A Randomized, Double-Blind Noninferiority Study to Evaluate the Efficacy of the Cabozantinib Tablet at 60 mg Per Day Compared with the Cabozantinib Capsule at 140 mg Per Day in Patients with Progressive, Metastatic Medullary Thyroid Cancer.

Background: Cabozantinib inhibits pathways involved in medullary thyroid cancer (MTC). Cabozantinib is approved as 140 mg/day in capsules for MTC and 60 mg/day in tablets for other solid tumors. This study compared the two doses in progressive metastatic MTC. Methods: In this Phase 4, randomized, double-blind noninferiority (NI) trial (NCT01896479), patients with progressive metastatic MTC were randomized 1:1 to cabozantinib 60 mg/day tablet or 140 mg/day capsules. The primary end point was progression-free survival (PFS) by blinded independent radiology committee (BIRC) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. NI would be concluded if the upper 95% confidence interval [CI] for the PFS hazard ratio (HR) was less than the NI margin, 1.58. The secondary end point was objective response rate (ORR) by BIRC per RECIST v1.1; additional end points included safety and pharmacokinetics. Results: At data cutoff (July 15, 2020), 247 patients were randomized to the 60 mg/day tablet arm (n = 123) and the 140 mg/day capsules arm (n = 124). NI was not met (median PFS 11.0 months vs. 13.9 months in the 60 and 140 mg/day arms [HR 1.24; CI 0.90-1.70; p = 0.19]). The ORR was 33% in both arms. Generally, adverse event (AE) incidence was lower in the 60 mg/day arm (Grade 3/4, 63% vs. 72%), as were dose reductions (69% vs. 81%) and treatment discontinuations due to AEs (23% vs. 36%). Initially, cabozantinib plasma concentrations were higher in the 140 mg/day arm but became similar between arms at later time points. Conclusions: PFS NI of the cabozantinib 60 mg/day tablet vs. 140 mg/day capsules was not met. The 60 mg/day tablet had the same ORR and lower rates of AEs. Clinical Trial Registry: ClinicalTrials.gov NCT01896479.

A Phase 1a/b Open-Label, Dose-Escalation Study of Etigilimab Alone or in Combination with Nivolumab in Patients with Locally Advanced or Metastatic Solid Tumors.

PURPOSE: TIGIT (T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain) is a co-inhibitory receptor of T-cell and natural killer cell activity. Targeting TIGIT with or without PD-1/PD-L1 checkpoint inhibition may enhance antitumor immunity. PATIENTS AND METHODS: This Phase 1a/b trial was a first-in-human, open-label, multicenter, dose-escalation and -expansion study in patients with locally advanced or metastatic solid tumors. Using 3 + 3 design, patients underwent 14-day treatment cycles with anti-TIGIT antibody etigilimab alone (Phase 1a; 0.3, 1.0, 3.0, 10.0, 20.0 mg/kg intravenously) or in combination with anti-PD-1 antibody nivolumab (Phase 1b; 3.0, 10.0, 20.0 mg/kg etigilimab and 240 mg nivolumab). Primary objective was safety and tolerability. RESULTS: Thirty-three patients were enrolled (Phase 1a, n = 23; Phase 1b, n = 10). There were no dose-limiting toxicities (DLT). MTD for single and combination therapy was not determined; maximum administered dose was 20 mg/kg. The most commonly reported adverse events (AE) were rash (43.5%), nausea (34.8%), and fatigue (30.4%) in Phase 1a and decreased appetite (50.0%), nausea (50.0%), and rash (40%) in Phase 1b. Six patients experienced Grade ≥3 treatment-related AEs. In Phase 1a, 7 patients (30.0%) had stable disease. In Phase 1b, 1 patient had a partial response; 1 patient had prolonged stable disease of nearly 8 months. Median progression-free survival was 56.0 days (Phase 1a) and 57.5 days (Phase 1b). Biomarker correlative analyses demonstrated evidence of clear dose-dependent target engagement by etigilimab. CONCLUSIONS: Etigilimab had an acceptable safety profile with preliminary evidence of clinical benefit alone and in combination with nivolumab and warrants further investigation in clinical trials.

