An Italian survey on the use of denosumab for the management of skeletal-related events in patients with bone metastases

OBJECTIVE

The Italian Association for Medical Oncology (AIOM) recommends preventive treatment of skeletal-related events in order to improve survival and the quality of life of patients with advanced malignancies. The aim of the study was to evaluate whether routine clinical practice is in agreement with recommendations about the use of denosumab.

PATIENTS AND METHODS

A survey was carried out in Italy in the oncological setting.

RESULTS

The answers to the survey showed that a large proportion of patients with metastases from solid tumors receive treatment; almost all oncologists administered denosumab every 4 weeks but for a shorter period of time than recommended.

CONCLUSIONS

This survey showed that Italian oncologists favor the use of bone-targeted therapy to prevent skeletal-related events in patients affected by metastatic breast, prostate or lung cancer, in agreement with current recommendations.

Lurbinectedin as second- or third-line palliative therapy in malignant pleural mesothelioma: an international, multi-centre, single-arm, phase II trial (SAKK 17/16)

BACKGROUND

Systemic second- and third-line therapies for malignant pleural mesothelioma (MPM) result in a median progression-free survival (mPFS) of <2 months and median overall survival (mOS) of 6-9 months. Lurbinectedin binds to the DNA of the regulatory region while inhibiting tumour-associated macrophage transcription. In early trials, encouraging outcomes occurred in patients (pts) with MPM treated with lurbinectedin. We aimed to generate lurbinectedin efficacy and safety data among pts with progressive MPM.

PATIENTS AND METHODS

Pts with progressing MPM treated with first-line platinum-pemetrexed chemotherapy with or without immunotherapy received lurbinectedin monotherapy. Treatment was given intravenously at 3.2 mg/m² dose every 3 weeks until progression or unacceptable toxicity. Using Simon's two-stage design, the primary endpoint, progression-free survival (PFS) at 12 weeks (PFS_12wks), was met if achieved by ≥21 pts (p0 ≤35% versus p1 ≥55%).

RESULTS

Forty-two pts from nine centres across Switzerland and Italy were recruited. Histology was epithelioid in 33 cases, sarcomatoid in 5, and biphasic in 4. Overall 10/42 (23.8%) underwent prior immunotherapy and 14/42 (33.3%) had progressed ≤6 months after first-line chemotherapy. At data cut-off PFS_12wks was met by 22/42 pts (52.4%; 90% confidence interval (CI): 38.7% to 63.5%; P = 0.015) with an mPFS of 4.1 months and mOS of 11.1 months. The best response was complete and partial remission observed in one patient each and stable disease in 20 pts. The duration of disease control was 6.6 months (95% CI: 5.2-7.4). No significant difference in PFS_12wks, mPFS, and mOS was recorded in epithelioid versus non-epithelioid cases and pts with prior immunotherapy versus those without. Similar mPFS but shorter mOS were observed among pts who progressed within ≤6 months after first-line chemotherapy. Lurbinectedin-related grade 3-4 toxicity was seen in 21 pts, mostly being neutropenia (23.8%) and fatigue (16.7%).

CONCLUSIONS

The primary efficacy endpoint was reached with acceptable toxicity. Lurbinectedin showed promising activity regardless of histology, prior immunotherapy, or outcome on prior treatment. CLINICALTRIALS.

GOV IDENTIFIER

NCT03213301.

Role of proton-coupled folate transporter in pemetrexed resistance of mesothelioma: clinical evidence and new pharmacological tools

BACKGROUND

Thymidylate synthase (TS) has a predictive role in pemetrexed treatment of mesothelioma; however, additional chemoresistance mechanisms are poorly understood. Here, we explored the role of the reduced-folate carrier (RFC/SLC19A1) and proton-coupled folate transporter (PCFT/SLC46A1) in antifolate resistance in mesothelioma.

