bluuebunny/crossref_metadata_2025 huggingface dataset:
P5-23-01: The Impact of Primary Tumor Resection on the Survival of Patients with Stage IV Breast Cancer According to Molecular Subtype.
Authors: Ahn SK , Moon H-G , Kim JS , You JM , Shin HC , Han W , Noh D-Y
Published: June 2012

Purpose: The main treatment for stage IV breast cancer is currently systemic therapy. Surgical resection of the primary tumor is usually done for treating the tumor-related complications. Recent studies have suggested that surgery may improve the long-term survival of stage IV breast cancer patients. We evaluated the impact of the primary surgical resection site on the survival of stage IV breast cancer patients according to molecular subtype using nationwide Korean breast cancer registry data.

Methods: We analyzed the records of the stage IV breast cancer patients from Korean Central Cancer Registry (KCCR) between 1999 and 2008. We used clinical assays to distinguish luminal A (HR+/HER2−, n=290), luminal B (HR+/HER2+, n=154), Basal-like (HR-/HER2−, n=107) and HER2 (HR-/HER2+, n=145). The clinical and tumor characteristics, the type of treatments and the overall survival were compared between the surgically versus nonsurgically treated patients according to molecular subtype.

Results: Of the 1091 identified patients, 719 (65.9%) received surgical excision of their primary tumor and 372 (34.1%) did not. The mean survival was 86 months versus 43 months for the surgically treated patients vs. the patients without surgery, respectively (p<0.001). On a multivariate analysis with using the Cox model and after adjusting for tumor size, visceral metastases, the number of metastatic sites and bone only metastases, surgery was an independent factor for improved survival in patients with luminal A type (Hazard Ratio, 0.505; 95% Confidence Interval, 0.265−0.962, p=0.038) but not in those with luminal B (p=0.192), basal-like (p=0.128) and HER2 subtype (p=0.114).

Conclusion: Surgical resection of the primary tumor in stage IV breast cancer patients was independently associated with improved survival only in luminal A subtype.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-23-01.
PD01-07: AR Overexpression and Aromatase Inhibitor Resistance in Breast Cancer.
Authors: Rechoum Y , Iacopetta D , Barone I , Ando’ S , Morales SF , Weigel NL , Fuqua SAW
Published: June 2012

Background: Aromatase inhibitors (AIs) have emerged as the therapy of choice for the treatment of estrogen receptor alpha (ERα)-positive breast cancer. However, many patients develop resistance to AI treatment. Although the involvement of the ERα in AI resistance is well established, the role of the androgen receptor (AR) is not known. It has been estimated that about 60%-70% of ERα-positive breast cancer co-express the AR, and that AR agonists can either inhibit or stimulate breast cancer cell proliferation. Thus it is important to determine if there are biomarkers predicting AR's effects in breast tumors. We have previously shown a role for AR-overexpression in tamoxifen resistance in ERα-positive MCF-7 breast cancer cells; here we hypothesized that AR overexpression might similarly be involved in resistance to the AI anastrazole (Anas).

Materials and Methods: Stable transfection of MCF-7 cells was performed to generate cell lines that express the aromatase gene (MCF-7 BK Arom) and then co-transfected with an AR expression vector (MCF-7 AR Arom). Aromatase and AR expression levels were evaluated by western blot analysis, and the enzyme activity was evaluated using aromatase activity assays. Proliferation was tested using anchorage independent soft agar assays and MTT in the presence of the androgen substrate androstenedione (AD), or AD plus Anas. ERα and AR transcriptional activities were tested with ERE-luciferase reporter assays. Localization of ERα and AR within the cells was visualized using immunofluorescence microscopy.

Results: ERα-positive MCF-7 cells were stably transfected with either aromatase, or aromatase plus AR. MCF-7 aromatase clones overexpressing AR were resistant to the growth inhibitory effects of Anas when stimulated with the androgen AD. Resistance was not mediated through changes in aromatase expression or activity. The growth of several of the AR Arom-overexpressing cells was stimulated with treatment of Anas alone, suggesting that Anas was acting as an agonist. As expected, AD treatment stimulated ERα transcriptional activity, but Anas was unable to block AD-stimulated activity in AR Arom-overexpressing cells using ERE-Luciferase reporter assay. Anas was able to enhance AR and ERα colocalization in AR-overxpressing cells. Resistance was not associated with activation of known mechanisms of resistance, such as HER2, IGF-1R, or MAPK. However AR-overexpressing cells had higher constitutive phosphorylation of Akt. Accordingly, resistance to Anas was blocked using an Akt1/2 inhibitor.

Conclusion: Using a model of ERα-positive breast cancer cells expressing exogenous aromatase and AR, we have demonstrated that AR overexpression confers resistance to the AI Anas. These results suggest that in patients recurring on hormonal therapy whose tumors express elevated levels of AR, targeted therapy to Akt might restore hormone sensitivity.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD01-07.
PD01-08: Heterogeneity of Lapatinib Responses in HCC1954 HER2−Overexpressing Breast Cancer Cells Revealed by Single-Cell Automated Microscopy.
Authors: Hardeman KN , Tyson D , Quaranta V
Published: June 2012

