The categorical definition of response assessed via the Response Evaluation Criteria in Solid Tumors has documented limitations. We sought to identify alternative metrics for tumor response that improve prediction of overall survival.
Individual patient data from three North Central Cancer Treatment Group trials (N0026, n=117; N9741, n=1109; N9841, n=332) were used. Continuous metrics of tumor size based on longitudinal tumor measurements were considered in addition to a trichotomized response (TriTR: Response vs. Stable vs. Progression). Cox proportional hazards models, adjusted for treatment arm and baseline tumor burden, were used to assess the impact of the metrics on subsequent overall survival, using a landmark analysis approach at 12-, 16- and 24-weeks post baseline. Model discrimination was evaluated using the concordance (c) index.
The overall best response rates for the three trials were 26%, 45%, and 25% respectively. While nearly all metrics were statistically significantly associated with overall survival at the different landmark time points, the c-indices for the traditional response metrics ranged from 0.59-0.65; for the continuous metrics from 0.60-0.66 and for the TriTR metrics from 0.64-0.69. The c-indices for TriTR at 12-weeks were comparable to those at 16- and 24-weeks.
Continuous tumor-measurement-based metrics provided no predictive improvement over traditional response based metrics or TriTR; TriTR had better predictive ability than best TriTR or confirmed response. If confirmed, TriTR represents a promising endpoint for future Phase II trials.
continuous; tumor measurement; RECIST; prediction; survival
Non-Hodgkin lymphoma (NHL) represents a heterogenous group of neoplasias originating from lymphoid cells. Increased angiogenesis and expression of Vascular Endothelial Growth Factor (VEGF) and its receptors (VEGFR) have been found to be associated with NHL disease progression. Increase in VEGF and other cytokines stimulate signaling cascades, including the Ras/Raf/Mek/Erk pathway, resulting in increased proliferation and decreased apoptosis. Here, we report the in vitro antilymphoma activity of sorafenib, an inhibitor of VEGFR and Raf kinase. Sorafenib induced potent cytotoxicity in NHL cell lines and patient samples. This induction of cytotoxicity was associated with a corresponding increase in apoptotic cell death. Mechanism of action of sorafenib was investigated in follicular (DoHH2) and Burkitt lymphoma (Raji) cell lines. pStat3, pAkt, Mcl1, and Xiap were downregulated in both cell lines, whereas pErk decreased in Raji but not in DoHH2 cells following sorafenib treatment. IL6 was unable to prevent sorafenib induced repression of pStat3, pAkt, Mcl1, and Bcl-Xl. Sorafenib in combination with an mTORC1 inhibitor rapamycin demonstrated synergy in inducing cytotoxicity in NHL cells. Sorafenib/rapamycin combination resulted in downregulation of pAkt, pmTOR, p-p70S6K, p4EBP1, pGSK3β, Mcl1, and Bcl-Xl. On the basis of our results, a clinical trial is underway using sorafenib with everolimus in NHL patients.
Expression of the receptor tyrosine kinase c-MET in many cancers, and its participation in multiple signal transduction pathways involved in malignant tumor growth, suggest a wide therapeutic potential for MET inhibition in human cancer. Here we describe the discovery and early clinical development of ARQ 197, a novel, selective, non–ATP-competitive inhibitor of MET. Data from ARQ 197 clinical trials in hepatocellular, germ-cell, pancreatic (in combination with gemcitabine), and colorectal (in combination with cetuximab and irinotecan) cancers further highlight the potential role of ARQ 197 in existing and emerging anticancer therapeutic regimens.
Expression of the receptor tyrosine kinase c-MET (MET, mesenchymal-epithelial transition factor) in many cancers, and its participation in multiple signal transduction pathways involved in malignant tumor growth, suggest a wide therapeutic potential for MET inhibition in human cancer. Here we describe the discovery and early clinical development of ARQ 197, a novel, selective, non–ATP-competitive inhibitor of MET. Phase I studies demonstrate that ARQ 197 has a predictable pharmacokinetics and favorable safety profile, making it a potentially ideal partner for combination with cytotoxic chemotherapies and targeted anticancer agents. Results from phase I and phase II trials demonstrate preliminary evidence of anticancer activity. New data from a global phase II randomized trial comparing a combination of ARQ 197 plus erlotinib with erlotinib/placebo, in endothelial growth factor receptor inhibitor-naïve patients with locally advanced/metastatic non–small cell lung cancer, demonstrate improvement in progression-free and overall survival with combined therapy. Results were especially pronounced for patients with non–squamous lung cancer histologies, and in particular molecularly defined subgroups including KRAS mutations. These and other data from ARQ 197 clinical trials in hepatocellular, germ-cell, pancreatic (in combination with gemcitabine), and colorectal (in combination with cetuximab and irinotecan) cancers further highlight the potential role of ARQ 197 in existing and emerging anticancer therapeutic regimens.
