Novel targets for lung cancer therapy: part II

Phase I/II study of sorafenib in combination with erlotinib for recurrent glioblastoma as part of a 3-arm sequential accrual clinical trial: NABTC 05-02

Background

Receptor tyrosine kinases such as epidermal growth factor receptors (EGFRs) and their downstream signaling pathways such as the Ras-Raf-mitogen-activated protein kinase (MAPK) pathway play important roles in glioblastoma (GBM). This study investigated the safety, pharmacokinetics, and efficacy of sorafenib (Ras/Raf/MAPK inhibitor) in combination with erlotinib (EGFR inhibitor) for treatment of recurrent GBMs.

Methods

Patients with recurrent GBM were eligible. A novel sequential accrual trial design was used, where patients were sequentially accrued into separate treatment arms in phase I and phase II investigations to optimize recruitment efficiency. In phase I, a standard 3 + 3 format was used to identify dose-limiting toxicities (DLTs), determine maximum tolerated dose (MTD), and investigate pharmacokinetics. Phase II followed a 2-stage design with the primary endpoint being 6-month progression-free survival (PFS6).

Results

Sixteen patients were recruited for phase I, and the MTD was determined to be sorafenib 200 mg twice daily and erlotinib 100 mg once daily. DLTs include Grade 3 hypertension, Grade 3 elevated liver transaminases, and Grade 4 elevated lipase. While erlotinib did not affect sorafenib levels, sorafenib reduced erlotinib levels. In phase II, 3 of 19 stage 1 participants were progression free at 6 months. This did not meet the predetermined efficacy endpoint, and the trial was terminated.

Conclusion

This study identified the MTD and DLTs for sorafenib and erlotinib combination therapy for recurrent GBMs; however, efficacy data did not meet the primary endpoint. This study also demonstrates the feasibility of a novel sequential accrual clinical trial design that optimizes patient recruitment for multiarm studies, which is particularly effective for multicenter clinical trials.

MAGE3 and Survivin activated dendritic cell immunotherapy for the treatment of non-small cell lung cancer

Dendritic cell (DC) immunotherapy is an optimal cancer treatment, resulting in its emergence as a therapeutic choice; however, there are limited studies investigating dual antigen-pulsed DC immunotherapy in non-small cell lung cancer (NSCLC). In order to determine the effect of a recombinant melanoma-associated antigen (rMAGE-3) and recombinant Survivin (rSurvivin) peptide-pulsed DC immunotherapy in patients with NSCLC, the present clinical study was performed. DC immunotherapy was generated from the monocytes of patients with NSCLC and primed with rMAGE-3 and rSurvivin peptides. The present open-label, non-randomised study enrolled 16 patients with histologically confirmed stage I-IIIB NSCLC between December 2013 and October 2014. A prime immunotherapy (9.1×10⁷ cells/dose) and a single boost (8.2×10⁷ cells/dose) were administered 1 month apart intradermally and the patients were evaluated for immunological and clinical response. DC immunotherapy was well tolerated, with no serious adverse events. There was a single incidence of grade 1 fever, chills and fatigue. Out of the 16 patients enrolled, 11 patients showed stable disease and 5 showed disease progression. There was a significant increase in IFN-γ expression on day 60 vs. day 0 (P=0.048). An increasing trend in the mean cluster of differentiation (CD)4:CD8 values of day 30 and day 90 was observed, but this was not significant. The present study established that DCs primed with rMAGE-3 and rSurvivin may be used in NSCLC treatment. However, a larger study is required to address prominent issues, including secretion of immunosuppressive cytokines and mechanisms of tumour escape from immune surveillance. Several factors associated with the manufacturing and quality of immunotherapy also require standardisation.

Phase I study of sorafenib and tipifarnib for recurrent glioblastoma: NABTC 05-02

Recurrent glioblastoma (GBM) has a very low 6-month progression free survival (PFS) with currently available treatments. Combination chemotherapy to target multiple cell signaling pathways is currently being investigated in order to improve prognosis for recurrent disease. The purpose of this phase I study was to determine the maximum tolerated dose (MTD) for the combination of tipifarnib and sorafenib for the treatment of recurrent GBM. Patients with pathologically proven WHO grade IV GBM and radiographically proven tumor recurrence were eligible for this study. Treatments included sorafenib at twice daily and escalating dosages of tipifarnib. Dose-limiting toxicity (DLT) was determined over the first 28-days of treatments, and the MTD was determined in a 3 + 3 study design. We enrolled 24 patients, and 21 patients completed the MTD period. The study was stopped early with no MTD determination for excessive toxicities. The last dose level reached was sorafenib at 200 mg twice a day and tipifarnib 100 mg twice a day on an alternating week schedule. The DLTs included diarrhea, lipase elevation, hypophosphatemia, and arthralgia. The combination of sorafenib and tipifarnib has excessive toxicities and full single agent dosages could not be achieved in combination.

IQGAP3 promotes EGFR-ERK signaling and the growth and metastasis of lung cancer cells

Proteins of the IQGAP family display complicated and often contradictory activities in tumorigenesis. IQGAP1 has well documented oncogenic potential and IQGAP2 has putative tumor-suppressive function. IQGAP3 is the latest addition to this family and its role in cancer development remains to be defined. Here we demonstrate IQGAP3 expression is markedly increased in lung cancer tissues at both mRNA and protein levels. Overexpression of IQGAP3 promoted tumor cell growth, and migration and invasion, whereas knockdown of IQGAP3 exhibited opposite effects. Moreover, suppression of IQGAP3 in a lung cancer cell line caused a reduction in the tumorigenicity of these cells in lung tissue after intravenous injection. Furthermore, we showed that IQGAP3 is able to interact with ERK1 and enhance its phosphorylation following treatment with EGF. These data suggest that IQGAP3 may contribute to the pathogenesis of lung cancer by modulating EGFR-ERK signaling.

