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Dive into the research topics where George R. Simon is active.

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Featured researches published by George R. Simon.


Clinical Cancer Research | 2006

Combination of p53 cancer vaccine with chemotherapy in patients with extensive stage small cell lung cancer

Scott Antonia; Noweeda Mirza; Ingo Fricke; Alberto Chiappori; Patricia Thompson; Nicholas Williams; Gerold Bepler; George R. Simon; William Janssen; Ji-Hyun Lee; Kerstin Menander; Sunil Chada; Dmitry I. Gabrilovich

Purpose: The initial goal of this study was to test the immunologic and clinical effects of a new cancer vaccine consisting of dendritic cells (DC) transduced with the full-length wild-type p53 gene delivered via an adenoviral vector in patients with extensive stage small cell lung cancer. Experimental Design: Twenty-nine patients with extensive stage small cell lung cancer were vaccinated repeatedly at 2-week intervals. Most of the patients received three immunizations. p53-specific responses were evaluated, and phenotype and function of T cells, DCs, and immature myeloid cells were analyzed and correlated with antigen-specific immune responses. Objective clinical response to vaccination as well as subsequent chemotherapy was evaluated. Results: p53-specific T cell responses to vaccination were observed in 57.1% of patients. Immunologic responses to vaccination were positively associated with a moderate increase in the titer of antiadenovirus antibodies, and negatively with an accumulation of immature myeloid cells. One patient showed a clinical response to vaccination whereas most of the patients had disease progression. However, we observed a high rate of objective clinical responses to chemotherapy (61.9%) that immediately followed vaccination. Clinical response to subsequent chemotherapy was closely associated with induction of immunologic response to vaccination. Conclusions: This study provides clinical support for an emerging paradigm in cancer immunotherapy, wherein optimal use of vaccination might be more effective, not as a separate modality, but in direct combination with chemotherapy.


Journal of Clinical Oncology | 2006

RRM1 modulated in vitro and in vivo efficacy of gemcitabine and platinum in non-small-cell lung cancer.

Gerold Bepler; Irina Kusmartseva; Swati Sharma; Ashish Gautam; Alan Cantor; Anupama Sharma; George R. Simon

PURPOSE RRM1 encodes the regulatory subunit of ribonucleotide reductase and is a molecular target of gemcitabine. Previous studies showed increased RRM1 expression on continuous exposure of cell lines to gemcitabine and suggested improved survival for patients with low as opposed to high tumoral RRM1 expression when treated with gemcitabine-containing chemotherapy. However, the principal hypothesis that intratumoral levels of gene expression are associated with disease response has not been addressed. PATIENTS AND METHODS We constructed genetically modified lung cancer cell lines with increased and decreased RRM1 expression to investigate the in vitro 50% inhibitory concentration (IC50) for gemcitabine, cisplatin, and carboplatin. A prospective phase II clinical trial in patients with locally advanced non-small-cell lung cancer was conducted with pretreatment tumor collection for determination of RRM1 and ERCC1 expression by real-time reverse transcriptase polymerase chain reaction. The levels of gene expression were correlated with tumor response after two cycles of gemcitabine and carboplatin. RESULTS In cell lines with a genetically engineered 15-fold RRM1 expression range, the gemcitabine IC50 had a 100-fold range, and the cisplatin and carboplatin IC50 had a two-fold range. They were highest in constructs with high RRM1 expression. In the prospective clinical trial, RRM1 expression was significantly (P = .002) and inversely correlated (r = -0.498) with disease response. ERCC1 expression showed a similar trend (P = .099). CONCLUSION The results strongly suggest that tumoral RRM1 expression is a major predictor of disease response to gemcitabine/platinum chemotherapy. ERCC1 expression is predictive of response albeit to a lesser degree.


