

A comprehensive literature search (covering literature published until April 2020), including primary and secondary scientific literature on pharmacokinetics and dose individualisation strategies for OADs, together with US FDA Clinical Pharmacology and Biopharmaceutics Reviews and the Committee for Medicinal Products for Human Use European Public Assessment Reports was conducted.

RESULTS

OADs are highly potent drugs, which have substantially changed treatment options for cancer patients. Nevertheless, high pharmacokinetic variability and low treatment adherence are risk factors for treatment failure. TDM is a powerful tool to individualise drug dosing, ensure drug concentrations within the therapeutic window and increase treatment success rates. After reviewing the literature for 71 approved OADs, we show that exposure-response and/or exposure-toxicity relationships have been established for the majority. Moreover, TDM has been proven to be feasible for individualised dosing of abiraterone, everolimus, imatinib, pazopanib, sunitinib and tamoxifen in prospective studies. There is a lack of experience in how to best implement TDM as part of clinical routine in OAD cancer therapy.

CONCLUSION

Sub-therapeutic concentrations and severe adverse events are current challenges in OAD treatment, which can both be addressed by the application of TDM-guided dosing, ensuring concentrations within the therapeutic window.

A chemical genetic screen identifies Aurora kinases as a therapeutic target in EGFR T790M negative, gefitinib-resistant head and neck squamous cell carcinoma (HNSCC)

BACKGROUND

Overexpression of epidermal growth factor receptor (EGFR), and downstream pathway activation appears to be a common oncogenic driver in the majority of head and neck squamous cell cancers (HNSCCs); yet targeting EGFR for the treatment of HNSCC has met with limited success. Apart from the anti-EGFR antibody cetuximab, no small molecule EGFR/tyrosine kinase inhibitors (TKIs) have progressed to routine clinical use. The aim of this study was to determine factors contributing to the lack of response to TKIs and identify alternative therapeutic vulnerabilities.

METHODS

Genomic and transcriptomic sequencing, high-throughput compound screens, overexpression and siRNA knockdown, western blot, in vivo xenograft studies.

FINDINGS

We derived three pairs of isogenic gefitinib (TKI)-sensitive and resistant patient-derived HNSCC cell lines. Genomic sequencing of gefitinib-resistant cell lines identified a lack of activating and resistance-associated EGFR mutations. Instead, transcriptomic sequencing showed upregulated EMT gene signature in the gefitinib-resistant cells with a corresponding increase in their migratory phenotype. Additionally, the resistant cell displayed reduced growth rate. Surprisingly, while gefitinib-resistant cells were independent of EGFR for survival, they nonetheless displayed activation of downstream ERK and AKT signalling. High-throughput screening (HTS) of druggable, small molecule libraries revealed that the gefitinib-resistant cells were particularly sensitive to inhibitors of genes involved in cell cycle and mitosis, such as Aurora kinase inhibitors (AKIs), cyclin-dependent kinase (CDK) inhibitors, and microtubule inhibitors. Notably our results showed that in the EGFR inhibited state, Aurora kinases are essential for cell survival.

INTERPRETATION

Our study demonstrates that in the absence of activating EGFR mutations, HNSCCs may gain resistance to gefitinib through decreased cell proliferation, which makes them exceptionally vulnerable to cell-cycle inhibitors.

FUNDING

Agency for Science, Technology, and Research (A*STAR), National Medical Research Council (NMRC), and the National Institutes of Health (NIH)/National Cancer Institute (NCI).

Multikinase inhibitor-induced liver injury in patients with cancer: A review for clinicians

BACKGROUND

Multikinase inhibitors (MKI) are targeted molecular agents that have revolutionized cancer management. However, there is a paucity of data concerning MKI-related liver injury risk and clinical guidelines for the management of liver toxicity in patients receiving MKI for cancer are scarce.

DESIGN

We conducted a PubMed search of articles in English published from January 2000 to December 2018 related to hepatotoxicity of the 29 FDA-approved MKIs at doses used in clinical practice. The search terms were the international non-proprietary name of each agent cross-referenced with «hepatotoxicity», «hepatitis», «hepatic adverse event», or «liver failure», and «phase II clinical trial», «phase III clinical trial», or «case report».

RESULTS

Following this search, 140 relevant studies and 99 case reports were considered. Although asymptomatic elevation of aminotransferase levels has been frequently observed in MKI clinical trials, clinically significant hepatotoxicity is a rare event. In most cases, the interval between treatment initiation and the onset of liver injury is between one week and two months. Liver toxicity is often hepatocellular and less frequently mixed. Life-threatening MKI-induced hepatic injury has been described, involving fulminant liver failure or death. Starting from existing data, a description of MKI-related liver events, grading of hepatotoxicity risk, and recommendations for management are also given for various MKI molecules.

