Gefitinib Therapy for Advanced Non–Small-Cell Lung Cancer

Glioblastoma: Current Status, Emerging Targets, and Recent Advances

Glioblastoma (GBM) is a highly malignant brain tumor characterized by a heterogeneous population of genetically unstable and highly infiltrative cells that are resistant to chemotherapy. Although substantial efforts have been invested in the field of anti-GBM drug discovery in the past decade, success has primarily been confined to the preclinical level, and clinical studies have often been hampered due to efficacy-, selectivity-, or physicochemical property-related issues. Thus, expansion of the list of molecular targets coupled with a pragmatic design of new small-molecule inhibitors with central nervous system (CNS)-penetrating ability is required to steer the wheels of anti-GBM drug discovery endeavors. This Perspective presents various aspects of drug discovery (challenges in GBM drug discovery and delivery, therapeutic targets, and agents under clinical investigation). The comprehensively covered sections include the recent medicinal chemistry campaigns embarked upon to validate the potential of numerous enzymes/proteins/receptors as therapeutic targets in GBM.

Lung cancer genotype-based therapy and predictive biomarkers: present and future

CONTEXT

The advent of genotype-based therapy and predictive biomarkers for lung cancer has thrust the pathologist into the front lines of precision medicine for this deadly disease.

OBJECTIVE

To provide the clinical background, current status, and future perspectives of molecular targeted therapy for lung cancer patients, including the pivotal participation of the pathologist.

DATA SOURCES

Data were obtained from review of the pertinent peer-reviewed literature.

CONCLUSIONS

First-generation tyrosine kinase inhibitors have produced clinical response in a limited number of non-small cell lung cancers demonstrated to have activating mutations of epidermal growth factor receptor or anaplastic lymphoma kinase rearrangements with fusion partners. Patients treated with first-generation tyrosine kinase inhibitors develop acquired resistance to their therapy. Ongoing investigations of second-generation tyrosine kinase inhibitors and new druggable targets as well as the development of next-generation genotyping and new antibodies for immunohistochemistry promise to significantly expand the pathologist's already crucial role in precision medicine of lung cancer.

Induction of Na+/K+/2Cl- cotransporter expression mediates chronic potentiation of intestinal epithelial Cl- secretion by EGF

Alterations in EGF receptor (EGFR) signaling occur in intestinal disorders associated with dysregulated epithelial transport. In the present study, we investigated a role for the EGFR in the chronic regulation of intestinal epithelial secretory function. Epithelial Cl(-) secretion was measured as changes in short-circuit current (Isc) across voltage-clamped monolayers of T84 cells in Ussing chambers. Acute treatment of T84 cells with EGF (100 ng/ml, 15 min) chronically enhanced Isc responses to a broad range of secretagogues. This effect was apparent within 3 h, maximal by 6 h, and sustained for 24 h after treatment with EGF. The Na+/K+/2Cl(-) cotransporter (NKCC1) inhibitor bumetanide (100 microM) abolished the effect of EGF, indicating increased responses are due to potentiated Cl(-) secretion. Neither basal nor agonist-stimulated levels of intracellular Ca2+ or PKA activity were altered by EGF, implying that the effects of the growth factor are not due to chronic alterations in levels of second messengers. EGF increased the expression of NKCC1 with a time course similar to that of its effects on Cl(-) secretion. This effect of EGF was maximal after 6 h, at which time NKCC1 expression in EGF-treated cells was 199.9 +/- 21.9% of that in control cells (n = 21, P < 0.005). EGF-induced NKCC1 expression was abolished by actinomycin D, and RT-PCR analysis demonstrated EGF increased expression of NKCC1 mRNA. These data increase our understanding of mechanisms regulating intestinal fluid and electrolyte transport and reveal a novel role for the EGFR in the chronic regulation of epithelial secretory capacity through upregulation of NKCC1 expression.

Clinical implications of EGFR expression in the development and progression of solid tumors: focus on non-small cell lung cancer

Dysregulation of the epidermal growth factor receptor (EGFR) signaling pathway is associated with the development and progression of malignancy, and EGFR-targeted therapies offer the promise of better treatment for many types of solid tumors, including non-small cell lung cancer. Anti-EGFR agents include monoclonal antibodies (mAbs) targeting the EGFR extracellular receptor domain and small-molecule tyrosine kinase inhibitors (TKIs) targeting the EGFR intracellular kinase domain. Both mAbs and TKIs have demonstrated encouraging results as monotherapies and in combination with chemotherapy and radiotherapy. This review provides a critical update on the status of these novel therapeutics.