In breast cancer, 20–30% of patients present with HER2 overexpression, making them potential candidates for targeted HER2 therapies such as lapatinib. Lapatinib is a dual, intracellular tyrosine kinase inhibitor of HER2 & EGFR and is standard care for metastatic breast cancer. Drug resistance to this type of therapy is a major cause of death in cancer patients. Intra-tumor heterogeneity with respect to drug response can be a driving force for relapse and/or drug resistance. In current drug response end-point assays (IC50), information on heterogeneity is lost because cell differences are averaged out over the whole population. To produce a more realistic appreciation of drug response variability within a tumor, our lab has developed an extension of high content automated microscopy, called Extended Time Resolved Automated Microscopy (ETRAM). ETRAM entails the visual tracking of single cells with fine temporal & spatial resolution, allowing for the calculation of proliferation, death, and quiescence rates from image stacks and movies. HER2+ breast cancer HCC1954 cells were fluorescently labeled w/a nuclear tag (H2BmRFP) and treated w/lapatinib in a dose-dependent manner, from 2000 nM to 0 nM (DMSO control). Using the ETRAM method we followed nearly 1000 single cells/treatment condition over 72 hours, acquiring images every 10–12 minutes. Unexpectedly, we discovered that small but significant subpopulations of HCC1954 cells are unaffected by high lapatinib concentrations (2000 nM) and continue to divide. Furthermore, a substantial subpopulation responds to high lapatinib by entering quiescence, not apoptosis. Since HCC1954 cells have a previously reported lapatinib IC50 of 300 nM, our data demonstrate a need to further investigate these subpopulations of cells in order to determine their contribution to the IC50. Image stacks are being further analyzed to extract cellular metrics of division, quiescence and death rates in the presence of lapatinib. We are also investigating single cells by immunofluorescence of signaling molecules in the HER2 pathway, along with downstream targets such as PI3K, mTOR/AKT, SHC, and RAF1, to assess molecular differences regarding dividing and quiescent subpopulations in lapatinib, versus lapatinib-sensitive cells that apoptose. Our ETRAM-based single cell analyses may stimulate a re-interpretation of lapatinib responses in HER2−overexpressing breast cancer, and hopefully point to improved strategies of lapatinib treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD01-08.
PD02-08: Validation over Time of a Nomogram Predicting the Sentinel Node Positivity in Early Breast Carcinoma According to the Molecular Subtypes Classification.
Authors: Ngô C , De Rycke Y , Mouttet D , Reyal F , Fourchotte V , Hugonnet F , Falcou M-C , Bidard F-C , Vincent-Salomon A , Fourquet A , Sigal-Zafrani B , Alran S
Published: June 2012

Background: The molecular subtypes of breast cancer have different axillary status. A new nomogram including the interaction covariate between estrogen receptor (ER) and HER2 status has been recently published (Reyal et al. PLOSone, may 2011) and allows to identify before surgery the patients with a high risk of positive sentinel lymph node (SLN). The purpose of our study was to validate this model on an independent population.

Patients and methods: We studied 755 consecutive patients treated for operable breast cancer with sentinel node biopsies in 2009, from the Institut Curie breast cancer prospective database. Baseline characteristics were compared between our population and the population used to build the model, using Chi-square test for categorical variables and Kruskal-Wallis test for continuous variables. The multivariate model, including age, tumor size, lymphovascular invasion and interaction covariate between ER and HER2 status, was used to calculate the theoretical risk of positive sentinel lymph node (SLN) for all patients. The performance of the model on our population was then evaluated in terms of discrimination (area under the curve AUC) and of calibration (Hosmer-Lemeshow HL test).

Results: Characteristics of our population were significantly different from the training population for the following variables: tumor size (median 12mm [1-60] versus 13mm [1-100] p=0.005), lymphovascular invasion (18.6% versus 23.7% p=0.006), positive ER (91.4% versus 87% p=0.002) and age as followed: 56.7% of patients ≤ 60 versus 63.1%, 17.5% of patients between 60 and 65 versus 14.1% and 25.8% of patients above 65 versus 22.8% p=0.01. The nomogram showed similar results in our population than in the training population in terms of discrimination (AUC= 0.72 [0.68−0.76] versus 0.73 [0.7−0.75] and calibration (HL p= 0.4 versus p=0.35).

Conclusions: Despite significant differences between the two populations concerning variables which are part of the nomogram, the model was validated in our population. Our study shows that this nomogram is efficient and robust over time to predict the likelihood of positive SLN according to molecular subtypes defined by surrogate markers ER and HER2 determined by immunohistochemistry in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD02-08.
PD05-04: Quantitative Measurement of Antigen Degradation in NCCTG N9831 Tissue Microarrays.
Authors: Cheng H , Rimm DL , Reinholz MM , Lingle WL , Ballman KV , Dueck AC , Chen B , McCullough AE , Jenkins RB , Perez EA
Published: June 2012

Background: Unstained recuts from formalin-fixed paraffin-embedded tissues are commonly collected for cooperative group studies. There is concern among pathologists that improper storage conditions can lead to antigen degradation. In an effort to quantify this effect, we compared the expression of HER1 and HER2 on two sets of identical cohort tissue microarrays (TMAs) from the N9831 HER2+ adjuvant phase III trial (NCT00005970; www.clinicaltrials.gov); one freshly cut set (cut April 18, 2011) and a second set stored at 4 degrees for over two years (cut between Nov, 2007 and Jan, 2008).

Methods: The two sets of TMA slides containing 1580 tumor samples from the N9831 cohort were treated identically using the AQUA method of quantitative immunofluorescence. HER1 was tested with D38B1 (rabbit monoclonal, Cell Signaling Technology, Inc.) and HER2 with CB11 (mouse monoclonal, Biocare, Inc.) on tumors from 695 patients (712 specimens) in the fresh TMAs and 779 patients (800 specimens) in the old TMAs in up to three-fold redundancy per specimen.