Cabozantinib for radioiodine-refractory differentiated thyroid cancer (COSMIC-311): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Patients with radioiodine-refractory differentiated thyroid cancer (DTC) previously treated with vascular endothelial growth factor receptor (VEGFR)-targeted therapy have aggressive disease and no available standard of care. The aim of this study was to evaluate the tyrosine kinase inhibitor cabozantinib in this patient population. METHODS: In this global, randomised, double-blind, placebo-controlled, phase 3 trial, patients aged 16 years and older with radioiodine-refractory DTC (papillary or follicular and their variants) and an Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (2:1) to oral cabozantinib (60 mg once daily) or matching placebo, stratified by previous lenvatinib treatment and age. The randomisation scheme used stratified permuted blocks of block size six and an interactive voice-web response system; both patients and investigators were masked to study treatment. Patients must have received previous lenvatinib or sorafenib and progressed during or after treatment with up to two VEGFR tyrosine kinase inhibitors. Patients receiving placebo could cross over to open-label cabozantinib on disease progression confirmed by blinded independent radiology committee (BIRC). The primary endpoints were objective response rate (confirmed response per Response Evaluation Criteria in Solid Tumours [RECIST] version 1.1) in the first 100 randomly assigned patients (objective response rate intention-to-treat [OITT] population) and progression-free survival (time to earlier of disease progression per RECIST version 1.1 or death) in all patients (intention-to-treat [ITT] population), both assessed by BIRC. This report presents the primary objective response rate analysis and a concurrent preplanned interim progression-free survival analysis. The study is registered with ClinicalTrials.gov, NCT03690388, and is no longer enrolling patients. FINDINGS: Between Feb 27, 2019, and Aug 18, 2020, 227 patients were assessed for eligibility, of whom 187 were enrolled from 164 clinics in 25 countries and randomly assigned to cabozantinib (n=125) or placebo (n=62). At data cutoff (Aug 19, 2020) for the primary objective response rate and interim progression-free survival analyses, median follow-up was 6·2 months (IQR 3·4-9·2) for the ITT population and 8·9 months (7·1-10·5) for the OITT population. An objective response in the OITT population was achieved in ten (15%; 99% CI 5·8-29·3) of 67 patients in the cabozantinib group versus 0 (0%; 0-14·8) of 33 in the placebo (p=0·028) but did not meet the prespecified significance level (α=0·01). At interim analysis, the primary endpoint of progression-free survival was met in the ITT population; cabozantinib showed significant improvement in progression-free survival over placebo: median not reached (96% CI 5·7-not estimable [NE]) versus 1·9 months (1·8-3·6); hazard ratio 0·22 (96% CI 0·13-0·36; p<0·0001). Grade 3 or 4 adverse events occurred in 71 (57%) of 125 patients receiving cabozantinib and 16 (26%) of 62 receiving placebo, the most frequent of which were palmar-plantar erythrodysaesthesia (13 [10%] vs 0), hypertension (11 [9%] vs 2 [3%]), and fatigue (ten [8%] vs 0). Serious treatment-related adverse events occurred in 20 (16%) of 125 patients in the cabozantinib group and one (2%) of 62 in the placebo group. There were no treatment-related deaths. INTERPRETATION: Our results show that cabozantinib significantly prolongs progression-free survival and might provide a new treatment option for patients with radioiodine-refractory DTC who have no available standard of care. FUNDING: Exelixis.

Activating NOTCH1 Mutations Define a Distinct Subgroup of Patients With Adenoid Cystic Carcinoma Who Have Poor Prognosis, Propensity to Bone and Liver Metastasis, and Potential Responsiveness to Notch1 Inhibitors.

