Francesco Caponigro

The ErbB receptors and their ligands in cancer: an overview.

This review article provides an overview on the most recent advances on the role of ErbB receptors and growth factors of the epidermal growth factor (EGF)-family of peptides in cancer pathogenesis and progression. The ErbB tyrosine kinases and the EGF-like peptides form a complex system. In fact, the interactions occurring between receptors and ligands of these families affect the type and the duration of the intracellular signals that derive from receptor activation. Interestingly, activation of ErbB receptors is also driven by different classes of membrane receptor, suggesting that ErbB kinases can amplify growth promoting signals carried by different pathways. The importance of ErbB receptors and EGF-like peptides in development of organs and tissues has been demonstrated by using different mouse models. In vitro and in vivo studies have also shown that ErbB receptors and their ligands can act as transforming genes. However, evidence suggests that cooperation of different receptors and ligands is necessary to induce a fully transformed phenotype. Indeed, co-expression of different ErbB receptors and EGF-like growth factors is a common phenomenon in human primary carcinomas. This observation suggests that the growth and the survival of carcinoma cells is sustained by a network of receptors/ligands of the ErbB family. In this respect, the contemporary expression of different ErbB tyrosine kinases and/or EGF-like growth factors in human carcinomas might also affect tumor response to target based agents directed against the ErbB receptor/ligand system.

Critical role of both p27KIP1 and p21CIP1/WAF1 in the antiproliferative effect of ZD1839 ('Iressa'), an epidermal growth factor receptor tyrosine kinase inhibitor, in head and neck squamous carcinoma cells.

High expression of the epidermal growth factor receptor (EGFR) has been implicated in the development of squamous‐cell carcinomas of head and neck (SCCHN). ZD1839 (‘Iressa’) is an orally active, selective EGFR‐TKI (EGFR‐tyrosine kinase inhibitor) that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host‐dependent processes promoting cancer growth. We have demonstrated that ZD1839 induces growth arrest in SCCHN cell lines by inhibiting EGFR‐mediated signaling. Cell cycle kinetic analysis demonstrated that ZD1839 induces a delay in cell cycle progression and a G1 arrest together with a partial G2/M block; this was associated with increased expression of both p27KIP1 and p21CIP1/WAF1 cyclin‐dependent kinase (CDK) inhibitors. The activity of CDK2, the main target of CIP/KIP CDK inhibitors, was reduced in a dose‐dependent fashion after 24 h of ZD1839 treatment and this effect correlated to the increased amount of p27KIP1 and p21CIP1/WAF1 proteins associated with CDK2‐cyclin‐E and CDK2‐cyclin‐A complexes. In addition, ZD1839‐induced growth inhibition was significantly reduced in cell transfectants expressing p27KIP1 or p21CIP1/WAF1 antisense constructs. Overall, these results as well as the timing of the effect of ZD1839 on G1 arrest and p27KIP1 and p21CIP1/WAF1 upregulation, suggest a mechanistic connection between these events.

Phase I-II Study of Gemcitabine and Carboplatin in Stage IIIB-IV Non–Small-Cell Lung Cancer

PURPOSE Platinum-based chemotherapy currently represents standard treatment for advanced non-small-cell lung cancer. Gemcitabine is one of the most interesting agents currently in use in advanced non-small-cell lung cancer, and high response rates have been reported when it is administered in combination with cisplatin. The aim of the present study was to evaluate the combination of gemcitabine and carboplatin in a phase I-II study. PATIENTS AND METHODS Chemotherapy-naive patients with stage IIIB-IV non-small-cell lung cancer received carboplatin at area under the concentration-time curve (AUC) 5 mg/mL/min and gemcitabine at an initial dose of 800 mg/m2, subsequently escalated by 100 mg/m2 per step. Gemcitabine was administered on days 1 and 8 and carboplatin on day 8 of the 28-day cycle. Dose escalation proceeded up to dose-limiting toxicity (DLT), which was defined as grade 4 neutropenia or thrombocytopenia or grade 3 nonhematologic toxicity. RESULTS Neutropenia was DLT, inasmuch as it occurred in three of five patients receiving gemcitabine 1,200 mg/m2. Nonhematologic toxicities were mild. Gemcitabine 1,100 mg/m2 plus carboplatin AUC 5 was recommended for phase II studies. An objective response was observed in 13 (50%) of 26 patients, including four complete responses (15%) and nine partial responses (35%). Median duration of response was 13 months (range, 3 to 23 months). Median overall survival was 16 months (range, 3 to 26 months). CONCLUSION The combination of gemcitabine and carboplatin is well tolerated and active. Neutropenia was DLT. The observed activity matches that observable in cisplatin-gemcitabine studies, whereas duration of response and survival are even higher. A phase II trial is under way.

