Sorafenib is efficacious and tolerated in combination with cytotoxic or cytostatic agents in preclinical models of human non-small cell lung carcinoma

Therapeutic strategies for BRAF mutation in non-small cell lung cancer: a review

Lung cancer is the leading cause of cancer related deaths. Among the two broad types of lung cancer, non-small cell lung cancer accounts for 85% of the cases. The study of the genetic alteration has facilitated the development of targeted therapeutic interventions. Some of the molecular alterations which are important targets for drug therapy include Kirsten rat sarcoma (KRAS), Epidermal Growth Factor Receptor (EGFR), V-RAF murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase gene (ALK). In the setting of extensive on-going clinical trials, it is imperative to periodically review the advancements and the newer drug therapies being available. Among all mutations, BRAF mutation is common with incidence being 8% overall and 1.5 - 4% in NSCLC. Here, we have summarized the BRAF mutation types and reviewed the various drug therapy available - for both V600 and nonV600 group; the mechanism of resistance to BRAF inhibitors and strategies to overcome it; the significance of comprehensive profiling of concurrent mutations, and the role of immune checkpoint inhibitor in BRAF mutated NSCLC. We have also included the currently ongoing clinical trials and recent advancements including combination therapy that would play a role in improving the overall survival and outcome of NSCLC.

Unraveling the Post-Translational Modifications and therapeutical approach in NSCLC pathogenesis

Non-Small Cell Lung Cancer (NSCLC) is the most prevalent kind of lung cancer with around 85% of total lung cancer cases. Despite vast therapies being available, the survival rate is low (5 year survival rate is 15%) making it essential to comprehend the mechanism for NSCLC cell survival and progression. The plethora of evidences suggests that the Post Translational Modification (PTM) such as phosphorylation, methylation, acetylation, glycosylation, ubiquitination and SUMOylation are involved in various types of cancer progression and metastasis including NSCLC. Indeed, an in-depth understanding of PTM associated with NSCLC biology will provide novel therapeutic targets and insight into the current sophisticated therapeutic paradigm. Herein, we reviewed the key PTMs, epigenetic modulation, PTMs crosstalk along with proteogenomics to analyze PTMs in NSCLC and also, highlighted how epi‑miRNA, miRNA and PTM inhibitors are key modulators and serve as promising therapeutics.

BRAF-Mutated Non-Small Cell Lung Cancer: Current Treatment Status and Future Perspective

V-Raf murine sarcoma viral oncogene homolog B (BRAF) kinase, which was encoded by BRAF gene, plays critical roles in cell signaling, growth, and survival. Mutations in BRAF gene will lead to cancer development and progression. In non-small cell lung cancer (NSCLC), BRAF mutations commonly occur in never-smokers, women, and aggressive histological types and accounts for 1%-2% of adenocarcinoma. Traditional chemotherapy presents limited efficacy in BRAF-mutated NSCLC patients. However, the advent of targeted therapy and immune checkpoint inhibitors (ICIs) have greatly altered the treatment pattern of NSCLC. However, ICI monotherapy presents limited activity in BRAF-mutated patients. Hence, the current standard treatment of choice for advanced NSCLC with BRAF mutations are BRAF-targeted therapy. However, intrinsic or extrinsic mechanisms of resistance to BRAF-directed tyrosine kinase inhibitors (TKIs) can emerge in patients. Hence, there are still some problems facing us regarding BRAF-mutated NSCLC. In this review, we summarized the BRAF mutation types, the diagnostic challenges that BRAF mutations present, the strategies to treatment for BRAF-mutated NSCLC, and resistance mechanisms of BRAF-targeted therapy.

How to Improve SBRT Outcomes in NSCLC: From Pre-Clinical Modeling to Successful Clinical Translation

Simple Summary

Despite major research and clinical efforts, lung cancer remains the leading cause of cancer-related death. Stereotactic body radiotherapy (SBRT) has emerged as a major treatment modality for lung cancer in the last decade. Additional research is needed to elucidate underlying mechanisms of resistance and to develop improved therapeutic strategies. Clinical progress relies on accurate preclinical modelling of human disease in order to yield clinically meaningful results; however, successful translation of pre-clinical research is still lagging behind. In this review, we summarize the major clinical developments of radiation therapy for non-small-cell lung cancer (NSCLC), and we discuss the pre-clinical research models at our disposal, highlighting ongoing translational challenges and future perspectives.

Abstract

Despite major research and clinical efforts, lung cancer remains the leading cause of cancer-related death. While the delivery of conformal radiotherapy and image guidance of stereotactic body radiotherapy (SBRT) have revolutionized the treatment of early-stage non-small-cell lung cancer (NSCLC), additional research is needed to elucidate underlying mechanisms of resistance and identify novel therapeutic combinations. Clinical progress relies on the successful translation of pre-clinical work, which so far has not always yielded expected results. Improved clinical modelling involves characterizing the preclinical models and selecting appropriate experimental designs that faithfully mimic precise clinical scenarios. Here, we review the current role of SBRT and the scope of pre-clinical armamentarium at our disposal to improve successful clinical translation of pre-clinical research in the radiation oncology of NSCLC.

ERK5 signalling pathway is a novel target of sorafenib: Implication in EGF biology

Sorafenib is a multikinase inhibitor widely used in cancer therapy with an antitumour effect related to biological processes as proliferation, migration or invasion, among others. Initially designed as a Raf inhibitor, Sorafenib was later shown to also block key molecules in tumour progression such as VEGFR and PDGFR. In addition, sorafenib has been connected with key signalling pathways in cancer such as EGFR/EGF. However, no definitive clue about the molecular mechanism linking sorafenib and EGF signalling pathway has been established so far. Our data in HeLa, U2OS, A549 and HEK293T cells, based on in silico, chemical and genetic approaches demonstrate that the MEK5/ERK5 signalling pathway is a novel target of sorafenib. In addition, our data show how sorafenib is able to block MEK5-dependent phosphorylation of ERK5 in the Ser218/Tyr220, affecting the transcriptional activation associated with ERK5. Moreover, we demonstrate that some of the effects of this kinase inhibitor onto EGF biological responses, such as progression through cell cycle or migration, are mediated through the effect exerted onto ERK5 signalling pathway. Therefore, our observations describe a novel target of sorafenib, the ERK5 signalling pathway, and establish new mechanistic insights for the antitumour effect of this multikinase inhibitor.

Phase I dose escalation study of sorafenib plus S-1 for advanced solid tumors

S-1, an oral pyrimidine fluoride-derived agent, is effective against various cancers. Sorafenib, an oral multikinase inhibitor, was found to prolong the survival of various cancers and enhance the cytotoxicity of chemotherapeutic agents. We conducted a phase I dose escalation study to determine dose-limiting toxicity (DLT) and maximal tolerated dose (MTD) of S-1 when combined with sorafenib for refractory solid tumors. Eligible patients received escalating doses (30, 35, and 40 mg/m² bid) of S-1 Day 1 (D1)-D14 and continuous sorafenib 400 mg bid from cycle 1 D8 every 21 days in a standard 3 + 3 study design. Primary endpoint was MTD. Thirteen patients were enrolled between May 2010 and Feb 2012. DLT developed in two (one grade 3 erythema and one prolonged grade 2 hand-foot-skin reaction) of the 6 patients at 35 mg/m² dose level. One pancreatic neuroendocrine tumor (pNET) patient achieved a durable partial response (27.9 months). Four colon cancer patients had stable disease and 3 of them had progression-free survival greater than 6 months. This study determined the recommended (MTD) S-1 dose of 30 mg/m² bid for this regimen. This result warrants further phase II studies for advanced pNET and colon cancer to evaluate the efficacy of this combination.