Results: Frequency distributions of the expression of HER2 revealed bimodality in the fresh TMAs compared to an attenuated distribution of the old cases. The average score of the entire cohort was significantly lower in old TMAs compared to fresh cuts (paired t-test, p<0.0001). Linear regression of the average HER2 scores from new TMAs versus the average scores from old TMAs showed a slope term of 0.52, which is statistically significantly different from the hypothetical value of 1 (p<0.0001). Regressions between any two fresh slides showed slopes close to 1.0. Similar results were seen for HER1, but fewer positive cases made the changes less dramatic.

Conclusions: The storage condition of tissue slides is a critical pre-analytical variable that can dramatically lower the score of HER1 and HER2, artificially. Thus, studies done on inadequately stored slides, either whole sections or TMAs, must be interpreted with caution. Tissue collection and analysis of biomarkers for cooperative group studies should not include unstained recuts, but rather, entire blocks or large cores from tissue blocks.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD05-04.
S1-3: Long-Term Survival Outcomes among Postmenopausal Women with Hormone Receptor-Positive Early Breast Cancer Receiving Adjuvant Letrozole and Zoledronic Acid: 5-Year Follow-Up of ZO-FAST.
Authors: de Boer R , Bundred N , Eidtmann H , Neven P , von Minckwitz G , Martin N , Modi A , Coleman R
Published: June 2012

Introduction: Recent clinical trials suggest potential anticancer activity for bisphosphonates combined with adjuvant endocrine therapy in patients with hormone receptor-positive (HR+) early breast cancer (EBC). Data from the interim analysis of AZURE suggest that the benefits of adding zoledronic acid (ZOL) may be greatest in patients with low estrogen levels (Coleman RE, et al. SABCS 2010). In ZO-FAST, we have previously demonstrated that adding ZOL to adjuvant therapy significantly improved bone mineral density (BMD) and prolonged disease-free survival (DFS) vs delayed ZOL (de Boer R, et al. SABCS 2010). We report here the effect of time since menopause at breast cancer diagnosis (ie, baseline menopausal status) on DFS benefits with ZOL.

Methods: Postmenopausal women with HR+ EBC receiving letrozole (LET; 2.5 mg qd x 5 yr) with a BMD T-score ≥-2 (N=1065) were randomized to ZOL (4 mg q6mo): immediate (IMZOL) or delayed (DZOL; initiated for postbaseline T-score <-2 or nontraumatic/asymptomatic fracture). Patients were followed for disease recurrence and overall survival (OS) for 5 years. Patients were eligible for the study if they had established menopause at the time of diagnosis, or if they became menopausal because of chemotherapy or ovarian suppression (ie, recently postmenopausal). The effect of baseline menopausal status on DFS was examined in Cox regression analyses.

Results: At 60 months’ follow-up in the overall population (N=1065), IMZOL significantly reduced the risk of a DFS event by 34% vs DZOL (hazard ratio [HR]=0.66; 95% confidence interval [CI], 0.44−0.97; P=.034). In exploratory analyses of women who were postmenopausal for >5 years or >60 years old at study entry (n=670), IMZOL improved DFS (HR=0.63; 95% CI, 0.39−1.01; P=.052) and significantly prolonged OS (HR=0.50; 95% CI, 0.27−0.92; P=.022) vs DZOL. Additional subgroup analyses including patterns of breast cancer recurrence will be presented. During 5 years of treatment, osteonecrosis of the jaw (ONJ) was reported in 4/669 patients (0.6%) who received ZOL, and there was no increase in renal adverse events (AEs) in the ZOL-treated patients. Overall, AEs were consistent with the known safety profiles of both study drugs.

Conclusions: Long-term follow-up in ZO-FAST confirms the overall survival benefits of adding ZOL (4 mg q6mo) to adjuvant LET therapy for EBC. However, subset analyses suggest that women with established postmenopausal status may benefit from ZOL therapy more than others. These results are consistent with observations in the AZURE trial, and support potentially greater ZOL benefits in a low-estrogen environment. Additional studies are needed to fully define the patient populations most likely to benefit from adjuvant ZOL in this setting.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S1-3.
S4-1: Overdiagnosis in Breast Cancer Screening: Methodological Considerations of Current Estimates.
Authors: Smith RA , Duffy SW
Published: June 2012

Background

A harm that has received considerable attention in breast cancer screening is overdiagnosis, i.e., the detection through screening of breast cancer that is non-progressive. Since there is no way to distinguish a truly non-progressive tumor from one that is progressive, overdiagnosis is a statistical phenomenon that is estimated as the difference between observed and expected incidence rates. However, there is no agreement on the true rate of overdiagnosis in breast cancer screening. Estimates vary widely, with the highest estimates reported in the scientific literature having received significant media attention under the premise that a signifiant fraction of newly diagnosed breast cancers are non-progressive and thus overtreated. We examined the range of overdiagnosis estimates in the context of factors that influence observed and expected breast cancer incidence rates over time.

Methods

Only studies that compared incidence rates of invasive breast cancer, or invasive breast cancer and ductal carcinoma in situ (DCIS), in a group invited or exposed to mammography compared with a group not invited or not exposed to mammography were included in our analysis. Studies were evaluated based on whether or not they adjusted for contemporaneous trends in the underlying incidence of disease, which may differ in different age groups, and age-specific effect on incidence rates due to lead time.