Identification of candidate genes for lung cancer somatic mutation test kits

Over the past three decades, mortality from lung cancer has sharply and continuously increased in China, ascending to the first cause of death among all types of cancer. The ability to identify the actual sequence of gene mutations may help doctors determine which mutations lead to precancerous lesions and which produce invasive carcinomas, especially using next-generation sequencing (NGS) technology. In this study, we analyzed the latest lung cancer data in the COSMIC database, in order to find genomic “hotspots” that are frequently mutated in human lung cancer genomes. The results revealed that the most frequently mutated lung cancer genes are EGFR, KRAS and TP53. In recent years, EGFR and KRAS lung cancer test kits have been utilized for detecting lung cancer patients, but they presented many disadvantages, as they proved to be of low sensitivity, labor-intensive and time-consuming. In this study, we constructed a more complete catalogue of lung cancer mutation events including 145 mutated genes. With the genes of this list it may be feasible to develop a NGS kit for lung cancer mutation detection.

Clinical benefit for patients with non-small cell lung cancer enrolled in phase I trials

AIM

To analyze the clinical features and outcomes of advanced non-small cell lung cancer (NSCLC) patients treated in phase I trials.

PATIENTS AND METHODS

The clinical characteristics, efficacy and toxicity data of 70 pretreated NSCLC patients enrolled in 17 phase I trials between January 2005 and June 2010 were analyzed at our institution.

RESULTS

The histological types were: adenocarcinoma (79%), squamous cell carcinoma (13%), and others. Patients received a median number of 3 prior lines of treatment before inclusion. 1 complete response (CR), 11 (16%) partial responses (PRs), and 29 (41%) stable diseases (SDs) were observed (according to Response Evaluation Criteria in Solid Tumors (RECIST)). The median overall survival (OS) time was 18 months and the median progression-free survival (PFS) time was 4.1 months. The median PFS of these patients within their prior therapy line before phase I inclusion was 4.3 months. A performance status score of 0 and the number of prior lines of treatment were significant for OS and PFS in multivariate analysis, respectively. Grade 3/4 toxicities were observed in 20 (27%) patients, and there was 1 treatment-related death.

CONCLUSION

Patients in good general condition and with limited pretreatment derived an improved benefit, suggesting that phase I studies may be a valid option for pretreated NSCLC patients.

Effects of CAY10404 on the PKB/Akt and MAPK pathway and apoptosis in non-small cell lung cancer cells

BACKGROUND AND OBJECTIVE

Lung cancer is the most common cause of cancer death in men and women worldwide. The mechanism of cell death induced by CAY10404, a highly selective cyclooxygenase-2 inhibitor, was evaluated in three non-small cell lung cancer (NSCLC) cell lines (H460, H358, H1703).

METHODS

To measure the effects of CAY10404 on proliferation of NSCLC cells, 3 x 10(3) cells/well were plated in 96-well plates and allowed to adhere overnight at 37 degrees C. After treatment with CAY10404 for 3 days, cell proliferation was measured by the 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In the H460 NSCLC cells, evidence of apoptosis was sought using the terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) assay and western blot analysis.

RESULTS

Treatment with CAY10404 in the range of 10-100 microM caused dose-dependent growth inhibition, with an average 50% inhibitory concentration (IC(50)) of 60-100 micromol/L, depending on the cell line. Western blot analysis of CAY10404-treated cells showed cleavage of poly (ADP-ribose) polymerase (PARP) and procaspase-3, signifying caspase activity and apoptotic cell death. CAY10404 treatment inhibited the phosphorylation of Akt, glycogen synthase kinase-3beta and extracellular signal-regulated kinases 1/2 in H460 and H358 cells.

CONCLUSIONS

These results suggest that CAY10404 is a potent inducer of apoptosis in NSCLC cells, and that it may act by suppressing multiple protein kinase B/Akt and mitogen-activated protein kinase pathways.

Enhanced clonogenic survival induced by protein tyrosine phosphatase (PTP) inhibition after Cr(VI) exposure is mediated by c-Raf and Ras activity

Our recent studies showed that maintenance of protein tyrosine phosphorylation by PTP inhibition enhanced cell growth, clonogenic survival, and mutagenesis after a single low-level Cr(VI) exposure, thereby suggesting that tyrosine phosphorylation-dependent signaling may govern inappropriate survival in human lung fibroblasts (HLFs). Our goal is to identify specific phospho-tyrosine regulator(s)/ downstream effectors involved in enhanced survival after Cr(VI) exposure and PTP inhibition. Phosphotyrosine profiling array showed that PTP inhibition following Cr(VI) exposure increased tyrosine phosphorylation of specific proteins, such as FGR and ABL, which are upstream regulators of both Erk and Akt pathways. To explore the roles of these pathways in the PTP-induced increase in clonogenic survival after Cr(VI) exposure, we examined the effect of combined Akt1 and Erk1/2 knockdown via siRNA technology. Akt1 and/or Erk1/2 silencing had no effect on the PTP inhibitor-induced increase in survival following Cr(VI) exposure, suggesting the presence of non-Akt/non-Erk-mediated survival signaling. Interestingly, geldanamycin, an HSP90 inhibitor and non-specific Raf inhibitor, abrogated the PTP inhibitor-mediated increase in survival following Cr(VI) exposure and abolished the expression/activity of c-Raf and activity of Mek. These findings prompted us to explore upstream regulators of Erk, i.e., Ras, c-Raf and Mek for their potential roles in clonogenic survival. GW5074, a specific c-Raf kinase inhibitor did not alter the effect of the PTP inhibitor but decreased Cr(VI)-mediated clonogenic lethality, potentially though Mek hyperactivation. A genetic approach with a c/a Mek1 mutant also showed that Mek activity was not directly associated with the PTP inhibitor effect. Finally, a genetic approach with d/n or c/a Ras and c-Raf mutants, showed that Ras and c-Raf activities play a substantive role in enhancing clonogenic survival by PTP inhibition following Cr(VI) insult. In conclusion, these studies highlight a novel pro-survival mechanism for clonogenic survival in the face of genotoxic stress in the presence of PTP inhibition via an Erk/Mek-independent and Ras/c-Raf-dependent regulation in normal human lung fibroblasts.