c-MET; EGFR; Epithelial growth factor inhibitor; Kinase receptor inhibitor; Hepatocyte growth factor
This phase I/II study evaluated the safety and anti-tumor effect of the combination of erlotinib with cixutumumab, a recombinant fully humanized anti-insulin-like growth factor-1 receptor IgG1 monoclonal antibody, in advanced non-small cell lung cancer (NSCLC).
Patients with advanced NSCLC were treated in an initial safety-lead and drop-down cohorts using erlotinib 150 mg/d with cixutumumab 6 or 5 mg/kg on days 1, 8, 15, and 22 in 28-day cycles (cohorts 1 and 2). Emerging pharmacokinetic data led to an additional cohort (3 + 3 design) with cixutumumab at 15 mg/kg on day 1 in 21-day cycles (cohort 3).
Eighteen patients entered the study (6 at 6 mg/kg, 8 at 5 mg/kg, and 4 at 15 mg/kg), with median age of 65 years. Four of six patients at 6 mg/kg experienced dose-limiting toxicities (DLTs), whereas at 5 mg/kg, one of eight patients experienced DLT but three of eight patients still required a dose delay during cycle 1. At 15 mg/kg every 21 days, two of four patients experienced DLTs. In all cohorts, DLTs were either G3 rash or fatigue. Five patients had stable disease as best response and 14 patients had progressive disease. The median progression-free survival was 39 days (range 21–432+ days). Biomarkers analyses showed a trend toward better progression-free survival seen with higher free baseline insulin-like growth factor-1 levels as seen with other insulin-like growth factor-1R inhibitors.
The combinations of cixutumumab at 6 mg/kg every 7 days and 15 mg/kg every 21 days and full-dose erlotinib are not tolerable in unselected patients with NSCLC, as measured by DLT. Cixutumumab at 5 mg/kg every 7 days was tolerable per DLT, but dose delays were common. Efficacy in unselected patients with NSCLC seems to be low.
Non-small cell lung cancer; IGF1R monoclonal antibody; EGFR; Metastatic disease
We investigated the putative surrogate endpoints (PSEs) of best response (BR), complete response (CR), confirmed response (CoR), and progression-free survival (PFS) for associations with Overall Survival (OS), and as possible surrogate endpoints for OS.
Individual patient (pt) data from 870 untreated ES-SCLC pts participating in 6 single-arm (274 pts) and 3 randomized trials (596 pts) were pooled. Patient-level associations between PSEs and OS were assessed by Cox models using landmark analyses. Trial-level surrogacy of PSEs assessed by the association of treatment effects on OS and individual PSEs. Trial-level surrogacy measures included: R2 from weighted least squares regression model (WLS R2), Spearman's correlation coefficient, and R2 from bivariate survival model (Copula R2).
Median OS and PFS were 9.6 (95% CI: 9.1-10.0) and 5.5 (95% CI: 5.2-5.9) months, respectively; BR, CR, and CoR rates were 44%, 22%, and 34%, respectively. Patient-level associations showed that PFS status at 4 months was a strong predictor of subsequent survival (HR=0.42 (95% CI: 0.35-0.51); concordance index=0.63; p<0.01), with 6-month PFS being the strongest (HR=0.41 (95% CI: 0.35-0.49); concordance index=0.66; p<0.01). At the trial-level, PFS showed the highest level of surrogacy for OS (WLS R2=0.79; Copula R2=0.80), explaining 79% of the variance in OS. Tumor response endpoints showed lower surrogacy levels (WLS R2≤0.48).