PATIENTS AND METHODS

PCFT, RFC and TS RNA and PCFT protein levels were determined by quantitative RT-PCR of frozen tissues and immunohistochemistry of tissue-microarrays, respectively, in two cohorts of pemetrexed-treated patients. Data were analyzed by t-test, Fisher's/log-rank test and Cox proportional models. The contribution of PCFT expression and PCFT-promoter methylation to pemetrexed activity were evaluated in mesothelioma cells and spheroids, through 5-aza-2'-deoxycytidine-mediated demethylation and siRNA-knockdown.

RESULTS

Pemetrexed-treated patients with low PCFT had significantly lower rates of disease control, and shorter overall survival (OS), in both the test (N = 73, 11.3 versus 20.1 months, P = 0.01) and validation (N = 51, 12.6 versus 30.3 months, P = 0.02) cohorts. Multivariate analysis confirmed PCFT-independent prognostic role. Low-PCFT protein levels were also associated with shorter OS. Patients with both low-PCFT and high-TS levels had the worst prognosis (OS, 5.5 months), whereas associations were neither found for RFC nor in pemetrexed-untreated patients. PCFT silencing reduced pemetrexed sensitivity, whereas 5-aza-2'-deoxycytidine overcame resistance.

CONCLUSIONS

These findings identify for the first time PCFT as a novel mesothelioma prognostic biomarker, prompting prospective trials for its validation. Moreover, preclinical data suggest that targeting PCFT-promoter methylation might eradicate pemetrexed-resistant cells characterized by low-PCFT expression.

Prognostic factors in elderly patients with malignant pleural mesothelioma: results of a multicenter survey

BACKGROUND

The incidence of malignant pleural mesothelioma (MPM) in elderly patients is increasing. There are no specific guidelines for their management.

METHODS

The clinical records of elderly patients (⩾70 years old) with MPM referred from January 2005 to November 2011 to six Italian Centres were reviewed. Age, gender, histology, International Mesothelioma Interest Group (IMIG) stage, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), Charlson Comorbidity Index (CCI) and treatment modalities were analysed and correlated to overall survival (OS).

RESULTS

In total, 241 patients were identified. Charlson Comorbidity Index was ⩾1 in 92 patients (38%). Treatment was multimodality therapy including surgery in 18, chemotherapy alone in 180 (75%) and best supportive care in 43 cases (18%). Chemotherapy was mainly pemetrexed based. Median OS was 11.4 months. Non-epithelioid histology (HR 2.32; 95% CI 1.66-3.23, P<0.001), age ⩾75 years (HR 1.44; 95% CI 1.08-1.93, P=0.014), advanced (III-IV) stage (HR 1.47; 95% CI 1.09-1.98, P=0.011) and CCI⩾1 (HR 1.38; 95% CI 1.02-1.85, P=0.034) were associated to a shorter OS. Treatment with pemetrexed was associated with improved OS (HR 0.40; 95% CI 0.28-0.56, P<0.001).

CONCLUSIONS

Non-epithelioid histology, age ⩾75 years, advanced IMIG stage and presence of comorbidities according to CCI were significant prognostic factors in elderly patients with MPM. Treatment with pemetrexed-based chemotherapy was feasible in this setting. Prospective dedicated trials in MPM elderly patients selected according to prognostic factors including comorbidity scales are warranted.

Abstract OT1-4-05: Phase I dose-escalation study of oral administration of abexinostat (S 78454, PCI-24781) given with tamoxifen 20 mg in the treatment of patients with advanced breast cancer

Background: Around 20% of patients initially diagnosed with local stage breast cancer will develop metastatic breast cancer, with an about 23% median 5-year survival rate from diagnosis. Patients whose tumors express ER and PR (ER+, PR+) are frequently treated with antiestrogens and aromatase inhibitors (AI). Primary and secondary resistances to hormone therapy lead to tumor progression and shorten survival expectancy.

In preclinical models, treatment of ER+ breast cancer cells with HDAC inhibitors leads to transcriptional down regulation and post-translation modification of the ER. This treatment reverses tamoxifen-induced ER stabilization, followed by induction of pro-apoptotic genes and apoptotic cell death. Epigenetic modulation of ER signaling by HDAC inhibitor represents a novel strategy to reverse hormonal resistance.