Phase I/II study of atrasentan, an endothelin A receptor antagonist, in combination with paclitaxel and carboplatin as first-line therapy in advanced non-small cell lung cancer

PURPOSE

Endothelins and their cell membrane receptors (ET(A)R and ET(B)R) are implicated in neoplastic pathogenesis. atrasentan, a potent, selective ET(A)R antagonist, has a direct effect on tumor proliferation, apoptosis, and angiogenesis. This study was designed to assess the influence of atrasentan on paclitaxel pharmacokinetics and to determine the safety and efficacy of atrasentan in combination with paclitaxel-carboplatin.

EXPERIMENTAL DESIGN

Chemonaive patients with stage IIIB (malignant pleural effusion) and IV non-small cell lung cancer were enrolled. Toxicity and response were determined using the National Cancer Institute Common Toxicity Criteria version 2.0 and Response Evaluation Criteria in Solid Tumors criteria, respectively. Treatment consisted of paclitaxel (225 mg/m(2)) and carboplatin (area under the curve, 6) administered on day 1 every 3 weeks. A fixed 10 mg daily oral dose ofAtrasentan was administered continuously, starting on day 4 of cycle 1. Paclitaxel clearance was calculated during the first two cycles (pre- and post-atrasentan) in the first 10 patients.

RESULTS

All 44 patients were evaluable for survival, toxicity, and response. No significant change in mean paclitaxel clearance was detected (mean +/- SD, 21.2 +/- 4.5 L/h versus 21.3 +/- 4.9 L/h) for pre- and post-atrasentan values, respectively (P = 0.434). Grade 3/4 toxicities > or = 10% were lymphopenia (22.7%), neutropenia (20.5%), dyspnea (11.4%), and hyperglycemia (11.4%). Response rate was 18.2%, with progression-free survival of 4.2 months, median survival of 10.6 months, and 1-year survival of 43%.

CONCLUSION

Atrasentan plus paclitaxel-carboplatin was safe and well tolerated, with no apparent paclitaxel-atrasentan pharmacokinetic interaction. Efficacy and survival in advanced non-small cell lung cancer were comparable with studies of chemotherapy alone.

Inflammation in lung carcinogenesis: new targets for lung cancer chemoprevention and treatment

Lung carcinogenesis is a complex process involving the acquisition of genetic mutations that confer cancer development and the malignant phenotype, and is critically linked to apoptosis resistance, unregulated proliferation, invasion, metastasis, and angiogenesis. Epithelial mesenchymal transition (EMT) in cancer is an unregulated process in a host environment with deregulated inflammatory response that impairs cell-mediated immunity and permits cancer progression. Given the immunosuppressive tumor environment, strategies to reverse these events by stimulating host immune responses are an important area of investigation. Cyclooxygenase 2 (COX-2) and its downstream signaling pathways are potential targets for lung cancer chemoprevention and therapy. Clinical trials are underway to evaluate COX-2 inhibitors as adjuvants to chemotherapy in patients with lung cancer and to determine efficacy in prevention of bronchogenic carcinoma. The understanding of molecular mechanisms involved in inflammation and lung carcinogenesis provide insight for new drug development that target reversible, non-mutational events in the chemoprevention and treatment of lung cancer.

Antitumour effect of combination treatment with Sabarubicin (MEN 10755) and cis-platin (DDP) in human lung tumour xenograft

PURPOSE

Sabarubicin (MEN 10755), a new disaccaride anthracycline, has shown greater efficacy than Doxorubicin in a large panel of preclinical models and now it is in phase II clinical trials. Its promising antitumour activity promoted considerable interest to combine Sabarubicin with other antitumour agents. Thus, the purpose of this study was to evaluate in vitro cytotoxic effects and in vivo antitumour activities produced by the combination of Sabarubicin and cisplatin (DDP).

METHODS

The antitumour effect of Sabarubicin and DDP association was investigated, in vitro and in vivo, in preclinical models of lung cancer i.e.: the non-small cell lung carcinoma (NSCLC) H460 and the small-cell lung carcinoma (SCLC) GLC4 in terms of synergism, additivity or antagonism in order to establish the best schedule for the combined treatment. Further, the correlation between antitumour activity and the pharmacokinetic parameters of the studied combination was also evaluated.

RESULTS

The drug combination in vitro was in general more cytotoxic than the single drug alone, indicating the presence of a synergistic effect in both tumour cell lines. Also, in the xenograft experiments a superior antitumoral effect was observed when Sabarubicin was combined with DDP. The antitumour efficacy of Sabarubicin (6 mg/kg q4d x 5) combined with DDP (6 mg/kg q4d x 3) greatly depended on the schedule of administration. In H460 tumour line, the sequential combination was more effective than the simultaneous administration of the two agents, although the antitumour efficacy was not dependent on the sequence of combination. On the other hand, a strong sequence-dependent effect was observed when Sabarubicin was combined with DDP in SCLC, GLC4. In particular, the highest value of LCK = 6.7 was obtained when administration of DDP followed by 24 h that of Sabarubicin. Pharmacokinetics of Sabarubicin in combination with DDP was evaluated at 6 mg/kg for both drugs with different sequential schedule. The experimental data showed no evidence for pharmacokinetics drug-drug interaction.

CONCLUSION

These preclinical results indicate the potential for a strong antitumour activity in lung tumours of the combination Sabarubicin and DDP. In particular, in SCLC the best response should be given by a sequence with administration of Sabarubicin followed 24 h later by that of DDP. Clinical trials based on these results are ongoing.