Factors that influence response classifications in chemotherapy treated patient-derived xenografts (PDX)

In this study, we investigated the impact of initial tumor volume, rate of tumor growth, cohort size, study duration, and data analysis method on chemotherapy treatment response classifications in patient-derived xenografts (PDXs). The analyses were conducted on cisplatin treatment response data for 70 PDX models representing ten cancer types with up to 28-day study duration and cohort sizes of 3-10 tumor-bearing mice. The results demonstrated that a 21-day dosing study using a cohort size of eight was necessary to reliably detect responsive models (i.e., tumor volume ratio of treated animals to control between 0.1 and 0.42)-independent of analysis method. A cohort of three tumor-bearing animals led to a reliable classification of models that were both highly responsive and highly nonresponsive to cisplatin (i.e., tumor volume ratio of treated animals to control animals less than 0.10). In our set of PDXs, we found that tumor growth rate in the control group impacted treatment response classification more than initial tumor volume. We repeated the study design factors using docetaxel treated PDXs with consistent results. Our results highlight the importance of defining endpoints for PDX dosing studies when deciding the size of cohorts to use in dosing studies and illustrate that response classifications for a study do not differ significantly across the commonly used analysis methods that are based on tumor volume changes in treatment versus control groups.

Phase 1 study of the combination of vemurafenib, carboplatin, and paclitaxel in patients with BRAF-mutated melanoma and other advanced malignancies

BACKGROUND

BRAF inhibitors are effective against selected BRAFV600 -mutated tumors. Preclinical data suggest that BRAF inhibition in conjunction with chemotherapy has increased therapeutic activity.

METHODS

Patients with advanced cancers and BRAF mutations were enrolled into a dose-escalation study (3+3 design) to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs).

RESULTS

Nineteen patients with advanced cancers and BRAF mutations were enrolled and received vemurafenib (480-720 mg orally twice a day), carboplatin (area under the curve [AUC] 5-6 intravenously every 3 weeks), and paclitaxel (100-135 mg/m2 intravenously every 3 weeks). The MTD was not reached, and vemurafenib at 720 mg twice a day, carboplatin at AUC 5, and paclitaxel at 135 mg/m2 were the last safe dose levels. DLTs included a persistent grade 2 creatinine elevation (n = 1), grade 3 transaminitis (n = 1), and grade 4 thrombocytopenia (n = 1). Non-dose-limiting toxicities that were grade 3 or higher and occurred in more than 2 patients included grade 3/4 neutropenia (n = 5), grade 3/4 thrombocytopenia (n = 5), grade 3 fatigue (n = 4), and grade 3 anemia (n = 3). Of the 19 patients, 5 (26%; all with melanoma) had a partial response (PR; n = 4) or complete response (CR; n = 1); these responses were mostly durable and lasted 3.1 to 54.1 months. Of the 13 patients previously treated with BRAF and/or mitogen-activated protein kinase kinase (MEK) inhibitors, 4 (31%) had a CR (n = 1) or PR (n = 3). Patients not treated with prior platinum therapy had a higher response rate than those who did (45% vs 0%; P = .045).

CONCLUSIONS

The combination of vemurafenib, carboplatin, and paclitaxel is well tolerated and demonstrates encouraging activity, predominantly in patients with advanced melanoma and BRAFV600 mutations, regardless of prior treatment with BRAF and/or MEK inhibitors.

Pediatric hepatocellular carcinoma: challenges and solutions

Hepatocellular carcinoma (HCC) is a very rare entity in children, making it nearly impossible to orchestrate Phase II/III studies even as multinational cooperative trials. In contrast to adults, nearly 50% of the children have a response (α-fetoprotein decline and/or tumor shrinkage) to chemotherapeutic agents such as cisplatin and doxorubicin (PLADO), demonstrating that HCC in childhood can be chemotherapy sensitive. As a result, the main treatment options in pediatric HCC focus on systemic drug therapies and resection as the central therapy. In nonmetastatic patients with complete resection upfront, the 5-year event-free survival and overall survival has reached 80%–90%. In almost all reported studies, children received adjuvant chemotherapy (mostly PLADO), but it has never been proven that postoperative chemotherapy is superior to observation. No data are available for the effects of sorafenib. The 3-year survival is <20% in children with unresectable HCC independent of the chemotherapy given preoperatively. Currently, PLADO in combination with sorafenib is recommended with the goal of achieving operability status. Alternatively, data are promising for the combination of sorafenib with gemcitabine and oxaliplatin. For children with nonresectable and nonmetastastic liver tumors, it has been shown that the Milan criteria regarding liver transplantation are not applicable – individual decisions have to be made. Transarterial chemoembolization could be offered to patients with chemotherapy-resistant liver tumors for palliative care or potentially to achieve surgical resectability, and therefore cure. Information about the feasibility or effects of new agents or approaches as discussed in adult HCC patients is not available for childhood HCC. Research has to be done for characterizing the molecular and genomic mechanisms of pediatric HCC to support the development of novel therapeutic approaches and the implementation of personalized medicine.

Phase I/II Trial of Sorafenib in Combination with Vinorelbine as First-Line Chemotherapy for Metastatic Breast Cancer

Background

Preclinical models have reported a synergistic interaction between sorafenib and vinorelbine. We investigated the toxicity, efficacy, and pharmacokinetics interaction of this combination as first-line treatment for patients with metastatic breast cancer.

Methods

Patients were HER2-negative and treated with vinorelbine 30 mg/m² IV days 1,8 every 21 plus daily oral sorafenib. In the phase I portion (3+3 design) patients received sorafenib 200 mg BID (cohort 1) or 400 mg BID (cohort 2). In the phase II expansion, 21 more evaluable patients were planned to receive the maximum tolerated dose (MTD). Pharmacokinetic analysis was performed in 6 patients: blood concentrations were compared for each drug in the presence or absence of the other drug.

Results

In cohort 1, one patient experienced a dose-limiting toxicity (DLT) (grade 3 pancreatitis), requiring the expansion of this cohort to 6 patients, without further documented DLTs. In cohort 2, one patient of six experienced a grade 4 DLT (asymptomatic rise in amylase not requiring drug discontinuation), establishing this dose level as the MTD (sorafenib 400 mg BID). After expansion at the MTD, a total of 27 patients (median age 57) were treated for a median of 8 cycles. One grade 5 febrile neutropenia occurred. With repeated cycles, 52% of patients required at least 1 dose reduction of either drug. One patient experienced a sustained grade 3 fatigue resulting in treatment discontinuation. The response rate was 30%. Median PFS was 5.7 months (95% CI 4.4–7.6), and clinical benefit (absence of disease progression at 6 months) was 48%. PK analysis showed a significant interaction between the two drugs, resulting in a higher Cmax of vinorelbine in the presence of sorafenib.

