Hans Skovgaard Poulsen

Cetuximab, bevacizumab, and irinotecan for patients with primary glioblastoma and progression after radiation therapy and temozolomide: a phase II trial

The aim of this clinical trial was to investigate safety and efficacy when combining cetuximab with bevacizumab and irinotecan in patients with recurrent primary glioblastoma multiforme (GBM). Patients were included with recurrent primary GBM and progression within 6 months of ending standard treatment (radiotherapy and temozolomide). Bevacizumab and irinotecan were administered IV every 2 weeks. The first 10 patients received bevacizumab 5 mg/kg, but this was increased to 10 mg/kg after interim safety analysis. Irinotecan dose was based on whether patients were taking enzyme-inducing antiepileptic drugs or not: 340 and 125 mg/m(2), respectively. Cetuximab 400 mg/m(2) as loading dose followed by 250 mg/m(2) weekly was administered IV. Forty-three patients were enrolled in the trial, of which 32 were available for response. Radiographic responses were noted in 34%, of which 2 patients had complete responses and 9 patients had partial responses. The 6-month progression-free survival probability was 30% and median overall survival was 29 weeks (95% CI: 23-37 weeks). One patient had lacunar infarction, 1 patient had multiple pulmonary embolisms, and 3 patients had grade 3 skin toxicity, for which 1 patient needed plastic surgery. One patient was excluded due to suspicion of interstitial lung disease. Three patients had deep-vein thrombosis; all continued on study after adequate treatment. Cetuximab in combination with bevacizumab and irinotecan in recurrent GBM is well tolerated except for skin toxicity, with an encouraging response rate. However, the efficacy data do not seem to be superior compared with results with bevacizumab and irinotecan alone.

Impact of therapy on quality of life, neurocognitive function and their correlates in glioblastoma multiforme: a review

The maintenance of quality of life (QoL) in patients with high-grade glioma is an important endpoint during treatment, particularly in those with glioblastoma multiforme (GBM) given its dismal prognosis despite limited advances in standard therapy. It has proven difficult to identify new therapies that extend survival in patients with recurrent GBM, so one of the primary aims of new therapies is to reduce morbidity, restore or preserve neurologic functions, and the capacity to perform daily activities. Apart from temozolomide, cytotoxic chemotherapeutic agents do not appear to significantly impact response or survival, but produce toxicity that is likely to negatively impact QoL. New biological agents, such as bevacizumab, can induce a clinically meaningful proportion of durable responses among patients with recurrent GBM with an acceptable safety profile. Emerging evidence suggests that bevacizumab produces an improvement or preservation of neurocognitive function in GBM patients, suggestive of QoL improvement, in most poor-prognosis patients who would otherwise be expected to show a sudden and rapid deterioration in QoL.

Activation of the EGFR Gene Target EphA2 Inhibits Epidermal Growth Factor–Induced Cancer Cell Motility

EphA2 overexpression has been reported in many cancers and is believed to play an important role in tumor metastasis and angiogenesis. We show that the activated epidermal growth factor receptor (EGFR) and the cancer-specific constitutively active EGFR type III deletion mutant (EGFRvIII) induce the expression of EphA2 in mammalian cell lines, including the human cancer cell lines A431 and HN5. The regulation is partially dependent on downstream activation of mitogen-activated protein kinase/extracellular signal–regulated kinase kinase and is a direct effect on the EphA2 promoter. Furthermore, EGFR and EphA2 both localize to the plasma membrane and EphA2 coimmunoprecipitates with activated EGFR and EGFRvIII. Ligand activation of EphA2 and EphA2 knockdown by small interfering RNA inhibit EGF-induced cell motility of EGFR-overexpressing human cancer cells, indicating a functional role of EphA2 in EGFR-expressing cancer cells. (Mol Cancer Res 2007;5(3):283–93)

Bevacizumab plus irinotecan in the treatment patients with progressive recurrent malignant brain tumours

Material and Methods. We retrospectively determined the efficacy and safety of a combination of bevacizumab and irinotecan in a consecutive series of 52 heavily pre-treated patients with recurrent high-grade brain tumours. Patients received bevacizumab (10 mg/kg) and irinotecan [340 mg/m2 for those receiving enzyme-inducing antiepileptic drugs (EIAEDs) and 125 mg/m2 for those not receiving EIAEDs] every 2 weeks. Fifty-two patients were included and 47 were evaluable for response. Results. Complete or partial response was observed in 25% of all cases (30% response in grade IV glioma and 15% in grade III glioma). Estimated median progression-free survival (PFS) for both grade IV and grade III glioma was 22 weeks. The 6-month PFS was 32% for all patients, 40% for grade IV glioma and 33% for grade III glioma. Estimated median overall survival was 30 weeks for all patients, 28 weeks for grade IV glioma and 32 weeks for grade III glioma. Four patients discontinued treatment because of unmanageable toxicity: cerebral haemorrhage, cardiac arrhythmia, intestinal perforation and diarrhoea, the latter resulting in death. Discussion. We conclude that the combination of bevacizumab and irinotecan shows acceptable safety and is a clinically relevant choice of therapy in heavily pre-treated patients with recurrent high-grade brain tumours.