Serum levels of intercellular adhesion molecule ICAM-1 and E-selectin in advanced stage non-small cell lung cancer

Cell adhesion is a basic count in inter- and intra-cellular communication and plays an important role in tumor progression. This study was conducted to investigate the serum levels of intercellular adhesion molecule (ICAM-1) and E-selectin in patients with advanced stage non-small cell lung cancer (NSCLC) and the relationships with known prognostic parameters and therapy. These serum factors were measured of 57 NSCLC patients pathologically verified before and after chemotherapy in comparison with 24 healthy controls by using ELISA method. Serum levels of ICAM-1 were increased significantly in NSCLC patients compared with the healthy controls (P = 0.006). However, serum E-selectin levels were not significantly different from healthy control groups (0.643). No statistically significant relationships were found between investigated all serum parameters and various characteristics of patients, and the diseases such as stage and tumor burden. Likewise, we also found no correlation between serum ICAM-1 and E-selectin (P = 0.78). We found that serum ICAM-1 levels were decreased owing to the chemotherapy effect, independently from chemotherapy response. However, serum E-selectin levels were not changed by the chemotherapy effect. The median survival of all patients was 11.9 months and 1-year survival rate was 47.6%. We found that patients performance status (P = 0.013), age (P = 0.015), and weight loss (P = 0.007) were prognostic factors for survival. Serum E-selectin levels showed a trend (P = 0.08) related to worse prognosis, however serum ICAM-1 levels were determined as ineffective on survival (P = 0.11). Multivariate analysis revealed that only weight loss (P = 0.005) and E-selectin levels (P = 0.002) remained as an independent prognostic factor for survival in patients with advanced NSCLC. In conclusion, our data suggest that higher serum ICAM-1 can be useful for diagnosis while E-selectin levels have prognostic significance and could be a potential prognostic factor in NSCLC patients.

A phase II clinical trial of ZD1839 (Iressa) in combination with docetaxel as first-line treatment in patients with advanced breast cancer

This was a phase II multi-institutional trial to determine the efficacy and tolerability of gefitinib (Iressatrade) and docetaxel as first-line treatment in patients with metastatic breast cancer. All patients had histologically confirmed breast cancer with metastatic disease. They were permitted to have received adjuvant chemotherapy, but no prior docetaxel or prior chemotherapy for metastatic disease. Patients received gefitinib 250 mg once daily and docetaxel 75 mg/m(2) every 3 weeks, until tumor progression, toxicity or other reasons for discontinuation. Thirty-three patients were enrolled and received a median of 5 cycles of treatment. The clinical benefit rate was 51.5% (95% CI: 33.5-69.2%). There were 1 confirmed complete response and 12 confirmed partial responses, and the overall objective response rate was 39.4% (95% CI: 22.9-57.9%). Four patients had stable disease for > or =24 weeks. The median duration of clinical benefit was 10.9 months (95% CI: 6.0-17.6 months). The most common reason for study discontinuation was disease progression (16 patients), followed by toxicity (ten patients). Toxicities were mainly attributable to docetaxel, including > or =grade 3 neutropenia in 43% of patients. The combination of gefitinib and docetaxel is an active regimen in patients with previously untreated metastatic breast cancer, with a clinical benefit rate and toxicity profile in the range of that reported for docetaxel alone.

Significance of cyclooxygenase-2 in prognosis, targeted therapy and chemoprevention of NSCLC

Evaluation of: Tsubochi H, Nobuyuki S, Hiyama M et al.: Combined analysis of cyclooxygenase-2 expression with p53 and Ki-67 in nonsmall cell lung cancer. Ann. Thorac. Surg. 82(4), 1198–1204 (2006).The report by Tsubochi and colleagues adds to the growing evidence indicating that tumor cyclo-oxygenase (Cox)-2 has a multifaceted role in conferring the malignant phenotype of non-small-cell lung cancer (NSCLC), and provides insight into the use of markers to provide prognostic information. Cox-2 has been implicated in apoptosis resistance, angiogenesis, decreased host immunity and enhanced invasion and metastasis, and, thus, has a critical involvement in carcinogenesis. This study, as well as others, has contributed to providing an insight into opportunities for targeted therapies in NSCLC. Cox-2 is one of the novel targets being studied for lung cancer therapy and chemoprevention.

Radiosensitivity enhancement by combined treatment of celecoxib and gefitinib on human lung cancer cells

PURPOSE

To characterize the radiation-enhancing effects and underlying mechanisms of combined treatment with celecoxib, a cyclooxygenase-2 selective inhibitor, and gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in human lung cancer cells.

EXPERIMENTAL DESIGN

Clonogenic cytotoxicity assays and clonogenic radiation survival assays after treatments with celecoxib and gefitinib with or without radiation were done on three human lung cancer cell lines. Synergisms after combined treatment with celecoxib, gefitinib, and radiation were investigated using isobologram and statistical analyses according to an independent action model. Alterations in apoptosis and cell cycle were measured to identify the mechanisms underlying the cell killing or radiation-enhancing effects of celecoxib and gefitinib combination treatment. Western blots for phosphorylated EGFR, EGFR, cyclooxygenase-2, and G(2) checkpoint molecules were conducted after treatment with celecoxib and/or gefitinib with or without radiation.

RESULTS

Combination celecoxib, gefitinib, and radiation treatments were shown to be synergistic in causing clonogenic cell deaths in all cell lines tested, but the nature of synergism was cell type specific. The combined drug treatments induced apoptosis in an additive manner in A549 cells and in a synergistic manner in NCI-H460 and VMRC-LCD cells. Celecoxib or gefitinib attenuated radiation-induced G(2)-M arrest, and combined drug treatment additively attenuated radiation-induced G(2)-M arrest in all cell lines. Radiation-induced checkpoint kinase (Chk) 1 and Chk2 phosphorylation were inhibited by celecoxib and gefitinib treatment, respectively.

CONCLUSIONS

Combined celecoxib and gefitinib treatments were shown to synergistically enhance the effect of radiation on lung cancer cells. The mechanisms underlying these synergistic effects seem to involve the synergistic enhancement of apoptosis and cooperative attenuation of radiation-induced G(2)-M arrest, possibly via Chk1 and Chk2 inhibition, by the combined drug treatments.

A Phase I Trial to Determine the Optimal Biological Dose of Celecoxib when Combined with Erlotinib in Advanced Non–Small Cell Lung Cancer

PURPOSE

Overexpression of cyclooxygenase-2 (COX-2) activates extracellular signal-regulated kinase/mitogen-activated protein kinase signaling in an epidermal growth factor receptor (EGFR) tyrosine kinase inhibition (TKI)-resistant manner. Because preclinical data indicated that tumor COX-2 expression caused resistance to EGFR TKI, a phase I trial to establish the optimal biological dose (OBD), defined as the maximal decrease in urinary prostaglandin E-M (PGE-M), and toxicity profile of the combination of celecoxib and erlotinib in advanced non-small cell lung cancer was done.