CONCLUSION

All MKIs can potentially cause liver injury, which is sometimes irreversible. As there is still no strategy available to prevent MKI-related hepatotoxicity, early detection remains crucial. The surveillance of liver function during treatment may help in the early detection of hepatotoxicity. Furthermore, the exclusion of potential causes of hepatic injury is essential to avoid unnecessary MKI withdrawal.

Challenges and new perspectives in the treatment of advanced cutaneous squamous cell carcinoma

Despite the overall excellent survival rates in patients affected by early cutaneous squamous cell carcinoma (CSCC), advanced forms of CSCC are associated with high patient mortality. To date, only limited therapeutic modalities have been implemented, including chemotherapy and radiotherapy. Systemic therapy was enriched by the addition of epidermal growth factor receptor inhibitors (EGFRi) in the last years. Unfortunately, the overall outcome of all these therapeutic strategies remains poor, therefore important unmet clinical needs persist. Thanks to a better understanding of the biology of advanced CSCC, new treatment options are now available. This article presents the current definition of advanced CSCC along with actual therapeutic options and discusses the strengths and limitations of a new promising systemic approach, which involves the use of immune checkpoint inhibitors.

Advanced cutaneous squamous cell carcinoma: how is it defined and what new therapeutic approaches are available?

PURPOSE OF REVIEW

Despite the overall excellent survival rates in patients with cutaneous squamous cell carcinoma (cSCC), advanced cutaneous SCCs are associated with high patient morbidity and mortality. Therefore, important unmet clinical needs persist: identifying high risk patients and choosing optimal treatment approaches.

RECENT FINDINGS

In recent years, a better understanding of the biology of cSCC and its clinical progression have led to improved staging systems and new promising treatments for advanced disease. Such treatments include PD1 inhibitors, such as cemiplimab, which was recently approved for the treatment of cutaneous SCC, and pembrolizumab whose efficacy in the treatment cSCC is still being investigated. Other treatments, such as epidermal growth factor receptor inhibitors have also been used in the treatment of cSCC with moderate success. Several clinical and histological risk factors are considered key in estimating the risk or recurrence or metastasis in cSCCs and, therefore, influence the appropriate treatment choice and patient monitoring.

SUMMARY

The present study reviews the current definition of advanced cSCC and discusses the new systemic approaches, including checkpoint inhibitors.

Molecular genetics of head and neck squamous cell carcinoma

PURPOSE OF REVIEW

The aim of this review is to summarize the current knowledge on the genomic characterization of squamous cell carcinomas of the head and neck (HNSCC) and discusses how these abnormalities could be incorporated into a therapeutic approach.

RECENT FINDINGS

Tobacco and HPV infection, the two main risk factors of HNSCC, allow the definition of two groups with distinct anatomoclinical and genetic features. As tobacco and HPV infection are not exclusive, exposure to both risk factors is associated with an intermediate prognostic. HPV-positive, nontobacco-related HNSCCs are associated with a better prognosis, a rather more simple genomic profile, frequent activating mutations of genes involved in pi3kinase pathway, and the very low incidence of mutations of tumor suppressor genes. HPV-negative, tobacco-related HNSCC are genetically more complex. HPV-negative HNSCC are characterized by almost mandatory inactivating mutations/deletions of tumor suppressor genes (especially TP53 and CDKN2A) and the occurrence, though less frequent, of activating mutations or amplifications of some oncogenes that encode for cell cycle proteins or receptors with tyrosine kinase activity. Despite many efforts to improve therapeutic targeting in RM HNSCC, Cetuximab, a monoclonal antibody targeting REGF, remains the sole approved targeted treatment in RM HNSCC.

SUMMARY

Despite the increasingly precise genomic characterization of HNSCCs, precision medicine is struggling to find its place in the management of HNSCCs. Inclusion of enriched populations in dedicated trials is likely to help implement precision medicine in the management of HNSCCs.

