A phase I study of oral ZD 1839 given daily in patients with solid tumors: IND.122, a study of the Investigational New Drug Program of the National Cancer Institute of Canada Clinical Trials Group

Progress and prospects of targeted therapy and immunotherapy for urachal carcinoma

Introduction: Urachal carcinoma (UrC) is a rare and aggressive disease. Systematic chemotherapy shows limited efficacy in patients with advanced disease, while targeted therapy and immunotherapy may provide a reasonable alternative for specific populations. The molecular pattern of colorectal cancer (CRC) have recently been identified; this understanding has significantly influenced the clinical management of CRC in terms of molecular-targeted therapy. Although some genetic alterations have been associated with UrC, there is still no systematic overview of the molecular profile of this rare malignancy. Methods: In this review, we comprehensively discuss the molecular profile of UrC and further identify potential targets for the personalized treatment of UrC as well as immune checkpoint inhibitors that represent underlying biomarkers. A systematic literature search was carried out by searching the PubMed, EMBASE, and Web of Science databases to identify all literature related to targeted therapy and immunotherapy in urachal carcinoma from inception to February 2023. Results: A total of 28 articles were eligible, and most studies included were case report sand retrospective case series. Furthermore, 420 cases of UrC were identified to analyze the association between mutations and UrC. The most commonly mutated gene in UrC was TP53 with the prevalence of 70%, followed by KRAS mutations in 28.3%, MYC mutations in 20.3%, SMAD4 mutations in 18.2% and GNAS mutations in 18%, amongst other genes. Discussion: The molecular patterns of UrC and CRC are similar yet distinct. Notably, targeted therapy, especially EGFR-targeting therapy, might provide curative efficacy for patients with UrC by applying specific molecular markers. Additional potential biomarkers for the immunotherapy of UrC are mismatch repair (MMR) status and PD-L1 expression profile. In addition, combined regimens featuring targeted agents and immune checkpoint blockers might increase antitumor activity and exert better efficacy in UrC patients with specific mutational burden.

Urachal carcinoma: The journey so far and the road ahead

Urachal carcinoma, a rare cancer arising from urachus, accounts for about 1% of bladder cancer. The diagnosis at stage I shows about 63% 5-year survival whereas only 8% of the patients at stage IV shows a 5-year survival. Above 90% of urachal carcinomas are adenocarcinomas and most of the urachal carcinoma cases are invasive, showing a high resemblance to adenocarcinoma of various origins, making it hard for a conclusive diagnosis. Even though inconclusive, immunohistochemistry can play a significant role in identifying urachal carcinoma. Most cases show the biomarkers CK20 and CDX2, whereas CK7 and β-catenin are expressed at a lesser frequency. Due to the few cases available, there is a lack of evidence regarding specific markers differentiating urachal carcinoma from colorectal or primary bladder adenocarcinomas. In addition to immunohistochemistry, genomic characterization is emerging to play a role in the classification and treatment of the disease. Urachal carcinoma has been reported to have a molecular level similarity with colorectal malignancies regarding certain gene expressions. The TP53 mutations inactivating the tumor suppressor can probably be explored as a possible target in treating urachal carcinoma. Additionally, certain targets identified in gastric and breast cancer along with anti-HER2 treatment strategies can be explored. Immuno-oncology utilizes immune checkpoint inhibitors for the treatment of MSI-H tumors whereas a combination of tyrosine kinase inhibitors along with immune checkpoint inhibitors are being studied to treat MSI stable tumors. The article is an in-depth overview of urachal carcinoma addressing the current landscape with an emphasis on the future scenario.

Clinical sequencing identifies potential actionable alterations in a high rate of urachal and primary bladder adenocarcinomas

OBJECTIVE

Administration of targeted therapies provides a promising treatment strategy for urachal adenocarcinoma (UrC) or primary bladder adenocarcinoma (PBAC); however, the selection of appropriate drugs remains difficult. Here, we aimed to establish a routine compatible methodological pipeline for the identification of the most important therapeutic targets and potentially effective drugs for UrC and PBAC.

METHODS

Next-generation sequencing, using a 161 cancer driver gene panel, was performed on 41 UrC and 13 PBAC samples. Clinically relevant alterations were filtered, and therapeutic interpretation was performed by in silico evaluation of drug-gene interactions.