EXPERIMENTAL DESIGN

Twenty-two subjects with stage IIIB and/or IV non-small cell lung cancer received increasing doses of celecoxib from 200 to 800 mg twice daily (bid) and a fixed dose of erlotinib. Primary end points included evaluation of toxicity and determination of the OBD of celecoxib when combined with erlotinib. Secondary end points investigate exploratory biological markers and clinical response.

RESULTS

Twenty-two subjects were enrolled, and 21 were evaluable for the determination of the OBD, toxicity, and response. Rash and skin-related effects were the most commonly reported toxicities and occurred in 86%. There were no dose-limiting toxicities and no cardiovascular toxicities related to study treatment. All subjects were evaluated on intent to treat. Seven patients showed partial responses (33%), and five patients developed stable disease (24%). Responses were seen in patients both with and without EGFR-activating mutations. A significant decline in urinary PGE-M was shown after 8 weeks of treatment, with an OBD of celecoxib of 600 mg bid.

CONCLUSIONS

This study defines the OBD of celecoxib when combined with a fixed dose of EGFR TKI. These results show objective responses with an acceptable toxicity profile. Future trials using COX-2 inhibition strategies should use the OBD of celecoxib at 600 mg bid.

Targeted therapy for non-small cell lung cancer

The overall survival for the treatment of lung cancer patients is less than 15%, despite advances in chemotherapy, radiation therapy, and surgery, due to the inability to control metastatic disease. Over the past three decades, the genetics of lung cancer has been progressively delineated. Small molecule drugs or monoclonal antibodies have been developed that target and inactivate specific cancer-related proteins, such as growth factor receptors or their kinases. This article will review the therapeutic implications of molecular changes associated with non-small cell lung cancer and the status of targeted therapies in its treatment.

Targeting multiple signal transduction pathways in lung cancer

Growth factor signals are propagated from the cell surface to intracellular processes that control critical functions such as growth, differentiation, angiogenesis, and inhibition of apoptosis via sequential kinase signaling. These kinases are receptor kinases, which are transmembrane proteins such as epidermal growth factor receptor or cytoplasmic kinases such as Src kinase. In malignancies, these signaling pathways are often exploited to optimize tumor growth and metastasis. Thus, they represent attractive targets for cancer therapy. This review will summarize current knowledge of the small-molecule multiple-kinase inhibitors in lung cancer therapy. These inhibitors generally hinder the phosphorylation of several protein kinases of membrane receptors, such as vascular endothelial growth factor receptors, platelet-derived growth factor receptors, the human epidermal growth factor receptor family, and cytoplasmic receptors such as c-Kit, Raf kinase, and FLT3. These inhibitors include ZD6474, SU11248, AEE 788, sorafenib, vatalanib, and AG-013736.

Phase I/IIa study of cetuximab with gemcitabine plus carboplatin in patients with chemotherapy-naive advanced non-small-cell lung cancer

PURPOSE

This multicenter, open-label, phase I/IIa study was undertaken to establish the safety/toxicity profile of cetuximab in combination with gemcitabine and carboplatin in patients with chemotherapy-naïve, epidermal growth factor receptor-positive, stage IV non-small-cell lung cancer. Secondary objectives were to gather preliminary evidence of efficacy including tumor response rate, time to progression, and overall survival.

PATIENTS AND METHODS

Thirty-five patients received a total of 264 3-week cycles of treatment with cetuximab, carboplatin, and gemcitabine. An initial dose of cetuximab 400 mg/m2 intravenously was administered the first week, followed by weekly doses of 250 mg/m2. Carboplatin (area under the curve = 5, day 1) and gemcitabine 1,000 mg/m2 on days 1 and 8 were administered every 3 weeks. Patients were evaluated for tumor response after every two cycles of therapy.

RESULTS

The most frequently reported adverse events related to cetuximab included an acne-like rash (88.6%), dry skin (34.3%), asthenia and skin disorders (31.4%), mucositis/stomatitis (25.7%), fever/chills (20%), and nausea/vomiting (17.1%). The majority of these toxicities were mild to moderate. One patient withdrew from the study because of a grade 3 allergic reaction. Myelosuppression was the most frequently observed toxicity related to chemotherapy. Responses among 35 assessable patients included 10 partial responses (28.6%). Twenty-one patients had stable disease. The median time to progression was 165 days, and the median overall survival was 310 days.

CONCLUSION

The combination of cetuximab, carboplatin, and gemcitabine was well tolerated with an acceptable toxicity profile. Most grade 3 adverse events were attributable to chemotherapy. The response rate and median survival are encouraging and warrant additional investigation.

Molecular Staging and the Selection of Therapy for Non-Small Cell Lung Cancer

The stage-specific selection of therapy is the standard for patients with non-small cell lung cancer. Investigation of the molecular biology of lung cancer has provided pathways and targets that may be used to improve the efficacy of therapy and improve the survival for patients with lung cancer.

Novel therapies in lung cancer

This article reviews novel therapies that are under development for non-small cell lung cancer and small cell lung cancer.

Suppression of cyclic GMP-specific phosphodiesterase 5 promotes apoptosis and inhibits growth in HT29 cells

Phosphodiesterase 5 (PDE5) is a major isoform of cGMP phosphodiesterase in a variety of human tumor cell lines and plays a key role in regulating intracellular cGMP concentrations ([cGMP]i). Here, we demonstrate that suppression of PDE5 gene expression by antisense pZeoSV2/ASP5 plasmid transfection results in a sustained increase in [cGMP]i, growth inhibition, and apoptosis in human colon tumor HT29 cells. With stable transfection, antisense transcripts exhibited a specific suppression in PDE5 activity, mRNA levels, and a 93 kDa hPDE5A1 protein. In cloned antisense cells, prolongation of the cell growth doubling times correlate positively with suppressed PDE5 activity and increased [cGMP]i. The growth inhibition in PDE5 antisense clones is due to an increased apoptotic rate and delayed cell-cycle progression. These results corroborate previous findings with the PDE5 inhibitor exisulind and its derivatives showing that sustained [cGMP]i induces apoptosis and growth inhibition in tumor cells. Furthermore, an inducible mitotic inhibitor p21WAF1/CIP1 has been found to account for the delay of cell-cycle progression in PDE5 antisense clones at G2/M phase. A proteolytic cleavage of p21WAF1/CIP1 in the antisense clones is also increased at the later stage of serum stimulation. The protein kinase G (PKG) inhibitor, KT5823, can prevent the cleavage of p21(WAF1/CIP). These data substantiate a pivotal role for PDE5 as a modulator of apoptosis and cell-cycle progression for human carcinoma via a mechanism involving the activation of [cGMP]i/PKG signaling pathways.