Conclusion

The combination of sorafenib and vinorelbine at full doses is feasible but not devoid of toxicity, likely also due to a significant PK interaction.

Trial Registration

ClinicalTrials.gov NCT00764972

Synergistic effects of sorafenib in combination with gemcitabine or pemetrexed in lung cancer cell lines with K-ras mutations

K-ras is currently accepted as the most frequently mutated oncogene in non-small cell lung cancer (NSCLC, including squamous carcinoma, adenocarcinoma, and large cell carcinoma). NSCLC patients with the K-ras mutation appear to be refractory to the majority of systemic therapies. In the present study, the in vitro antitumor effects and correlated molecular mechanisms of sorafenib combined with gemcitabine or pemetrexed were explored in the K-ras mutation-positive NSCLC A549 cell line. Sorafenib was seen to exhibit dose-dependent growth inhibition in the A549 cells, while sorafenib combined with pemetrexed demonstrated a greater synergism compared with sorafenib combined with gemcitabine. Sorafenib arrested the cell cycle at the G1 phase, while gemcitabine and pemetrexed caused arrest at the S phase. The molecular mechanism of this synergism was due to the downstream signalling pathways, which were efficiently suppressed by sorafenib, therefore increasing the incidence of the entry of the chemotherapeutic drugs into the apoptotic pathways. Moreover, sorafenib and pemetrexed demonstrated stronger synergism, demonstrating that inhibiting the Ras/Raf/Mek/Erk and Ras/PI3K/Akt pathways concurrently may achieve improved antitumor effects.

Inhibition of MAPK and VEGFR by Sorafenib Controls the Progression of Endometriosis

INTRODUCTION

Sorafenib is a strong multikinase inhibitor targeting 2 different pathways of endometriosis pathogenesis: RAF kinase and vascular endothelial growth factor receptor (VEGFR). We investigate whether Sorafenib could control the growth of endometriotic lesions both in vitro and in vivo.

METHODS

Stromal primary cells were extracted from endometrial and endometriotic biopsies from patients with (n = 10) and without (n = 10) endometriosis. Proliferation, apoptosis, mitogen-activated protein kinases, and VEGFR-2 autophosphorylation were explored with and without Sorafenib treatment. Human endometriotic lesions were implanted in 30 nude mice randomized according to Sorafenib or placebo treatment.

RESULTS

Treating endometriotic cells with Sorafenib abrogated the phosphorylation of extracellular signal-regulated kinase in stromal cells of women with endometriosis compared to controls. In addition, this study highlights the antiangiogenic role of Sorafenib which translates as a decreased phosphorylated VEGFR-2-VEGFR-2 ratio in endometriosis. Using a xenogenic mouse model of endometriosis, we confirmed that Sorafenib regulates the endometriosis activity in vivo by targeting endometriosis-related proliferation and inflammation.

CONCLUSION

Our data suggest that Sorafenib controls the growth of endometriotic lesions in vitro and in vivo.

Preclinical Murine Models for Lung Cancer: Clinical Trial Applications

Murine models for the study of lung cancer have historically been the backbone of preliminary preclinical data to support early human clinical trials. However, the availability of multiple experimental systems leads to debate concerning which model, if any, is best suited for a particular therapeutic strategy. It is imperative that these models accurately predict clinical benefit of therapy. This review provides an overview of the current murine models used to study lung cancer and the advantages and limitations of each model, as well as a retrospective evaluation of the uses of each model with respect to accuracy in predicting clinical benefit of therapy. A better understanding of murine models and their uses, as well as their limitations may aid future research concerning the development and implementation of new targeted therapies and chemotherapeutic agents for lung cancer.

Converting biology into clinical benefit: lessons learned from BRAF inhibitors

The identification and pharmacological targeting of activating BRAF mutations in melanoma has led to significant improvements in patient outcomes. This perspective paper illustrates the lessons learned from the study of BRAF mutations and the development of BRAF inhibitors. The relevance of these lessons to the development of future targeted therapies is highlighted.

Inhibition of myeloid cell leukemia-1: Association with sorafenib-induced apoptosis in human mucoepidermoid carcinoma cells and tumor xenograft

BACKGROUND

The purpose of our study was to investigate the anticancer effect of sorafenib on mucoepidermoid carcinoma (MEC) and find its new molecular mechanism.

METHODS

The apoptotic effects of sorafenib were performed using MTS assay, diamidino-phenylindole (DAPI) staining, Western blotting, reverse transcription-polymerase chain reaction (RT-PCR), siRNA, and xenograft.

RESULTS

Sorafenib had apoptotic effects on MC-3 and YD15 cells and decreased myeloid cell leukemia-1 (Mcl-1) through proteasome-dependent protein degradation and the inhibition of protein synthesis. Sorafenib significantly affected truncated bid (t-Bid) and siMcl-1 resulting in the upregulation of t-Bid to induce apoptosis. Signal transducer and activator of transcription 3 (STAT3) phosphorylation was also blocked by sorafenib and a potent STAT3 inhibitor, cryptotanshinone clearly induced poly ADP-ribose polymerase (PARP) cleavage by inhibiting Mcl-1 and increasing t-Bid. Finally, administration of sorafenib significantly suppressed tumor growth and induced apoptosis in tumor xenograft model in association with downregulation of Mcl-1 without any side effects.

CONCLUSION

Taken together, these findings suggest that sorafenib can be a good anticancer drug candidate for the treatment of MEC.

Sorafenib: targeting multiple tyrosine kinases in cancer

Sorafenib (BAY 43-9006, Nexavar®) is an oral multiple tyrosine kinase inhibitor. Main targets are receptor tyrosine kinase pathways frequently deregulated in cancer such as the Raf-Ras pathway, vascular endothelial growth factor (VEGF) pathway, and FMS-like tyrosine kinase 3 (FLT3). Sorafenib was approved by the FDA in fast track for advanced renal cell cancer and hepatocellular cancer and shows good clinical activity in thyroid cancer. Multiple clinical trials are undertaken to further investigate the role of sorafenib alone or in combination for the treatment of various tumor entities.

Comprehensive biomarker analysis and final efficacy results of sorafenib in the BATTLE trial

PURPOSE

To report the clinical efficacy of sorafenib and to evaluate biomarkers associated with sorafenib clinical benefit in the BATTLE (Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination) program.

PATIENTS AND METHODS

Patients with previously treated non-small cell lung cancer (NSCLC) received sorafenib until progression or unacceptable toxicity. Eight-week disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were assessed. Prespecified biomarkers included K-RAS, EGFR, and B-RAF mutations, and EGFR gene copy number. Gene expression profiles from NSCLC cell lines and patient tumor biopsies with wild-type EGFR were used to develop a sorafenib sensitivity signature (SSS).