Abexinostat is a hydroxamate-based pan-HDAC inhibitor of class I/II, in phase I/II clinical trials. Abexinostat inhibits tumor growth in a panel of commonly used ER+ breast cancer cell lines including ATCC and NCI. Abexinostat potentiates the anti-tumor activity of tamoxifen in vitro in ER+ breast cancer cells, by down-regulation of ER protein expression and its pro-growth response genes (PgR, Cyclin D). It abrogates AKT cell signaling by directly down-regulating AKT1 at the transcriptional and post-translational level. Furthermore, cell death is induced by activating the apoptotic program.

Study design: phase I dose-finding of abexinostat for 4 consecutive days each week of a 3-week cycle given in combination with daily tamoxifen at 20 mg. Dose levels of abexinostat, 120, 140 and 160 mg bid, of 3 to 6 patients will be explored. Two dose de-escalation levels (100/80 mg) are allowed depending on toxicity. Dose-Limiting Toxicities assessment will be done at the end of cycle 2. Once the Maximum Tolerated Dose is determined up to 20 additional patients will be treated at the recommended dose in a confirmatory cohort.

Main eligibility criteria: Female≥ 18 years with histologically confirmed primary adenocarcinoma of the breast; ER+ (IHC≥ 10%), HER2- tumors. Patients must have had tumor progression on an AI administered for advanced/metastatic disease OR recurrence while on or within 12 months of completion of adjuvant AI, OR recurrence within 12 months of adjuvant tamoxifen completion and must have had up to 3 prior chemotherapy regimens in metastatic/advanced setting. Patients must have progressive tumor measurable or evaluable (RECIST criteria version 1.1).

Main objectives: Primary: to assess the safety and the tolerability of the combination treatment and to determine a recommended Phase II dose. Secondary: to determine the pharmacokinetic profile of both the drugs in combination and metabolites; to measure tumor response to the combination; to measure drug target inhibition by assessing acetylation state of histones proteins, HbF level and HDAC2 expression in peripheral blood mononuclear cells and in peripheral blood samples; to assess circulating tumor cells; to analyze biomarkers on tissue sample and pharmacogenomic of genes implicated in the metabolism of combination (optional).

Status: Study opened in September 2012, currently recruiting.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-4-05.

Vinorelbine in pemetrexed-pretreated patients with malignant pleural mesothelioma

BACKGROUND

Pemetrexed-platinum chemotherapy is the standard first-line treatment of unresectable malignant pleural mesothelioma (MPM). At progression, patients are generally selected to experimental trials, when available, or, in every-day clinical practice, they are offered second-line chemotherapy. The optimal treatment has not yet been defined. The aim of this retrospective, single-center study was to evaluate the activity and toxicity of vinorelbine administered to a consecutive series of pemetrexed-pretreated MPM patients.

METHODS

Vinorelbine 25 mg/m(2) was administered intravenously as a single agent on days 1, 8 every three weeks, either as second-line (2L) or further-line (>2L) therapy. Treatment was repeated for a maximum of 6 cycles, until progression, or unacceptable toxicity.

RESULTS

Fifty-nine patients were included in this analysis. Vinorelbine was given to 34 patients as 2L, and to 25 as > 2L treatment. The median age was 69 years (range 45-80). Forty-two patients (71.2%) had a good EORTC prognostic score. Partial response was observed in 9 (15.2%) cases, stable disease in 20 (33.9%). The overall disease control rate (DCR) was 49.1%. Median progression-free survival (PFS) and overall survival (OS) were 2.3 and 6.2 months, respectively. ECOG performance status (PS) (HR(0 vs. 1-2) 0.50; 95%CI: 0.3-0.8; p = 0.014) and PFS ≥ 6 months following first-line (FL) chemotherapy (HR(FL-PFS>6 ms vs. <6 ms) 0.50; 95%CI: 0.3-0.9; p = 0.031) were significantly associated to OS in multivariate analysis. No difference was observed in terms of DCR, PFS, and OS in relation to age, histology, sex, line of vinorelbine therapy, or response to FL treatment. Hematological toxicity was acceptable, with grade 3/4 neutropenia occurring in 5 (8.4%) patients, and there were no cases of febrile neutropenia. The main non-hematological toxicities were grade 2 fatigue in 17 (28.8%) and constipation in 7 (11.8%) patients.