PPAR-gamma activation inhibits angiogenesis by blocking ELR+CXC chemokine production in non-small cell lung cancer

Activation of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) results in inhibition of tumor growth in various types of cancers, but the mechanism(s) by which PPAR-gamma induces growth arrest has not been completely defined. In a recent study, we demonstrate that treatment of A549 (human non small cell lung cancer cell line) tumor-bearing SCID mice with PPAR-gamma ligands troglitazone (Tro) and pioglitazone significantly inhibits primary tumor growth. In this study, immunohistochemical analysis of Tro-treated and Pio-treated tumors with factor VIII antibody revealed a significant reduction in blood vessel density compared to tumors in control animals, suggesting inhibition of angiogenesis. Further analysis showed that treatment of A549 cells in vitro with Tro or transient transfection of A549 cells with constitutively active PPAR-gamma (VP16-PPAR-gamma) construct blocked the production of the angiogenic ELR+CXC chemokines IL-8 (CXCL8), ENA-78 (CXCL5), and Gro-alpha (CXCL1). Similarly, an inhibitor of NF-kappa B activation (PDTC) also blocked CXCL8, CXCL5, and CXCL1 production, consistent with their NF-kappa B-dependent regulation. Conditioned media from A549 cells induce human microvascular endothelial cell (HMVEC) chemotaxis. However, conditioned media from Tro-treated A549 cells induced significantly less HMVEC chemotaxis compared to untreated A549 cells. Furthermore, PPAR-gamma activation inhibited NF-kappa B transcriptional activity, as assessed by TransAM reporter gene assay. Collectively, our data suggest that PPAR-gamma ligands can inhibit tumor-associated angiogenesis by blocking the production of ELR+CXC chemokines, which is mediated through antagonizing NF-kappaB activation. These antiangiogenic effects likely contribute to the inhibition of primary tumor growth by PPAR-gamma ligands.

Gene mutations in lung cancer: promising predictive factors for the success of molecular therapy

Gefitinib and erlotinib are two new treatments for advanced lung cancer. Gene mutations in the cancer may help predict which patients will respond to these treatments

Multifaceted roles of cyclooxygenase-2 in lung cancer

Lung cancer is the leading cause of cancer death in the United States. Although the low 5-year survival rate (under 15%) has changed minimally in the last 25 years, new agents and combinations of agents that target tumor proliferation, invasion, and survival may lead to improvement in patient outcomes. There is evidence that cyclooxygenase-2 (COX-2) is overexpressed in lung cancer and promotes tumor proliferation, invasion, angiogenesis, and resistance to apoptosis. COX-2 inhibitors have been found to inhibit tumor growth in animal models and have demonstrated responses when combined with conventional therapy in phase II clinical trials. Further understanding of the mechanisms involved in COX-2-mediated tumorigenesis and its interaction with other molecules in lung cancer may lead to improved therapeutic strategies for this disease. In addition, delineation of how COX-2-dependent genes modulate the malignant phenotype will provide novel insights in lung cancer pathogenesis.

Signal transduction pathways as novel therapy targets in lung cancer

Cytotoxic therapy for lung-cancer patients has only moderately improved during the last decades. Simultaneously, efforts of intensive research to increase our understanding of the molecular basis of lung cancer have been undertaken. The cancer cell has been characterised by several genetic changes that lead to altered cellular functions. In addition, multiple factors of the cancer-cell environment further affect the tumour cell via various receptors and subsequent signaling pathways. The increased knowledge of cellular signaling offers the opportunity to develop novel substances that target specific pathway molecules. In the current review, some of the most essential receptors and signaling pathways involved in lung cancer will be described. In conjunction, examples of novel target-specific agents that have already found their way into clinical trials will be discussed.

Angiogenesis in non-small cell lung cancer

Two processes are necessary for a tumor colony to grow and become invasive: angiogenesis and basement membrane degradation. Angiogenesis is the formation of new blood vessels from the endothelium of existing vasculature, in response to the metabolic demand of the tumor. Assessment of the degree of tumor angiogenesis may improve risk stratification in patients with lung cancer, especially those with early-stage disease. In addition, the strategy of blocking the mechanism of angiogenesis may prove to be an effective therapeutic alternative for patients with nonsmall cell lung cancer. Clinical trials evaluating novel antiangiogenic agents, including antibodies to vascular endothelial growth factor (VEGF) and compounds directed at the tyrosine kinase receptor, are ongoing.

Autologous dendritic cell vaccines for non-small-cell lung cancer

PURPOSE

Therapeutic outcomes of definitively treated non-small-cell lung cancer (NSCLC) are unacceptably poor. A wealth of preclinical information, and a modest amount of clinical information indicate that dendritic cell (DC) vaccines have therapeutic potential. Only a handful of NSCLC patients have been included in DC clinical trials. We delivered autologous DC vaccines to 16 individuals with stage IA to IIIB NSCLC treated with surgery, chemoradiation, or multimodality therapy. The objectives of the study were to evaluate tolerability and measure immunologic responses to DC vaccines in a heterogeneous group of NSCLC patients.

METHODS

DC vaccines were generated from CD14+ precursors, pulsed with apoptotic bodies of an allogeneic NSCLC cell line that overexpressed Her2/neu, CEA, WT1, Mage2, and survivin. DCs were partially matured with a factor that induced surface molecule expression but minimal cytokine production. Individuals were immunized intradermally two times, 1 month apart. Peripheral blood was drawn serially over 16 weeks, and immune responses were measured by interferon-gamma ELISPOT.