Transferrin-functionalised microemulsion co-delivery of β-elemene and celastrol for enhanced anti-lung cancer treatment and reduced systemic toxicity

In this study, we developed an intravenously injectable, transferrin-functionalised microemulsion that simultaneously carries β-elemene and celastrol (called Tf-EC-MEs) for enhanced anti-lung cancer treatment and reduced systemic toxicity. These dual-drug-loaded Tf-EC-MEs not only displayed synergistic antiproliferative effects on cultured cells in vitro, but also showed enhanced efficacy in vivo via active tumour targeting. In preparatory experiments, we found that β-elemene was capable of being used as oil phase, which enhanced drug-loading efficiency and allowed the mass ratio of β-elemene and celastrol to be optimised. In cellular studies, Tf-EC-MEs exhibited significantly improved A549 cellular uptake compared with β-elemene+celastrol (conventional combination treatment) and EC-MEs (non-active targeted treatment), demonstrating remarkable synergistic antiproliferative effects and higher rates of cell apoptosis. In A549-bearing xenograft mouse tumour models, Tf-EC-MEs exhibited enhanced antitumour activity compared to all other treatments. More importantly, Tf-EC-MEs did not cause the obvious systemic toxicity commonly found with mono-celastrol treatment. Collectively, these findings suggest that Tf-EC-MEs are a promising strategy for the combination drug treatment of lung cancer.

Individualized dosing of oral targeted therapies in oncology is crucial in the era of precision medicine

PURPOSE

While in the era of precision medicine, the right drug for each patient is selected based on molecular tumor characteristics, most novel oral targeted anticancer agents are still being administered using a one-size-fits-all fixed dosing approach. In this review, we discuss the scientific evidence for dose individualization of oral targeted therapies in oncology, based on therapeutic drug monitoring (TDM).

METHODS

Based on literature search and our own experiences, seven criteria for drugs to be suitable candidates for TDM will be addressed: (1) absence of an easily measurable biomarker for drug effect; (2) long-term therapy; (3) availability of a validated sensitive bioanalytical method; (4) significant variability in pharmacokinetic exposure; (5) narrow therapeutic range; (6) defined and consistent exposure-response relationships; (7) feasible dose-adaptation strategies.

RESULTS

All of these requirements are met for most oral targeted therapies in oncology. Also, prospective studies have already shown TDM to be feasible for imatinib, pazopanib, sunitinib, everolimus, and endoxifen.

CONCLUSIONS

In order to realize the full potential of personalized medicine in oncology, patients should not only be treated with the right drug, but also at the right dose. TDM could be a suitable tool to achieve this.

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.

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.

Practical Recommendations for Therapeutic Drug Monitoring of Kinase Inhibitors in Oncology

Despite the fact that pharmacokinetic exposure of kinase inhibitors (KIs) is highly variable and clear relationships exist between exposure and treatment outcomes, fixed dosing is still standard practice. This review aims to summarize the available clinical pharmacokinetic and pharmacodynamic data into practical guidelines for individualized dosing of KIs through therapeutic drug monitoring (TDM). Additionally, we provide an overview of prospective TDM trials and discuss the future steps needed for further implementation of TDM of KIs.

AKT can modulate the in vitro response of HNSCC cells to irreversible EGFR inhibitors

Epidermal growth factor receptor (EGFR) is overexpressed in up to 90% of head and neck squamous cell carcinoma (HNSCC) tumors. Cetuximab is the first targeted (anti-EGFR) therapy approved for the treatment of HNSCC patients. However, its efficacy is limited due to primary and secondary resistance, and there is no predict biomarkers of response. New generation of EGFR inhibitors with pan HER targeting and irreversible action, such as afatinib and allitinib, represents a significant therapeutic promise. In this study, we intend to compare the potential cytotoxicity of two anti-EGFR inhibitors (afatinib and allitinib) with cetuximab and to identify potential predictive biomarkers of response in a panel of HNSCC cell lines. The mutational analysis in the eight HNSCC cell lines revealed an EGFR mutation (p.H773Y) and gene amplification in the HN13 cells. According to the growth inhibition score (GI), allitinib was the most cytotoxic drug, followed by afatinib and finally cetuximab. The higher AKT phosphorylation level was associated with resistance to anti-EGFR agents. Therefore, we further performed drug combinations with anti-AKT agent (MK2206) and AKT1 gene editing, which demonstrated afatinib and allitinib sensitivity restored. Additionally, in silico analysis of TCGA database showed that AKT1 overexpression was present in 14.7% (41/279) of HNSCC cases, and was associated with perineural invasion in advanced stage. In conclusion, allitinib presented a greater cytotoxic profile when compared to afatinib and cetuximab. AKT pathway constitutes a predictive marker of allitinib response and combination with AKT inhibitors could restore response and increase treatment success.