RESULTS

After data processing, 45/54 samples passed the quality control. Sequencing analysis revealed 191 pathogenic mutations in 68 genes. The most frequent gain-of-function mutations in UrC were found in KRAS (33%), and MYC (15%), while in PBAC KRAS (25%), MYC (25%), FLT3 (17%) and TERT (17%) were recurrently affected. The most frequently affected pathways were the cell cycle regulation, and the DNA damage control pathway. Actionable mutations with at least one available approved drug were identified in 31/33 (94%) UrC and 8/12 (67%) PBAC patients.

CONCLUSIONS

In this study, we developed a data-processing pipeline for the detection and therapeutic interpretation of genetic alterations in two rare cancers. Our analyses revealed actionable mutations in a high rate of cases, suggesting that this approach is a potentially feasible strategy for both UrC and PBAC treatments.

Primary urachal signet ring cell carcinoma: A case report

Urachal signet ring cell carcinoma is a kind of rare but aggressive tumor, and a few cases have been reported previously. A 49-year-old male patient with primary complaints of increased frequency of urination, urodynia, and hematuria was diagnosed to have primary urachal signet ring cell carcinoma by our department. Multiple metastases were found in the sigmoid colon, terminal ileum, mesentery, and peritoneum during the operation, and palliative surgery involving partial cystectomy with en bloc resection of the urachus was then performed. A chemotherapy regimen of fluorouracil combined with cisplatin was made for this case. In addition, this patient also received anlotinib for targeted therapy. So far, this patient has done well on regular follow-up for 6 months and is in stable condition. We reported this additional urachal signet ring cell carcinoma case and conducted a literature review to strengthen our cognition of this disease.

Purchase of prophylactic topical corticosteroids is associated with improved survival in NSCLCs treated with EGFR TKI: real-world cohort study

BACKGROUND

With the first- and second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), clinical benefit and rash correlate together. EGFR TKI-induced rash can be alleviated with topical corticosteroids and tetracyclines. This study investigates whether prophylaxis with topical corticosteroids is associated with improved survival among the EGFR TKI-treated non-small cell lung cancers (NSCLCs).

MATERIAL AND METHODS

We collected all the patients (n = 1271) who had received reimbursement for the first- or second-generation EGFR TKIs in Finland 2011-2016, had purchased TKIs, and had data available at the Finnish Cancer Registry (FCR). Survival was analyzed from the first EGFR TKI purchase to death or the end of follow-up, and patients were stratified according to the TKIs, purchases of topical corticosteroids, and their timing.

RESULTS

A total of 270 (21%) patients had corticosteroid purchases -14 to +200 d (all), and 196 (15%) had purchased corticosteroids as prophylaxis (-14 to +14 d) from the first EGFR TKI purchase. Corticosteroid purchases were associated with improved survival in all (0.64 95% CI 0.56-0.74) and prophylactic (0.78, 95% CI 0.66-0.92) groups when compared to non-purchasers, although these results were limited to the erlotinib users only. The survival benefit of prophylactic corticosteroids among the erlotinib users remained in multivariate analysis including sex, stage, histology, and tetracycline prophylaxis (HR 0.78, 95% CI 0.64-0.95). The prophylactic use of corticosteroids was associated with a longer erlotinib treatment duration (HR 0.75, 95% CI 0.64-0.90).

CONCLUSIONS

Prophylactic topical corticosteroids may improve the survival of NSCLC patients treated with EGFR TKIs, and they should be considered as prophylaxis when initiating EGFR TKIs with a high incidence of rash.

Tetracyclines increase the survival of NSCLC patients treated with EGFR TKIs: a retrospective nationwide registry study

BACKGROUND

With the first and second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), clinical benefit and rash correlate together. EGFR TKI-induced rash can be alleviated with tetracyclines, but it is unknown whether the use of tetracyclines can increase the survival of non-small-cell lung cancer (NSCLC) patients treated with EGFR TKIs.

METHODS

We collected all the patients (n=1271) who had reimbursement for EGFR TKIs (gefitinib, erlotinib and afatinib) in Finland 2011-2016, had purchased TKIs, and had data available at nationwide cancer registry. The survival was analysed from the first EGFR TKI purchase to death or end-of follow-up, and patients were stratified according to TKIs, purchases of antibiotics, their ATC class and timing.