RESULTS

There were no unanticipated or serious adverse events. Immunologic responses followed three distinct patterns of reactivity: (1) five of 16 patients showed no clear immunologic response, (2) five of 16 patients showed a tumor-antigen independent response, and (3) six of 16 show an antigen specific response. Immunologic responses were independent of stage and prior therapy. Favorable and unfavorable clinical outcomes were independent of measured immunologic responses.

CONCLUSION

Vaccines were well tolerated and had biologic activity in a variety of NSCLC patients. Establishing an optimal approach will require comparative studies in well-defined NSCLC patient groups.

Molecular targeting in radiotherapy of lung cancer

Molecular targeting is a promising option to increase the radiation response of tumours and to decrease normal tissue reactions, i.e. to achieve therapeutic gain. Molecular targeting substances in themselves are not curative while radiation is a highly efficient cytotoxic agent, with local recurrences often occurring from only few surviving clonogenic cells. High-dose radiotherapy therefore offers optimal conditions to evaluate the potential of specific biology-driven drugs for oncology. This review summarises the current status of preclinical and clinical research on combined radiation with examples of molecular targeting substances relevant for the treatment of NSCLC (EGFR, COX-2, VEGFR, KGF, TGF-beta, BBI).

[Prognostic indicators in stage I non-small cell lung cancer]

INTRODUCTION

Determinating the prognosis of patients with stage I non-small cell lung cancer (NSCLC) is a challenge. Since up to 30% of patients who have undergone surgical resection experience recurrence, generally in distant organs, it is reasonable to postulate that neo-adjuvant or adjuvant treatments might be useful. Better knowledge of prognostic factors could perhaps define which patient populations should be targeted with such treatments.

STATE OF THE ART

Numerous potential prognostic factors, relating to the disease (TNM classification, histology, tumor size, blood vessels invasion, micro-metastasis, serum or molecular markers), the patient (gender, age, co-morbidity) as well as the treatment (delay, resection, lymph node dissection, neo-adjuvant and adjuvant treatments), are discussed.

PERSPECTIVES

These prognostic factors should be integrated into the design of future clinical trials of chemotherapy and/or radiotherapy attempting to evaluate the effectiveness of various combinations of neo-adjuvant or adjuvant therapies.

CONCLUSIONS

These factors may offer the opportunity to clinically and biologically characterize the different subgroups of patients, leading to a more rational, and perhaps individualized, choice of therapy.

The role of targeted therapy in non-small cell lung cancer

The therapy of non-small cell lung cancer (NSCLC) has reached a plateau in improving patient survival, with overall disappointing results. Thus, clinical research for new treatment strategies is warranted. Advances in the singling out molecular targets for NSCLC treatment has granted the development of several new biological agents. In the present paper we describe the main clinical data currently available on targeted agents in the treatment of NSCLC, focusing on epidermal growth factor receptor family inhibitors, angiogenesis inhibitors, signal transduction inhibitors, eicosanoid pathway inhibitors, vaccines and gene therapy. Several targeted agents have been introduced into clinical trials in NSCLC, mainly in advanced disease, with the first phase III study results being recently made available. To date, few of these new agents can offer hope of a substantial impact on the natural history of NSCLC, and negative results are more commonly reported than positive ones. Nevertheless, clinically-meaningful advances have already been achieved in chemotherapy refractory advanced NSCLC patients, with gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, representing a further chance of tumor control and symptom palliation. Moreover, important lessons can be learned from this first generation of clinical trials.

COX-2 inhibition and lung cancer

Cyclooxygenase-2 (COX-2) overexpression is seen in many malignancies including lung cancer. In non-small cell lung cancer (NSCLC), COX-2 is overexpressed in most adenocarcinomas and squamous cell carcinomas. Elevated tumor COX-2 prostaglandin E(2) (PGE(2)) levels have been implicated in angiogenesis, tumor invasion, resistance to apoptosis, and suppression of antitumor immunity. Preclinical animal model studies show tumor reduction when animals are treated with either nonspecific or specific inhibitors of COX-2. These studies suggest nonsteroidal anti-inflammatory drugs may act on multiple tumor-progression targets via both COX-2-dependent and-independent pathways. Consistent with these findings, epidemiologic evidence has shown a decreased incidence of lung cancer in patients who use nonsteroidal anti-inflammatory drugs. Based on these observations, celecoxib, a selective COX-2 inhibitor, has been evaluated in combination with chemotherapy for the management of metastatic NSCLC in patients who have failed prior chemotherapy. Several clinical trials are ongoing that evaluate celecoxib in combination with chemoradiation for unresectable, locally advanced NSCLC. Another trial evaluating celecoxib in a preoperative combination with paclitaxel and carboplatin has generated overall clinical response rates at least comparable to those reported in the Bimodality Lung Oncology Team trial. Ongoing clinical trials are also evaluating the combination of celecoxib with chemotherapy and/or radiation or celecoxib in combination with epidermal growth factor receptor inhibitors of NSCLC. This article reviews preclinical information on COX-2 inhibitors in lung cancer and presents updated data from several ongoing clinical trials that are evaluating celecoxib in NSCLC.

ERK1/2 is activated in non-small-cell lung cancer and associated with advanced tumours

Activation of the ERK1/2 pathway is involved in malignant transformation both in vitro and in vivo. Little is known about the role of activated ERK1/2 in non-small cell lung cancer (NSCLC). The purpose of this study was to characterise the extent of the activation of ERK1/2 by immunohistochemistry in patients with NSCLC, and to determine the relationship of ERK1/2 activation with clinicopathological variables. Specimens from 111 patients with NSCLC (stages I-IV) were stained for P-ERK. Staining for epidermal growth factor receptor (EGFR) and Ki-67 was also performed. In all, 34% of the tumour specimens showed activation for ERK1/2, while normal lung epithelial tissue was consistently negative. There was a strong statistical correlation between nuclear and cytoplasmic P-ERK staining and advanced stages (P<0.05 and P<0.001, respectively), metastatic hilar or mediastinal lymph nodes (P<0.01, P<0.001), and higher T stages (P<0.01, P<0.001). We did not find correlation of nuclear or cytoplasmic P-ERK staining with either EGFR expression or Ki-67 expression. Total ERK1/2 expression was evaluated with a specific ERK1/2 antibody and showed that P-ERK staining was not due to ERK overexpression but rather to hyperactivation of ERK1/2. Patients with a positive P-ERK cytoplasmic staining had a significant lower survival (P<0.05). However, multivariate analysis did not show significant survival difference. Our study indicates that nuclear and cytoplasmic ERK1/2 activation positively correlates with stage, T and lymph node metastases, and thus, is associated with advanced and aggressive NSCLC tumours.