Non-melanoma skin cancer: new and future synthetic drug treatments

INTRODUCTION

Non-melanoma skin cancers (NMSC) mainly comprise two different entities: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC); beneath these two entities, Merkel cell carcinoma, adnexal tumors, dermatofibrosarcoma protuberans, angiosarcoma, and cutaneous lymphoma belong to NMSC. These rare skin tumors are not the topic of this review. BCC and SCC are the most common cancers diagnosed in humans. The preferred treatment is surgery, which in most cases is curative. Although a high recurrence rate is seen, these cancers rarely metastasize. Therefore, systemic treatments were not a priority for these patients. It is long known that the abnormal activation of Hedgehog and epidermal growth factor receptor pathways were involved in BCC and SCC. In the last decade, metastatic disease became an important area of research, mostly because new therapies that targeted components of these two pathways became available. Areas covered: Here we cover the available therapeutic options for patients diagnosed with BCC and SCC, focus on systemic and targeted therapies. Expert opinion: BCC and SCC are common cancers, with good prognosis. More than the metastatic disease, advanced local disease and recurrent disease pose clinicians a great challenge. Albeit there are promising results with targeted therapies, resistance development has already been described.

Randomized, placebo-controlled window trial of EGFR, Src, or combined blockade in head and neck cancer

BACKGROUND. EGFR and Src family kinases are upregulated in head and neck squamous cell carcinoma (HNSCC). EGFR interacts with Src to activate STAT3 signaling, and dual EGFR-Src targeting is synergistic in HNSCC preclinical models. pSrc overexpression predicted resistance to the EGFR inhibitor, erlotinib, in a prior window trial. We conducted a 4-arm window trial to identify biomarkers associated with response to EGFR and/or Src inhibition. METHODS. Patients with operable stage II-IVa HNSCC were randomized to 7-21 days of neoadjuvant erlotinib, the Src inhibitor dasatinib, the combination of both, or placebo. Paired tumor specimens were collected before and after treatment. Pharmacodynamic expression of EGFR and Src pathway components was evaluated by IHC of tissue microarrays and reverse-phase protein array of tissue lysates. Candidate biomarkers were assessed for correlation with change in tumor size. RESULTS. From April 2009 to December 2012, 58 patients were randomized and 55 were treated. There was a significant decrease in tumor size in both erlotinib arms (P = 0.0014); however, no effect was seen with dasatinib alone (P = 0.24). High baseline pMAPK expression was associated with response to erlotinib (P = 0.03). High baseline pSTAT3 was associated with resistance to dasatinib (P = 0.099). CONCLUSIONS. Brief exposure to erlotinib significantly decreased tumor size in operable HNSCC, with no additive effect from dasatinib. Baseline pMAPK expression warrants further study as a response biomarker for anti-EGFR therapy. Basal expression of pSTAT3 may be independent of Src, explain therapeutic resistance, and preclude development of dasatinib in biomarker-unselected cohorts. TRIAL REGISTRATION. NCT00779389. FUNDING. National Cancer Institute, American Cancer Society, Pennsylvania Department of Health, V Foundation for Cancer Research, Bristol-Myers Squibb, and Astellas Pharma.

Molecular pathways in head and neck cancer: EGFR, PI3K, and more

The treatment of head and neck squamous cell carcinoma (HNSCC) is set to undergo rapid changes, as novel treatment targets informed by genomic profiling and novel molecularly targeted therapies continue to make strides. In this review we provide an overview of the latest developments regarding (1) EGFR targeting for HNSCC, (2) PI3K as a novel treatment target, and (3) newly described key genetic events in HNSCC such as NOTCH1 mutations and emerging candidate targets including ALK1 and hedgehog. The first molecular targeting strategy to demonstrate a survival advantage for patients with HNSCC has emerged in the context of EGFR biology. Cetuximab remains the only U.S. Food and Drug Administration (FDA)-approved targeted therapy available for HNSCC, but EGFR as a target has not been individualized in this disease. The PI3K-AKT pathway is downstream of EGFR and is emerging as potentially one of the most important pathways in HNSCC. PIK3CA is the most frequently mutated oncogene for HNSCC (approximately 20%) and may play a role for both HPV-negative and HPV-positive tumors. Multiple therapeutic strategies targeting PI3K are being explored, and multiple agents either alone or in combination are in development. NOTCH1 is a key tumor suppressor gene and its genetic alterations lead to abnormal pathway activation. ALK1 is a novel target involved in angiogenesis, and efficacy in patients with HNSCC was documented in an early inhibitor trial. The hedgehog pathway modulates EGFR dependence and epithelial to mesenchymal transition (EMT), a key invasion and drug-resistance mechanism in HNSCC.