Journal of Clinical Oncology | 2007

Feasibility and Efficacy of Molecular Analysis-Directed Individualized Therapy in Advanced Non–Small-Cell Lung Cancer

George R. Simon; Anupama Sharma; Xueli Li; Todd R. Hazelton; Frank Walsh; Charles Williams; Alberto Chiappori; Eric B. Haura; Tawee Tanvetyanon; Scott Antonia; Alan Cantor; Gerold Bepler

PURPOSE The treatment of patients with advanced non-small-cell lung cancer (NSCLC) is based on clinical trials experience. Molecular characteristics that impact metabolism and efficacy of chemotherapeutic agents are not used for decision making. Ribonucleotide reductase subunit 1 (RRM1) is crucial for nucleotide metabolism, and it is the dominant molecular determinant of gemcitabine efficacy. Excision repair cross-complementing group 1 gene (ERCC1), a component of the nucleotide excision repair complex, is important for platinum-induced DNA adduct repair. We hypothesized that selection of double-agent chemotherapy based on tumoral RRM1 and ERCC1 expression would be feasible and beneficial for patients with advanced NSCLC. PATIENTS AND METHODS We conducted a prospective phase II clinical trial in patients with advanced NSCLC. Patients were required to have a dedicated tumor biopsy for determination of RRM1 and ERCC1 gene expression by real-time quantitative reverse transcriptase polymerase chain reaction. Double-agent chemotherapy consisting of carboplatin, gemcitabine, docetaxel, and vinorelbine was selected based on gene expression. Disease response and patient survival were monitored. RESULTS Eighty-five patients were registered, 75 had the required biopsy without significant complications, 60 fulfilled all eligibility criteria, and gene expression analysis was not feasible in five patients. RRM1 expression ranged from 0 to 1,637, ERCC1 expression ranged from 1 to 8,103, and their expression was correlated (Spearmans rho = 0.46; P < .01). Disease response was 44%. Overall survival was 59% and progression-free survival was 14% at 12 months, with a median of 13.3 and 6.6 months, respectively. CONCLUSION Therapeutic decision making based on RRM1 and ERCC1 gene expression for patients with advanced NSCLC is feasible and promising for improvement in patient outcome


Journal of Clinical Oncology | 2004

RRM1 and PTEN as prognostic parameters for overall and disease-free survival in patients with non-small-cell lung cancer

Gerold Bepler; Swati Sharma; Alan Cantor; Ashish Gautam; Eric B. Haura; George R. Simon; Anupama Sharma; Eric Sommers; Lary A. Robinson

PURPOSE RRM1 has important functions in the determination of the malignant phenotype. It controls cell proliferation through deoxynucleotide production and metastatic propensity through PTEN induction. It is located in a region of loss of heterozygosity in non-small-cell lung cancer (NSCLC), which is a predictor of poor survival. We hypothesized that RRM1 expression would be a significant predictor of outcome in NSCLC. PATIENTS AND METHODS A retrospective data set of 49 patients and a prospective data set of 77 patients with resectable NSCLC were studied. RNA was extracted from tumor and normal lung tissue, and expression of the genes RRM1, PTEN, and RRM2 was determined by real-time quantitative polymerase chain reaction. RESULTS RRM1 expression was significantly correlated with PTEN and RRM2 expression in tumor tissue. RRM1 and PTEN expression in tumor tissue was highly predictive of overall (P =.011 and.018, respectively) and disease-free survival (P =.002 and.026, respectively). Patients with high levels of expression lived longer and had disease recurrence later than patients with low levels of RRM1 and PTEN. In a multivariate analysis, high RRM1 expression was predictive of long survival independent of tumor stage, performance status, and weight loss. CONCLUSION RRM1 is a biologically and clinically important determinant of malignant behavior in NSCLC. Knowing the level of expression of this gene adds significant information to management decisions independent of the currently used outcome predictors of tumor stage, performance status, and weight loss. Future clinical trials should stratify patients based on expression of this gene to avoid unwanted biases.


