New developments in chemotherapy for advanced non-small cell lung cancer

Glutathione S-transferase π: a potential role in antitumor therapy

Glutathione S-transferase π (GSTπ) is a Phase II metabolic enzyme that is an important facilitator of cellular detoxification. Traditional dogma asserts that GSTπ functions to catalyze glutathione (GSH)-substrate conjunction to preserve the macromolecule upon exposure to oxidative stress, thus defending cells against various toxic compounds. Over the past 20 years, abnormal GSTπ expression has been linked to the occurrence of tumor resistance to chemotherapy drugs, demonstrating that this enzyme possesses functions beyond metabolism. This revelation reveals exciting possibilities in the realm of drug discovery, as GSTπ inhibitors and its prodrugs offer a feasible strategy in designing anticancer drugs with the primary purpose of reversing tumor resistance. In connection with the authors' current research, we provide a review on the biological function of GSTπ and current developments in GSTπ-targeting drugs, as well as the prospects of future strategies.

A study of weekly docetaxel and carboplatin as first-line chemotherapy for advanced non-small cell lung cancer

BACKGROUND

Weekly docetaxel demonstrated similar efficacy but better tolerability than standard triweekly docetaxel, and carboplatin was less nephrotoxic, neurotoxic and emetogenic than cisplatin. This study aimed to evaluate the efficacy and safety of weekly docetaxel with carboplatin as first-line chemotherapy for advanced non-small cell lung cancer (NSCLC).

METHODS

Forty-three Chinese patients have been included. Patients were administered docetaxel at a dose of 35 mg/m(2) on days 1, 8, 15 and carboplatin at an area under the curve (AUC) 5 on day 1 every 28-day cycle (maximum six cycles).

RESULTS

Of the 43 eligible patients, the assessed overall response rate (RR) was 30.2% with 30.2% partial response (PR) in 13 patients, 48.8% stable disease (SD) in 21 patients and 20.9% progressive disease (PD) in 9 patients. The estimated median progression free survival and median overall survival (OS) time were respectively, 120 days (95% CI: 80-160 days) and 340 days (95% CI: 224-456 days) with the patients surviving of 46.5% (95% CI: 31.6-61.4%) at one year and 20.0% (95% CI: 7.1-33.3%) at two years. The major grade 3/4 hematological toxicities were included leucocytopenia in 6 patients (13.9%) and neutropenia in 8 patients (18.6%). One patient (2.3%) suffered grade 1 febrile neutropenia. All grade of the nonhematological toxicities, such as nausea, vomiting, alopecia and fatigue held the proportion of 48.8% (grade 3/4 4.6%), 27.9%, 55.8% and 53.5% (grade 3/4 9.3%), respectively.

CONCLUSIONS

The combination of weekly docetaxel and carboplatin showed feasible efficacy with acceptable hematologic toxicities for advanced lung cancer.

ASDCD: antifungal synergistic drug combination database

Finding effective drugs to treat fungal infections has important clinical significance based on high mortality rates, especially in an immunodeficient population. Traditional antifungal drugs with single targets have been reported to cause serious side effects and drug resistance. Nowadays, however, drug combinations, particularly with respect to synergistic interaction, have attracted the attention of researchers. In fact, synergistic drug combinations could simultaneously affect multiple subpopulations, targets, and diseases. Therefore, a strategy that employs synergistic antifungal drug combinations could eliminate the limitations noted above and offer the opportunity to explore this emerging bioactive chemical space. However, it is first necessary to build a powerful database in order to facilitate the analysis of drug combinations. To address this gap in our knowledge, we have built the first Antifungal Synergistic Drug Combination Database (ASDCD), including previously published synergistic antifungal drug combinations, chemical structures, targets, target-related signaling pathways, indications, and other pertinent data. Its current version includes 210 antifungal synergistic drug combinations and 1225 drug-target interactions, involving 105 individual drugs from more than 12,000 references. ASDCD is freely available at http://ASDCD.amss.ac.cn.

Southwest Oncology Group phase II trial (S0341) of erlotinib (OSI-774) in patients with advanced non-small cell lung cancer and a performance status of 2

PURPOSE

This phase II study (S0341) evaluated the efficacy and tolerability of single-agent erlotinib in unselected chemotherapy-naive patients with advanced non-small cell lung cancer (NSCLC) and a performance status (PS) of 2. Exploratory analyses of a number of biomarkers relating to epidermal growth factor receptor pathway activation were also performed.

PATIENTS AND METHODS

Patients with stage IIIB (pleural effusion) or stage IV NSCLC with a PS of 2 and no prior chemotherapy or biologic treatment for NSCLC received erlotinib 150 mg daily.

RESULTS

A total of 81 patients entered the study; 76 were assessable. One complete and 5 partial responses were noted for an overall response rate of 8% (95% CI 3%-16%). Stable disease (SD) was seen in 26 patients (34%) resulting in a disease control rate (DCR = CR/PR/SD) of 42%. Progression free and median survival were 2.1 months (95% CI 1.5-3.1) and 5 months (95% CI 3.6-7.2), respectively. One-year survival was 24% (95% CI 15%-34%). Although treatment was generally well tolerated, grade 3 to 4 toxicity was reported in 30 patients (40%), including fatigue (16%), rash (9%), diarrhea (7%), and anorexia (7%). There was one possible treatment related death (pneumonitis).

CONCLUSIONS

In chemotherapy-naive patients with advanced NSCLC and a PS of 2, single agent erlotinib resulted in an acceptable but significant level of treatment-related side effects. With an overall DCR of 42% and median survival of 5 months, results are comparable to those achieved with chemotherapy in this population. Development of an epidermal growth factor receptor-directed biomarker selection strategy may optimize use of erlotinib in PS 2 patients.

Plant-derived natural product research aimed at new drug discovery

Many important bioactive compounds have been discovered from natural sources using bioactivity-directed fractionation and isolation (BDFl) [Balunas MJ, Kinghorn AD (2005) Drug discovery from medicinal plants. Life Sci 78:431-441]. Continuing discovery has also been facilitated by the recent development of new bioassay methods. These bioactive compounds are mostly plant secondary metabolites, and many naturally occurring pure compounds have become medicines, dietary supplements, and other useful commercial products. Active lead compounds can also be further modified to enhance the biological profiles and developed as clinical trial candidates. In this review, the authors will summarize research on many different useful compounds isolated or developed from plants with emphasis placed on those recently discovered by the authors' laboratories as antitumor and anti-HIV clinical trial candidates.

Lung cancer: Future directions

Increasingly, basic research is being translated into clinical benefits for patients. Recent studies have shed more light on the clinical use of targeted therapies such as tyrosine kinase and angiogenesis inhibitors, and predictive factors for their clinical benefit and their role in different clinical settings are now being elucidated. New insights into the basic biology of lung cancer hold translational promise in risk assessment, early detection, molecular staging, treatment response prediction and novel therapies. New targeted agents directed at apoptotic and developmental pathways have the potential to exploit newly discovered vulnerabilities in the basic machinery of cancer. In addition, exploration of the cancer stem cell phenomenon in lung cancer may generate new approaches to prevent recurrence in surgically respectable lung cancer, and for the long-term control of extensive disease. Molecular profiling may also allow for highly individualized prognostic, predictive and therapeutic treatment plans tailored for each patient based on the molecular diagnostic profile of their tumour. Advances in genetic susceptibility, early detection and individualized therapy based on each tumour's unique biological properties all hold promise for the future management of lung cancer.