RESULTS

A total of 105 patients were eligible and randomized to receive sorafenib. Among 98 patients evaluable for eight-week DCR, the observed DCR was 58.2%. The median PFS and OS were 2.83 [95% confidence interval (CI), 2.04-3.58] and 8.48 months (95% CI, 5.78-10.97), respectively. Eight-week DCR was higher in patients with wild-type EGFR than patients with EGFR mutation (P = 0.012), and in patients with EGFR gene copy number gain (FISH-positive) versus patients FISH-negative (P = 0.048). In wild-type EGFR tumors, the SSS was associated with improved PFS (median PFS 3.61 months in high SSS vs. 1.84 months in low SSS; P = 0.026) but not with eight-week DCR. Increased expression of fibroblast growth factor-1, NF-κB, and hypoxia pathways were identified potential drivers of sorafenib resistance.

CONCLUSION

Sorafenib demonstrates clinical activity in NSCLC, especially with wild-type EGFR. SSS was associated with improved PFS. These data identify subgroups that may derive clinical benefit from sorafenib and merit investigation in future trials.

Inauhzin sensitizes p53-dependent cytotoxicity and tumor suppression of chemotherapeutic agents

Toxicity and chemoresistance are two major issues to hamper the success of current standard tumor chemotherapy. Combined therapy of agents with different mechanisms of action is a feasible and effective means to minimize the side effects and avoid the resistance to chemotherapeutic drugs while improving the antitumor effects. As the most essential tumor suppressor, p53 or its pathway has been an attractive target to develop a new type of molecule-targeting anticancer therapy. Recently, we identified a small molecule, Inauhzin (INZ), which can specifically activate p53 by inducing its deacetylation. In this study, we tested if combination with INZ could sensitize tumor cells to the current chemotherapeutic drugs, cisplatin (CIS) and doxorubicin (DOX). We found that compared with any single treatment, combination of lower doses of INZ and CIS or DOX significantly promoted apoptosis and cell growth inhibition in human non-small lung cancer and colon cancer cell lines in a p53-dependent fashion. This cooperative effect between INZ and CIS on tumor suppression was also confirmed in a xenograft tumor model. Therefore, this study suggests that specifically targeting the p53 pathway could enhance the sensitivity of cancer cells to chemotherapeutic agents and markedly reduce the doses of the chemotherapy, possibly decreasing its adverse side effects.

Phase I/II trial of vinorelbine and sorafenib in metastatic breast cancer

PURPOSE

We investigated the efficacy and toxicity of sorafenib, a multikinase inhibitor of vascular endothelial growth factor receptor tyrosine kinase, in combination with vinorelbine therapy in a phase I/II trial in patients with metastatic breast cancer.

PATIENTS AND METHODS

We enrolled 11 patients in the phase I portion to determine the maximum tolerated dose (MTD) of the combination, followed by 35 extra patients treated at the MTD in phase II. The median age of patients was 54 years old (range, 31-72 years old). Tumors were estrogen receptor and progesterone receptor (ER/PR) positive in 54% (22/54) of patients, and triple negative (ER(-), PR(-), HER2(-)) in 41% (17/54) of patients. Of all patients, 22% received sorafenib and vinorelbine as first-line therapy, 37% as second-line therapy, and 41% as third-line therapy.

RESULTS

In total, 41 patients were treated at the MTD (6 during phase I; 35 in phase II). The observed 44% 4-month progression-free survival rate was similar to the estimated historical rate of 43% with vinorelbine treatment. The combination was tolerated with expected toxicities. Patients treated at the MTD who had received prior bevacizumab treatment received a median of 1.5 cycles (range, 1-10 cycles) compared with a median of 5 cycles (range, 2-12 cycles) for patients without prior bevacizumab treatment.

CONCLUSION

Further evaluation of vinorelbine and sorafenib in bevacizumab-naive patients may be of interest if specific biomarkers guiding patient selection can be identified.

Alteration in the balance of prosurvival and proapoptotic signalling pathways leads to sequence-dependent synergism between docetaxel and sorafenib in human non-small cell lung cancer cell lines

To examine the antiproliferative effect of the combination of docetaxel and sorafenib, applied to the representative non-small cell lung cancer cell line A549 cells either wild type or with acquired resistance to docetaxel (A549/D). The aim of this study is to evaluate the synergistic effect of combination treatment on cell growth inhibition and to elucidate the involved molecular mechanisms. A549 cells with acquired resistance to docetaxel were established by continuous exposure to docetaxel. We examined the effect of different combinatorial treatment on cell proliferation and cell cycle distribution. In addition, the effect of combinatorial treatments on proliferative and apoptotic signalling pathway were studied. Our results showed that the synergistic effect presented when A549 cells were treated with docetaxel followed by sorafenib or when A549/D cells were treated in reverse sequence. Furthermore, we suggested that synergistic effect in A549/D cells was caused by inhibiting P-gp function and altering in the balance of growth and apoptotic signalling pathways. Our data suggested a potential role of sorafenib in chemosensitizing docetaxel-resistant cancer cells. This study also provides molecular evidence for applying different therapeutic strategies for patients with different genetic and proteomic profile.

Aspirin minimized the pro-metastasis effect of sorafenib and improved survival by up-regulating HTATIP2 in hepatocellular carcinoma

Background & Aims

We previously demonstrated the pro-metastasis effect of sorafenib in hepatocellular carcinoma (HCC), which is mediated by down-regulation of tumor suppressor HTATIP2. The aim of the present study was to determine whether aspirin minimizes this effect and improves survival.

Methods

The effects of sorafenib, aspirin, and combined sorafenib and aspirin were observed in HCCLM3 and HepG2 xenograft nude mice. Tumor growth, intrahepatic metastasis (IHM), lung metastasis, and survival were assessed. Polymerase chain reaction (PCR) array, real-time (RT)-PCR, and Western blotting were used to examine gene expression. The anti-invasion and anti-metastasis effects of aspirin were studied in HTATIP2-knockdown and HTATIP2-overexpressing HCC cell lines. The molecular mechanism of HTATIP2 regulation by aspirin was explored.

Results

Aspirin suppressed the pro-invasion and pro-metastasis effects of sorafenib in HCC and up-regulated HTATIP2 expression. Aspirin did not inhibit the proliferation of HCC cells, but it decreased the invasiveness of HCC with lower expression of HTATIP2 and increased expression of a set of markers, indicating a mesenchymal-to-epithelial transition in tumor cells. The up-regulation of HTATPI2 expression by aspirin is most likely mediated through inhibition of cyclooxygenase (COX) 2 expression.

Conclusions

Aspirin minimized the pro-metastasis effect of sorafenib by up-regulating the tumor suppressor HTATIP2; this mechanism is mediated through inhibition of COX2.

Sunitinib in combination with gemcitabine for advanced solid tumours: a phase I dose-finding study

BACKGROUND

This phase I, dose-finding study determined the maximum tolerated dose (MTD), safety, and pharmacokinetics of sunitinib plus gemcitabine in patients with advanced solid tumours.