PFS was strongly associated with OS at both the patient and trial-level. PFS also shows promise as a potential surrogate for OS, but further validation is needed using data from a larger number of randomized phase III trials.
extensive-stage small cell lung cancer; surrogate endpoints; pooled analysis; progression-free survival; tumor response
BACKGROUND & AIMS
Heparan sulfate proteoglycans (HSPGs) act as co-receptors or storage sites for growth factors and cytokines such as FGF and Wnts. Glypican 3 (GPC3) is the most highly expressed HSPG in hepatocellular carcinomas (HCCs). Sulfatase 2 (SULF2), an enzyme with 6-O desulfatase activity on HSPGs, is upregulated in 60% of primary HCCs and associated with a worse prognosis. We have previously shown that the oncogenic effect of SULF2 in HCC may be mediated in part through up-regulation of GPC3. Here we demonstrate that GPC3 stimulates the Wnt/β-catenin pathway and mediates SULF2 oncogenic function in HCC.
Wnt signaling in vitro and in vivo was assessed in SULF2-negative Hep3B HCC cells transfected with SULF2 and SULF2-expressing Huh7 cells transfected with shRNA targeting SULF2. The interaction between GPC3, SULF2, and Wnt3a was assessed by co-immunoprecipitation and flow cytometry. β-catenin-dependent transcriptional activity was assessed by the TOPFLASH luciferase assay.
In HCC cells, SULF2 increased cell surface GPC3 and Wnt3a expression, stabilized β-catenin, and activated TCF transcription factor activity and expression of the Wnt/β-catenin target gene cyclin D1. Opposite effects were observed in SULF2-knockdown models. In vivo, nude mouse xenografts established from SULF2-transfected Hep3B cells showed enhanced GPC3, Wnt3a and β-catenin levels.
Together, these findings identified a novel mechanism mediating the oncogenic function of SULF2 in HCC including GPC3-mediated activation of Wnt signaling via the Wnt3a/GSK3β axis.
SULF2; heparan sulfate proteoglycan (HSPG); heparan sulfate glycosaminoglycan (HSGAG); glypican 3 (GPC3); Wnt signaling pathway; beta catenin; hepatocellular carcinoma; oncogene
The c-MET (mesenchymal–epithelial transition factor) pathway is dysregulated in many human cancers and promotes tumor growth, invasion and dissemination. The c-MET receptor tyrosine kinase can be activated via gene mutation, gene amplification, protein overexpression and/or a ligand-dependent autocrine/paracrine loop. Abnormalities in c-MET signaling have been reported to correlate with poor clinical outcomes and drug resistance in patients with cancer. Significant progress has been made in advancement of c-MET pathway inhibitors through to clinical trials. A robust pipeline of high-quality inhibitors targeting different aspects of c-MET activation is currently being explored in phase I, II and III clinical trials across multiple tumor types. Preliminary data demonstrate promising clinical activity with these agents, along with an acceptable toxicity profile. In this manuscript, the pharmacological profile of drugs targeting the c-MET pathway and available data from ongoing clinical trials of these drugs are discussed.
cabozantinib; c-MET; foretinib; MetMAb; tivantinib
Sulfatase 2 (SULF2), an extracellular heparan sulphate 6-O-endosulphatase, has an oncogenic effect in hepatocellular carcinoma (HCC) that is partially mediated through glypican 3, which promotes heparin-binding growth factor signalling and HCC cell growth. SULF2 also increases phosphorylation of the anti-apoptotic Akt kinase substrate GSK3β and SULF2 expression is associated with a decreased apoptotic index in human HCCs.
We investigated the functional and mechanistic effects of SULF2 on drug-induced apoptosis of HCC cells using immunohistochemistry, Western immunoblotting, gene transfection, real-time quantitative polymerase chain reaction, MTT and apoptosis assays and immunocytochemistry.