Results

We identified 17 studies (Table 1) that attempted to estimate overdiagnosis of breast cancer resulting from mammography screening. The main determinant of high estimated rates of overdiagnosis was a failure to adjust for lead time. The highest rate of overdiagnosis (33%) occurred in the one study that did not correct for either lead time or confounders. Studies that only partially corrected for lead time and confounding also had high estimates of overdiagnosis (mean = 30%), whereas studies that corrected for both lead time and confounders had the lowest estimate of overdiagnosis (mean =5%).

Conclusion

The possibility that some breast cancers detected by mammography are indolent and not life threatening within the patient's natural life is real. However, it is clear from our analysis that the wide range of estimates of overdiagnosis are due to whether or not studies have adjusted for factors in and outside of screening programs known to influence incidence rates over time. Our findings suggest that the true rate of overdiagnosis associated with breast cancer screening, to the extent that it exits at all, is small.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S4-1.
SR2-3: Integrative Genomic Analyses of Breast Cancer from The Cancer Genome Atlas (TCGA).
Authors: Creighton C
Published: June 2012

Cancer is a disease characterized by genetic aberrations, which lead to widespread deregulation of cell signaling and gene transcription. Over ten years ago, gene transcription profiling of human cancers was found to distinguish distinct intrinsic molecular subtypes of the disease (luminal A/B, HER2, basal, normal-like). TCGA is a large-scale collaborative effort which seeks to comprehensively catalogue the molecular aberrations in various cancers, including breast cancer, at levels of somatic mutation, copy alteration, DNA promoter methylation, protein signaling, and gene and miRNA transcription. Having all of these molecular data on the same set of ∼500 human breast tumors, allows us to construct a more complete molecular portrait of the intrinsic subtypes, along with their candidate molecular drivers. Among other things, integrative analysis of the p53 and PI3K pathways in breast cancer reveal differences in pathway alteration and pathway activity among the subtypes.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr SR2-3.
Abstract A78: Cancer in Hinkley: What was the real problem?
Authors: Morgan John W. , Reeves Mark E.
Published: June 2012

Background: Hinkley, California, is a poor desert community known for a $333 million legal settlement and for the “Erin Brockovich” film that alleged a cancer excess from groundwater contaminated with chromium 6 [Cr(VI)] released by a public utility. The carcinogenic role for aqueous Cr(VI) in humans is disputed.

Methods: We assessed observed and expected counts of new cancers, including 19 cancer subtypes in the Hinkley tract for 1996–2008. Indirect standardization yielded expected counts adjusted for age, sex, race/ethnicity, population size, and change in population size. Observed numbers of cancers divided by adjusted expected counts defined standardized incidence ratios (SIR) with 95 percent confidence intervals (CI).

Results: After adjusting for demographic characteristics, the observed number of cervix cancers was significantly above the expected count (SIR; 95% CI=2.83; 1.82, 5.86). Findings for all cancers combined (SIR; 95% CI=0.91; 0.78, 1.04) and each of 15 specific cancers did not differ significantly from expected counts. Observed counts for childhood, hematopoietic, and respiratory cancers were slightly above expected counts, while observed counts for digestive and breast cancers were below expected. No nasopharyngeal carcinoma or pancreatic cancers were identified, and the observed prostate cancer count (SIR; 95% CI=0.65; 0.40, 0.98) was significantly below the expected number. The observed count for colorectal cancer was below the expected number, although a markedly larger fraction of Hinkley cases were diagnosed at advanced stage compared to the county, region and state.

Conclusions: These findings do not support claims of a generalized cancer excess in Hinkley, although the cervix, prostate, and colorectal cancer findings reveal underutilization of cancer screening in the Hinkley tract. These findings are consistent with previous assessments that did not identify a cancer excess in the Hinkley tract.

Funding: The California Department of Public Health, National Cancer Institute (Grant N01-PC-35136 and N01-PC-35139), and Centers for Disease Control and Prevention (Grant N02-PC-54404) funded cancer surveillance necessary for this study.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A78.
Abstract A148: Palomid 529, a dual mTor1/2 inhibitor, efficiently penetrates the blood-brain barrier and may be an attractive agent for treatment of glioblastoma
Authors: Fan Lin , Buil Levi , Beijnen Jos H. , Sherris David , van Tellingen Olaf
Published: June 2012

High-grade gliomas (WHO grade III anaplastic astrocytoma and grade IV glioblastoma multiforme) are the most common primary tumors in the central nervous system in adults and uniformly lethal. The current standard treatment (radiotherapy and temozolomide chemotherapy) has only a modest efficacy and better treatments are urgently needed. Activation of the EGFR/PI3K/Akt/mTor signaling cascade is a common event, especially in de novo glioblastoma (GBM) and, therefore, an attractive target for intervention by inhibitors. However, the blood-brain barrier (BBB) is an impediment for the delivery of many agents into the brain. Although GBM has the capacity to disrupt the blood-brain barrier, it is also a very invasive tumor with many tumor cells residing within areas of the brain where the BBB is still intact. Consequently it is important to consider the BBB penetration of novel candidate drugs for treatment of gliomas.

