Discovery of novel quinazoline derivatives bearing semicarbazone moiety as potent EGFR kinase inhibitors

Background Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2nd EGFR-TKI administration. Methods We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment. Results Three patients (27%) were treated with gefitinib as the 2nd EGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2nd EGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2nd EGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2nd EGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy. Conclusions Our results indicate that a 2nd EGFR-TKI treatment can be an effective treatment option for gefitinib responders.

On May 5, 2003, gefitinib (Iressa), ZD1839) 250-mg tablets received accelerated approval by the U.S. Food and Drug Administration as monotherapy treatment for patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of both platinum-based and docetaxel chemotherapies. Information provided in this summary includes efficacy and safety results of relevant clinical trials. Effectiveness was demonstrated in a randomized, double-blind, phase II, multicenter trial comparing two oral doses of gefitinib (250 mg/day versus 500 mg/day). Two hundred sixteen patients were enrolled. The 142 patients who were refractory to or intolerant of a platinum and docetaxel comprised the evaluable population for the efficacy analysis. A partial tumor response occurred in 14% (9 of 66) of patients receiving gefitinib 250 mg/day and in 8% (6 of 76) of patients receiving gefitinib 500 mg/day. The overall objective response rate for both doses combined was 10.6% (15 of 142 patients) (95% confidence interval 6.0%-16.8%). Responses were more frequent in females and in nonsmokers. The median duration of response was 7.0 months (range 4.6-18.6+ months). Other submitted data included the results of two large trials conducted in chemotherapy-naive, stage III and IV NSCLC patients. Patients were randomized to receive gefitinib (250 mg or 500 mg daily) or placebo, in combination with either gemcitabine plus cisplatin (n = 1,093) or carboplatin plus paclitaxel (n = 1,037). Results from those studies showed no benefit (response rate, time to progression, or survival) from adding gefitinib to chemotherapy. Consequently, gefinitib is only recommended for use as monotherapy. Common adverse events associated with gefitinib treatment included diarrhea, rash, acne, dry skin, nausea, and vomiting. Most toxicities were Common Toxicity Criteria grade 1 or 2. Interstitial lung disease (ILD) has been observed in patients receiving gefitinib. Worldwide, the incidence of ILD is about 1% (2% in the Japanese postmarketing experience and about 0.3% in a U.S. expanded access program). Approximately one-third of the cases were fatal. Physicians should promptly evaluate new or worsening pulmonary symptoms. If ILD is confirmed, appropriate management includes discontinuation of gefitinib. Gefitinib was approved under accelerated approval regulations on the basis of a surrogate end point response rate. No controlled gefitinib trials, to date, demonstrate a clinical benefit, such as improvement in disease-related symptoms or greater survival. Accelerated approval regulations require the sponsor to conduct further studies to verify that gefitinib therapy produces such a benefit.

AKT (also known as PKB) plays a central role in a variety of cellular processes including cell growth, motility and survival in both normal and tumor cells. The AKT pathway is also instrumental in epithelial mesenchymal transitions (EMT) and angiogenesis during tumorigenesis. AKT functions as a cardinal nodal point for transducing extracellular (growth factors including insulin, IGF-1 and EGF ) and intracellular (such as mutated/activated receptor tyrosine kinases, PTEN, Ras and Src) signals. It is positively regulated by phosphatidylinositol 3-kinase and inhibited by phosphatase PTEN. Deregulation of the PI3K/PTEN/AKT pathway is one of the most common altered pathways in human malignancy. In the past few years, significant advances have been made in the understanding of AKT signaling in human oncogenesis and the development of small molecule inhibitor of AKT pathway. Here, we will discuss the regulation and function of AKT as well as targeting AKT for anti-cancer drug discovery.