RESULTS

802 (63.1%) patients had antibiotic purchases -14 to +200 days from the first EGFR TKI purchase, 447 of these tetracyclines. 322 (25.3%) had had purchased antibiotics -14 to +14 days (prophylaxis) from the first EGFR TKI purchase, 188 of these tetracyclines. Purchase of antibiotics was associated with improved survival (HR 0.80, 95% CI 0.71 to 0.91), which limited to tetracycline purchases only (HR 0.72, 95% CI 0.64 to 0.82). The largest survival benefit was seen with the prophylactic use of tetracyclines (HR 0.74, 95% CI 0.62 to 0.88). The benefit from tetracyclines was limited to erlotinib only (HR 0.68, 95% CI 0.58 to 0.78) which was retained in multivariate analysis. Prophylactic use of tetracyclines was associated with a longer erlotinib treatment duration (HR 0.81, 95% CI 0.61 to 0.96) but not with dose reductions or treatment breaks.

CONCLUSIONS

Tetracyclines improve the survival of NSCLC patients treated with the first and second-generation EGFR TKIs and they should be considered as a prophylaxis when initiating EGFR TKIs with high incidence of rash.

Current Understanding of Urachal Adenocarcinoma and Management Strategy

PURPOSE OF REVIEW

The aim of this review is to sum up the state of the art of urachal carcinoma (UC) in order to easily guide clinicians.

RECENT FINDINGS

UC is a rare and aggressive disease with consequent few data about diagnosis and treatment. Dates are mainly based on retrospective trial and case reports with limited prospective trial. Clinical presentation is not specific, often with urinary symptoms. Diagnosis is mainly based on CT scan and MRI, useful to evaluate local invasion and nodal status and to detect the presence of distant metastases. Therefore, biopsy is needed to obtain histological confirmation. Surgery is the gold standard for localized disease, while different chemotherapy schemes have been used in metastatic setting. Novel findings based on mutational analysis of the tumor include the use of biological treatment, such as cetuximab, and immunotherapy, such as atezolizumab, with satisfactory responses, suggesting that personalized treatment could be the most suitable option for UC.

Clinicopathological features of malignant urachal tumor: A hospital-based cancer registry data in Japan

OBJECTIVES

To identify the clinicopathological features of malignant urachal tumor in Japan, and analyze the 5-year overall survival of malignant urachal tumor patients.

METHODS

We used the hospital-based cancer registry data to extract malignant urachal tumor cases that were diagnosed in 2008-2009 and 2012-2015, histologically confirmed, and received the first course of treatment. We analyzed the 5-year overall survival using the 2008-2009 cohort's data.

RESULTS

We identified 456 patients, and malignant urachal tumor accounted for 0.4% of all malignant bladder cancers. The median age was 61 years (range 2-97), and 66% were men. The most common histology was adenocarcinoma (80%), followed by urothelial carcinoma (11%) and squamous cell carcinoma (3%). The proportions of patients were: 19% Ta/Tis/T1N0M0, 55% T2-3N0M0, 13% T4/N+ and 13% M+. Regarding the initial treatment, the proportions of surgery alone were 79% and 33% in cases of T3 or less N0M0 and T4/N+, respectively. The proportion of combination therapy including surgery and chemotherapy were 13% and 44% in T2-3N0M0 and T4/N+, respectively. Radiation therapy was not common at any stage. In the 2008-2009 cohort, the 5-year overall survival rate in Ta/Tis/T1N0M0, T2-3N0M0, T4/N+ and M+ were 60%, 64%, 63% and 12%, respectively.

CONCLUSIONS

Malignant urachal tumors are quite rare in Japan, and most of those without metastasis are likely to be treated by surgery alone, even at advanced stages. A standard of care must be established for malignant urachal tumor patients at advanced stages or with metastasis, as the prognosis of these patients can be poor.

Epidermal growth factor receptor first generation tyrosine-kinase inhibitors

The epidermal growth factor receptor (EGFR) oncogene was positioned as an attractive target for drug development in non-small cell lung cancer (NSCLC). Gefitinib and erlotinib were the first two reversible inhibitors of the EGFR kinase. The discovery of EGFR kinase domain-activating mutations that significantly correlated with a high likelihood of response to EGFR tyrosine-kinase inhibitors (TKIs) allowed to design studies to test these drugs as potential first-line therapies. In the same way, the feasibility of personalized medicine was established in patients with advanced NSCLC. Currently in the field of NSCLC with EGFR mutation have developed second and even third generation TKIs that would be gaining the positioning in the treatment of this subset population of NSCLC. In spite of this, without the knowledge that EGFR first generation TKIs have provided, we would not have gotten so far. We will review step by step how it was forged the exciting history of the subpopulation of lung cancer with EGFR mutated, through the various clinical trials performed with first generation TKIs that changed the focus, the future of NSCLC as well as survival of these patients.