Purpose Adenoid cystic carcinomas (ACCs) represent a heterogeneous group of chemotherapy refractory tumors, with a subset demonstrating an aggressive phenotype. We investigated the molecular underpinnings of this phenotype and assessed the Notch1 pathway as a potential therapeutic target. Methods We genotyped 102 ACCs that had available pathologic and clinical data. Notch1 activation was assessed by immunohistochemistry for Notch1 intracellular domain. Luciferase reporter assays were used to confirm Notch1 target gene expression in vitro. The Notch1 inhibitor brontictuzumab was tested in patient-derived xenografts from patients with ACC and in a patient with ACC who was enrolled in a phase I study. Results NOTCH1 mutations occurred predominantly (14 of 15 patients) in the negative regulatory region and Pro-Glu-Ser-Thr-rich domains, the same two hotspots seen in T-cell acute lymphoblastic leukemias, and led to pathway activation in vitro. NOTCH1-mutant tumors demonstrated significantly higher levels of Notch1 pathway activation than wild-type tumors on the basis of Notch1 intracellular domain staining ( P = .004). NOTCH1 mutations define a distinct aggressive ACC subgroup with a significantly higher likelihood of solid subtype ( P < .001), advanced-stage disease at diagnosis ( P = .02), higher rate of liver and bone metastasis ( P ≤ .02), shorter relapse-free survival (median, 13 v 34 months; P = .01), and shorter overall survival (median 30 v 122 months; P = .001) when compared with NOTCH1 wild-type tumors. Significant tumor growth inhibition with brontictuzumab was observed exclusively in the ACC patient-derived xenograft model that harbored a NOTCH1 activating mutation. Furthermore, an index patient with NOTCH1-mutant ACC had a partial response to brontictuzumab. Conclusion NOTCH1 mutations define a distinct disease phenotype characterized by solid histology, liver and bone metastasis, poor prognosis, and potential responsiveness to Notch1 inhibitors. Clinical studies targeting Notch1 in a genotype-defined ACC subgroup are warranted.

The EphB4 receptor tyrosine kinase promotes lung cancer growth: a potential novel therapeutic target.

Despite progress in locoregional and systemic therapies, patient survival from lung cancer remains a challenge. Receptor tyrosine kinases are frequently implicated in lung cancer pathogenesis, and some tyrosine kinase inhibition strategies have been effective clinically. The EphB4 receptor tyrosine kinase has recently emerged as a potential target in several other cancers. We sought to systematically study the role of EphB4 in lung cancer. Here, we demonstrate that EphB4 is overexpressed 3-fold in lung tumors compared to paired normal tissues and frequently exhibits gene copy number increases in lung cancer. We also show that overexpression of EphB4 promotes cellular proliferation, colony formation, and motility, while EphB4 inhibition reduces cellular viability in vitro, halts the growth of established tumors in mouse xenograft models when used as a single-target strategy, and causes near-complete regression of established tumors when used in combination with paclitaxel. Taken together, these data suggest an important role for EphB4 as a potential novel therapeutic target in lung cancer. Clinical trials investigating the efficacy of anti-EphB4 therapies as well as combination therapy involving EphB4 inhibition may be warranted.

Targeted and cytotoxic therapy in coordinated sequence (TACTICS): erlotinib, bevacizumab, and standard chemotherapy for non-small-cell lung cancer, a phase II trial.

BACKGROUND: This trial focused on optimally combining existing targeted therapies and cytotoxic chemotherapy in the treatment of unselected patients with advanced non-small-cell lung cancer (NSCLC). METHODS: Patients with previously untreated advanced-stage nonsquamous NSCLC were eligible for this trial. In module A, patients received up to 4 cycles of erlotinib 150 mg daily and bevacizumab 15 mg/kg every 3 weeks. Patients then received carboplatin (AUC = 6), paclitaxel 200 mg/m2, and bevacizumab 15 mg/kg for 4 cycles in module B. Patients who did not have progressive disease in module A received maintenance erlotinib 150 mg daily and bevacizumab 15 mg/kg every 3 weeks in module C. RESULTS: Forty-eight patients were enrolled in this multicenter phase II trial. Most patients were male (62.5%) and white (77.1%) with stage IV disease (93.8%) and adenocarcinoma histologic type (66.7%). The overall response rate in module A was 10.4%, in module B it was 15.1%, and in module C it was 5.5%. The study achieved its primary endpoint, with a nonprogression rate of 45.8% in module A. The median overall survival (OS) was 12.6 months. CONCLUSION: The novel systemic therapy regimen is feasible in patients with advanced NSCLC. However there is no further role for developing this regimen in unselected patients with NSCLC.

Proteomic characterization of non-small cell lung cancer in a comprehensive translational thoracic oncology database.