METHODS

Two schedules with sunitinib (25-50 mg per day) and IV gemcitabine (750-1250 mg m(-2)) in escalating doses were studied. First, patients received sunitinib on a 4-weeks-on-2-weeks-off schedule (Schedule 4/2) plus gemcitabine on days 1, 8, 22, and 29. Second, patients received sunitinib on a 2-weeks-on-1-week-off schedule (Schedule 2/1) plus gemcitabine on days 1 and 8. The primary endpoint was determination of MTD and tolerability.

RESULTS

Forty-four patients received the combination (Schedule 4/2, n=8; Schedule 2/1, n=36). With no dose-limiting toxicities (DLTs) at maximum dose levels on Schedule 2/1, MTD was not reached. Grade 4 treatment-related AEs and laboratory abnormalities included cerebrovascular accident, hypertension, and pulmonary embolism (n=1 each), and neutropenia (n=3), thrombocytopenia and increased uric acid (both n=2), and lymphopenia (n=1). There were no clinically significant drug-drug interactions. Antitumor activity occurred across dose levels and tumour types. In poor-risk and/or high-grade renal cell carcinoma patients (n=12), 5 had partial responses and 7 stable disease ≥ 6 weeks.

CONCLUSION

Sunitinib plus gemcitabine on Schedule 2/1 with growth factor support was well tolerated and safely administered at maximum doses of each drug, without significant drug-drug interactions.

Sorafenib combined with gemcitabine in EGFR-TKI-resistant human lung cancer cells

Sorafenib is a multi-targeted agent and has been reported to have potent antitumor effects against various types of tumors, including human non-small cell lung cancer (NSCLC). In this study, we explored in vitro the antitumor effects of sorafenib alone and in combination with gemcitabine in epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-resistant human lung cancer cell lines and the related molecular mechanisms. The NSCLC cell lines A549 (mutant KRAS), H1666 (mutant BRAF) and H1975 (mutant EGFR-T790M) were treated with sorafenib and gemcitabine alone and in combination. The cytotoxicity was assessed by MTT assay, cell cycle distribution was analyzed by flow cytometry, and alterations in signaling pathways were analyzed by western blotting. We found that sorafenib exhibited dose-dependent growth inhibition in all three EGFR-TKI-resistant NSCLC cell lines. When sorafenib was combined with gemcitabine, synergistic activity was observed in the A549 and H1666 cells and antagonistic activity was observed in the H1975 cells. Sorafenib arrested the cell cycle at the G1 phase, whereas gemcitabine arrested the cell cycle at the S phase. Sorafenib inhibited C-RAF and p-ERK in the A549 cells and B-RAF and p-ERK in the H1666 and H1975 cells. The molecular mechanism of this synergism is that RAF/MEK/ERK which are activated by gemcitabine are efficiently suppressed by simultaneously administered sorafenib. By contrast, the mechanism of antagonism may be due to mutual interference with the cell cycle in the H1975 cells. In conclusion, we found that sorafenib exhibits antiproliferative effects in EGFR-TKI-resistant NSCLC cell lines and when combined with gemcitabine demonstrates synergistic activity in A549 and H1666 cells but antagonistic activity in H1975 cells.

Sorafenib down-regulates expression of HTATIP2 to promote invasiveness and metastasis of orthotopic hepatocellular carcinoma tumors in mice

BACKGROUND & AIMS

Antiangiogenic agents can sometimes promote tumor invasiveness and metastasis, but little is known about the effects of the antiangiogenic drug sorafenib on progression of hepatocellular carcinoma (HCC).

METHODS

Sorafenib was administered orally (30 mg · kg(-1) · day(-1)) to mice with orthotopic tumors grown from HCC-LM3, SMMC7721, or HepG2 cells. We analyzed survival times of mice, along with tumor growth, metastasis within liver and to lung, and induction of the epithelial-mesenchymal transition. Polymerase chain reaction arrays were used to determine the effects of sorafenib on gene expression patterns in HCC cells. We analyzed regulation of HIV-1 Tat interactive protein 2 (HTATIP2) by sorafenib and compared levels of this protein in tumor samples from 75 patients with HCC (21 who received sorafenib after resection and 54 who did not).

RESULTS

Sorafenib promoted invasiveness and the metastatic potential of orthotopic tumors grown from SMMC7721 and HCC-LM3 cells but not from HepG2 cells. In gene expression analysis, HTATIP2 was down-regulated by sorafenib. HCC-LM3 cells that expressed small hairpin RNAs against HTATIP2 (knockdown) formed less invasive tumors in mice following administration of sorafenib than HCC-LM3 without HTATIP2 knockdown. Alternatively, HepG2 cells that expressed transgenic HTATIP2 formed more invasive tumors in mice following administration of sorafenib. Sorafenib induced the epithelial-mesenchymal transition in HCC cell lines, which was associated with expression of HTATIP2. Sorafenib regulated expression of HTATIP2 via Jun-activated kinase (JAK) and signal transducer and activator of transcription (STAT)3 signaling. Sorafenib therapy prolonged recurrence-free survival in patients who expressed lower levels of HTATIP2 compared with higher levels.

CONCLUSIONS

Sorafenib promotes invasiveness and the metastatic potential of orthotopic tumors from HCC cells in mice, down-regulating expression of HTATIP2 via JAK-STAT3 signaling.

Phase II trial of sorafenib in combination with carboplatin and paclitaxel in patients with metastatic uveal melanoma: SWOG S0512

BACKGROUND

Sorafenib, a multikinase inhibitor of cell proliferation and angiogenesis, inhibits the mitogen-activated protein kinase pathway that is activated in most uveal melanoma tumors. This phase II study was conducted by the SWOG cooperative group to evaluate the efficacy of sorafenib in combination with carboplatin and paclitaxel (CP) in metastatic uveal melanoma.

METHODS

Twenty-five patients with stage IV uveal melanoma who had received 0-1 prior systemic therapy were enrolled. Treatment included up to 6 cycles of carboplatin (AUC = 6) and paclitaxel (225 mg/m(2)) administered IV on day 1 plus sorafenib (400 mg PO twice daily), followed by sorafenib monotherapy until disease progression. The primary endpoint was objective response rate (ORR); a two-stage design was used with the study to be terminated if no confirmed responses were observed in the first 20 evaluable patients. Secondary efficacy endpoints included progression-free survival (PFS) and overall survival (OS).

RESULTS

No confirmed objective responses occurred among the 24 evaluable patients (ORR = 0% [95% CI: 0-14%]) and the study was terminated at the first stage. Minor responses (tumor regression less than 30%) were seen in eleven of 24 (45%) patients. The median PFS was 4 months [95% CI: 1-6 months] and the 6-month PFS was 29% [95% CI: 13%-48%]. The median OS was 11 months [95% CI: 7-14 months].

CONCLUSION

In this study, the overall efficacy of CP plus sorafenib in metastatic uveal melanoma did not warrant further clinical testing when assessed by ORR, although minor tumor responses and stable disease were observed in some patients.