CONCLUSIONS

Vinorelbine was moderately active in pemetrexed-pretreated MPM patients, with an acceptable toxicity profile, particularly in patients with ECOG-PS0 and FL-PFS ≥ 6 months.

Phase II study of pemetrexed and carboplatin plus bevacizumab as first-line therapy in malignant pleural mesothelioma

Background:

The aim of this open label phase II study (NCT00407459) was to assess the activity of the vascular endothelial growth factor (VEGF) inhibitor bevacizumab combined with pemetrexed and carboplatin in patients with previously untreated, unresectable malignant pleural mesothelioma (MPM).

Methods:

Eligible patients received pemetrexed 500 mg m⁻², carboplatin area under the plasma concentration–time curve (AUC) 5 mg ml⁻¹ per minute and bevacizumab 15 mg kg⁻¹, administered intravenously every 21 days for six cycles, followed by maintenance bevacizumab. The primary end point of the study was progression-free survival (PFS). A 50% improvement in median PFS in comparison with standard pemetrexed/platinum combinations (from 6 to 9 months) was postulated.

Results:

Seventy-six patients were evaluable for analysis. A partial response was achieved in 26 cases (34.2%, 95% CI 23.7–46.0%). Forty-four (57.9%, 95% CI 46.0–69.1%) had stable disease. Median PFS and overall survival were 6.9 and 15.3 months, respectively. Haematological and non-haematological toxicities were generally mild; however, some severe adverse events were reported, including grade 3–4 fatigue in 8% and bowel perforation in 4% of patients. Three toxic deaths occurred.

Conclusion:

The primary end point of the trial was not reached. However, due to the limitation of a non-randomised phase II design, further data are needed before drawing any definite conclusion on the role of bevacizumab in MPM.

Reproducibility of the WHO classification of thymomas: practical implications

BACKGROUND

The WHO-classification was shown to be an independent prognostic marker in some but not all retrospective studies possibly due to lack of reproducibility. We investigated the reproducibility of the WHO-classification and its prognostic implication using a large series of resected thymomas.

METHODS

Four independent pathologists histologically classified a surgical series of 129 thymic tumors in a blinded fashion. Fleiss' kappa-coefficient was used to assess the pathologists' overall agreement, and Cohen-Kappa to assess the agreement between two observers. Disease-related-survival (DRS) and progression-free-survival (PFS) curves were generated by Kaplan-Meier method and compared by log-rank test.

RESULTS

In 63/129 (48.8%) cases there was a complete agreement; in 43/129 (33.3%) cases 3/4 pathological diagnoses were identical; in 15/129 (11.6%) cases the diagnoses were identical by pair; in 8/129 (6.2%) cases three different pathological diagnoses were on record. The Kappa-correlation coefficient was only moderate (0.53). A following web review carried out on the 23 cases with at least two different diagnoses reached a complete consensus. The histotype showed a statistically significant impact on PFS and DRS in the classification provided by only two pathologists.

CONCLUSIONS

In this study, the agreement on WHO classification of thymomas was only moderate and this impacted on patients management. Web consensus conference on the diagnosis, more stringent diagnostic criteria or the adoption of referral diagnostic centres may substantially reduce discrepancies.