Journal of Clinical Oncology | 2007

Phase I Trial of Histone Deacetylase Inhibition by Valproic Acid Followed by the Topoisomerase II Inhibitor Epirubicin in Advanced Solid Tumors: A Clinical and Translational Study

Pamela N. Munster; Douglas C. Marchion; Elona Bicaku; Morgen Schmitt; Ji-Hyun Lee; Ronald C. DeConti; George R. Simon; Mayer Fishman; Susan Minton; Chris R. Garrett; Alberto Chiappori; Richard M. Lush; Daniel M. Sullivan; Adil I. Daud

PURPOSE To determine the safety, toxicity, and maximum-tolerated dose of a sequence-specific combination of the histone deacetylase inhibitor (HDACi), valproic acid (VPA), and epirubicin in solid tumor malignancies and to define the clinical feasibility of VPA as an HDACi. PATIENTS AND METHODS Patients were treated with increasing doses of VPA (days 1 through 3) followed by epirubicin (day 3) in 3-week cycles. The study evaluated pharmacokinetic and pharmacodynamic end points, toxicities, and tumor response. RESULTS Forty-eight patients were enrolled, and 44 received at least one cycle of therapy. Patients (median age, 54 years; range, 39 to 78 years) received the following doses of VPA: 15, 30, 45, 60, 75, 90, 100, 120, 140, and 160 mg/kg/d. Dose-limiting toxicities were somnolence (n = 1), confusion (n = 3), and febrile neutropenia (n = 1). No exacerbation of epirubicin-related toxicities was observed. Partial responses were seen across different tumor types in nine patients (22%), and stable disease/minor responses were seen in 16 patients (39%), despite a median number of three prior regimens (range, zero to 10 prior regimens). Patients received a median number of four treatment cycles (range, one to 10 cycles), and treatment was stopped after reaching maximal epirubicin doses rather than progression in 13 (32%) of 41 patients patients. Total and free VPA plasma concentrations increased linearly with dose and correlated with histone acetylation in peripheral-blood mononuclear cells. CONCLUSION The maximum-tolerated dose and recommended phase II dose was VPA 140 mg/kg/d for 48 hours followed by epirubicin 100 mg/m2. Sustained plasma concentrations of VPA exceeding those required for in vitro synergy were achieved with acceptable toxicity. Noteworthy antitumor activity was observed in heavily pretreated patients and historically anthracycline-resistant tumors.


Cancer Control | 2006

Malignant Pleural Mesothelioma: A Comprehensive Review

Roohi Ismail-Khan; Lary A. Robinson; Charles Williams; Chris R. Garrett; Gerold Bepler; George R. Simon

BACKGROUND The incidence of malignant mesothelioma continues to increase, but the disease remains difficult to detect early and treat effectively. METHODS The authors review the pathogenesis, incidence, clinical presentation, diagnosis, pathology, and both standard and experimental treatments for mesothelioma. RESULTS When possible, surgery (video-assisted thoracoscopy, pleurectomy/decortication, or extrapleural pneumonectomy) is utilized. Effects on underlying structures limit application of radiation therapy, but some systemic agents are beginning to enhance survival. CONCLUSIONS The disease is expected to increase in incidence till 2020, so awareness of this entity as a possible diagnosis should be heightened. In patients with advanced disease, several newer antitumor agents are already showing a capability of extending survival so it is not unreasonable to expect further progress in this area.


Journal of Clinical Oncology | 2010

Phase I/II Study of the Src Inhibitor Dasatinib in Combination With Erlotinib in Advanced Non–Small-Cell Lung Cancer

Eric B. Haura; Tawee Tanvetyanon; Alberto Chiappori; Charles Williams; George R. Simon; Scott Antonia; Jhanelle E. Gray; Sharon Litschauer; Leticia Tetteh; Anthony Neuger; Lanxi Song; Bhupendra Rawal; Michael J. Schell; Gerold Bepler