The increased expression of SULF2 in human HCCs was confirmed by immunohistochemistry and immunoblotting. Treatment with inhibitors of MEK, JNK and PI3 kinases decreased the viability of SULF2-negative Hep3B HCC cells and induced apoptotic caspase 3 and 7 activity, which was most strongly induced by the PI3K inhibitor LY294002. Forced expression of SULF2 in Hep3B cells significantly decreased activity of the apoptotic caspases 3 and 7 and induced resistance to LY294002-induced apoptosis. As expected, LY294002 inhibited activation of Akt kinase by PI3K. Conversely, knockdown of SULF2 using an shRNA construct targeting the SULF2 mRNA induced profound cell growth arrest and sensitized the endogenously SULF2-expressing HCC cell lines Huh7 and SNU182 to drug-induced apoptosis. The effects of knockdown of SULF2 on HCC cells were mediated by decreased Akt phosphorylation, downregulation of cyclin D1 and the anti-apoptotic molecule Bcl-2, and upregulation of the pro-apoptotic molecule BAD.
The prosurvival, anti-apoptotic effect of SULF2 in HCC is mediated through activation of the PI3K/Akt pathway.
Akt pathway; apoptosis; caspase; heparan sulphate glycosaminoglycan (HSGAG); heparan sulphate proteoglycan (HSPG); oncogene; SULF2
To evaluate the efficacy and toxicity of pemetrexed combined with bevacizumab as second-line therapy for patients with advanced non–small-cell lung cancer (NSCLC) and to correlate allelic variants in pemetrexed-metabolizing genes with clinical outcome.
Patients and Methods
Patients with previously treated NSCLC received pemetrexed (500 mg/m2 intravenous) combined with bevacizumab (15 mg/kg intravenous) every 3 weeks. The primary end point, evaluated using a one-stage Fleming design for detecting a true success rate of at least 70%, was the proportion of patients who were progression free and on treatment at 3 months. Polymorphisms in genes responsible for pemetrexed transport (reduced folate carrier [SLC19A1]) and metabolism (folylpolyglutamate synthase [FPGS] and gamma-glutamyl hydrolase [GGH]) evaluated in germline DNA (blood) were correlated with treatment outcome.
Forty-eight evaluable patients (14 females and 34 males) received a median of four cycles (range, one to 20 cycles). The most common grade 3 or 4 nonhematologic adverse events (AEs) were fatigue (13%), dyspnea (10%), and thrombosis (10%). Grade 3 or 4 hematologic AEs were neutropenia (19%) and lymphopenia (13%). Twenty-four (57%; 95% CI, 41% to 72%) of the first 42 patients met the success criteria. Median overall survival (OS) and progression-free survival (PFS) times were 8.6 and 4.0 months, respectively. The exon 6 (2522)C→T polymorphism in SLC19A1 correlated with 3-month progression-free status (P = .01) and with PFS (P = .05). The IVS1(1307)C→T polymorphism in GGH correlated with OS (P = .04).
The study did not meet its primary end point. However, the median PFS time of 4 months is promising. Pharmacogenetic studies in larger cohorts are needed to definitively identify polymorphisms that predict for survival and toxicity of pemetrexed.
We investigated the relationships between progression-free survival (PFS), response, confirmed response, and failure-free survival (FFS) with overall survival (OS) to assess their suitability as primary endpoints in phase II (P2) trials for advanced NSCLC.
Individual data of 284 patients from 4 P2 trials were pooled. Progression status and response were modeled as time dependent variables in a multivariable (adjusted for baseline age, gender, stage, and performance status) Cox proportional hazards (PH) model for OS, stratified by trial. Subsequently, Cox PH models were used to assess the impact of PFS, response, confirmed response and FFS on subsequent survival, using landmark analysis at 8, 12, 16, 20, and 24 weeks. Model discrimination was evaluated using the concordance (c) index.
The overall median OS, PFS and FFS were 9.6, 3.7 and 2.8 months, and the response and confirmed response rates were 21% and 15% respectively. Both progression status and response as time dependent covariates were significantly associated with OS (p<0.0001; p=0.009). PFS and FFS at 12 weeks significantly predicted for subsequent survival with the strongest c-index and hazard ratio (HR) combination in landmark analyses (HR, c-index: PFS - 0.39, 0.67; FFS - 0.37, 0.67). The c-indices for response and confirmed response were low (0.59-0.60), indicating their inability to sufficiently discriminate subsequent patient survival outcomes.