We here present a pre-clinical pharmacokinetic study of Palomid 529, which is a novel small molecule inhibitor of mTor. This agent is attractive because it inhibits both the Torc1 and Torc2 complexes, thereby preventing upstream Akt activation through feedback loops. We have used in vitro transwell assays and found that Palomid 529 has negligible affinities for P-glycoprotein (Pgp) and Bcrp1, the two most dominant drug transporters that are expressed at the BBB. Subsequent studies in transporter knockout mouse models receiving i.v. P529 as a micronized drug formulation at a high dose (54 mg/kg) or low dose (5.4 mg/kg) confirmed these results and demonstrated that Palomid 529 penetrates the BBB efficiently with brain-to-plasma ratios exceeding 1. Only at the lowest dose level a minor effect of Pgp and Bcrp1 was observed. Based on these results we are now executing pre-clinical testing of Palomid 529 against orthotopic brain tumor models.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A148.
Abstract B192: Preclinical characterization of BMS-833923 (XL139), a hedgehog (HH) pathway inhibitor in early clinical development
Authors: Gendreau Steven B. , Hawkins Don , Ho Ching-Ping , Lewin Anne , Lin Tara , Merchant Akil , Rowley R. Bruce , Wang Qiuju , Matsui William , Fargnoli Joseph
Published: June 2012

Background: Aberrant HH pathway signaling has been implicated in human malignancies ranging from semi-malignant tumors of the skin to highly aggressive cancers of the brain, lung, pancreas, breast, prostate, and lymphohematopoietic lineages. Dysregulation of this pathway contributes to uncontrolled proliferation, invasion, metastasis, evasion of apoptosis, and resistance to chemotherapy.

Results: BMS-833923 is a potent inhibitor of SMO, a GPCR-like 7-transmembrane receptor that is a critical regulator of the HH pathway. In vitro, BMS-833923 inhibits the expression of downstream effectors in the HH pathway (GLI1 and PTCH1) in cell lines that express wild-type SMO and those which express activated mutant forms of SMO (IC50 values of 6–35 nM). In FACS-based binding assays, BMS-833923 inhibits BODIPY cyclopamine binding to SMO in a dose-dependent manner with an IC50 of 21 nM. Prior work has demonstrated that HH pathway blockade inhibits the in vitro clonal expansion of multiple myeloma (MM) precursor cells in both established cell lines and in clinical samples from patients with MM (Peacock et al 2007, PNAS 104:4048). Consistent with these observations, BMS-833923 inhibited the in vitro growth of MM clones and proportion of ALDH+ cancer stem cells derived from bone marrow samples from subjects with MM. Furthermore, BMS-833923 inhibited the clonogenic growth of multiple tumor cell lines derived from patients with hematological malignancies including CML, ALL and AML, suggesting that targeting the HH pathway may have broad therapeutic utility for patients with hematologic malignancies. In vivo pharmacodynamic studies show that BMS-833923 robustly inhibits HH pathway activity with a long duration of action after a single oral dose in medulloblastoma and pancreatic carcinoma xenograft models. The pharmacodynamic effects of BMS-833923 observed in these models translate into tumor growth inhibition at well-tolerated doses. These results are consistent with pharmacokinetic parameters demonstrated in nonclinical studies.

Conclusions: BMS-833923 is an orally bioavailable, potent and selective inhibitor of the HH pathway as measured by in vitro cell-based assays and in vivo pharmacodynamic and efficacy models, supporting the clinical development of BMS-833923 in both hematological and non-hematological malignancies.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B192.
Abstract B197: Phase II, single-arm study of tasisulam-sodium (LY573636-sodium) as 2nd–4th line therapy for platinum resistant ovarian cancer
Authors: Gordon Michael , McMeekin D. Scott , Temkin Sarah , Tew William , Yapp Stephanie , Scambia Giovanni , Streltsova Olga , Kaiser Christopher , Ilaria Robert , Look Katherine
Published: June 2012

Background: Tasisulam-sodium (tasisulam) is a novel anti-cancer agent that induces mitochondrial mediated apoptosis and anti-angiogenesis. The mechanism of action is being further evaluated. Phase I trials defined the dose and schedule for this agent and suggested activity in chemotherapy-resistant ovarian cancer (OvCa).

Methods: Patients (Pts) with no more than 2 prior systemic regimens for platinum-resistant OvCa received tasisulam by 2-hour intravenous infusion every 21 days, targeting a maximum concentration (Cmax) of 420 µg/mL. The primary endpoint was objective response rate (ORR). Secondary endpoints were clinical benefit rate [(CBR = complete response (CR) + partial response (PR) + stable disease (SD)], progression-free survival (PFS), overall survival (OS) and safety.

Results: From February 2007– May 2008, 55 pts were enrolled [median age of 55 years (range: 27–78); ECOG PS of 0–2]. Fifty pts had measurable disease by RECIST. A median of 3 cycles (range: 1–18) was administered. Hematologic adverse events (AEs) were the most common grade (G) 3/4 AEs, regardless of causality. G 3/4 thrombocytopenia or neutropenia occurred in 7.3%/20.0% and 12.7%/14.5% of pts, respectively. Febrile neutropenia occurred in 3.6% of pts, and G 3/4 anemia in 12.7%/1.8%. Other G 3/4 non-hematologic AEs in ≥ 2% of pts included infections (12.7%), pain (10.9%), metabolic abnormalities (14.5%), vomiting (7.3%), GI obstruction (5.6%) and dehydration and renal failure (3.6% each). Five deaths occurred on study (or within 30 days of discontinuation), 3 of which were confounded by complications of the underlying disease. A total of 8 investigator-assessed (RECIST) responses were reported in the 50 patients with measurable disease, and 6 were confirmed, for a response rate of 12.0% (90% CI: 4.4–19.6). Another 17 pts (34.0%) had SD for a CBR of 46% (90% CI: 34.4–57.6%). Median PFS was 1.9 months (90% CI: 1.5–3.0; 16.4% censored) and median OS was 12.9 months (90% CI: 8.6–17.7; 47.3% censored) in the 55 enrolled pts. Study is on-going with 3 pts still on treatment.