TRIAL REGISTRATION

ClinicalTrials.govNCT00329641.

Synergistic interaction between sorafenib and gemcitabine in EGFR-TKI-sensitive and EGFR-TKI-resistant human lung cancer cell lines

Sorafenib is a highly selective multi-targeted agent and has been reported to have potent antitumor effects against various tumors, including human non-small cell lung cancer (NSCLC). In the present study, we explored the antitumor effect and associated molecular mechanisms of sorafenib against human lung cancer cell lines in vitro. We also investigated the efficacy of concurrent and sequential administration of sorafenib and gemcitabine in epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI)-sensitive and EGFR-TKI-resistant NSCLC cell lines. The PC-9 (EGFR-TKI-sensitive, EGFR-mutated) and A549 (EGFR-TKI-resistant, K-Ras-mutated) NSCLC cell lines were treated with sorafenib and gemcitabine, alone, in combination or with different schedules. Cytotoxicity was assessed by MTT assay, cell cycle distribution was analyzed by flow cytometry and alterations in signaling pathways were analyzed by western blotting. We found that sorafenib exhibited dose-dependent growth inhibition in the EGFR-TKI-sensitive and EGFR-TKI-resistant NSCLC cell lines, and the sequence gemcitabine→sorafenib exhibited the strongest synergism. Sorafenib arrested the cell cycle at G1 phase, whereas gemcitabine caused arrest at S phase. The molecular mechanism of this synergism is that the downstream signaling pathways that were initially activated by gemcitabine exposure were efficiently suppressed by the subsequent exposure to sorafenib. By contrast, the reverse of this sequential administration resulted in antagonism, which may be due to differential effects on cell cycle arrest. The results suggest that sorafenib as a single agent exhibits anti-proliferative effects in vitro in NSCLC cell lines with EGFR and K-Ras mutations and that the sequential administration of gemcitabine followed by sorafenib is superior to sorafenib followed by gemcitabine and concurrent administration.

Antitumor activity of motesanib alone and in combination with cisplatin or docetaxel in multiple human non-small-cell lung cancer xenograft models

BACKGROUND

Non-small-cell lung cancer (NSCLC) is categorized into various histologic subtypes that play an important role in prognosis and treatment outcome. We investigated the antitumor activity of motesanib, a selective antagonist of vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3, platelet-derived growth factor receptor, and Kit, alone and combined with chemotherapy in five human NSCLC xenograft models (A549, Calu-6, NCI-H358, NCI-H1299, and NCI-H1650) containing diverse genetic mutations.

RESULTS

Motesanib as a single agent dose-dependently inhibited tumor xenograft growth compared with vehicle in all five of the models (P < 0.05). When combined with cisplatin, motesanib significantly inhibited the growth of Calu-6, NCI-H358, and NCI-H1650 tumor xenografts compared with either single agent alone (P < 0.05). Similarly, the combination of motesanib plus docetaxel significantly inhibited the growth of A549 and Calu-6 tumor xenografts compared with either single agent alone (P < 0.05). In NCI-H358 and NCI-H1650 xenografts, motesanib with and without cisplatin significantly decreased tumor blood vessel area (P < 0.05 vs vehicle) as assessed by anti-CD31 staining. Motesanib alone or in combination with chemotherapy had no effect on tumor cell proliferation in vitro.

CONCLUSIONS

These data demonstrate that motesanib had antitumor activity against five different human NSCLC xenograft models containing diverse genetic mutations, and that it had enhanced activity when combined with cisplatin or docetaxel. These effects appeared to be mediated primarily by antiangiogenic mechanisms.

Sunitinib malate provides activity against murine bladder tumor growth and invasion in a preclinical orthotopic model

OBJECTIVE

To evaluate the effects of sunitinib on localized bladder cancer in a mouse orthotopic bladder tumor model.

METHODS

We used an established orthotopic mouse bladder cancer model in syngeneic C3H/He mice. Treatment doses of 40 mg/kg of sunitinib or placebo sterile saline were administrated daily by oral gavage. Tumor volume, intratumoral perfusion, and in vivo vascular endothelial growth factor receptor-2 expression were measured using a targeted contrast-enhanced micro-ultrasound imaging system. The findings were correlated with the total bladder weight, tumor stage, and survival. The effects of sunitinib malate on angiogenesis and cellular proliferation were measured by immunostaining of CD31 and Ki-67.

RESULTS

Significant inhibition of tumor growth was seen after sunitinib treatment compared with the control. The incidence of extravesical extension of the bladder tumor and hydroureter in the sunitinib-treated group (30% and 20%, respectively) was lower than the incidence in the control group (66.7% and 55.6%, respectively). Sunitinib therapy prolonged the survival in mice, with statistical significance (log-rank test, P = .03). On targeted contrast-enhanced micro-ultrasound imaging, in vivo vascular endothelial growth factor receptor-2 expression was reduced in the sunitinib group and correlated with a decrease in microvessel density.

CONCLUSION

The results of our study have demonstrated the antitumor effects of sunitinib in the mouse localized bladder cancer model. Sunitinib inhibited the growth of bladder tumors and prolonged survival. Given that almost 30% of cases in our treatment arm developed extravesical disease, sunitinib might be suited as a part of a multimodal treatment regimen for bladder cancer.

New oral multitargeted antiangiogenics in non-small-cell lung cancer treatment

Non-small-cell lung cancer is a particularly aggressive cancer. Combination chemotherapy remains the standard therapy for patients with advanced or metastatic disease. However, despite the available treatment options for patients who progress beyond first-line therapy, prognosis remains poor. Angiogenesis is a tightly regulated process controlled by a delicate balance between pro- and antiangiogenic factors and their receptors; tumors induce angiogenesis by disrupting this balance and secreting various growth factors. Inhibition of tumor-related angiogenesis has become an attractive target for anticancer therapy. Antiangiogenic strategy includes monoclonal antibodies against VEGF and VEGF receptor and small molecule inhibitors of VEGF tyrosine kinase activity (tyrosine kinase inhibitors). Tyrosine kinase inhibitors are orally active, small molecules that represent a new class of drugs with a relatively high safety profile. They are targeted therapies that play their anticancer role interfering with specific cell signaling. This review focuses on such oral antiangiogenic agents that have been approved and are in advanced clinical development for the treatment of patients with advanced non-small-cell lung cancer.

Patient-derived xenografts of non small cell lung cancer: resurgence of an old model for investigation of modern concepts of tailored therapy and cancer stem cells

Current chemotherapy regimens have unsatisfactory results in most advanced solid tumors. It is therefore imperative to devise novel therapeutic strategies and to optimize selection of patients, identifying early those who could benefit from available treatments. Mouse models are the most valuable tool for preclinical evaluation of novel therapeutic strategies in cancer and, among them, patient-derived xenografts models (PDX) have made a recent comeback in popularity. These models, obtained by direct implants of tissue fragments in immunocompromised mice, have great potential in drug development studies because they faithfully reproduce the patient's original tumor for both immunohistochemical markers and genetic alterations as well as in terms of response to common therapeutics They also maintain the original tumor heterogeneity, allowing studies of specific cellular subpopulations, including their modulation after drug treatment. Moreover PDXs maintain at least some aspects of the human microenvironment for weeks with the complete substitution with murine stroma occurring only after 2-3 passages in mouse and represent therefore a promising model for studies of tumor-microenvironment interaction. This review summarizes our present knowledge on mouse preclinical cancer models, with a particular attention on patient-derived xenografts of non small cell lung cancer and their relevance for preclinical and biological studies.