Concomitant cetuximab and radiation therapy: A possible promising strategy for locally advanced inoperable non-melanoma skin carcinomas

Non-melanoma skin cancers (NMSCs) include a heterogeneous group of malignancies arising from the epidermis, comprising squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Merkel cell carcinoma and more rare entities, including malignant pilomatrixoma and sebaceous gland tumours. The treatment of early disease depends primarily on surgery. In addition, certain patients present with extensive local invasion or metastasis, which renders these tumours surgically unresectable. Improving the outcome of radiotherapy through the use of concurrent systemic therapy has been demonstrated in several locally advanced cancer-treatment paradigms. Recently, agents targeting the human epidermal growth factor receptor (EGFR) have exhibited a consolidated activity in phase II clinical trials and case series reports. Cetuximab is a monoclonal antibody that binds to and completely inhibits the EGFR, which has been revealed to be up-regulated in a variety of SCCs, including NMSCs. The present review aimed to summarize the role of anti-EGFR agents in the predominant types of NMSC, including SCC and BCC, and focuses on the cetuximab-based studies, highlighting the biological rationale of this therapeutic option. In addition, the importance of the association between cetuximab and radiotherapy for locally advanced NMSC is discussed.

Cytotoxic effect of lapatinib is restricted to human papillomavirus-positive head and neck squamous cell carcinoma cell lines

Background

Lapatinib is a dual epidermal growth factor receptor (EGFR) and HER2 inhibitor. Overexpression of these receptors is frequently observed in head and neck squamous cell carcinoma (HNSCC). As growing proportion of HNSCC is characterized by human papillomavirus (HPV) infection, we aimed at evaluating the efficacy of lapatinib as function of HPV status in HNSCC cell lines.

Methods

Two HPV-positive and two HPV-negative HNSCC cell lines were used. Proliferation, cell cycle, and Annexin V assays were performed to test their sensitivity to lapatinib. Combination of lapatinib and ionizing radiation was evaluated with clonogenic survival assays. Akt, EGFR and HER2, and E6/E7 expression and activation were analyzed by immunoblotting and quantitative reverse transcription polymerase chain reaction.

Results

Lapatinib reduced E6 and E7 expression and Akt phosphorylation, inhibited cell proliferation and induced cell death in HPV-positive cell lines. An additive effect of lapatinib with radiation was observed in these cells. Lapatinib had no effect on HPV-negative cells.

Conclusion

Lapatinib efficacy restricted to the HPV-positive cells suggests that HPV status could be a potential marker for enhanced response to lapatinib in HNSCC.

A randomized, phase II study of afatinib versus cetuximab in metastatic or recurrent squamous cell carcinoma of the head and neck

BACKGROUND

Afatinib is an oral, irreversible ErbB family blocker that has shown activity in epidermal growth factor receptor (EGFR)-mutated lung cancer. We hypothesized that the agent would have greater antitumor activity compared with cetuximab in recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) patients, whose disease has progressed after platinum-containing therapy.

PATIENTS AND METHODS

An open-label, randomized, phase II trial was conducted in 43 centers; 124 patients were randomized (1 : 1) to either afatinib (50 mg/day) or cetuximab (250 mg/m(2)/week) until disease progression or intolerable adverse events (AEs) (stage I), with optional crossover (stage II). The primary end point was tumor shrinkage before crossover assessed by investigator (IR) and independent central review (ICR).

RESULTS

A total of 121 patients were treated (61 afatinib, 60 cetuximab) and 68 crossed over to stage II (32 and 36 respectively). In stage I, mean tumor shrinkage by IR/ICR was 10.4%/16.6% with afatinib and 5.4%/10.1% with cetuximab (P = 0.46/0.30). Objective response rate was 16.1%/8.1% with afatinib and 6.5%/9.7% with cetuximab (IR/ICR). Comparable disease control rates were observed with afatinib (50%) and cetuximab (56.5%) by IR; similar results were seen by ICR. Most common grade ≥3 drug-related AEs (DRAEs) were rash/acne (18% versus 8.3%), diarrhea (14.8% versus 0%), and stomatitis/mucositis (11.5% versus 0%) with afatinib and cetuximab, respectively. Patients with DRAEs leading to treatment discontinuation were 23% with afatinib and 5% with cetuximab. In stage II, disease control rate (IR/ICR) was 38.9%/33.3% with afatinib and 18.8%/18.8% with cetuximab.