An Approach to Evaluating Drug-Nutrient Interactions

Although the significance of interactions between drugs is widely appreciated, little attention has been given to interactions between drugs and nutrients. Pharmacists are challenged to remember documented interactions involving available drugs, and they face the possibility that each newly approved therapeutic agent may be involved not only in unrecognized drug-drug interactions but in drug-nutrient interactions as well. A more consistent approach to evaluating drug-nutrient interactions is needed. The approach must be systematic in order to assess the influence of nutritional status, food, or specific nutrients on a drug's pharmacokinetics and pharmacodynamics, as well as the influence of a drug on overall nutritional status or on the status of a specific nutrient. We provide such a process, using several recently approved drugs as working examples. Risk factors and clinical relevance are described, with distinctions made between documented and potential interactions. Application of this process by the pharmacist to any drug will help increase their expertise. Furthermore, full consideration by pharmacists of all possible interactions of the drug regimens used in practice can allow for improved patient care.

Phase II Study of Gefitinib in Patients with Relapsed or Persistent Ovarian or Primary Peritoneal Carcinoma and Evaluation of Epidermal Growth Factor Receptor Mutations and Immunohistochemical Expression: A Gynecologic Oncology Group Study

PURPOSE

This phase II trial assessed the activity and tolerability of a daily oral dose of 500 mg gefitinib (ZD1839, Iressa) in patients with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma, and explored the clinical value of determining the status of the epidermal growth factor receptor (EGFR).

EXPERIMENTAL DESIGN

Primary measure of efficacy was progression-free survival at 6 months. Mutations in exons 18 to 21 of EGFR and/or immunohistochemical expression of EGFR were evaluated in tumor specimens from patients enrolled in this trial as well as from patients not treated with gefitinib.

RESULTS

Twenty-seven of 30 (90%) patients were eligible and evaluable for analysis of gefitinib efficacy and toxicity. Of these, four survived progression-free >6 months with one objective response (4%). The most commonly observed grade 3 toxicities were dermatologic (15%, 4 of 27) and diarrhea (30%, 8 of 27). Specimens from 26 of 26 or 25 of 26 patients were evaluable for immunohistochemical or mutation analysis, respectively. The response rate for patients with EGFR-positive tumors was 9% (1 of 11). EGFR expression was associated with longer progression-free survival (P = 0.008) and possibly longer survival (P = 0.082). The patient with the only objective response had a mutation in the catalytic domain of the tumor's EGFR (P = 0.04). Among 32 invasive tumors from patients not treated with gefitinib, one exhibited a catalytic domain mutation.

CONCLUSIONS

Gefitinib was well tolerated but had minimal activity in unscreened patients with recurrent ovarian or primary peritoneal carcinoma. Prescreening patients for activating mutations in EGFR may improve response rate to gefitinib. This report is the first to document activating mutations in catalytic domain of EGFR in 3.5% (2 of 57) of ovarian cancers.

Adverse drug interactions and reactions in dermatology: current issues of clinical relevance

This article highlights several adverse drug interactions and reactions relevant to current dermatologic practice. Absorption interactions between drugs and compounds containing polyvalent cations, potential interactions between herbal and conventional medicines, the meaning of sulfa allergy, and adverse cutaneous reactions caused by epidermal growth factor receptor inhibitors are discussed.

Gefitinib: a review of its use in the management of advanced non-small-cell lung cancer

Gefitinib (Iressa), the first commercially available epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitor, is indicated in the management of patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC). However, approved uses differ between countries; in most markets, gefitinib is approved for third-line use only (e.g. the US, Canada and Switzerland), although in some it is approved for both second- and third-line use (e.g. Japan and Australia) and, additionally, in patients considered unsuitable for chemotherapy (e.g. Indonesia and the Philippines). Few third-line treatment options exist for patients with inoperable advanced NSCLC who have failed both platinum-based and docetaxel chemotherapies. Gefitinib represents a significant advance in the treatment of this population; a once-daily, oral dosage of 250 mg/day was well tolerated, produced objective tumour responses and disease stabilisation, and improved disease-related symptoms and quality of life. It also produced overall survival outcomes that compared favourably with historical outcomes in a similar group of patients treated with three or four different chemotherapy regimens. These findings have been supported by observations from a global compassionate-use programme. Ongoing or planned clinical trials are designed to confirm and/or further define the role of the drug in the above and other clinical settings.