Conclusion: Tasisulam has encouraging activity in platinum-resistant OvCa. An alternative treatment schedule is currently being explored in this patient population to minimize the risk of serious myelosuppression while preserving efficacy.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B197.
Abstract B27: Correlation between TNFα and LCL161 anti-tumor activity in patient derived xenograft models of human cancer
Authors: Firestone Brant , Conway Colleen , Yang Guizhi , Gao Hui , Porter Dale , Slisz Joanna , He Dan , Mosher Rebecca , Monahan John , Straub Christopher , Morrissey Michael , Yao Yung-mae , Zawel Leigh
Published: June 2012

LCL161, a small molecule antagonist of inhibitor of apoptosis proteins (IAPs), induces TNF -mediated apoptosis in a subset of tumor cell lines including the MDA-MB-231 breast cancer line. To investigate the in vivo activity of LCL161, MDA-MB-231 tumor bearing mice were treated with a once weekly oral dose. We observed anti-tumor activity that was associated with pharmacodynamic responses including degradation of CIAP1 and induction of cleaved caspase 3. The loss of CIAP1, specifically the E3 ligase activity of this protein, has been shown to directly impact the stability of a number of client proteins including NIK (NF-κB inducing kinase), Mad1 (MAX-binding protein), and others. Gene expression analysis on LCL161 treated MDA-MB-231 tumors revealed a striking upregulation of NF-κB regulated target genes. These data were further supported by the observation that TNFα, a direct target of NF-κB, was induced in LCL161 treated MDAMB-231 tumor lysates. To explore whether TNFα expression levels could be used to predict single agent efficacy in a more clinically relevant context, a series of human primary tumor xenografts were profiled for baseline TNFα mRNA levels and evaluated for response to LCL161 in vivo. We observed that tumors with the highest TNFα expression levels showed the greatest sensitivity to LCL161. These studies demonstrate an essential role of the NF-κB pathway in IAP antagonist anti-tumor activity. Ongoing efforts focus on delineating the contribution of the canonical and non-canonical NF-κB pathways to efficacy and on leveraging this mechanism for LCL161 patient selection.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B27.
Abstract B270: Profiling the biochemical and cellular activities of TAK-901, a potent multi-targeted Aurora-B kinase inhibitor
Authors: Farrell Pamela , Shi Lihong , Matuszkiewicz Jennifer , Balakrishna Deepika , Elliott Sarah , Halkowycz Petro , Feher Victoria , Paraselli Bheema , Grimshaw Charles , Sang BiChing , de Jong Ron
Published: June 2012

Aurora A, B, and C comprise a family of serine-threonine protein kinases that are key cell cycle regulators ensuring an orderly and accurate execution of mitosis and cell division. Aurora A localizes to centrosomes and spindle poles and is required for mitotic spindle assembly and centrosome maturation, whereas Aurora B is a chromosome passenger protein essential for phosphorylation of histone H3, chromosome segregation, and cytokinesis. Aurora A and B are overexpressed in many malignancies, making them attractive therapeutic targets. Derived from the azacarboline scaffold representing a unique kinase hinge-binder chemotype, TAK-901 is a novel inhibitor of Aurora A, B, and C kinases with IC50 values in the low nanomolar range. It potently inhibits Aurora A-TPX2 and Aurora B-INCENP (IC50 = 21 and 15 nM, respectively) and is a time-dependent, tight binding inhibitor of Aurora B-INCENP. Dissociation of TAK-901 from Aurora B-INCENP was slow with a t1/2 of 920 minutes, and the affinity constant for TAK-901 binding to Aurora B-INCENP was determined to be 0.02 nM. TAK-901 induced inhibition of cell proliferation in cultured human cancer cell lines from different tissues with IC50s ranging from 40 to 500 nM. Consistent with Aurora B inhibition, TAK-901 treatment produced polyploidy in human PC3 prostate cancer and HL60 acute myeloid leukemia cells as measured by immunofluorescence and flow cytometry. Examination of a broad panel of kinases revealed that multiple kinases, including FLT3, FGFR and the Src family kinases, were inhibited by TAK-901 with IC50 values similar to those for Aurora A and B. In cells, TAK-901 suppressed the Flt3 and FGFR2 autophosphorylation with IC50 values close to that of Aurora B as measured by cellular histone H3 phosphorylation, whereas the IC50s for inhibition of cellular Src and BcrAbl were 20-fold weaker. In a panel of pathway specific reporter-based cell models, TAK-901 inhibited the NFkB and JAK/STAT pathways with submicromolar potency. However, phosphorylation or subcellular localization of the signaling mediators NFkB and STAT5 were unaffected by TAK-901 treatment. The expression of a subset of NFkB-regulated genes was altered by TAK-901. Furthermore, TAK-901 treated human PBMCs exhibited multiple differentially expressed genes, as identified using gene expression profiling by microarray analysis, which were subsequently confirmed by quantitative RT-PCR. The mechanism by which TAK-901 alters expression of these genes remains unknown and is under investigation. Altogether, these findings have led to increased understanding of the biological activities of TAK-901 and identification of potential novel biomarkers for clinical use. TAK-901 is currently in Phase I clinical trials.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B270.
Abstract B4: Regorafenib: a new oral multikinase inhibitor of angiogenic, stromal and oncogenic (receptor tyrosine) kinases with potent preclinical antitumor activity
Authors: Wilhelm Scott , Adnane Jalila , Lynch Mark , Hornberg Jorrit , Schütz Gunnar , Thierauch Karl-Heinz , Zopf Dieter
Published: June 2012