CONCLUSION

Afatinib showed antitumor activity comparable to cetuximab in R/M HNSCC in this exploratory phase II trial, although more patients on afatinib discontinued treatment due to AEs. Sequential EGFR/ErbB treatment with afatinib and cetuximab provided sustained clinical benefit in patients after crossover, suggesting a lack of cross-resistance.

Erlotinib, erlotinib-sulindac versus placebo: a randomized, double-blind, placebo-controlled window trial in operable head and neck cancer

PURPOSE

The EGF receptor (EGFR) and COX2 pathways are upregulated in head and neck squamous cell carcinoma (HNSCC). Preclinical models indicate synergistic antitumor activity from dual blockade. We conducted a randomized, double-blind, placebo-controlled window trial of erlotinib, an EGFR inhibitor; erlotinib plus sulindac, a nonselective COX inhibitor; versus placebo.

EXPERIMENTAL DESIGN

Patients with untreated, operable stage II-IVb HNSCC were randomized 5:5:3 to erlotinib, erlotinib-sulindac, or placebo. Tumor specimens were collected before and after seven to 14 days of treatment. The primary endpoint was change in Ki67 proliferation index. We hypothesized an ordering effect in Ki67 reduction: erlotinib-sulindac > erlotinib > placebo. We evaluated tissue microarrays by immunohistochemistry for pharmacodynamic modulation of EGFR and COX2 signaling intermediates.

RESULTS

From 2005-2009, 47 patients were randomized for the target 39 evaluable patients. Thirty-four tumor pairs were of sufficient quality to assess biomarker modulation. Ki67 was significantly decreased by erlotinib or erlotinib-sulindac (omnibus comparison, two-sided Kruskal-Wallis, P = 0.04). Wilcoxon pairwise contrasts confirmed greater Ki67 effect in both erlotinib groups (erlotinib-sulindac vs. placebo, P = 0.043; erlotinib vs. placebo, P = 0.027). There was a significant trend in ordering of Ki67 reduction: erlotinib-sulindac > erlotinib > placebo (two-sided exact Jonckheere-Terpstra, P = 0.0185). Low baseline pSrc correlated with greater Ki67 reduction (R(2) = 0.312, P = 0.024).

CONCLUSIONS

Brief treatment with erlotinib significantly decreased proliferation in HNSCC, with additive effect from sulindac. Efficacy studies of dual EGFR-COX inhibition are justified. pSrc is a potential resistance biomarker for anti-EGFR therapy, and warrants investigation as a molecular target.

Epidermal growth factor receptor inhibitors: a review of cutaneous adverse events and management

Epidermal growth factor inhibitors (EGFRI), the first targeted cancer therapy, are currently an essential treatment for many advance-stage epithelial cancers. These agents have the superior ability to target cancers cells and better safety profile compared to conventional chemotherapies. However, cutaneous adverse events are common due to the interference of epidermal growth factor receptor (EGFR) signaling in the skin. Cutaneous toxicities lead to poor compliance, drug cessation, and psychosocial discomfort. This paper summarizes the current knowledge concerning the presentation and management of skin toxicity from EGFRI. The common dermatologic adverse events are papulopustules and xerosis. Less common findings are paronychia, regulatory abnormalities of hair growth, maculopapular rash, mucositis, and postinflammatory hyperpigmentation. Radiation enhances EGFRI rash due to synergistic toxicity. There is a positive correlation between the occurrence and severity of cutaneous adverse effects and tumor response. To date, prophylactic systemic tetracycline and tetracycline class antibiotics have proven to be the most effective treatment regime.

Lower gefitinib dose led to earlier resistance acquisition before emergence of T790M mutation in epidermal growth factor receptor-mutated lung cancer model

Non-small-cell lung cancers with epidermal growth factor receptor (EGFR) mutations are sensitive to EGFR tyrosine kinase inhibitors (TKIs); however, unlike cytotoxic agents, it is generally accepted that minimal doses of drugs inhibiting target molecules are sufficient when molecular-targeted agents, including EGFR-TKIs, are used. Thus, any utility of higher doses remains unclear. We compared low-dose (15 mg/kg) gefitinib therapy with high-dose (50 mg/kg) therapy using an EGFR-mutated lung cancer xenograft model. Both gefitinib doses induced tumor shrinkage, but tumors regrew in the low-dose group within 1 month, whereas tumors in the high-dose group did not. Neither the T790M mutation nor MET amplification was apparent in regrown tumors. We also compared outcomes after two doses of gefitinib (5 and 25 mg/kg) in a transgenic EGFR-mutated lung cancer mouse model. In line with the results obtained using the xenograft model, both gefitinib doses completely inhibited tumor growth, but tumors treated with the lower dose of gefitinib developed earlier drug resistance. In conclusion, a low gefitinib dose caused tumors to become drug-resistant prior to acquisition of the T790M mutation or MET amplification in EGFR-mutated models of lung cancer. This suggests that it is important to optimize the EGFR-TKI dose for treatment of EGFR mutation-associated lung cancer. Gefitinib may need to be given at a dose greater than the minimum required for inhibition of target molecules.