Treatment approaches to nasopharyngeal carcinoma: a review.

Early-stage nasopharyngeal carcinoma (T1–2a;N0;M0) represents a small proportion of nasopharyngeal tumors. Radiotherapy alone is the current treatment approach for this tumor and the emerging role of new radiotherapy techniques will hopefully further improve the treatment outcome for these patients. The vast majority of patients with nasopharyngeal carcinoma is diagnosed with locally advanced disease. Concomitant chemoradiotherapy is now acknowledged as being a standard treatment option, even though it induces a considerable incidence of acute mucosal and hematologic toxicity. The issue of adding adjuvant chemotherapy is somewhat more controversial. Similarly, the role of neoadjuvant chemotherapy before concomitant chemoradiotherapy is a matter of interest. In patients with recurrent/metastatic nasopharyngeal carcinoma the prognosis is generally grim, as platinum-based chemotherapy results in a 50–70% response rate and in a median survival time of 11 months. Several trials have been performed on this subset of patients with both cytotoxic and biologic agents, but the results have not been particularly encouraging thus far. Epstein–Barr virus is associated with the vast majority of nasopharyngeal carcinoma. Concentrations of plasma Epstein–Barr virus DNA have been associated with treatment outcome in the clinic. Immunotherapy is generally well tolerated and can sometimes elicit significant immune response, which possibly induces clinical benefit in some patients.

Isoprenylation of intracellular proteins as a new target for the therapy of human neoplasms: preclinical and clinical implications.

Cell proliferation, differentiation, and survival are regulated by a number of extracellular hormones, growth factors, and cytokines in complex organisms. The transduction of the signals by these factors from the outside to the nucleus often requires the presence of small intracellular proteins (i.e. ras and other small G proteins) that are linked to the plasma membrane through a isoprenyl residue that functions as hydrophobic anchor. Isoprenylation is a complex process regulated by different enzymatic steps that could represent potential molecular targets for anti-cancer strategies. In the present paper the different transduction pathways regulated by some isoprenylated proteins such as ras and other small G proteins are described. Moreover, the molecular mechanisms of the isoprenylation process and the mode of action of the different isoprenylation inhibitors are discussed with attention to statins, farnesyltransferase inhibitors (FTI) and aminobisphosphonates. The role of different candidate targets in the determination of anti-tumour effects by FTIs is also described in order to define potential molecular markers predictor of clinical response. On the basis of several preclinical data, new strategies based on multi-step enzyme inhibition or on target prioritization are proposed in order to enhance the anti-tumour activity of agents inhibiting isoprenylation. Finally, a summary of the principal data on clinical trials based on the use of FTIs and statins is given. In conclusion, the inhibition of isoprenylation is an attractive, but still not completely investigated therapeutic alternative that requires optimization for the translation in the current treatment of neoplasms.

Monoclonal antibodies targeting epidermal growth factor receptor and vascular endothelial growth factor with a focus on head and neck tumors.