Failure-free survival or progression-free survival at 12 weeks is a stronger predictor of subsequent patient survival compared to tumor response, and should be routinely used as endpoints in phase II trials for advanced NSCLC.
advanced NSCLC; endpoints; failure-free survival; progression-free survival; tumor response
We evaluated the role of glutathione-related genotypes on overall survival, time to progression, adverse events, and quality of life (QOL) in stage IIIB/IV non-small cell lung cancer patients who were stable or responding from initial treatment with platinum-based chemotherapy and subsequently randomized to receive daily oral carboxyaminoimidazole or a placebo.
Of the 186 total patients, 113 had initial treatment with platinum therapy and DNA samples of whom 46 also had QOL data. These samples were analyzed using six polymorphic DNA markers that encode five important enzymes in the glutathione metabolic pathway. Patient QOL was assessed using the Functional Assessment of Cancer Therapy-Lung and the UNISCALE QOL questionnaires. A clinically significant decline in QOL was defined as a 10% decrease from baseline to week-8. Multivariate analyses were used to evaluate the association of the genotypes on the four endpoints.
Patients carrying a GCLC 77 genotype had a worse overall survival (hazard ratio (HR) = 1.5, p = 0.05). Patients carrying the GPX1-CC genotype had a clinically significant decline in the UNISCALE (odds ratio (OR): 7.5; p = 0.04), total Functional Assessment of Cancer Therapy-Lung score (OR: 11.0; p = 0.04), physical (OR: 7.1; p = 0.03), functional (OR: 5.2; p = 0.04), and emotional well-being constructs (OR: 23.8; p = 0.01).
Genotypes of glutathione-related enzymes, especially GCLC, may be used as host factors in predicting patients' survival after platinum-based chemotherapy. GPX1 may be an inherited factor in predicting patients' QOL. Further investigation to define and measure the effects of these genes in chemotherapeutic regimens, drug toxicities, disease progression, and QOL are critical.
Gluthathione metabolic genes; Non small cell lung cancer; Platinum-based chemotherapy
We conducted this pooled analysis to assess the prognostic value of pretreatment Quality of Life (QOL) assessments on overall survival (OS) in advanced non-small cell lung cancer (NSCLC).
Four hundred twenty patients with advanced NSCLC (stages IIIB with pleural effusion and IV) from six North Central Cancer Treatment Group trials were included in this study. QOL assessments included the single-item Uniscale (355 patients), Lung Cancer Symptom Scale (217 patients), and Functional Assessment of Cancer Therapy-Lung (197 patients). QOL scores were transformed to a 0 to 100 scale with higher scores representing better status and categorized using the sample median or clinically deficient score (CDS, ≤50 versus >50). Cox proportional hazards models stratified by study were used to evaluate the prognostic importance of QOL on OS alone and in the presence of other prognostic factors such as performance status, age, gender, body mass index, and laboratory parameters.
Pretreatment QOL accessed by Uniscale was significantly associated with OS univariately (p < 0.0001). Uniscale (p < 0.0001; hazard ratio = 1.6 for the sample median and 2.0 for the CDS categorization) and body mass index were the only significant predictors of OS multivariately. The median survival of patients who had a Uniscale score less than or equal to the CDS (≤50) was 5.7 versus 11.1 months for the >50 group; and 7.8 versus 13 months for the less than or equal to sample median (≤83) group and >83 group, respectively. The Lung Cancer Symptom Scale and the Functional Assessment of Cancer Therapy-Lung total scores were not significant predictors of OS.
Pretreatment QOL measured by Uniscale is a significant and an independent prognostic factor for OS, and QOL should be routinely integrated as a stratification factor in advanced NSCLC trials.
Non-small cell; QOL; Survival
An analysis of 14 Small Cell Lung Cancer (SCLC) trials was performed to improve our understanding of potential prognostic factors for overall survival (OS) and progression-free survival (PFS) in limited-stage (LD-SCLC) and extensive disease (ED-SCLC) groups separately.
Data on 688 pts with LD-SCLC and 910 pts with ED-SCLC disease were included. Clinical and laboratory factors were tested for prognostic significance using Cox regression models, stratified by protocol. A recursive partitioning and amalgamation (RPA) analyses was used for identification of prognostic subgroups.