PURPOSE Src family kinase (SFK) proteins are frequently activated in cancer and can coordinate tumor cell growth, survival, invasion, and angiogenesis. Given the importance of SFK signaling in cancer, known cooperation between SFK and epidermal growth factor receptor (EGFR) signaling, and efficacy of EGFR inhibitors, we performed a phase I trial combining dasatinib, an SFK and multikinase inhibitor, with erlotinib, an EGFR inhibitor, in patients with advanced non-small-cell lung cancer. PATIENTS AND METHODS Patients received erlotinib for 1 week before addition of dasatinib; pharmacokinetics were performed after weeks 1 and 2. Four cohorts were examined, including twice-daily and daily dasatinib dosing. Responses were assessed after 8 weeks. Plasma levels of angiogenic markers (vascular endothelial growth factor [VEGF], interleukin-8, and basic fibroblast growth factor [bFGF]) were determined before and during treatment. RESULTS Thirty-four patients were enrolled. The average duration of treatment was 73 days. The main adverse events include GI (diarrhea, anorexia, and nausea), skin rash, cytopenias, pleural effusions, and fatigue. No effect of escalating doses of dasatinib was observed on erlotinib pharmacokinetics. Two partial responses and one bone response were observed, and the disease control rate was 63%. Reductions in plasma VEGF and bFGF were observed, and reductions in VEGF correlated with disease control. CONCLUSION The combination of erlotinib and dasatinib is tolerable, with adverse effects consistent with the two agents. Disease control and inhibition of plasma angiogenesis markers were observed. Personalized strategies for deployment of SFK should receive further attention.


British Journal of Cancer | 2009

Phase I trial of vorinostat and doxorubicin in solid tumours: histone deacetylase 2 expression as a predictive marker

Pamela N. Munster; Douglas C. Marchion; S. Thomas; M. Egorin; Susan Minton; Gregory M. Springett; Ji-Hyun Lee; George R. Simon; Alberto Chiappori; Daniel M. Sullivan; Adil Daud

Background:Histone deacetylase inhibitors (HDACi) can sensitise cancer cells to topoisomerase inhibitors by increasing their access and binding to DNA.Methods:This phase I trial was designed to determine the toxicity profile, tolerability, and recommended phase II dose of escalating doses of the HDACi vorinostat, with weekly doxorubicin.Results:In total, 32 patients were treated; vorinostat was dosed at 400, 600, 800, or 1000 mg day−1 on days 1–3, followed by doxorubicin (20 mg m−2) on day 3 for 3 of 4 weeks. Maximal tolerated dose was determined to be 800 mg day−1 of vorinostat. Dose-limiting toxicities were grade 3 nausea/vomiting (two out of six) and fatigue (one out of six) at 1000 mg day−1. Non-dose-limiting grade 3/4 toxicities included haematological toxicity and venous thromboembolism. Antitumor activity in 24 evaluable patients included two partial responses (breast and prostate cancer). Two patients with melanoma had stable disease for ⩾8 months. Histone hyperacetylation changes in peripheral blood mononuclear and tumour cells were comparable. Histone hyperacetylation seemed to correlate with pre-treatment HDAC2 expression.Conclusion:These findings suggest that vorinostat can be combined with weekly doxorubicin in this schedule at a dose of 800 mg day−1. The HDAC2 expression may be a marker predictive of HDAC inhibition. Antitumor activity of this regimen in breast cancer, prostate cancer, and melanoma seems interesting.


Clinical Cancer Research | 2007

A Phase 1 Escalating Single-Dose and Weekly Fixed-Dose Study of Cetuximab: Pharmacokinetic and Pharmacodynamic Rationale for Dosing

Paula M. Fracasso; Howard A. Burris; Matthew A. Arquette; Ramaswamy Govindan; Feng Gao; Lisa P. Wright; Sherry A. Goodner; F. Anthony Greco; Suzanne F. Jones; Noel Willcut; Catherine Chodkiewicz; Amit P Pathak; Gregory M. Springett; George R. Simon; Daniel M. Sullivan; Raphaël Marcelpoil; Shelley Mayfield; David J. Mauro; Chris R. Garrett