Mutational Profile Using Next-Generation Sequencing May Aid in the Diagnosis and Treatment of Urachal Adenocarcinoma

Objectives. The rare urachal adenocarcinoma (UAC) of the bladder has striking morphologic and immunohistochemical overlap with colorectal adenocarcinoma (CAC) and bladder adenocarcinoma (BAC). To date, the mutational status in UAC and BAC has not been well investigated. Methods. We retrospectively evaluated 34 UACs (mucinous, n = 9; intestinal, n = 3; signet ring cell, n = 1; not otherwise specified, n = 21) and 4 BACs (n = 4). Next-generation sequencing analysis of 50 cancer "hotspot" gene mutations using the Ampliseq Cancer Hotspot Panel v2 was performed. Two UAC cases did not have adequate DNA quality with poor sequencing coverage and were excluded from the study. Results. RAS mutations were identified in 16 of 32 (50%) UACs (15 KRAS; 1 NRAS) and none of the BACs (0%). TP53 mutations were found in both UACs (18/32; 56%) and BACs (4/4; 100%). GNAS (n = 4), SMAD4 (n = 3), and BRAF (n = 1) mutations were only found in UACs. In contrast, APC (n = 2) mutations were only found in BACs. The mucinous subtype of UAC contained a SMAD4 mutation in 33% of cases (3/9), which was not identified in any other subtype (0/23; 0%) (P = .0169). The only BRAF mutation was identified in the single signet ring cell subtype of UAC. There were no other differences in the mutation profile when comparing histologic subtypes of UAC. Conclusions. In summary, UAC and BAC have overlapping but distinct mutation profiles and these differences may aid in separating these 2 entities. Next-generation sequencing to identify therapeutic targets or resistance markers may aid treatment decisions.

Mutations of KRAS, NRAS, BRAF, EGFR, and PIK3CA genes in urachal carcinoma: Occurence and prognostic significance

Purpose

Targeted therapy represents an attractive alternative for rare tumors such as urachal carcinoma (UrC). The aim of this study was to assess the mutations of the most commonly affected 5 genes in the targetable EGFR-pathway in UrC and comapre their frequencies to those of found in urothelial and colorectal cancer.

Materials and Methods

Mutational hot-spots of selected genes were tested in 22 UrC samples by pyrosequencing. Mutational patterns were compared to those published for colorectal and urothelial cancers. Furthermore, we sought correlations between mutations and clinicopathological and follow-up data.

Results

We found 11 mutations in 10 of 22 (45%) patients. The most frequently mutated gene was KRAS (27%) followed by BRAF (18%) and NRAS (5%), while no mutations were detected in the EGFR and PIK3CA genes. No correlation was found between the mutation status and clinicopathological parameters (Sheldon/Mayo stage, tumor grade, metastases). Furthermore, none of the mutations correlated with progression-free or overall survival.

Conclusions

The mutation pattern of UrC is more similar to colorectal than to urothelial cancer. However, the mutation characteristics of UrC seems to be unique suggesting that clinical decision-making for UrC cannot be simply adopted from urothelial or colorectal carcinoma. The high occurence of EGFR-pathway mutations warrants the testing for KRAS and BRAF mutations when considering anti-EGFR therapy in UrC.

Common EGFR-mutated subgroups (Del19/L858R) in advanced non-small-cell lung cancer: chasing better outcomes with tyrosine kinase inhibitors

Ten years ago, somatic mutations in EGFR were identified in patients with non-small-cell lung cancer. Demonstration of the antitumor efficacy of EGF receptor-directed tyrosine kinase inhibitors resulted in their approval for the treatment of advanced non-small-cell lung cancer. Insights into the role of EGFR-sensitizing mutations and acquired and de novo T790M resistance mutations followed, and differences in progression-free survival for patients with EGFR Del19- and L858R-mutated tumors treated with reversible first-generation EGF receptor tyrosine kinase inhibitors were reported. Recently, overall survival benefit in patients with Del19- but not L858R-mutated tumors has been demonstrated after treatment with afatinib, an irreversible ErbB family blocker. Although the biology underlying this difference in survival is currently unclear, this review examines several hypotheses.