Poorer PS led to worse OS and PFS within ED-SCLC, but not within LD-SCLC. The prognostic impact of PS was strong in males, but weak in females within ED-SCLC (interaction p-value < 0.012 for OS, PFS). Other negative prognostic factors included increased age and male sex for LD-SCLC, and increased age, male sex, increased number of metastatic sites at baseline, and increased creatinine levels for ED-SCLC. For ED-SCLC patients, the RPA analyses identified 5 subgroups with different prognosis: based on baseline PS, creatinine levels, sex, and number of metastatic sites.
This pooled analysis identified baseline creatinine levels and the number of metastatic sites as important prognostic factors within ED-SCLC, in addition to the well established factors of sex, age, and PS. There was a significant interaction between sex and PS within ED-SCLC, suggesting that PS is highly prognostic in males, with no significant impact in females. Within LD-SCLC, only age and sex were important prognostic factors. The RPA analyses confirmed many of these findings.
Multivariate Modeling; SCLC; Pooled Analysis; Prognostic Factors
The incorporation of biomarkers into the drug development process will improve understanding of how new therapeutics work and allow for more accurate identification of patients who will benefit from those therapies. Strategically planned biomarker evaluations in phase II studies may allow for the design of more efficient phase III trials and better screening of therapeutics for entry into phase III development, hopefully leading to increased chances of positive phase III trial results. Some examples of roles that a biomarker can play in a phase II trial include predictor of response or resistance to specific therapies, patient enrichment, correlative endpoint, or surrogate endpoint. Considerations for using biomarkers most effectively in these roles are discussed in the context of several examples. The substantial technical, logistic, and ethical challenges that can be faced when trying to incorporate biomarkers into phase II trials are also addressed. A rational and coordinated approach to the inclusion of biomarker studies throughout the drug development process will be the key to attaining the goal of personalized medicine.
Topotecan resistance can result from drug efflux by P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) as well as survival signals initiated by epidermal growth factor receptor family members. The present studies were done to determine the effect of combining topotecan and the dual epidermal growth factor receptor/HER2 inhibitor lapatinib in tissue culture, a murine xenograft model, and a phase I clinical trial.
The effects of lapatinib on topotecan accumulation and cytotoxicity in vitro were examined in paired cell lines lacking or expressing Pgp or BCRP. Antiproliferative effects of the combination were assessed in mice bearing HER2+ BT474 breast cancer xenografts. Based on tolerability in this preclinical model, 37 patients with advanced-stage cancers received escalating doses of lapatinib and topotecan in a phase I trial.
Lapatinib increased topotecan accumulation in BCRP- or Pgp-expressing cells in vitro, and the combination showed enhanced efficacy in HER2+ BT474 xenografts. In the phase I study, nausea, vomiting, diarrhea, and fatigue were dose limiting. The maximum tolerated doses were 1,250 mg/d lapatinib by mouth for 21or 28 days with 3.2 mg/m2 topotecan i.v. on days1, 8, and 15 of 28-day cycles. Pharmacokinetic analyses showed that combined drug administration resulted in decreased topotecan clearance consistent with transporter-mediated interactions. Seventeen (46%) patients had disease stabilization.
The lapatinib/topotecan combination is well tolerated and warrants further study.
Metaplastic breast carcinoma, a rare tumor composed of adenocarcinomatous and nonglandular growth patterns, is characterized by a propensity for distant metastases and resistance to standard anticancer therapies. We sought confirmation that this tumor is a basal-like breast cancer, expressing epidermal growth factor receptor (EGFR) and stem cell factor receptor (KIT). EGFR activating mutations and high copy number (associated with response to tyro-sine kinase inhibitor gefitinib) and KIT activating mutations (associated with imatinib sensitivity) were then investigated. Seventy-seven metaplastic cases were identified (1976-2006); 38 with tumor blocks available underwent pathologic confirmation before EGFR and KIT immunohistochemical analyses. A tissue microarray of malignant glandular and metaplastic elements was constructed and analyzed immunohistochemically for cytokeratin 5/6, estrogen receptor, progesterone receptor, and p63, and by fluorescence in situ hybridization for EGFR and HER-2/neu. DNA isolated from individual elements was assessed for EGFR and KIT activating mutations. All assessable cases were negative for estrogen receptor, progesterone receptor, and (except one) HER2. The majority were positive for cytokeratin 5/6 (58%), p63 (59%), and EGFR overexpression (66%); 24% were KIT positive. No EGFR or KIT activating mutations were present; 26% of the primary metaplastic breast carcinomas were fluorescence in situ hybridization-positive, displaying high EGFR copy number secondary to aneusomy (22%) and amplification (4%). We report here that metaplastic breast carcinoma is a basal-like breast cancer lacking EGFR and KIT activating mutations but exhibiting high EGFR copy number (primarily via aneusomy), suggesting that EGFR tyrosine kinase inhibitors should be evaluated in this molecular subset of breast carcinomas.