Sorafenib and cisplatin/doxorubicin (PLADO) in pediatric hepatocellular carcinoma

PURPOSE

Overall survival is poor in children with primary unresectable hepatocellular carcinoma. Sorafenib has been shown to significantly improve progression-free survival in adult hepatocellular carcinoma (HCC) patients. We evaluated the experience of PLADO (cisplatin 80 mg/m(2) /day, doxorubicin 2 × 30 mg/m(2) /day) in combination with sorafenib in pediatric HCC patients.

PATIENTS AND METHODS

Clinical data of 12 patients (7-16 years), 7 with unresectable tumor, were retrospectively assessed.

RESULTS

In total 6/12 (50%) patients are in complete remission after a median follow-up of 20 months (4 with PLADO/sorafenib/resection, 2 with liver transplantation after local relapse). Of the seven patients with unresectable tumor, PLADO/sorafenib resulted in partial response (PR) in four, stable disease (SD) in two, and progression in one. Three are alive in CR after complete resection after 12 (alternative therapy after two cycles PLADO/sorafenib), 12 and 18 months (six cycles PLADO/sorafenib), respectively. All four patients with elevated alpha-fetoprotein levels had a marked drop after two cycles. Of the five patients with primary complete tumor resection one is alive disease-free at 27 months. Four had local or metastatic relapses (13, 7, 12, and 13 months), two of whom were rescued by liver transplantation (CR after 25 and 32 months). The main toxicity attributable to sorafenib was a hand-foot skin reaction (HFSR) in seven patients.

CONCLUSION

Sorafenib in combination with PLADO may be a promising approach in pediatric HCC; HFSR was the most important toxicity. Data based on prospective studies are needed to evaluate pharmacokinetics, resectability rates, and survival in pediatric HCC treated with sorafenib.

New antiangiogenics in non-small cell lung cancer treatment: Vargatef™ (BIBF 1120) and beyond

Lung cancer is the leading cause of mortality worldwide. Non-small cell lung cancer (NSCLC) is a particularly aggressive cancer, the optimum management of which is still being determined. In the metastatic disease, the standard therapy is a platinum-based combination chemotherapy; however, in spite of available treatment options for patients who progress beyond first-line therapy, prognosis remains poor. Angiogenesis is a tightly regulated process which comprises a complex, complementary, and overlapping network. Inhibition of tumor-related angiogenesis has become an attractive target for anticancer therapy. Antiangiogenic strategy includes: monoclonal antibodies against vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR), small molecule inhibitors of VEGF tyrosine kinase activity, VEGF Trap, and a new class named "vascular disrupting agents," tested in ongoing clinical trials which will further define their role in the management of NSCLC. BIBF 1120 is an investigational orally administered receptor tyrosine kinase inhibitor that has shown antiangiogenic and antineoplastic activity, inhibiting VEGFR, platelet-derived growth factor receptor, and fibroblast growth factor receptor tyrosine kinases, preventing tumor growth and interfering with the angiogenesis-signaling cascade and overcoming drug resistances.

[Randomize trial of cisplatin plus gemcitabine with either sorafenib or placebo as first-line therapy for non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Platinum-based chemotherapy doublets reached an efficacy plateau in nonsmall-cell lung cancer (NSCLC). This randomized controlled study prospectively assessed the efficacy and safety of cisplatin plus gemcitabine with either Sorafenib or placebo as first-line therapy for NSCLC.

METHODS

Thirty patients, which were confirmed advanced NSCLC histologically or cytologically, were randomly assigned to receive up to six cycles of cisplatin plus gemcitabine with sorafenib or placebo. The maintenance of sorafenib or placebo after chemotherapy will continued in patients with response or stable disease until disease progression or unacceptable adverse events.

RESULTS

Overall demographics were balanced between experimental group (sorafenib+chemotherapy) and controlled group (chemotherapy only). Overall response (OS) rate was 55.6% and 41.7% in experimental arm and controlled arm, respectively (P=0.905). Median progressive-free survival (PFS) and median overall survival were similar (5 months vs 4 months, P=0.75; 18 months vs 18 months, P=0.68). Adverse events were tolerable, though the risk of hypertension and diarrhea was increase in experimental arm. Since patients with ECOG PS 0, stage IIIb, no liver metastasis and tyrasine kinasis inhibitor treatment after study had longer survive, these factors seemed to be predictive factors favor of survival in Cox regression analyses.

CONCLUSIONS

No additional benefit of response rate, PFS or OS were observed from adding targeted agent-sorafenib to regular cisplatin plus gemcitabine chemotherapy. Selecting aproper patients is needed in further study.

Characteristics of human Ewing/PNET sarcoma models

Ewing/PNET (peripheral neuroepithelioma) tumors are rare aggressive bone sarcomas occurring in young people. Rare-disease clinical trials can require global collaborations and many years. In vivo models that as accurately as possible reflect the clinical disease are helpful in selecting therapeutics with the most promise of positive clinical impact. Human Ewing/PNET sarcoma cell lines developed over the past 45 years are described. Several of these have undergone genetic analysis and have been confirmed to be those of Ewing/PNET sarcoma. The A673 Ewing sarcoma line has proven to be particularly useful in understanding the biology of this disease in the mouse. The chromosomal translocation producing the EWS/FLI1 fusion transcript characterizes clinical Ewing sarcoma. Cell lines that express this genetic profile are confirmed to be those of Ewing sarcoma. The A673 Ewing sarcoma line grows in culture and as a xenograft in immunodeficient mice. The A673 model has been used to study Ewing sarcoma angiogenesis and response to antiangiogenic agents. Many Ewing sarcoma clinical specimens express the cell surface protein endosialin. Several Ewing sarcoma cell lines, including the A673 line, also express cell surface endosialin when grown as subcutaneous tumor nodules and as disseminated disease; thus the A673 is a useful model for the study of endosialin biology and endosialin-directed therapies. With the advent of tools that allow characterization of clinical disease to facilitate optimal treatment, it becomes imperative, especially for rare tumors, to develop preclinical models reflecting disease subsets. Ewing PNET sarcomas are a rare disease where models are available.