BACKGROUND: In recent years, there has been tremendous growth and interest in translational research, particularly in cancer biology. This area of study clearly establishes the connection between laboratory experimentation and practical human application. Though it is common for laboratory and clinical data regarding patient specimens to be maintained separately, the storage of such heterogeneous data in one database offers many benefits as it may facilitate more rapid accession of data and provide researchers access to greater numbers of tissue samples. DESCRIPTION: The Thoracic Oncology Program Database Project was developed to serve as a repository for well-annotated cancer specimen, clinical, genomic, and proteomic data obtained from tumor tissue studies. The TOPDP is not merely a library-it is a dynamic tool that may be used for data mining and exploratory analysis. Using the example of non-small cell lung cancer cases within the database, this study will demonstrate how clinical data may be combined with proteomic analyses of patient tissue samples in determining the functional relevance of protein over and under expression in this disease. Clinical data for 1323 patients with non-small cell lung cancer has been captured to date. Proteomic studies have been performed on tissue samples from 105 of these patients. These tissues have been analyzed for the expression of 33 different protein biomarkers using tissue microarrays. The expression of 15 potential biomarkers was found to be significantly higher in tumor versus matched normal tissue. Proteins belonging to the receptor tyrosine kinase family were particularly likely to be over expressed in tumor tissues. There was no difference in protein expression across various histologies or stages of non-small cell lung cancer. Though not differentially expressed between tumor and non-tumor tissues, the over expression of the glucocorticoid receptor (GR) was associated improved overall survival. However, this finding is preliminary and warrants further investigation. CONCLUSION: Though the database project is still under development, the application of such a database has the potential to enhance our understanding of cancer biology and will help researchers to identify targets to modify the course of thoracic malignancies.

Randomized phase II study of bevacizumab in combination with chemotherapy in previously untreated extensive-stage small-cell lung cancer: results from the SALUTE trial.

PURPOSE: Because of promising efficacy signals in single-arm studies, a placebo-controlled, double-blind, randomized phase II trial was designed to assess the efficacy and safety of adding bevacizumab to first-line standard chemotherapy for treatment of extensive-stage small-cell lung cancer (SCLC). PATIENTS AND METHODS: Patients with SCLC were randomly assigned to receive bevacizumab or placebo, with cisplatin or carboplatin plus etoposide, for four cycles followed by single-agent bevacizumab or placebo until progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). RESULTS: Fifty-two patients were randomly assigned to the bevacizumab group and 50 to the placebo group; 69% versus 66%, respectively, completed four cycles of therapy. Median PFS was higher in the bevacizumab group (5.5 months) than in the placebo group (4.4 months; hazard ratio [HR], 0.53; 95% CI, 0.32 to 0.86). Median overall survival (OS) was similar for both groups (9.4 v 10.9 months for bevacizumab and placebo groups, respectively), with an HR of 1.16 (95% CI, 0.66 to 2.04). Overall response rates were 58% (95% CI, 43% to 71%) for the bevacizumab group and 48% (95% CI, 34% to 62%) for the placebo group. Median duration of response was 4.7 months for the bevacizumab group and 3.2 months for the placebo group. In the bevacizumab and placebo groups, 75% versus 60% of patients, respectively, experienced one or more grade 3 or higher adverse events. No new or unexpected safety signals for bevacizumab were observed. CONCLUSION: The addition of bevacizumab to cisplatin or carboplatin plus etoposide for treatment of extensive-stage SCLC improved PFS, with an acceptable toxicity profile. However, no improvement in OS was observed.

Generation of comprehensive thoracic oncology database--tool for translational research.

The Thoracic Oncology Program Database Project was created to serve as a comprehensive, verified, and accessible repository for well-annotated cancer specimens and clinical data to be available to researchers within the Thoracic Oncology Research Program. This database also captures a large volume of genomic and proteomic data obtained from various tumor tissue studies. A team of clinical and basic science researchers, a biostatistician, and a bioinformatics expert was convened to design the database. Variables of interest were clearly defined and their descriptions were written within a standard operating manual to ensure consistency of data annotation. Using a protocol for prospective tissue banking and another protocol for retrospective banking, tumor and normal tissue samples from patients consented to these protocols were collected. Clinical information such as demographics, cancer characterization, and treatment plans for these patients were abstracted and entered into an Access database. Proteomic and genomic data have been included in the database and have been linked to clinical information for patients described within the database. The data from each table were linked using the relationships function in Microsoft Access to allow the database manager to connect clinical and laboratory information during a query. The queried data can then be exported for statistical analysis and hypothesis generation.