[Urachal cancers]

Urachal cancer is a rare pathology (less than 1% among all bladder tumors) with a poor prognosis for all stages, because of clinical delay leading to a late diagnosis, difficult differential diagnosis with bladder cancer, and no consensus for the treatment, mostly about the chemotherapy for advanced stages, because there are no data from prospective studies. A surgical treatment can be performed for the localized stages, but there are no real guidelines for local relapses and metastatic progression treatment. Those cancers are not radio- or chemosensitive; nevertheless data from fundamental research are missing. As this pathology is really uncommon, there are no clinical studies with targeted therapies. The purpose of this review is to introduce the most important clinical and paraclinical features of those cancers, and the usual treatment performed.

Selective growth inhibition of human breast cancer cells by graviola fruit extract in vitro and in vivo involving downregulation of EGFR expression

The epidermal growth factor receptor (EGFR) is an oncogene frequently overexpressed in breast cancer (BC), and its overexpression has been associated with poor prognosis and drug resistance. EGFR is therefore a rational target for BC therapy development. This study demonstrated that a graviola fruit extract (GFE) significantly downregulated EGFR gene expression and inhibited the growth of BC cells and xenografts. GFE selectively inhibited the growth of EGFR-overexpressing human BC (MDA-MB-468) cells (IC(50) = 4.8 μg/ml) but had no effect on nontumorigenic human breast epithelial cells (MCF-10A). GFE significantly downregulated EGFR mRNA expression, arrested cell cycle in the G0/G1 phase, and induced apoptosis in MDA-MB-468 cells. In the mouse xenograft model, a 5-wk dietary treatment of GFE (200 mg/kg diet) significantly reduced the protein expression of EGFR, p-EGFR, and p-ERK in MDA-MB-468 tumors by 56%, 54%, and 32.5%, respectively. Overall, dietary GFE inhibited tumor growth, as measured by wet weight, by 32% (P < 0.01). These data showed that dietary GFE induced significant growth inhibition of MDA-MB-468 cells in vitro and in vivo through a mechanism involving the EGFR/ERK signaling pathway, suggesting that GFE may have a protective effect for women against EGFR-overexpressing BC.

Pharmacodynamics: biological activity of targeted therapies in clinical trials

Anticancer drug discovery and development in cancer are currently undergoing of fast transformation. The selection of a therapeutic and effective dose using conventional cytotoxic agents has been based on the consecution of the maximally tolerated dose. However, this principle does not apply for new targeted therapies, where the definition of the optimal biologic dose (OBD) should be preferred. The definition of OBD might be established based on pharmacokinetic endpoints and, ideally, on pharmacodynamic assays by demonstrating directly the biological effect on the target and its downstream molecules in normal or tumor tissues. Normal tissues, such as peripheral blood mononuclear cells, skin or mucosa, may be excellent surrogates for explore the exposure of a drug and the dynamic target inhibition in vivo. In addition, tumor pharmacodynamic assays may determine the biologic effects of a therapy because tumor cells respond in a different way to targeted drugs than normal tissues, and to identify biomarkers that would permit to predict the individual response. In conclusion, these studies provide demonstration of proof of concept for biological and molecular mechanisms of selected drug, to select the appropriate population to be treated, to help the interpretation of clinical data, to inform the identification of optimal dose and schedule, to evaluate the clinical response and to contribute to take decisions for final approval by authorities.

Understanding the new genetics of responsiveness to epidermal growth factor receptor tyrosine kinase inhibitors

The epidermal growth factor receptor (EGFR) is implicated in cancer progression and development and, being overexpressed in a variety of human malignancies, is an attractive target for selective anticancer therapy. EGFR tyrosine kinase inhibitors (TKIs) have been demonstrated to produce dramatic and durable responses in a fraction of non-small cell lung cancer patients. During the last few years, clinical and biological predictors for TKI sensitivity have been identified. Among clinical features, never-smoking history seemed the most critical factor, probably because of the different spectrum of molecular abnormalities associated with cigarette-smoking exposure. Among biological predictors, several studies indicate that EGFR mutations and increased EGFR gene copy number are implicated in response to TKI therapy, with conflicting results in survival. Mutations in the EGFR gene as well as in K-ras and HER2 genes seemed to impair TKI effects, leading to TKI resistance. Because most available data come from retrospective studies, there is an urgent need to validate these results in prospective trials. Several studies have been recently completed, and these data could indicate how to properly select patients who are candidates for TKI therapy.