Angiogenesis is a critical driver of tumor growth and progression, and is controlled by a number of interconnected signaling pathways. In these pathways, the two tyrosine kinase receptors, vascular endothelial growth factor receptor (VEGFR) 2 and tyrosine kinase with immunoglobulin and EGF homology domain 2 (TIE2) play crucial roles in the neovascularization, stabilization, and maintenance of normal and tumor vasculature. Regorafenib, a novel oral multikinase inhibitor, potently inhibits both VEGFR2 and TIE2 in biochemical and cellular kinase phosphorylation assays. It inhibits additional angiogenic kinases ie VEGFR1, VEGFR3, platelet-derived growth factor receptor- , and fibroblast growth factor receptor-1 and the mutant oncogenic kinases KIT and RET, which play a role in human gastrointestinal stromal and thyroid cancers, respectively, and B-RAF. The mechanism of action of regorafenib on the tumor vasculature was demonstrated in vivo by dynamic contrast-enhanced magnetic resonance imaging using Gadomer as contrast agent. Regorafenib significantly decreased tumor perfusion and extravasation of the contrast agent in a rat GS9L glioblastoma tumor xenograft model grown i.m. in the rat leg compared to rat muscle tissue after a single oral administration of 10 mg/kg. The pharmacodynamic effects persisted for 48 hours after the last drug administration and correlated with the tumor growth inhibition in a QDx4 once daily oral dosing study. A significant reduction in tumor microvessel area was observed in a human colorectal xenograft after QDx5 daily oral dosing at 10 and 30 mg/kg of regorafenib in tumor-bearing mice. Regorafenib exhibited potent dose-dependent tumor growth inhibition in various preclinical murine xenograft models including breast (MDA-MB-231), NSCLC (NCI-H460), renal (786-O), and several colorectal (Colo-205, HCT-15, HT-29) carcinoma, some of which carry mutant K-RAS and/or B-RAF. Tumor shrinkage was observed in the breast MDA-MB-231 and the renal 786-O carcinoma models. The compound was well tolerated and no significant weight loss or lethality was observed. Immunohistochemical analyses of the breast xenograft tumor revealed a strong reduction in staining of the proliferation marker Ki-67 and of the phosphorylated extracellular regulated kinases 1 and 2. Non-clinical metabolism studies have detected two pharmacokinetically stable regorafenib metabolites, with similar but distinct kinase profiles. These data demonstrate that regorafenib is a well-tolerated, orally active multikinase inhibitor with a unique target profile that may have therapeutic benefit in human malignancies.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B4.
Abstract B59: Preliminary clinical experiences of Phortress: Putative role for c-MET inhibition in antitumor activity
Authors: Bradshaw Tracey D. , Stevens Malcolm F.G. , Calvert Hilary , Plummer E. Ruth
Published: June 2012

Experimental antitumor agent Phortress elicits selective activity in vitro and in vivo in human breast, ovarian and renal carcinoma models via a novel mechanism(s) of action. Prodrug Phortress [2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) lysylamide dihydrochloride] liberates 5F 203 in the presence of cancer cells in vitro, and in plasma in vivo. 5F 203 is a potent aryl hydrocarbon receptor (AhR) ligand, resulting in induction of cyp1a1 transcription. CYP1A1-catalyzed biotransformation of 5F 203 to electrophilic species in sensitive tumor cells leads to cell death. Preclinical toxicokinetic studies in two rodent species led to a clinical starting dose of 3 mg/m2 Phortress.

Three and six patients have received 3 mg/m2 and 4.25 mg/m2 Phortress respectively, by intravenous injection over a 15 minute period on day 1 of consecutive 21 day cycles.

Phortress was generally well tolerated. Drug-related adverse reactions include fatigue and headache/arthralgia. In four patients, indications of stable disease have been achieved. One patient with colorectal carcinoma received nine 3 mg/m2 cycles before fatigue led to withdrawal. A mesothelioma patient received twelve 3 mg/m2 cycles; treatment was stopped after lung function tests revealed decreased TLco associated with disease progression. Two patients with renal cell carcinoma received four and sixteen 4.25 mg/m2 Phortress cycles before progressive disease led to withdrawal from trial.

Germline and somatic mutations in the MET oncogene encoding transmembrane hepatocyte growth factor receptor tyrosine kinase (HGFTK) are thought to play a key role in the pathophysiology of hereditary and sporadic renal cell carcinoma (RCC). Indeed, aberrant MET activation has been detected in many carcinomas including breast, ovary, gastric and metastatic colon, promoting aggressive invasive growth through stimulation of cell migration, and inhibition of apoptosis. MET-dependent signaling includes the Ras-Raf-Mek-Erk and PI3K-Akt cascades. Downregulation (85% and 69%) of MET (HGFTK) activity has been observed in protein isolated from MCF-7 and MDA 468 breast cancer cells treated for 24 h with 1 M 5F 203; downstream of MET, inhibition of Erk, MapK, Mek kinase activity was observed. Samples were subjected to antibody microarray which tracked phosphorylation status of cell signalling proteins that regulate cell proliferation, stress and apoptosis.

In scratch wound assays, 5F 203 (0.1 M) impeded renal TK10 as well as MCF-7 and MDA 468 cell motility.