The functional role of Notch signaling in human gliomas

Gliomas are among the most devastating adult tumors for which there is currently no cure. The tumors are derived from brain glial tissue and comprise several diverse tumor forms and grades. Recent reports highlight the importance of cancer-initiating cells in the malignancy of gliomas. These cells have been referred to as brain cancer stem cells (bCSC), as they share similarities to normal neural stem cells in the brain. The Notch signaling pathway is involved in cell fate decisions throughout normal development and in stem cell proliferation and maintenance. The role of Notch in cancer is now firmly established, and recent data implicate a role for Notch signaling also in gliomas and bCSC. In this review, we explore the role of the Notch signaling pathway in gliomas with emphasis on its role in normal brain development and its interplay with pathways and processes that are characteristic of malignant gliomas.

Expression of a naturally occurring constitutively active variant of the epidermal growth factor receptor in mouse fibroblasts increases motility

Tumor cell motility is one of the rate‐limiting steps of invasion, which defines progression toward a more malignant phenotype. Elevated expression of epidermal growth factor receptor (EGFR) in many cancers is associated with progression of superficial to invasive forms of the disease. The naturally occuring type III mutant epidermal growth factor receptor (EGFRvIII) is a tumor‐specific, ligand‐independent, constitutively active variant of the epidermal growth factor receptor. EGFRvIII is expressed frequently by a number of human solid tumours including those of the lung, breast, prostate, brain and ovary. Our study was designed to investigate the effect of EGFRvIII expression on cell motility and compare it to that of ligand‐activated EGFR using transfected fibroblasts. We show here using time‐lapse video recording that expression of EGFRvIII greatly enhances the motility of fibroblasts independently of ligand stimulation. In addition, expression of EGFRvIII caused a marked increase in the number of cellular protrusions (lamellipodia) and a reduction in the number of stress fibers and focal adhesions. The EGFR tyrosine kinase inhibitor, AG1478, and the MEK inhibitor, U0126, blocked these cellular effects of EGFRvIII. Two cell lines expressing different levels of EGFR were used for comparison. The low‐expressing cell line responded to EGF treatment by increasing motility in a manner very similar to the motility induced by EGFRvIII. In contrast, the high‐expressing cell line responded to EGF by detachment from the extracellular matrix and decreased motility. Cellular detachment was correlated to a high phosphorylation of PLC‐γ, whereas increased motility was correlated to a high level of ERK phosphorylation. Overall these results indicate that tumor‐associated EGFR mutations might be critical for tumor cell motility, invasion and thus progression of disease.

The prognostic value of immunohistochemical estrogen receptor analysis in paraffin-embedded and frozen sections versus that of steroid-binding assays

Estrogen receptors (ER) were independently analyzed using dextran-coated charcoal assays (ER-DCC) and immunohistochemical assays in frozen (ER-ICA) and paraffin-embedded tissue (ER-PAR) from 130 human breast cancer specimens drawn from postmenopausal high-risk patients registered in the Danish Breast Cancer Cooperative Group. ER was best detected with the ER-DCC assay followed by the ER-ICA (relative sensitivity 87%) and the ER-PAR assays (relative sensitivity 71%). The semiquantified staining features of the immunohistochemical assays were statistically significantly correlated with each other and with ER-DCC. Analysis of disease-free interval (DFI) and overall survival (OS) showed that all assays allowed statistically significant discrimination between a high risk and a low risk group, although the sensitivity differences tended to be reflected as small differences in clinical discriminatory power. The patient groups were then stratified according to adjuvant treatment [radiotherapy (RT) versus radiotherapy and tamoxifen (RT + TAM)]. The survival advantage was tied primarily to the receptor status itself in the steroid-binding assays, but was linked to both the receptor status and the adjuvant treatment in the immunohistochemical assays. Thus, the relative risks in terms of DFI and OS were of the same relative magnitude in the RT and RT + TAM groups for ER-DCC assays using a cut-off level of 10 fmol/mg cytosol protein, while there were large differences in the relative risks between RT and RT + TAM groups for ER-ICA and ER-PAR assays. We conclude that an ER assay in fresh tissue should be given first priority, but if there is no fresh tissue, an ER assay in paraffin-embedded tissue offers a reasonably good alternative as a prognosticator and an equivalent alternative as a predictor of the response to endocrine treatment.