Combination of bifunctional alkylating agent and arsenic trioxide synergistically suppresses the growth of drug-resistant tumor cells

Drug resistance is a crucial factor in the failure of cancer chemotherapy. In this study, we explored the effect of combining alkylating agents and arsenic trioxide (ATO) on the suppression of tumor cells with inherited or acquired resistance to therapeutic agents. Our results showed that combining ATO and a synthetic derivative of 3a-aza-cyclopenta[a]indenes (BO-1012), a bifunctional alkylating agent causing DNA interstrand cross-links, was more effective in killing human cancer cell lines (H460, H1299, and PC3) than combining ATO and melphalan or thiotepa. We further demonstrated that the combination treatment of H460 cells with BO-1012 and ATO resulted in severe G(2)/M arrest and apoptosis. In a xenograft mouse model, the combination treatment with BO-1012 and ATO synergistically reduced tumor volumes in nude mice inoculated with H460 cells. Similarly, the combination of BO-1012 and ATO effectively reduced the growth of cisplatin-resistant NTUB1/P human bladder carcinoma cells. Furthermore, the repair of BO-1012-induced DNA interstrand cross-links was significantly inhibited by ATO, and consequently, gammaH2AX was remarkably increased and formed nuclear foci in H460 cells treated with this drug combination. In addition, Rad51 was activated by translocating and forming foci in nuclei on treatment with BO-1012, whereas its activation was significantly suppressed by ATO. We further revealed that ATO might mediate through the suppression of AKT activity to inactivate Rad51. Taken together, the present study reveals that a combination of bifunctional alkylating agents and ATO may be a rational strategy for treating cancers with inherited or acquired drug resistance.

Targeted therapies for non-small cell lung cancer: an evolving landscape

Over the past decade, a multitude of targeted agents have been explored in the treatment of advanced non-small cell lung cancer (NSCLC). Thus far, two broad classes of agents have been implemented in clinical practice: (a) vascular endothelial growth factor (VEGF)-directed therapies and (b) antagonists of the epidermal growth factor receptor (EGFR). In the former category, the agent bevacizumab (a monoclonal antibody) has shown landmark improvements in survival when added to cytotoxic therapy. Small molecule tyrosine kinase inhibitors (TKI) targeting the VEGF receptor (i.e., sunitinib, sorafenib, and vandetanib) show activity in phase II clinical studies. With respect to EGFR-directed therapies, the TKIs gefitinib and erlotinib have shown significant benefit, and have uncovered valuable information about the biology of lung cancer. Outside of therapies directed specifically at VEGF- and EGFR-mediated signaling, trials evaluating insulin-like growth factor-1 receptor (IGF-IR)-targeting agents, cyclooxygenase-2 (COX-2) inhibitors, c-met inhibitors, irreversible pan-HER inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and histone deacetylase (HDAC) inhibitors are ongoing. Inhibitors of ALK show great promise in patients with the relevant gene translocation. Herein, the clinical development of novel therapies for NSCLC is described, including some discussion of relevant biomarkers and determination of synergy with both cytotoxic therapy and other targeted agents.

Targeting angiogenesis with multitargeted tyrosine kinase inhibitors in the treatment of non-small cell lung cancer

It has been >35 years since the link between angiogenesis and the growth of tumors was first reported. Targeting angiogenesis became feasible with the availability of bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody. Initial studies revealed that the combination of bevacizumab and chemotherapy led to longer overall survival times than with chemotherapy alone in patients with advanced colorectal cancer. Since then, drug development strategies have added small molecule tyrosine kinase inhibitors to the panel of antiangiogenic agents under evaluation; data from numerous trials are now available. The challenge now is to identify the optimal antiangiogenic agent for specific patient groups and to understand not only the mechanistic differences between agents, but also the variability in their antitumor activity across different tumor types and their differing side-effect profiles. As in other solid tumors, angiogenesis contributes to the development of non-small cell lung cancer (NSCLC), and this review summarizes the role of angiogenesis in this disease. We review the current developmental status of antiangiogenic tyrosine kinase inhibitors (including vandetanib, sunitinib, axitinib, sorafenib, vatalanib, and pazopanib) in NSCLC and conclude by briefly discussing the need for optimal patient selection and potential future directions.

Sorafenib

Sorafenib (BAY 43-9006, Nexavar) is a novel oral kinase inhibitor that targets multiple tyrosine kinases in vivo and in vitro. Main targets are receptor tyrosine kinase pathways frequently deregulated in cancer such as the raf-ras pathway, vascular endothelial growth factor (VEGF) pathway, and FMS-like tyrosine kinase 3 (FLT3). Sorafenib was approved by the FDA in fast track for advanced renal cell cancer and hepatocellular cancer and shows good clinical activity in thyroid cancer. Multiple clinical trials are undertaken to further investigate the role of sorafenib alone or in combination for the treatment of various tumor entities.

Chemotherapy for lung cancer: the state of the art in 2009

Lung cancer remains the most common cause of cancer-related death among men and women worldwide. Incremental and significant advances in available systemic treatments, however, have taken place in the last decade to provide improved survival rates and better palliation for patients with non-small-cell and small-cell lung cancer. Superior imaging techniques have enabled the detection of early-stage disease and adjuvant chemotherapy has earned a place for select patients following resection of their tumors. Perhaps the largest growth has been in the area of advanced non-small-cell lung cancer, in which multiple new combination and single-agent systemic therapies have become standard where previously only 'best supportive care' was thought appropriate. In concert with broader applicability of chemotherapy, translational studies have provided the rationale for using molecular markers to identify the patients most likely to benefit from biological and targeted therapies. This review will discuss the current role of chemotherapy in both early and advanced non-small-cell and small-cell lung cancer. Novel targeted systemic therapies and the appropriate selection of treatments for patients based on their tumors' molecular phenotypes and histologies will also be reviewed.

Phase II, multicenter, uncontrolled trial of single-agent sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer

PURPOSE

Sorafenib is an oral multikinase inhibitor that targets the Ras/Raf/MEK/ERK mitogenic signaling pathway and the angiogenic receptor tyrosine kinases, vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor beta. We evaluated the antitumor response and tolerability of sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer (NSCLC), most of whom had received prior platinum-based chemotherapy.

PATIENTS AND METHODS

This was a phase II, single-arm, multicenter study. Patients with relapsed or refractory advanced NSCLC received sorafenib 400 mg orally twice daily until tumor progression or an unacceptable drug-related toxicity occurred. The primary objective was to measure response rate.

RESULTS

Of 54 patients enrolled, 52 received sorafenib. The predominant histologies were adenocarcinoma (54%) and squamous cell carcinoma (31%). No complete or partial responses were observed. Stable disease (SD) was achieved in 30 (59%) of the 51 patients who were evaluable for efficacy. Four patients with SD developed tumor cavitation. Median progression-free survival (PFS) was 2.7 months, and median overall survival was 6.7 months. Patients with SD had a median PFS of 5.5 months. Major grades 3 to 4, treatment-related toxicities included hand-foot skin reaction (10%), hypertension (4%), fatigue (2%), and diarrhea (2%). Nine patients died within a 30-day period after discontinuing sorafenib, and one patient experienced pulmonary hemorrhage that was considered drug related. CONCLUSION Continuous treatment with sorafenib 400 mg twice daily was associated with disease stabilization in patients with advanced NSCLC. The broad activity of sorafenib and its acceptable toxicity profile suggest that additional investigation of sorafenib as therapy for patients with NSCLC is warranted.