Inhibition of MET signaling may afford an important 5F 203 target. Further translational research will more comprehensively elucidate mechanisms of action of Phortress. Such studies may ultimately guide patient selection and predict tumor response.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B59.
Abstract B88: A selective Raf kinase inhibitor induces cell death and tumor regression of human cancer cell lines encoding B-RafV600E mutation
Authors: Laquerre Sylvie , Arnone Marc , Moss Katherine , Yang Jingsong , Fisher Kelly , Kane-Carson Laurie S. , Smitheman Kimberly , Ward Jessica , Heidrich Bradley , Rheault Tara , Adjabeng George , Hornberger Keith , Stellwagen John , Waterson Alex , Han Chao , Mook Robert A. , Uehling David , King Alastair J.
Published: June 2012

Activation of the Ras-Raf-MEK-ERK pathway has been implicated in a large range of human cancers. Growth factor receptor stimulation by extracellular ligands activates Ras, which then sets in motion a signal transduction cascade through the Raf, MEK and ERK serine/threonine kinases. Mutation of the B-Raf kinase constitutively activates MAPK signalling, thus bypassing the need for upstream stimuli. This has been genetically associated with several human cancers, especially occurrence of the B-RafV600E mutant and its high prevalence in melanoma, colorectal carcinoma, ovarian cancer, papillary thyroid carcinoma, and cholangiocarcinoma. The ability to selectively and potently inhibit B-Raf should provide a potential therapy for patients with mutant B-Raf tumors, for which addictive dependency on this pathway is observed. We have identified a novel, potent, and selective Raf kinase inhibitor that is capable of inhibiting the kinase activity of wild-type B-Raf, B-RafV600E and c-Raf with IC50 values of 3.2, 0.8, and 5.0 nM, respectively. Kinase panel screening for over 270 kinases has indicated that this inhibitor is selective for Raf kinase, with ∼400 fold selectivity towards B-Raf over 91% of the other kinases tested. Specific cellular inhibition of B-RafV600E kinase by this inhibitor leads to decreased ERK phosphorylation and inhibition of cell proliferation by an initial arrest in the G1 phase of the cell cycle, followed by cell death. This inhibition is selective for cancer cells that specifically encode the mutation for B-RafV600E. Oral compound administration inhibits the growth of B-RafV600E mutant melanoma (A375P) and colon cancer (Colo205) human tumor xenografts, growing subcutaneously in immuno-compromised mice. This cell-specific B-RafV600E inhibitor is currently being evaluated in a human Phase I clinical trial.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B88.
Abstract C31: Phase 1 study of AV-412, a novel irreversible EGFR inhibitor, administered daily in patients with advanced solid tumors
Authors: Bhargava Pankaj , Laheru Dan , Pupareli Carmen , Van Kooten Maximiliano , Martinez Justina L. , Varela Monica , Cotreau Monette M. , Credi Marc , Al-Adhami Mohammed , Wood Debra L. , Hidalgo Manuel
Published: June 2012

Background: Acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib is a frequent clinical phenomenon in non-small cell lung cancer (NSCLC). Approximately 50% patients (pts) with acquired resistance to EGFR TKIs demonstrate the T790M mutation in EGFR gene. AV-412, an irreversible EGFR TKI, has demonstrated activity in chimeric mouse models with acquired resistance to EGFR TKIs (bearing the T790M mutation), and is being developed for treatment of NSCLC.

Methods: Pts with advanced, incurable solid tumors were enrolled in a phase 1 study and administered AV-412 orally once-a-day. Doses evaluated were: 50mg, 100mg, 150mg and 200mg. The goals of the study were to determine the maximum tolerated dose (MTD), safety, dose limiting toxicity (DLT), pharmacokinetics (PK) and activity of AV-412.

Results: 24 pts were treated: 13 males/11 females, median age 61 yrs (range 32–73). ECOG PS 0 (17 pts) or 1 (7 pts). Tumor types (No. of pts) were colorectal (5), NSCLC (3), pancreatic (3), uterine (3), melanoma (2), ovarian (2), hepatocellular (1), breast (1), head and neck (1) and other (3). Mean number of prior treatments were 6 (range 1–15). Five (20.8%) pts had received prior therapy with an EGFR inhibitor. The median duration of treatment was 32.5 days (range 7 – 214 days). Two pts experienced DLT at 200mg (grade 3 nausea and vomiting, and grade 3 diarrhea), following which anti-emetic premedications were instituted in the study. The MTD of AV-412 was 150mg; 11 pts were treated at this dose. The most common treatment-related adverse events (all grades) were nausea (54.2%), diarrhea (45.8%), and vomiting (41.7%); hematologic abnormalities included lymphopenia, increased INR, anemia, and leucopenia (12.5% each), hepatic and renal abnormalities included increased ALT, increased AST, and proteinuria (12.5% each). Drug-related laboratory abnormalities were generally mild to moderate in severity. Preliminary PK data indicate dose proportional exposure. Three patients had disease stabilization > 16 weeks: 2 pts with colorectal cancer (116 days, 170 days) and a pt with ovarian cancer (172 days).

Conclusions: AV-412 is well tolerated at a dose of 150 mg/day. The most frequent toxicities were nausea and diarrhea, which could be controlled with standard medications. This study is currently enrolling a cohort of patients with NSCLC to evaluate clinical activity of AV-412 in patients with EGFR mutations, and updated results will be available for presentation. A phase 1 study of intermittent dosing of AV-412 is also being conducted.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C31.