Analysis of the epidermal growth factor receptor specific transcriptome: Effect of receptor expression level and an activating mutation

Overexpression or expression of activating mutations of the epidermal growth factor receptor (EGFR) is common in cancer and correlates with neoplastic progression. The present study employed Affymetrix® oligonucleotide arrays to profile genes induced by ligand‐activated EGFR with the receptor either moderately expressed or overexpressed at an in‐itself transforming level. These changes were compared to those induced by the naturally occurring constitutively active variant EGFRvIII. This study provides novel insight on the activities and mechanisms of EGFRvIII and EGFR mediated transformation, as genes encoding proteins with functions in promoting cell proliferation, invasion, antiapoptosis, and angiogenesis featured prominently in the EGFRvIII‐ and EGFR‐expressing cells. Surprisingly, it was found that ligand‐activated EGFR induced the expression of a large group of genes known to be inducible by interferons. Expression of this module was absent in the EGFRvIII‐expressing cell line and the parental cell line. Treatment with the specific EGFR inhibitor AG1478 indicated that the regulations were primary, receptor‐mediated events. Furthermore, activation of this module correlated with activation of STAT1 and STAT3. The results thus demonstrate that ligand‐activated EGFR at different expression levels results in different kinetics of signaling and induction of gene expression. In addition, the constitutively active variant EGFRvIII seems to activate only a subset of signal pathways and induce a subset of genes as compared to the ligand‐activated EGFR.

PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53

Purpose: Small cell lung cancer (SCLC) is a highly malignant disease with poor prognosis, necessitating the need to develop new and efficient treatment modalities. PRIMA-1Met (p53-dependent reactivation of massive apoptosis), also known as APR-246, is a small molecule, which restores tumor suppressor function to mutant p53 and induces cancer cell death in various cancer types. Since p53 is mutated in more than 90% of SCLC, we investigated the ability of PRIMA-1Met to induce apoptosis and inhibit tumor growth in SCLC with different p53 mutations. Experimental Design: The therapeutic effect of PRIMA-1Met/APR-246 was studied in SCLC cells in vitro using cell viability assay, fluorescence-activated cell-sorting analysis, p53 knockdown studies, and Western blot analyses. The antitumor potential of PRIMA-1Met/APR-246 was further evaluated in two different SCLC xenograft models. Results: PRIMA-1Met/APR-246 efficiently inhibited the growth of the SCLC cell lines expressing mutant p53 in vitro and induced apoptosis, associated with increased fraction of cells with fragmented DNA, caspase-3 activation, PARP cleavage, Bax and Noxa upregulation and Bcl-2 downregulation in the cells. The growth suppressive effect of PRIMA-1Met/APR-246 was markedly reduced in SCLC cell lines transfected with p53 siRNA, supporting the role of mutant p53 in PRIMA-1Met/APR-246-induced cell death. Moreover, in vivo studies showed significant antitumor effects of PRIMA-1Met after i.v. injection in SCLC mouse models with no apparent toxicity. Conclusion: This study is the first to show the potential use of p53-reactivating molecules such as PRIMA-1Met/APR-246 for the treatment of SCLC. Clin Cancer Res; 17(9); 2830–41. ©2011 AACR.

A phase II trial with bevacizumab and irinotecan for patients with primary brain tumors and progression after standard therapy

Abstract The combination of irinotecan and bevacizumab has shown efficacy in the treatment of recurrent glioblastoma multiforme (GBM). A prospective, phase II study of 85 patients with various recurrent brain tumors was carried out. Primary endpoints were progression free survival (PFS) and response rate. Material and methods. Patients with recurrent primary brain tumors with performance status 0–2 were eligible. Intravenous bevacizumab 10 mg/kg and irinotecan 125/340 mg/m2 were administered every 14 days. Evaluation was carried out every eight weeks using MRI and Macdonald response criteria. Treatment was continued until progression. Results. In total 85 patients were included with the following histologies: GBM (n = 32), glioma WHO gr. III (n = 33), glioma WHO gr. II (n = 12) and others (n = 8). Patients received a median of four cycles. ORR (overall response rate) for glioblastoma was 25% and 59% achieved stable disease (SD). Median PFS was 5.2 months. For grade III gliomas ORR was 21% and 45% had SD. Median PFS was 3.7 months. No objective responses occurred in grade II gliomas. In the non-glioma population, one PR as well as several long PFS times were observed. Discussion and conclusion. The combination of bevacizumab and irinotecan is well tolerated and moderately efficacious in glioblastoma and glioma WHO gr. III. A majority of patients achieve at least disease stabilization. Prolonged progression-free survival in non-glioma patients warrants further research.