To assess the tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of the mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor AZD6244 (ARRY-142886) in patients with advanced cancer.
Patients and Methods
In part A, patients received escalating doses to determine the maximum-tolerated dose (MTD). In both parts, blood samples were collected to assess PK and PD parameters. In part B, patients were stratified by cancer type (melanoma v other) and randomly assigned to receive the MTD or 50% MTD. Biopsies were collected to determine inhibition of ERK phosphorylation, Ki-67 expression, and BRAF, KRAS, and NRAS mutations.
Fifty-seven patients were enrolled. MTD in part A was 200 mg bid, but this dose was discontinued in part B because of toxicity. The 50% MTD (100 mg bid) was well tolerated. Rash was the most frequent and dose-limiting toxicity. Most other adverse events were grade 1 or 2. The PKs were less than dose proportional, with a median half-life of approximately 8 hours and inhibition of ERK phosphorylation in peripheral-blood mononuclear cells at all dose levels. Paired tumor biopsies demonstrated reduced ERK phosphorylation (geometric mean, 79%). Five of 20 patients demonstrated ≥ 50% inhibition of Ki-67 expression, and RAF or RAS mutations were detected in 10 of 26 assessable tumor samples. Nine patients had stable disease (SD) for ≥ 5 months, including two patients with SD for 19 (thyroid cancer) and 22 (uveal melanoma plus renal cancer) 28-day cycles.
AZD6244 was well tolerated with target inhibition demonstrated at the recommended phase II dose. PK analyses supported twice-daily dosing. Prolonged SD was seen in a variety of advanced cancers. Phase II studies are ongoing.
Lung cancer is the leading cause of cancer-related mortality not only in the United States but also around the world. In North America, lung cancer has become more predominant among former than current smokers. Yet in some countries, such as China, which has experienced a dramatic increase in the cigarette smoking rate during the past 2 decades, a peak in lung cancer incidence is still expected. Approximately two-thirds of adult Chinese men are smokers, representing one-third of all smokers worldwide. Non–small cell lung cancer accounts for 85% of all lung cancer cases in the United States. After the initial diagnosis, accurate staging of non–small cell lung cancer using computed tomography or positron emission tomography is crucial for determining appropriate therapy. When feasible, surgical resection remains the single most consistent and successful option for cure. However, close to 70% of patients with lung cancer present with locally advanced or metastatic disease at the time of diagnosis. Chemotherapy is beneficial for patients with metastatic disease, and the administration of concurrent chemotherapy and radiation is indicated for stage III lung cancer. The introduction of angiogenesis, epidermal growth factor receptor inhibitors, and other new anticancer agents is changing the present and future of this disease and will certainly increase the number of lung cancer survivors. We identified studies for this review by searching the MEDLINE and PubMed databases for English-language articles published from January 1, 1980, through January 31, 2008. Key terms used for this search included non–small cell lung cancer, adenocarcinoma, squamous cell carcinoma, bronchioalveolar cell carcinoma, large cell carcinoma, lung cancer epidemiology, genetics, survivorship, surgery, radiation therapy, chemotherapy, targeted therapy, bevacizumab, erlotinib, and epidermal growth factor receptor.