A phase I clinical and pharmacokinetic study of oral CI-1033 in combination with docetaxel in patients with advanced solid tumors

PURPOSE

CI-1033 is an orally available 4-anilinoquinazolone irreversible tyrosine kinase inhibitor of erbB-1, erbB-2, and erbB-4. We conducted a dose escalation study of CI-1033 with docetaxel to assess the safety profile and pharmacokinetics of the combination and to establish the maximum tolerated dose.

EXPERIMENTAL DESIGN

Twenty-six patients with advanced solid tumors were treated on four dosing cohorts starting at CI-1033 (50 mg/d) + docetaxel (75 mg/m2). An intermittent dosing schedule avoided concurrent drug dosing.

RESULTS

CI-1033 alone was escalated from 50 to 75 mg/d (dose level 2), where diarrhea was dose limiting; a 38% incidence of cycle 1 febrile neutropenia prompted dose de-escalation of both CI-1033 and docetaxel for dose level 3, where dose-limiting toxicities prompted further de-escalation of CI-1033 to 45 mg/d. Given equivalent safety profiles for dose level 1 [CI-1033 (50 mg/d) + docetaxel (75 mg/m2)] and dose level 4 [CI-1033 (45 mg/d) + docetaxel (60 mg/m2)], the former was determined to be the recommended phase II dose, given greater dose intensity of both drugs. Antitumor activity was noted in three patients, including a complete response in a patient with cervix uteri cancer. Pharmacokinetic analysis showed a possible effect of docetaxel on CI-1033 pharmacokinetics.

CONCLUSIONS

It is feasible to combine the irreversible pan-erbB tyrosine kinase inhibitor CI-1033 with docetaxel on an intermittent dosing schedule in advanced cancer patients. We established the maximum tolerated dose and recommended phase II dose for the combination. Further investigation of this combination should include a rigorous analysis of the effect of docetaxel on CI-1033 pharmacokinetics.

Epidermal growth factor receptor tyrosine kinase inhibitors: present and future role in gastrointestinal cancer treatment: a review

BACKGROUND

Despite advances in conventional and targeted anticancer therapy, the prognosis remains poor for many patients with solid tumors. Ongoing research into the molecular basis of malignant disease, however, has yielded many novel agents with potential activity, including the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).

DESIGN

This review summarizes current clinical data for EGFR-TKIs as monotherapy or in combination with 5-fluorouracil/leucovorin, irinotecan, or oxaliplatin, focusing on the rapidly developing area of colorectal, gastroesophageal, and pancreatic cancers.

RESULTS

EGFR-TKIs have limited but valuable activity as monotherapy in non-small cell lung cancer patients who have received prior anticancer treatment. The potential for application as a single agent in colorectal, gastroesophageal, and pancreatic cancers has yet to be demonstrated conclusively and deserves further investigation, especially as second- or third-line therapy. In combination with oxaliplatin-based regimens and 5-fluorouracil/leucovorin-based regimens, TKIs have shown benefits, suggesting that there may be a synergistic effect with chemotherapy. However, combinations with irinotecan-based regimens have been limited by toxicities.

CONCLUSIONS

EGFR-TKIs show benefits when used in combination with chemotherapy, and the favorable toxicity profiles observed suggest that these may be of value in frail or elderly patients.

Role of Epidermal Growth Factor Receptor Pathway–Targeted Therapy in Patients With Recurrent and/or Metastatic Squamous Cell Carcinoma of the Head and Neck

The development of epidermal growth factor receptor (EGFR) inhibitors was greeted with tremendous enthusiasm in the therapy of squamous cell carcinoma of the head and neck (SCCHN) based on the nearly universal expression of this protein, the negative prognostic associations with expression, and robust preclinical data. Clinical trials to date have demonstrated modest activity of these drugs as single agents with reproducible major response rates of 5% to 15% in SCCHN depending on agent, dose, and schedule. The biology of responsiveness to these agents remains unclear, although an association of development of cutaneous toxicity with positive outcome has been reported repeatedly. Nevertheless, molecular markers of response or resistance have yet to be fully delineated. In the near future, phase III clinical trials will elucidate the role of these agents in second-line recurrent and/or metastatic (R/M) disease, the combination of EGFR inhibitors with other therapeutic strategies will be broadly advanced, and a set of molecular predictors of benefit will begin to emerge. This article will review the progress in utilization of EGFR inhibitors in R/M SCCHN.