Copy number aberrations of BCL2 and CDKN2A/B identified by array-CGH in thymic epithelial tumors

The molecular pathology of thymic epithelial tumors (TETs) is largely unknown. Using array comparative genomic hybridization (CGH), we evaluated 59 TETs and identified recurrent patterns of copy number (CN) aberrations in different histotypes. GISTIC algorithm revealed the presence of 126 significant peaks of CN aberration, which included 13 cancer-related genes. Among these peaks, CN gain of BCL2 and CN loss of CDKN2A/B were the only genes in the respective regions of CN aberration and were associated with poor outcome. TET cell lines were sensitive to siRNA knockdown of the anti-apoptotic molecules BCL2 and MCL1. Gx15-070, a pan-BCL2 inhibitor, induced autophagy-dependent necroptosis in TET cells via a mechanism involving mTOR pathways, and inhibited TET xenograft growth. ABT263, an inhibitor of BCL2/BCL-XL/BCL-W, reduced proliferation in TET cells when administered in combination with sorafenib, a tyrosine kinase inhibitor able to downregulate MCL1. Immunohistochemistry on 132 TETs demonstrated that CN loss of CDKN2A correlated with lack of expression of its related protein p16^INK4 and identified tumors with poor prognosis. The molecular markers BCL2 and CDKN2A may be of potential value in diagnosis and prognosis of TETs. Our study provides the first preclinical evidence that deregulated anti-apoptotic BCL2 family proteins may represent suitable targets for TET treatment.

2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) for postchemotherapy seminoma residual lesions: a retrospective validation of the SEMPET trial

BACKGROUND

2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) has been recommended in international guidelines in the evaluation of postchemotherapy seminoma residuals. Our trial was designed to validate these recommendations in a larger group of patients.

PATIENTS AND METHODS

FDG-PET studies in patients with metastatic seminoma and residual masses after platinum-containing chemotherapy were correlated with either the histology of the resected lesion(s) or the clinical outcome.

RESULTS

One hundred and seventy seven FDG-PET results were contributed. Of 127 eligible PET studies, 69% were true negative, 11% true positive, 6% false negative, and 15% false positive. We compared PET scans carried out before and after a cut-off level of 6 weeks after the end of the last chemotherapy cycle. PET sensitivity, specificity, negative predictive value (NPV), and positive predictive value were 50%, 77%, 91%, and 25%, respectively, before the cut-off and 82%, 90%, 95%, and 69% after the cut-off. PET accuracy significantly improved from 73% before to 88% after the cut-off (P=0.032).

CONCLUSION

Our study confirms the high specificity, sensitivity, and NPV of FDG-PET for evaluating postchemotherapy seminoma residuals. When carried out at an adequate time point, FDG-PET remains a valuable tool for clinical decision-making in this clinical setting and spares patients unnecessary therapy.

Second-line chemotherapy in malignant pleural mesothelioma: results of a retrospective multicenter survey

The pemetrexed-cisplatin chemotherapy is standard of care in first-line (FL) treatment of malignant pleural mesothelioma (MPM). The second-line (SL) chemotherapy is considered, but the optimal treatment has not been defined yet. The aim of this study was to evaluate the clinical outcomes of SL-therapy in a series of MPM-patients included in a retrospective multicenter database. Clinical records of MPM-patients who received SL-treatment from 1996 to 2008 were reviewed. Study endpoints were response, overall-survival (OS), and progression-free-survival (PFS) for SL, stratified for patient characteristics, FL-outcomes, and type of SL. Out of 423 patients, 181 with full clinical data were identified. Patients' characteristics: median-age 64 years (range: 36-85); male gender 115 (63.5%); good EORTC-score 109 (60.2%); epithelial histology 135 (74.6%). After FL, 147 (81.2%) patients achieved disease-control (DC) and 45 had a time-to-progression≥12 months (TTP≥12). After SL, 95 patients (52.6%) achieved DC (21 response; 74 stable-disease); median PFS and OS were 4.3 and 8.7 months, respectively. According to multivariate analysis, DC after SL-therapy was significantly related to pemetrexed-based treatment (OR: 2.46; p=0.017) and FL-TTP≥12 (OR: 3.50; p=0.006). PFS was related to younger age (<65 years) (HR: 0.70; p=0.045), ECOG-PS0 (HR: 0.67; p=0.022), and FL-TTP≥12 (HR: 0.45; p<0.001). OS was significantly related to ECOG-PS0 (HR: 0.43; p<0.001) and to FL-TTP≥12 (HR: 0.54; p=0.005). In pemetrexed pre-treated patients, re-treatment with a pemetrexed/platinum combination significantly reduced the risk-of-death than pemetrexed alone (HR: 0.11; p<0.001). In conclusion, SL-chemotherapy seems to be active in MPM-patients, particularly in younger patients with ECOG-PS0 and prolonged TTP after FL-pemetrexed-based chemotherapy. In selected patients, re-challenge with pemetrexed-based regimens, preferentially associated with platinum-compound, appears to be an option for SL-setting. Considering the important limitations of this study, due to retrospective nature and the possible selection bias, prospective clinical trials are warranted to clarify these issues.

