Showing papers by "Giampaolo Tortora published in 2006"

Phase II study of gefitinib in combination with docetaxel as first-line therapy in metastatic breast cancer

Abstract: We have evaluated the activity and safety of gefitinib, a small-molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in combination with docetaxel as first-line treatment of women with metastatic breast cancer (MBC). In total, 41 patients with MBC were enrolled in a first-line combination therapy study with oral gefitinib (250 mg day−1) and intravenous docetaxel (75 mg m−2, the first 14 patients; or 100 mg m−2, the following 27 patients, on day 1 of a 3-week cycle). Out of 41 patients, 38 received at least one cycle of therapy. There were no differences in activity or tolerability between the two docetaxel doses. G3/4 toxicities were neutropenia (49%), diarrhoea (10%), acne-like rash (5%), and anaemia (2%). Complete plus partial responses (CR+PR) were observed in 22 out of 41 patients with a 54% response rate (95% confidence interval (CI) 45–75%). The 22 patients that achieved a response following six cycles of docetaxel plus gefitinib continued gefitinib monotherapy (median duration, 24 weeks; range, 2–108+ weeks). Two patients with PR following combination therapy achieved a CR during gefitinib monotherapy. Complete plus partial responses correlated with oestrogen receptor (ER) status, since they occurred in 19 out of 27 (70%) patients with ER-positive tumours as compared to three out of 14 (21%) patients with ER-negative tumours (P=0.01).

Novel Toll-Like Receptor 9 Agonist Induces Epidermal Growth Factor Receptor (EGFR) Inhibition and Synergistic Antitumor Activity with EGFR Inhibitors

Abstract: Purpose: Immunostimulating Toll-like receptor 9 (TLR9) agonists cause antitumor activity interfering also with cancer proliferation and angiogenesis by mechanisms still incompletely understood. We hypothesized that modified TLR9 agonists could impair epidermal growth factor receptor (EGFR) signaling and, by this means, greatly enhance EGFR inhibitors effect, acting on both the receptor targeting and the immunologic arm. Experimental Design: We used a novel second-generation, modified, immunomodulatory TLR9 agonist (IMO), alone and in combination with the anti-EGFR monoclonal antibody cetuximab or tyrosine kinase inhibitor gefitinib, on the growth of GEO and cetuximab-resistant derivatives GEO-CR colon cancer xenografts. We have also evaluated the expression of several proteins critical for cell proliferation, apoptosis, and angiogenesis, including EGFR, mitogen-activated protein kinase, Akt, bcl-2, cyclooxygenase-2, vascular endothelial growth factor, and nuclear factor-κB. Results: IMO inhibited GEO growth and signaling by EGFR and the other proteins critical for cell proliferation and angiogenesis. IMO plus the anti-EGFR antibody cetuximab synergistically inhibited tumor growth, signaling proteins, and microvessel formation. EGFR signaling inhibition by IMO is relevant because IMO cooperated also with EGFR tyrosine kinase inhibitor gefitinib in GEO tumors, while it was inactive against GEO-CR xenografts. On the other hand, IMO boosted the non-EGFR-dependent cetuximab activity, causing a cooperative antitumor effect in GEO-CR cells. Finally, combination of IMO, cetuximab and chemotherapeutic irinotecan eradicated the tumors in 90% of mice. Conclusion: IMO interferes with EGFR-related signaling and angiogenesis and has a synergistic antitumor effect with EGFR inhibitors, especially with cetuximab, boosting both the EGFR dependent and independent activity of this agent. Moreover, this therapeutic strategy could be translated in patients affected by colorectal cancer.

Anti-tumor activity of the combination of cetuximab, an anti-EGFR blocking monoclonal antibody and ZD6474, an inhibitor of VEGFR and EGFR tyrosine kinases

Abstract: Purpose: The epidermal growth factor receptor (EGFR) autocrine pathway plays an important role in cancer cell growth. Vascular endothelial growth factor A (VEGF-A) is a key regulator of tumor-induced endothelial cell proliferation and vascular permeability. ZD6474 is an orally available, small molecule inhibitor of VEGF receptor-2 (VEGFR-2), EGFR and RET tyrosine kinase activity. We investigated the activity of ZD6474 in combination with cetuximab, an anti-EGFR blocking monoclonal antibody, to determine the anti-tumor activity of EGFR blockade through the combined use of two agents targeting the receptor at different molecular sites in cancer cells and of VEGFR-2 blockade in endothelial cells. Experimental Design: The anti-tumor activity in vitro and in vivo of ZD6474 and/or cetuximab was tested in human cancer cell lines with a functional EGFR autocrine pathway. Results: The combination of ZD6474 and cetuximab determined synergistic growth inhibition in all cancer cell lines tested as assessed by the Chou and Talalay method. In nude mice bearing established human colon carcinoma (GEO) or lung adenocarcinoma (A549) xenografts and treated with ZD6474 and/or cetuximab for 4 weeks, a reversible tumor growth inhibition was caused by each drug. In contrast, a more significant tumor growth delay resulted from the combination of the two agents with an approximately 100–110 days increase in mice median overall survival as compared to single agent treatment. Conclusions: This study provides a rationale for evaluating in a clinical setting the double blockade of EGFR in combination with inhibition of VEGFR-2 signaling as cancer therapy. J. Cell. Physiol. 208: 344–353, 2006. © 2006 Wiley-Liss, Inc.