Advances in the proteomic discovery of novel therapeutic targets in cancer

Proteomic approaches are continuing to make headways in cancer research by helping to elucidate complex signaling networks that underlie tumorigenesis and disease progression. This review describes recent advances made in the proteomic discovery of drug targets for therapeutic development. A variety of technical and methodological advances are overviewed with a critical assessment of challenges and potentials. A number of potential drug targets, such as baculoviral inhibitor of apoptosis protein repeat-containing protein 6, macrophage inhibitory cytokine 1, phosphoglycerate mutase 1, prohibitin 1, fascin, and pyruvate kinase isozyme 2 were identified in the proteomic analysis of drug-resistant cancer cells, drug action, and differential disease state tissues. Future directions for proteomics-based target identification and validation to be more translation efficient are also discussed.

A phase II study of temsirolimus and erlotinib in patients with recurrent and/or metastatic, platinum-refractory head and neck squamous cell carcinoma

OBJECTIVES

The epidermal growth factor receptor (EGFR) is a validated target in head and neck squamous cell carcinoma (HNSCC). In recurrent and/or metastatic (R/M) HNSCC, resistance to anti-EGFR therapy inevitably occurs. Downstream activation of the PI3K/Akt/mTOR pathway is an established resistance mechanism. Concurrent mTOR blockade may improve efficacy of anti-EGFR therapy.

MATERIALS AND METHODS

Erlotinib 150 mg daily and temsirolimus 15 mg weekly were administered to patients with platinum-refractory R/M HNSCC and ECOG performance status 0-2. The primary endpoint was progression-free survival (PFS). Correlative studies determined PIK3CA and HRAS mutation status; p16, EGFR, pS6K, pAkt and PTEN expression; and pre- and post-treatment plasma levels of 20 immunomodulatory cytokines.

RESULTS

Twelve patients enrolled; six withdrew within 6 weeks due to toxicity or death, prompting early closure of the trial. Grade ≥ 3 toxicities included fatigue, diarrhea, gastrostomy tube infection, peritonitis, pneumonia, dyspnea, and HN edema. Median PFS was 1.9 months. Median overall survival was 4.0 months. Six/12 tumors were p16(+), 9/11 lacked measurable PTEN expression, and 1/12 harbored a PIK3CA mutation. On exploratory analysis, high baseline plasma VEGF and interferon-gamma levels marginally associated with tumor progression.

CONCLUSIONS

The combination of erlotinib and temsirolimus was poorly tolerated. Low prevalence of PTEN expression and 8% incidence of PIK3CA mutations indicate biological relevance of this pathway in R/M disease. Investigation of more tolerable combinations of EGFR and PI3K/Akt/mTOR pathway inhibitors in selected HNSCC patients is warranted.

Multitargeted low-dose GLAD combination chemoprevention: a novel and promising approach to combat colon carcinogenesis

Preclinical studies have shown that gefitinib, licofelone, atorvastatin, and α-difluoromethylornithine (GLAD) are promising colon cancer chemopreventive agents. Because low-dose combination regimens can offer potential additive or synergistic effects without toxicity, GLAD combination was tested for toxicity and chemopreventive efficacy for suppression of intestinal tumorigenesis in adenomatous polyposis coli (APC)(Min/+) mice. Six-week-old wild-type and APC(Min/+) mice were fed modified American Institute of Nutrition 76A diets with or without GLAD (25 + 50 + 50 + 500 ppm) for 14 weeks. Dietary GLAD caused no signs of toxicity based on organ pathology and liver enzyme profiles. GLAD feeding strongly inhibited (80-83%, P < .0001) total intestinal tumor multiplicity and size in APC(Min/+) mice (means ± SEM tumors for control vs GLAD were 67.1 ± 5.4 vs. 11.3 ± 1.1 in males and 72.3 ± 8.9 vs 14.5 ± 2.8 in females). Mice fed GLAD had >95% fewer polyps with sizes of >2 mm compared with control mice and showed 75% and 85% inhibition of colonic tumors in males and females, respectively. Molecular analyses of polyps suggested that GLAD exerts efficacy by inhibiting cell proliferation, inducing apoptosis, decreasing β-catenin and caveolin-1 levels, increasing caspase-3 cleavage and p21, and modulating expression profile of inflammatory cytokines. These observations demonstrate that GLAD, a novel cocktail of chemopreventive agents at very low doses, suppresses intestinal tumorigenesis in APC(Min/+) mice with no toxicity. This novel strategy to prevent colorectal cancer is an important step in developing agents with high efficacy without unwanted side effects.