Where next for gefitinib in patients with lung cancer?

Gefitinib belongs to the small-molecule class of epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors. It was given conditional approval by the US Food and Drug Administration (FDA) in 2003 for treatment of advanced, chemorefractory non-small-cell lung cancer (NSCLC), but was relabelled for restricted use for patients that were already receiving and benefiting from it after the negative result of the phase III Iressa Survival Evaluation in Advanced Lung Cancer (ISEL) trial. By contrast, erlotinib, another EGFR tyrosine-kinase inhibitor, showed an overall survival benefit compared with placebo and best supportive care in the National Cancer Institute of Canada's BR21 trial, and now has full FDA approval for treatment of patients with NSCLC who have progressed after treatment with chemotherapy. Although the ISEL trial result was negative overall, preplanned subgroup analyses showed a significant overall survival benefit for gefitinib treatment in never-smokers and in patients of Asian origin. Here, we review the clinical experience with gefitinib and, in light of the licensing of erlotinib, address the lessons learned, the ongoing trials, and whether scope remains for clinical development of gefitinib in selected patients.

Current Status of Small-Molecule Tyrosine Kinase Inhibitors Targeting Epidermal Growth Factor Receptor in Colorectal Cancer

The epidermal growth factor receptor (EGFR) is expressed in the majority of colorectal cancers (CRCs) and is associated with poor clinical outcome. Ample evidence suggests that inhibition of this pathway by monoclonal antibodies directed against EGFR leads to antitumor activity in CRC. Small-molecule tyrosine kinase inhibitors (TKIs) provide distinct advantages over monoclonal antibodies by virtue of lower production costs, ease of oral administration, and ability to target multiple cellular survival pathways. Despite theoretical advantages, multiple early-phase trials of EGFR TKIs fail to demonstrate single-agent activity in CRC. However, the unusually high response rates observed when gefitinib, an EGFR TKI, is combined with chemotherapy for patients with metastatic CRC suggest a possible synergistic effect. This effect is not seen in non-small-cell lung cancer (NSCLC), for which larger phase III trials have been conducted. The differences between NSCLC and CRC with respect to EGFR expression and mutation status do not completely explain this dichotomy, and further investigation into the pharmacogenomics of EGFR tyrosine kinase inhibition in CRC is under way. Significant effort is directed toward newer strategies targeted at the EGFR in CRC. A new generation of small-molecule TKIs is emerging in which multiple receptor pathways, including ErbB2 and vascular endothelial growth factor receptor, can be simultaneously targeted with EGFR. These agents are still in early-phase clinical trials, and specific data for patients with CRC are forthcoming.

A phase II trial of ZD1839 (Iressa) 750 mg per day, an oral epidermal growth factor receptor-tyrosine kinase inhibitor, in patients with metastatic colorectal cancer

PURPOSE

The epidermal growth factor receptor (EGFR) appears relevant in the pathogenesis and progression of colorectal cancer. After completing a phase I pharmacodynamic trial of ZD1839, we undertook a dose expansion trial to examine the antitumour efficacy and adverse effect profile of this agent in a homogeneous group of patients with metastatic colorectal cancer (CRC).

EXPERIMENTAL DESIGN

Eligible patients with metastatic or recurrent CRC received ZD1839 750 mg daily by mouth. This dose was selected based on a phase I trial conducted by the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG). Treatment was continued until unacceptable toxicity or disease progression.

RESULTS

Twenty-eight patients were enrolled at three NCIC CTG centers. Twenty-three patients had received prior chemotherapy; 12 patients had received three or more regimens. No objective responses were observed in 24 evaluable patients, although 8 patients had stable disease (median duration of 2.2 months). The most frequent drug related adverse events were diarrhea, rash and nausea. Eleven patients required dosing modification (hold or reduction), while 3 patients discontinued therapy because of toxicity. There were no treatment related deaths.

CONCLUSIONS

ZD1839, when given at 750 mg/day to patients with pre-treated metastatic colorectal cancer, does not result in significant tumor regression.