BRIDGE: an open-label phase II trial evaluating the safety of bevacizumab + carboplatin/paclitaxel as first-line treatment for patients with advanced, previously untreated, squamous non-small cell lung cancer.

BACKGROUND: Patients with predominantly squamous non-small cell lung cancer (NSCLC) have been generally excluded from studies of bevacizumab treatment, because squamous histology was identified as a possible risk factor for severe (grade ≥3) pulmonary hemorrhage (PH) in a phase II study. BRIDGE was designed to determine whether delaying initiation of bevacizumab treatment and selecting patients without baseline risk factors for PH would lower the incidence of severe PH among patients with squamous NSCLC. METHODS: Patients in this open-label, single-arm study were treated with carboplatin/paclitaxel for two cycles, followed by carboplatin/paclitaxel and bevacizumab in cycles 3 to 6, followed by bevacizumab until progression or unacceptable toxicity. Eligible patients had stage IIIb, stage IV, or recurrent squamous NSCLC. The primary end point was incidence of grade ≥3 PH. RESULTS: Grade ≥3 PH occurred in 1 of 31 patients who received ≥1 dose of bevacizumab: estimated incidence was 3.2% (90% confidence interval 0.3-13.5%). The patient experienced grade 3 PH, discontinued from the study, then experienced grade 4 PH 10 days later, and died of progressive disease. No other serious bleeding events occurred. Nine patients (29.0%) experienced grade 3 adverse events, including five with hypertension; five patients experienced grade 4 adverse events (dyspnea, PH, basal ganglia infarction, cerebral ischemia, and pain). Median progression-free survival was 6.2 months (95% confidence interval 5.32-7.62 months). CONCLUSIONS: The incidence of grade ≥3 PH was 3.2% (one patient). No new safety signals were identified. Although the rate of PH was low, the number of patients in this study was also low. Treatment of squamous NSCLC with bevacizumab should be considered experimental.

EphA2 mutation in lung squamous cell carcinoma promotes increased cell survival, cell invasion, focal adhesions, and mammalian target of rapamycin activation.

Non-small cell lung cancer (NSCLC) has a poor prognosis and improved therapies are needed. Expression of EphA2 is increased in NSCLC metastases. In this study, we investigated EphA2 mutations in NSCLC and examined molecular pathways involved in NSCLC. Tumor and cell line DNA was sequenced. One EphA2 mutation was modeled by expression in BEAS2B cells, and functional and biochemical studies were conducted. A G391R mutation was detected in H2170 and 2/28 squamous cell carcinoma patient samples. EphA2 G391R caused constitutive activation of EphA2 with increased phosphorylation of Src, cortactin, and p130(Cas). Wild-type (WT) and G391R cells had 20 and 40% increased invasiveness; this was attenuated with knockdown of Src, cortactin, or p130(Cas). WT and G391R cells demonstrated a 70% increase in focal adhesion area. Mammalian target of rapamycin (mTOR) phosphorylation was increased in G391R cells with increased survival (55%) compared with WT (30%) and had increased sensitivity to rapamycin. A recurrent EphA2 mutation is present in lung squamous cell carcinoma and increases tumor invasion and survival through activation of focal adhesions and actin cytoskeletal regulatory proteins as well as mTOR. Further study of EphA2 as a therapeutic target is warranted.

MET/PKCbeta expression correlate with metastasis and inhibition is synergistic in lung cancer.