The effects of combining histone deacetylase (HDAC) inhibitors and proteasome inhibitors were evaluated in both established glioblastoma multiforme (GBM) cell lines and short-term cultures derived from the Mayo Clinic xenograft GBM panel. Coexposure of LBH589 and bortezomib at minimally toxic doses of either drug alone resulted in a striking induction of apoptosis in established U251, U87, and D37 GBM cell lines, as well as in GBM8, GBM10, GBM12, GBM14, and GBM56 short-term cultured cell lines. Synergism of apoptosis induction was also observed in U251 cells when coexposing cells to other HDAC inhibitors, including LAQ824 and trichostatin A, with the proteasome inhibitor MG132, thus demonstrating a class effect. In U251 cells, bortezomib alone or in combination with LBH589 decreased Raf-1 levels and suppressed Akt and Erk activation. LBH589 or bortezomib alone increased expression of the cell cycle regulators p21 and p27. Additionally, the combination, but not the individual agents, markedly enhanced JNK activation. Synergistic induction of apoptosis after exposure to LBH589 and bortezomib was partially mediated by Bax translocation from the cytosol to the mitochondria resulting from Bax conformational changes. Bax translocation precedes cytochrome c release and apoptosis, and selective down-regulation of Bax using siRNA significantly mitigates the cytotoxicity of LBH589 and bortezomib. This combination regimen warrants further preclinical and possible clinical study for glioma patients.
apoptosis; Bax; bortezomib (PS-341); glioma; LBH589
It has been shown that the heparin-degrading endosulfatase, sulfatase 1 (SULF1), functions as a liver tumor suppressor, but the role of the related sulfatase, sulfatase 2 (SULF2), in liver carcinogenesis remains to be elucidated. We investigated the effect of SULF2 on liver tumorigenesis. Expression of SULF2 was increased in 79 (57%) of 139 hepatocellular carcinomas (HCCs) and 8 (73%) of 11 HCC cell lines. Forced expression of SULF2 increased HCC cell growth and migration, whereas knockdown of SULF2 using short hairpin RNA targeting SULF2 abrogated HCC cell proliferation and migration in vitro. Because SULF1 and SULF2 desulfate heparan sulfate proteoglycans (HSPGs) and the HSPG glypican 3 (GPC3) is up-regulated in HCC, we investigated the effects of SULF2 on GPC3 expression and the association of SULF2 with GPC3. SULF2-mediated cell growth was associated with increased binding of fibroblast growth factor 2 (FGF2), phosphorylation of extracellular signal-regulated kinase and AKT, and expression of GPC3. Knockdown of GPC3 attenuated FGF2 binding in SULF2-expressing HCC cells. The effects of SULF2 on up-regulation of GPC3 and tumor growth were confirmed in nude mouse xenografts. Moreover, HCC patients with increased SULF2 expression in resected HCC tissues had a worse prognosis and a higher rate of recurrence after surgery.
In contrast to the tumor suppressor effect of SULF1, SULF2 has an oncogenic effect in HCC mediated in part through up-regulation of FGF signaling and GPC3 expression.
The chimeric monoclonal antibody cG250 recognises the
G250/CAIX/MN antigen found on 95% of
clear cell renal cell carcinomas (RCCs). We performed a phase I
clinical trial to evaluate the safety, blood pharmacokinetics (PK),
and biodistribution of repeated doses of cG250. The primary endpoint
was toxicity. Secondary endpoints were cG250 biodistribution and
PK; measurement of human anti-chimeric-antibodies (HACA); and tumour
response rates. Eligible patients had unresectable or metastatic
clear cell RCC. Doses of 5, 10, 25, or 50 mg/m2 were
given weekly by intravenous infusion for six weeks. Three patients
were treated at each dose level. Trace 131I-labelled
cG250 was administered on weeks 1 and 5. Thirteen patients participated
and were evaluable. One patient developed brain metastases and was
replaced. No grade 3 or 4 toxicities and no dose-limiting toxicity
occurred. One patient died due to progressive disease within 30
days of receiving the study drug. One patient developed HACA during
the second six-week cycle. PK analysis showed mean whole body and
blood alpha and beta half-lives of cG250 of 18.99 ± 6.84
and 180.19 ± 86.68 hours, respectively. All patients
had cG250 tumour localization by gamma camera imaging in week 1
and 5. One patient had a complete response, nine patients had stable
disease, and three had progressive disease. One patient received
11 six-week cycles of treatment with no toxicity or HACA. In conclusion,
repeated intravenous doses of up to 50 mg/m2 of
cG250 are safe. Furthermore cG250 has a long half-life and targets
clear cell RCC effectively.
phase I clinical trial; renal cell carcinoma; human CA9 protein; cG250; chimeric antibody