Synergistic Antitumor Activity of ZD6474, An Inhibitor of Vascular Endothelial Growth Factor Receptor and Epidermal Growth Factor Receptor Signaling, with Gemcitabine and Ionizing Radiation against Pancreatic Cancer

Abstract: Purpose: Standard treatments have modest effect against pancreatic cancer, and current research focuses on agents targeting molecular pathways involved in tumor growth and angiogenesis. This study investigated the interactions between ZD6474, an inhibitor of tyrosine kinase activities of vascular endothelial growth factor receptor-2 and epidermal growth factor receptor (EGFR), gemcitabine, and ionizing radiation in human pancreatic cancer cells and analyzed the molecular mechanisms underlying this combination. Experimental Design: ZD6474, ionizing radiation, and gemcitabine, alone or in combination, were given in vitro to MIA PaCa-2, PANC-1, and Capan-1 cells and in vivo to MIA PaCa-2 tumor xenografts. The effects of treatments were studied by the evaluation of cytotoxicity, apoptosis, cell cycle, EGFR and Akt phosphorylation, modulation of gene expression of enzymes related to gemcitabine activity (deoxycytidine kinase and ribonucleotide reductase), as well as vascular endothelial growth factor immunohistochemistry and microvessel count. Results: In vitro , ZD6474 dose dependently inhibited cell growth, induced apoptosis, and synergistically enhanced the cytotoxic activity of gemcitabine and ionizing radiation. Moreover, ZD6474 inhibited phosphorylation of EGFR and Akt and triggered cell apoptosis. PCR analysis showed that ZD6474 increased the ratio between gene expression of deoxycytidine kinase and ribonucleotide reductase. In vivo , ZD6474 showed significant antitumor activity alone and in combination with radiotherapy and gemcitabine, and the combination of all three modalities enhanced MIA PaCA-2 tumor growth inhibition compared with gemcitabine alone. Conclusions: ZD6474 decreases EGFR and Akt phosphorylation, enhances apoptosis, favorably modulates gene expression in cancer cells, and acts synergistically with gemcitabine and radiotherapy to inhibit tumor growth. These findings support the investigation of this combination in the clinical setting.

Capecitabine plus weekly oxaliplatin in gastrointestinal tumors: a phase I study.

Abstract: Objective: To investigate the maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT) of capecitabine plus oxaliplatin. Materials and Methods: Oxaliplatin was given by 2-hour iv infusion on days 1 and 8, and capecitabine was given orally, from day 1 to 14, every 3 weeks. We tested 4 levels of doses: 1) capecitabine 1650 mg/m 2 + oxaliplatin 50 mg/m 2 ; 2) capecitabine 2000 mg/m 2 + oxaliplatin 50 mg/m 2 ; 3) capecitabine 2000 mg/m 2 + oxaliplatin 60 mg/m 2 ; and 4) capecitabine 2500 mg/m 2 + oxaliplatin 60 mg/m 2 . Patients with gastrointestinal neoplasm were eligible for the study. Results: Thirty-two patients were enrolled. At dose level 4, 3 patients had unacceptable toxicity (grade 3 diarrhea, grade 4 diarrhea, and grade 3 mucositis, respectively), thus, level 4 was the MTD. Apart from DLT, overall toxicity was mild: grade ≥3 non-hematological toxicity occurred in 3 patients, and hematological toxicity was sporadic. Conclusion: This study demonstrates that clinically relevant doses of capecitabine (2000 mg/m 2 from day 1 to 14) plus oxaliplatin (60 mg/m 2 on days 1 and 8) every 3 weeks can be given without causing unacceptable toxicity.

Trattamenti in oncologia: il futuro prossimo

Abstract: The knowledge acquired in the past few years on the regulatory mechanisms of cancer growth and spreading have started to be translated in the development of a new therapeutic modality directed against previously defined molecular targets, now defined as "target therapy", thus introducing a truly revolutionary concept in the anticancer therapeutic strategies. The novel molecular targeted drugs are usually integrated in therapeutic regimens that combine such novel agents with the conventional chemotherapy and radiotherapy, and several studies have now demonstrated their efficacy in the clinical practice. The future goal of cancer therapy will be the tailoring of treatments based on the specific molecular features of the tumor of each patient, with the aim to obtain the maximum therapeutic efficacy with the lowest toxicity.

The Epidermal Growth Factor Receptor Pathway as a Selective Molecular-Targeted Treatment in Human Breast Cancer

Abstract: The regulation of normal breast development is dependent on several hormones Among these hormones, estrogens play an essential role in the control of normal mammary development and in the etiology and progression of breast cancer