BACKGROUND: Treatment of non-small cell lung cancer (NSCLC) remains a difficult task in oncology. Targeted inhibition of oncogenic proteins is promising. In this study, we evaluate the expression of MET and PKCbeta and in vitro effects of their inhibition using SU11274 and enzastaurin (LY317615.HCl) respectively. MATERIALS AND METHODS: Patient samples were analyzed by immunohistochemistry for expression of PKCbeta and MET, utilizing tissue microarrays under an IRB-approved protocol. Expression of PKCbeta and MET was evaluated in cell lines by immunoblotting. Treatment with SU1174 against MET and enzastaurin against PKCbeta was performed in H1993 and H358 cell lines, and cell proliferation and downstream signaling (phosphorylation of MET, AKT, FAK, and GSK3beta) were evaluated by immunoblotting. Statistical analysis was performed using SPSS 16.0. RESULTS: Expression of MET positively correlated with lymph node metastases (p=.0004), whereas PKCbeta showed no correlation (p=0.204). MET and PKCbeta expression were also strongly correlated (p<0.001). Expression of MET was observed in 5/8 cell lines (H358, H1703, A549, H1993, H2170; absent from H522, H661, or SW1573), whereas PKCbeta expression was observed in 8/8 cell lines. Cell proliferation was significantly impaired by treatment with SU11274 and enzastaurin, and their effects were synergistic in combination (CI=0.32 and 0.09). Phosphorylation of MET, FAK, AKT, and GSK3beta were strongly inhibited with both agents in combination. CONCLUSIONS: Concomitant inhibition of MET and PKCbeta significantly increased cytotoxicity in vitro against NSCLC, disrupting important downstream signaling pathways. Further evaluation in animal models is warranted.

The MET receptor tyrosine kinase is a potential novel therapeutic target for head and neck squamous cell carcinoma.

Recurrent/metastatic head and neck cancer remains a devastating disease with insufficient treatment options. We investigated the MET receptor tyrosine kinase as a novel target for the treatment of head and neck squamous cell carcinoma (HNSCC). MET/phosphorylated MET and HGF expression was analyzed in 121 tissues (HNSCC/normal) by immunohistochemistry, and in 20 HNSCC cell lines by immunoblotting. The effects of MET inhibition using small interfering RNA/two small-molecule inhibitors (SU11274/PF-2341066) on signaling, migration, viability, and angiogenesis were determined. The complete MET gene was sequenced in 66 head and neck cancer tissue samples and eight cell lines. MET gene copy number was determined in 14 cell lines and 23 tumor tissues. Drug combinations of SU11274 with cisplatin or erlotinib were tested in SCC35/HN5 cell lines. Eighty-four percent of the HNSCC samples showed MET overexpression, whereas 18 of 20 HNSCC cell lines (90%) expressed MET. HGF overexpression was present in 45% of HNSCC. MET inhibition with SU11274/PF-2341066 abrogated MET signaling, cell viability, motility/migration in vitro, and tumor angiogenesis in vivo. Mutational analysis of 66 tumor tissues and 8 cell lines identified novel mutations in the semaphorin (T230M/E168D/N375S), juxtamembrane (T1010I/R988C), and tyrosine kinase (T1275I/V1333I) domains (incidence: 13.5%). Increased MET gene copy number was present with >10 copies in 3 of 23 (13%) tumor tissues. A greater-than-additive inhibition of cell growth was observed when combining a MET inhibitor with cisplatin or erlotinib and synergy may be mediated via erbB3/AKT signaling. MET is functionally important in HNSCC with prominent overexpression, increased gene copy number, and mutations. MET inhibition abrogated MET functions, including proliferation, migration/motility, and angiogenesis. MET is a promising, novel target for HNSCC and combination approaches with cisplatin or EGFR inhibitors should be explored.

PAX5 is expressed in small-cell lung cancer and positively regulates c-Met transcription.

PAX5 is a nuclear transcription factor required for B cell development, and its expression was evaluated in upper aerodigestive malignancies and pancreatic cancer by immunoblotting. The PAX5 protein expression was relatively strong in small-cell lung cancer (SCLC, 11/12); however, its expression was not detected in non-SCLC (NSCLC, n=13), mesothelioma (n=7), pancreatic (n=6), esophageal (n=6) and head and neck cancer cell lines (n=12). In comparison, PAX8 and PAX3 expressions were absent or non-detectable in SCLC cell lines; however, PAX8 was expressed in most of the tested NSCLC cell lines (13/13) and also frequently in all the other cell lines. We also detected frequent expressions of PAX2 and PAX9 protein in the various cell lines. Utilizing neuroendocrine tumor samples, we found that the frequency as well as the average intensity of the expression of PAX5 increased from pulmonary carcinoid (9%, moderate and strong PAX5 expression, n=44), to large-cell neuroendocrine carcinoma (LCNC, 27%, n=11) to SCLC (33%, n=76). FISH analysis revealed no translocations of the PAX5 gene, but polyploidy in some SCLC tumor tissues (6/37). We determined that PAX5 could regulate the transcription of c-Met using luciferase-coupled reporter and chromatin immunoprecipitation analysis. In addition, the phospho-c-Met (active form) and PAX5 were both localized to the same intra-nuclear compartment in hepatocyte growth factor treated SCLC cells and interacted with each other. Finally, we determined the therapeutic translational potential of PAX5 using PAX5 knockdown SCLC cells in conjunction with Topoisomerase 1 (SN38) and c-Met (SU11274) inhibitors. Loss of endogenous PAX5 significantly decreased the viability of SCLC cells, especially when combined with SN38 or SU11274, and maximum effect was seen when both inhibitors were used. Therefore, we propose that PAX5 could be an important regulator of c-Met transcription and a potential target for therapy in SCLC.