Molecular phenotype predicts sensitivity of squamous cell carcinoma of the head and neck to epidermal growth factor receptor inhibition

Despite nearly universal expression of the wild-type epidermal growth factor receptor (EGFR) and reproducible activity of EGFR inhibitors in patients with squamous cell carcinoma of the head and neck (SCCHN), the majority of patients will not have objective responses. The mechanisms of this intrinsic resistance are not well established. We hypothesized that sensitivity to EGFR inhibitors can be predicted based on the inhibitors' effects on downstream signaling. Cell viability assays were used to assess sensitivity to the EGFR inhibitor gefitinib (ZD1839) in 8 SCCHN cell lines. Fluorescence in-situ hybridization showed the two most sensitive lines to be highly gene-amplified for EGFR. Western blotting confirmed that phosphoEGFR was inhibited at low concentrations of gefitinib in all lines tested. Phosphorylation of downstream signaling protein AKT was inhibited in sensitive lines while inhibition of phosphoERK displayed no relationship to gefitinib efficacy. Phosphatase and tensin homolog (PTEN) expression was evident in all cell lines. Activating PIK3CA mutations were found in two resistant cell lines where pAKT was not inhibited by gefitinib. In resistant cell lines harboring PIK3CA mutations, a PI3K inhibitor, LY294002, or AKT siRNA reduced cell viability with an additive effect demonstrated in combination with gefitinib. Additionally, LY294002 alone and in combination with gefitinib, was effective at treating PIK3CA mutated tumors xenografted into nude mice. Taken together this suggests that constitutively active AKT is a mechanism of intrinsic gefitinib resistance in SCCHN. This resistance can be overcome through targeting of the PI3K/AKT pathway in combination with EGFR inhibition.

Biologic therapy in head and neck cancer: a road with hurdles

The epidermal growth factor receptor (EGFR) is overexpressed in the vast majority of cases of squamous cell carcinoma of the head and neck (SCCHN). A high EGFR expression is associated with an unfavorable prognosis. Cetuximab is a chimeric human/murine IgG1 antibody which binds with high affinity to the EGFR. It is the only targeted agent which got approval for the treatment of SCCHN from the regulatory agencies of Europe and the United States, both in locoregionally advanced disease, in association with radiation, and in recurrent/metastatic disease. The outcome of trials involving other EGFR-directed monoclonal antibodies, that is, zalutumumab and panitumumab, was consistent with the results with cetuximab. However these trials failed to meet their primary endpoint. The results with EGFR-directed tyrosine kinase inhibitors have been disappointing. Other potential targets for treatment in SCCHN include the entire ErbB family, the vascular endothelial growth factor (VEGF) and its receptor (VEGFR), the insulin-like growth factor 1 receptor (IGF-1R), the insulin receptor (IR), histone deacetylases (HDAC), the mammalian target of rapamycin (mTOR), the platelet-derived growth factor receptor (PDGFR), heat-shock protein 90 (HSP90), nuclear factor-kappa B (NF-κB), aurora A or B, and phosphatidylinositol 3-kinase (PIK3CA).

Current treatment options for recurrent/metastatic head and neck cancer: a post-ASCO 2011 update and review of last year's literature

The majority of patients with a squamous cell carcinoma of the head and neck present with locally advanced tumors. The first-line treatment of locally advanced tumor stages consists of a combined modality management. Despite these aggressive protocols, many patients develop locoregional recurrences or metastasis and place particularly high demands on the interdisciplinary treatment team. Treatment with a curative intent must be differentiated from a palliative one. In addition to prior treatment, resectability, age and performance status, patient wishes must be taken into consideration in treatment planning, especially considering that most therapies offer little to no overall survival benefit. Salvage surgery, chemo- and target therapies, and reirradiation are head and neck surgeon's and radiooncologist's weapons in the fight against these strong opponents. This review focuses on publications and meeting news from last year and reviews the current status of the clinical application of each treatment modality in recurrent or metastatic head and neck cancer.