Purpose: This phase 1 study evaluated the pharmacokinetic and pharmacodynamic effects of cetuximab on patients with epithelial malignancies. Experimental Design: Following a skin and tumor biopsy, patients with advanced epithelial malignancies were randomized to receive a single dose of cetuximab at 50, 100, 250, 400, or 500 mg/m2 i.v. Repeat skin (days 2, 8, 15, and 22) and tumor (day 8) biopsies were obtained. Immunohistochemical expression of epidermal growth factor receptor (EGFR) and its pathway members was done on biopsies. Blood samples were obtained over 22 days for pharmacokinetic analyses. After day 22, all patients received weekly 250 mg/m2 cetuximab until disease progression or unacceptable toxicity. Results: Thirty-nine patients enrolled. Rash was noted in 26 (67%) patients. Three patients (two with colon cancer and one with laryngeal cancer) achieved a partial response and 13 patients had stable disease. Pharmacokinetic data revealed mean maximum observed cetuximab concentrations and mean area under the concentration-time curve from time zero to infinity increased in a dose-dependent manner up to 400 mg/m2 cetuximab. Mean clearance was similar at cetuximab doses ≥100 mg/m2, supporting saturation of EGFR binding at 250 mg/m2. Pharmacodynamic evaluation revealed that patients with partial response/stable disease had a higher-grade rash and higher cetuximab trough levels than those with progressive disease (P = 0.032 and 0.002, respectively). Administration of single doses (250-500 mg/m2) of cetuximab resulted in a dose-dependent decrease in EGFR protein expression levels in skin over time, supporting a minimal dose of cetuximab at 250 mg/m2 for a pharmacodynamic effect. Conclusion: This study provides a pharmacokinetic and pharmacodynamic rationale for the dosing of cetuximab.


Journal of Clinical Oncology | 2013

Randomized International Phase III Trial of ERCC1 and RRM1 Expression–Based Chemotherapy Versus Gemcitabine/Carboplatin in Advanced Non–Small-Cell Lung Cancer

Gerold Bepler; Charles Williams; Michael J. Schell; Wei Chen; Zhong Zheng; George R. Simon; Shirish M. Gadgeel; Xiuhua Zhao; Fred Schreiber; Julie R. Brahmer; Alberto Chiappori; Tawee Tanvetyanon; Mary Pinder-Schenck; Jhanelle E. Gray; Eric B. Haura; Scott Antonia; Juergen R. Fischer

PURPOSE We assessed whether chemotherapy selection based on in situ ERCC1 and RRM1 protein levels would improve survival in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Eligible patients were randomly assigned 2:1 to the trials experimental arm, which consisted of gemcitabine/carboplatin if RRM1 and ERCC1 were low, docetaxel/carboplatin if RRM1 was high and ERCC1 was low, gemcitabine/docetaxel if RRM1 was low and ERCC1 was high, and docetaxel/vinorelbine if both were high. In the control arm, patients received gemcitabine/carboplatin. The trial was powered for a 32% improvement in 6-month progression-free survival (PFS). RESULTS Of 331 patients registered, 275 were eligible. The median number of cycles given was four in both arms. A tumor rebiopsy specifically for expression analysis was required in 17% of patients. The median time from informed consent to expression analysis was 11 days. We found no statistically significant differences between the experimental arm and the control arm in PFS (6.1 months v 6.9 months) or overall survival (11.0 months v 11.3 months). A subset analysis revealed that patients with low levels for both proteins who received the same treatment in both treatment arms had a statistically better PFS (P = .02) in the control arm (8.1 months) compared with the experimental arm (5.0 months). CONCLUSION This demonstrates that protein expression analysis for therapeutic decision making is feasible in newly diagnosed patients with advanced-stage NSCLC. A tumor rebiopsy is safe, required in 17%, and acceptable to 89% (47 of 53) of patients.

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Alberto Chiappori

University of South Florida

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Eric B. Haura

University of South Florida

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Scott Antonia

University of South Florida

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Charles Williams

University of South Florida

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Neeta Somaiah

University of Texas MD Anderson Cancer Center

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Daniel M. Sullivan

University of South Florida

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Corey J. Langer

University of Pennsylvania

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John V. Heymach

University of Texas MD Anderson Cancer Center

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