Lymphatic vessel density is not associated with lymph node metastasis in non-small cell lung carcinoma.

CONTEXT: Angiogenesis is essential for tumors to grow and metastasize. Lymphatic metastasis is also an important means of tumor spread. In non-small cell lung carcinoma, the relationship of lymphangiogenesis with lymph node metastasis and, ultimately, patient prognosis is unknown. OBJECTIVE: To evaluate whether lymphangiogenesis is related to lymph node metastasis and/or overall survival. DESIGN: Seventy-eight cases of non-small cell lung carcinoma diagnosed from 1987 to 2004 were retrospectively analyzed for intratumoral, peritumoral, and uninvolved adjacent lung tissue lymphatic vessel density (LVD) by D2-40 immunostaining. Lymphatics in 6 cases of squamous dysplasia/carcinoma in situ were similarly evaluated. Appropriate statistical methods were used. RESULTS: Intratumoral and peritumoral LVD was significantly higher than in the uninvolved adjacent lung but showed no significant association with lymph node stage at the time of tumor resection. Survival in patients with above average D2-40 values was not significantly different when compared with those who had below average values (median survival, 895 vs 1131 days; P = .97). Furthermore, patients with affected lymph nodes had significantly shorter survival (median survival, 467 vs 1425 days; P = .002). Overall, regardless of lymph node status, there was a significantly higher intratumoral (P < .001) and peritumoral (P < .001) LVD when compared with the adjacent uninvolved lung LVD. There was a trend toward increasing LVD with higher grade of squamous dysplasia. CONCLUSIONS: The results suggest that although lymphangiogenesis occurs in association with non-small cell lung carcinoma, it may not be an important factor in lymph node metastasis. In fact, there is a suggestion that the number of lymphatics that a person inherently has appears to be more important than lymphangiogenesis when it comes to the development of lymph node metastasis.

Protein kinase C beta in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a disease with few therapeutic options. Protein kinase C beta (PKCbeta) is involved in important cellular functions. Enzastaurin (LY317615.HCl) is a novel inhibitor of PKC in clinical development. MPM cell lines (7) and patient tumor tissues (24) were evaluated for expression of PKCbeta by immunoblotting and immunohistochemistry, respectively. In-vitro cell growth assays were performed with enzastaurin with or without cisplatin. Cell migration was evaluated with the wound healing assay. Downstream signaling (survival and focal adhesion pathways) was studied by immunoblotting for related molecules in the presence of phorbol ester with or without enzastaurin. Expression for PKCbeta1 was seen in all cases, with a mean integrated optical density of 152.5 (standard deviation=95.47, n=24), whereas PKCbeta2 expression was less intense, with a mean integrated optical density of 11.45 (standard deviation=16.27, n=21). There was a trend toward lower overall survival among patients expressing above-median PKCbeta1 (P=0.064), but not PKCbeta2. Robust expression of PKCbeta1 and low expression of PKCbeta2 were observed in MPM cell lines. Treatment of MPM cell lines with enzastaurin revealed an IC50 of 5 micromol/l, and strong synergism was observed when combined with cisplatin. Wound healing assay revealed that treatment of H2461 cells with enzastaurin reduced migration by 59.2%. Enzastaurin treatment led to disruption of F-actin architecture. Downstream signaling showed reduced phosphorylation of AKT, FAK (focal adhesion kinase), p130Cas, S6 ribosomal protein, and paxillin. PKCbeta1 was expressed in the majority of MPM samples. Enzastaurin has preclinical activity against MPM, and exhibited synergism with cisplatin. PKCbeta inhibition in MPM might be able to reduce the invasiveness of MPM by affecting cytoskeletal function.