Purpose of review To provide an overview of recent clinical trials with monoclonal antibodies targeting epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in head and neck cancer (HNC) and in other tumors. To discuss future therapeutic strategies. Recent findings Cetuximab, a chimeric monoclonal antibody targeting EGFR, has induced improved locoregional control and survival in combination with radiotherapy in a phase III study in locally advanced inoperable HNC. The recent Bowel Oncology with Cetuximab Antibody (BOND) study has shown that the combination of irinotecan and cetuximab yields a better response rate and a longer time to progression with respect to cetuximab monotherapy in irinotecan-refractory metastatic colorectal cancer, pointing to both a cetuximab single-agent activity and a cetuximab potential for reversal of irinotecan resistance. Non - small cell lung cancer and pancreatic cancer represent further areas for cetuximab development. Bevacizumab is a humanized monoclonal antibody that targets VEGF. It is the first antiangiogenic drug to have induced a survival advantage in cancer therapy, within a randomized trial of irinotecan, 5-fluorouracil, leucovorin (IFL) combined with bevacizumab or placebo in metastatic colorectal cancer. The use of bevacizumab in HNC is supported by preclinical evidence of an angiogenic loop; a few clinical trials are exploring the feasibility and the therapeutic potential of a combination of bevacizumab and EGFR-targeted drugs. Summary Monoclonal antibodies targeting EGFR and VEGF represent exciting therapeutic strategies that should be further evaluated both in combination with drugs acting on the same target at a different level and in combination with other antisignaling agents acting on different pathways.

Phase I study of Caelyx (doxorubicin HCL, pegylated liposomal) in recurrent or metastatic head and neck cancer

BACKGROUND Pegylated liposome technology represents a favourable drug-carrier system, since stealth liposomal drugs have a reduced clearance with prolonged circulation half-life and selective drug accumulation in tissues with increased vascular permeability, such as tumor tissues. Caelyx is a pegylated liposome containing doxorubicin, which has been developed to target drug delivery to cancer cells, thus reducing toxicities. Biodistribution studies have shown a selective tumor uptake in patients with advanced head and neck cancer (HNC), thus justifying the present phase I study. PATIENTS AND METHODS Patients with recurrent or metastatic HNC were treated with Caelyx administered at the starting dose of 30 mg/m2 every three weeks and escalated by 5 mg/m2 per step. Dose escalation was stopped if more than a third of patients of a given cohort had dose-limiting toxicity (DLT), which was defined as grade 4 neutropenia or thrombocytopenia, grade 3 febrile neutropenia, grade 3 thrombocytopenia with bleeding, grade 3 non-hematologic toxicity (except for nausea and alopecia), or > 2 week delay in chemotherapy recycling. The above dose level was defined as maximum tolerated dose (MTD) and the dose level immediately below was recommended for phase II evaluation. Response was evaluated after three courses of chemotherapy. RESULTS Twenty-four patients were treated at five dose levels. At 50 mg/m2, three out of six patients had grade 3 stomatitis; therefore, this level was defined as MTD and 45 mg/m2 was the selected dose for phase II. Stomatitis occurred in 11 patients across all dose levels, considering all delivered cycles. Neutropenia occurred in 10 of 24 patients, but reached grade 4 in only 2 patients at fourth dose level. Skin toxicity, mainly appearing in the form of palmar-plantar erythrodysestesia, was the most frequent toxicity, occurring in 14 patients. Other side effects were mild. One complete response (4%) and seven partial responses (29%) were observed, for an overall response rate of 33% (95% confidence interval (95% CI): 16%-55%). CONCLUSIONS Caelyx is a safe and promising new treatment in HNC, that deserves further evaluation both alone and integrated within chemo-radiotherapy strategies.

Radioresistance in head and neck squamous cell carcinoma: Biological bases and therapeutic implications.

Head and neck squamous cell carcinoma (HNSCC) is strongly associated with alcohol and tobacco consumption. Lately, the incidence of human papillomavirus (HPV)‐related tumors has shown a significant increase, and HPV‐related tumors show distinctive features if compared with the HPV‐negative counterpart. Locally advanced HNSCC can be treated with concomitant chemoradiotherapy, but early recurrences sometimes occur. Relapses are often related to an intrinsic radioresistance of the tumors. Alterations in intracellular pathways, primarily involved in cell proliferation, apoptosis, and DNA repair, can lead to radioresistance. Preclinical and clinical evidence highlighted that 3 main pathways, including the epidermal growth factor receptor (EGFR), the phosphotidylinositol‐3‐kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), and the p53 signaling cascades, play a crucial role in radioresistance development. A future approach may consist in the association of radiotherapy (RT) and selective inhibition of the key pathways involved in radioresistance. Phase I, II, and III clinical trials are currently testing these novel treatment strategies.