Novel treatments in non–small cell lung cancer

Although it has been exciting for lung cancer doctors to observe objective remissions with gefitinib and erlotinib in heavily pretreated NSCLC patients, all of the reported phase III trials testing noncytotoxic, targeted therapies in NSCLC have been negative. Two basic strategies have been employed in developing and conducting these randomized studies. In the case of gefitinib and the matrix metalloproteinase inhibitors, phase III trials were launched based on preclinical data. The second strategy was based on survival results from phase II trials involving regimens consisting of the targeted agent and chemotherapy. Unfortunately, negative results have been observed with the first phase III study (chemotherapy +/- ISIS 3521), which was based on the results of a phase II trial. The initial negative results with targeted agents suggest that a paradigm shift in cancer drug development is needed. Typically, the development of a cytotoxic agent involves determination of the maximum tolerated dose, followed by an assessment of activity as defined by the objective response rate in specific tumor types. "Active" drugs are then moved into phase III testing to determine the effect on survival. Other than targeting the specific tumor type and defining the usual eligibility parameters, no attempt is made to select patients for treatment with new agents. It seems unlikely that there will be significant progress with the targeted therapies unless there is a paradigm shift from this classic model of cancer drug development to a model in which much greater effort is directed toward identifying the target or targets in preclinical models. Intensive effort should be devoted to the development of reliable, clinically applicable assays for the targets that could identify patients who are most likely to benefit from a specific treatment. Rothenberg et al recently made similar recommendations with respect to improving the drug discovery process for cancer. These investigators have emphasized testing new agents in the most appropriate setting, increasing efforts to understand the role of the target, and collection of tissue in an effort to select appropriate patients. Although results from initial randomized trials of targeted therapies in NSCLC have been relatively disappointing, this is not a time to be discouraged. Rather, it is a time to increase the collaborative efforts between basic scientists and clinical investigators.

Signal Events: Cell Signal Transduction and Its Inhibition in Cancer

Signal transduction refers to communication processes used by regulatory molecules to mediate the essential cell processes of growth, differentiation, and survival. Signal transduction elements interact through complex biochemically related networks. Aberrations in signal transduction elements can lead to increased proliferative potential, sustained angiogenesis, tissue invasion and metastasis, and apoptosis inhibition. Most human neoplasms have aberrant signal transduction elements. Several compounds that target aberrant signal transduction elements, such as those in the ErbB family of tyrosine kinase receptors and mammalian target of rapamycin, are in development. To date, commercially available signal-transduction-targeting compounds include trastuzumab, a monoclonal antibody against the ErbB-2 receptor for the treatment of metastatic breast cancer overexpressing the ErbB-2 (HER-2) receptor, and gefitinib, an inhibitor of the ErbB-1 receptor tyrosine kinase that recently received regulatory approval for the treatment of patients with non-small cell lung cancer. In contrast to traditional cytotoxic treatments, although signal transduction inhibitors are capable of inducing tumor regression, particularly in malignancies that are principally driven by specific target aberrations, preclinical and early clinical investigations suggest that their predominant beneficial effects are growth inhibitory in nature; therefore, new clinical trial designs and evaluation end points may be required to ultimately assess their value. Prospective profiling of patients and tumors to determine treatment response is also essential to the success of these clinical trials. However, responsiveness to these novel therapies is dependent on a multitude of factors that ultimately determine the robustness and quality of the downstream response.

Clinical studies with non-iressa EGFR tyrosine kinase inhibitors

During the last five years there has been interest in developing non-cytotoxic, targeted cancer treatments. This phenomenon has occurred as a result of increased information regarding factors which regulate tumor proliferation, survival, angiogenesis, invasiveness, and metastatic potential. In non-small cell lung cancer many investigators have focused their attention on the epidermal growth factor receptor (EGFR) because this membrane protein, which has an extracellular ligand binding domain, as well as, tyrosine kinase activity on the intracellular portion of the molecule, is expressed in a relatively high proportion of non-small cell lung cancers. Gefitinib which was the first EGFR specific tyrosine kinase inhibitor to be extensively tested in non-small cell lung cancer has shown single agent activity in non-small cell lung cancer. Subsequently, erlotinib, another EGFR specific tyrosine inhibitor, has also demonstrated single agent activity in non-small cell lung cancer. Phase III trials of erlotinib alone or in combination with chemotherapy have been completed, and data are being analyzed. Several dual inhibitors of erb B1 and erb B2 (PKI 166, GW 572016, EKB 569) have been or are being tested in phase I trials. In addition, CI 1033, a pan-erb inhibitor, is also being tested in phase I studies. Diarrhea and rash have been the predominant side effects of these agents. Life threatening toxicity has been rare. Although the erb tyrosine kinase inhibitors are attrative agents to use in treating non-small cell lung cancer because of their relatively benign toxicity profile, more data are needed to define the role of these agents in non-small cell lung cancer.

Ongoing and future trials of biologic therapies in lung cancer

Lung cancer is the leading world-wide cause of cancer death. The care rate remains less than 15% despite improvements in surgery, radiotherapy and chemotherapy. The majority of deaths can be attributed to systemic metastases. Chemotherapy prolongs survival but produces few complete responses and survival at 5-years is rare. Molecular advances have provided many new targets for lung cancer therapy. Many new agents have been developed to attack these targets. This article describes current and proposed trials for these new targeted therapies in both small cell and non-small cell lung cancers.