Efficacy and safety of bevacizumab plus erlotinib for patients with recurrent ovarian, primary peritoneal, and fallopian tube cancer: a trial of the Chicago, PMH, and California Phase II Consortia.

OBJECTIVES: The objectives of this phase II trial were to assess the activity and tolerability of the combination of bevacizumab and erlotinib in patients with recurrent ovarian, primary peritoneal or fallopian tube cancer. METHODS: This was a single arm, multicenter phase II trial with overall objective response as the primary endpoint. Eligible patients had two or fewer prior chemotherapy regimens for recurrent or refractory disease and no prior anti-VEGF or anti-EGFR agents. Bevacizumab, 15 mg/kg, was administered intravenously every 21 days and erlotinib, 150 mg orally, was given daily. RESULTS: Between July and October 2005, 13 patients were enrolled. There were two major objective responses, one complete response of 16+ month duration and one partial response of 11 month duration, for a response rate of 15% (95% CI 1.9% to 45.4%). Seven patients had a best response of stable disease. The most common grade 3 or 4 toxicities included anemia (n=1), nausea (n=2), vomiting (n=1), hypertension (n=1), and diarrhea (n=2). One patient with an ileostomy was removed from the study secondary to grade 3 diarrhea. Two patients had fatal gastrointestinal perforations. CONCLUSION: There was no strong suggestion that this combination was superior to single agent bevacizumab, and the rate of gastrointestinal perforation was of concern. The study was therefore stopped. Identification of risk factors for gastrointestinal perforation will be of importance for the use of bevacizumab in the treatment of ovarian cancer.

C. elegans as a model organism for in vivo screening in cancer: effects of human c-Met in lung cancer affect C. elegans vulva phenotypes.

Cancers typically harbour several mutant forms of key cellular genes that contribute to its complex phenotype. Our lab has previously identified gain-of-function mutations in some of the receptor tyrosine kinases such as c-Met in lung cancer. In order to investigate the mutant gene in the context of a whole organism, the current choice of in vivo model is limited to the mouse. To rapidly screen the functional aspects of mutant forms of c-Met detected in lung cancer, we used the nematode C. elegans as the model organism. Transgenic worms were generated that harbour wild type or the frequently seen mutant forms of c-Met in lung cancer (c-MetR988C and c-MetT1010I). Expression of the mutant human c-Met forms in C. elegans consistently resulted in significantly low fecundity and abnormal vulval development characterized by hyperplasia. Interestingly, exposure of c-Met mutant transgenic worms to nicotine resulted in enhanced abnormal vulval development, fecundity and locomotion. Our studies provide first evidence that human c-Met mutations can be studied in C. elegans, and that carcinogens can enhance mutant c-Met function expressed in C. elegans transgenic animals. We therefore propose the use of C. elegans as a model to rapidly assess the role of cancer specific gene mutations in the context of a whole organism.

Paxillin is a target for somatic mutations in lung cancer: implications for cell growth and invasion.

Lung cancer is characterized by abnormal cell growth and invasion, and the actin cytoskeleton plays a major role in these processes. The focal adhesion protein paxillin is a target of a number of oncogenes involved in key signal transduction and important in cell motility and migration. In lung cancer tissues, we have found that paxillin was highly expressed (compared with normal lung), amplified (12.1%, 8 of 66) and correlated with increased MET and epidermal growth factor receptor (EGFR) gene copy numbers, or mutated (somatic mutation rate of 9.4%, 18 of 191). Paxillin mutations (19 of 21) were clustered between LD motifs 1 and 2 and the LIM domains. The most frequent point mutation (A127T) enhanced lung cancer cell growth, colony formation, focal adhesion formation, and colocalized with Bcl-2 in vitro. Gene silencing from RNA interference of mutant paxillin led to reduction of cell viability. A murine in vivo xenograft model of A127T paxillin showed an increase in tumor growth, cell proliferation, and invasion. These results establish an important role for paxillin in lung cancer.