Docetaxel and cisplatin in locally advanced or metastatic squamous-cell carcinoma of the head and neck: A phase II study of the Southern Italy Cooperative Oncology Group (SICOG)

BACKGROUND Docetaxel is one of the most promising new drugs against squamous-cell carcinoma of the head and neck (SCCHN), while cisplatin is one of the most active single agents. A phase I study has shown the feasibility of the combination of the two drugs, and activity in SCCHN has been seen. PATIENTS AND METHODS Patients with locally advanced, inoperable, or metastatic SCCHN, never pretreated with radiotherapy or chemotherapy, received three courses of docetaxel 75 mg/m2 and cisplatin 100 mg/m2, every three weeks. Thereafter, responsive metastatic patients received additional chemotherapy, while patients with locally advanced disease underwent radiation therapy. RESULTS Forty-six patients (forty-five with locally advanced, one with metastatic disease) were entered into the study. Ten patients did not complete three courses of chemotherapy because of early death; one patient discontinued treatment after one course. Twenty-one objective responses were observed (46%, 95% confidence interval (CI): 31%-60%), including five complete responses (11%) and sixteen partial responses (35%). Following induction chemotherapy plus radiation therapy, 9 of 21 evaluable patients were rendered disease free, while 8 additional patients had a partial response. After a median follow-up of 18 months, the median duration of response was 12 months, (range 3-25+), and the median overall survival was 11 months. Six early deaths were considered possibly treatment-related (sepsis following grade 4 neutropenia in two cases, hypovolemic shock following severe diarrhea in four cases). Neutropenia was the most severe toxicity (grade 3-4 in 28 patients, median duration 4 days); diarrhea and vomiting were the most troublesome non-haematologic toxicities (grade 4 in 4 and 3 patients, respectively). CONCLUSIONS The combination of docetaxel and cisplatin is active in SCCHN, but toxicity is substantial. This schedule does not appear to offer any advantage compared with conventional regimens.

Phase I/II study of paclitaxel and vinorelbine in metastatic breast cancer

Paclitaxel and vinorelbine are among the most active new agents in metastatic breast cancer. Both in vitro and in vivo studies have shown that the combined administration of these two microtubule-targeting agents is feasible and worthwhile. Based on the promising preclinical data, patients with metastatic breast cancer no longer amenable to conventional treatment were entered into a phase I/II study in which the vinorelbine dose was fixed at 30 mg/sqm and paclitaxel was started at 90 mg/sqm and then subsequently escalated by 30 mg/sqm per step. Cycles were repeated every 21 days. Hematopoietic growth factor support was provided from the 4th dose level onwards. Grade III neutropenia was observed only in 2 patients treated at the 5th dose level. Thrombocytopenia never reached grade 3. Neurotoxicity was considered dose-limiting, since grade 3 peripheral neuropathy occured in all three patients treated at the 6th dose level. Other toxicities were mild. Paclitaxel 210 mg/sqm and vinorelbine 30 mg/sqm was the selected combination for phase II. Overall response rate in 34 evaluable patients was 38% (95% confidence interval (C.I.), 22% to 54%). In particular, 3 complete responses (9%) and 10 partial responses (29%) were observed. The observed level of antitumor activity, with an overall response rate of 38% and a median duration of response of 12 months, is of interest, since the study was targeted only to anthracycline-pretreated patients, most of whom had adverse prognostic features. The evaluation of a combination of vinorelbine and paclitaxel as first-line therapy in metastatic breast cancer seems worthwhile and is currently undergoing.