Advances in the biology of malignant pleural mesothelioma

Malignant pleural mesothelioma is a highly aggressive cancer with a very poor prognosis. Although the mechanism of carcinogenesis is not fully understood, approximately 80% of malignant pleural mesothelioma can be attributed to asbestos fiber exposure. This disease is largely unresponsive to conventional chemotherapy or radiotherapy, and most patients die within 10-17 months of their first symptoms. Currently, malignant pleural mesothelioma therapy is guided by clinical stage and patient characteristics rather than by the histological or molecular features of the tumor. Several molecular pathways involved in malignant pleural mesothelioma have been identified; these include cell cycle regulation, apoptosis, growth factor pathways, and angiogenesis. Unfortunately, several agents targeting these processes, including erlotinib, gefitinib, and imatinib, have proven ineffective in clinical trials. A greater understanding of the molecular pathways involved in malignant pleural mesothelioma is needed to develop better diagnostics, therapeutics, and preventative measures. Moreover, understanding the biological basis of mesothelioma progression may facilitate personalized treatment approaches, and early identification of poor prognostic indicators may help reduce the heterogeneity of the clinical response. This paper reviews advances in the molecular biology of malignant pleural mesothelioma in terms of pathogenesis, the major molecular pathways and the associated therapeutic strategies, and the roles of biomarkers.

Phase II study of NGR-hTNF, a selective vascular targeting agent (VTA), in previously treated patients with malignant pleural mesothelioma (MPM)

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Background: NGR-hTNF is a VTA exploiting a tumor-homing peptide (NGR) that selectively binds to an aminopeptidase N (CD13) overexpressed on tumor blood vessels. In preclinical models, NGR-hTNF has shown potent anti-vascular and antitumor activity, both at low and at high doses. Methods: Patients with advanced MPM were treated with a low-dose of NGR-hTNF given intravenously at 0.8 μg/m2 as 1-hour infusion every 3 weeks (q3w). This phase II trial had a 2-stage design with 16 and a total of 27 patients to be enrolled after first and second stage, respectively. Primary endpoint was progression-free survival (PFS) with restaging performed q6w according to MPM-modified RECIST criteria. Results: From May 2007 to January 2008, forty-three patients with radiologically-documented progressive disease after a pemetrexed-based regimen were evaluated over 167 cycles (range, 1 to 17). Patient characteristics were: median age 64 years (range, 54 to 80); male/female 27/16; epithelial/non-epithelial histology 34/9; PS 0/1/2 24/10/9; EORTC score good/poor 34/9. Main grade 1–2 toxicity was chills (71%), transiently occurring after the first infusions. Only one grade 3 treatment-related toxicity was observed. One patient (2%) had a partial response lasting 7.1+ months and 17 patients (40%) maintained stable disease for a median duration of 4.4 months (range, 1.3 to 12.4+ months). The median and 3-month PFS were 2.8 months and 43%, respectively, whereas the median and 1-year overall survival were 11.6 months and 48%, respectively. In an additional 14 patients treated at same dose with a weekly schedule, there was any suggestion of toxicity exacerbation. In this cohort, the PFS rate at 6 months was 36%, with 7 patients (50%) experiencing stable disease for a median duration of 6.9 months (range, 2.4 to 9.3+ months). Conclusions: NGR-hTNF 0.8 μg/m2 weekly is well tolerated, showing prolonged disease control in previously treated MPM patients, and will be further developed in this setting.

[Table: see text]

MET increased gene copy number and primary resistance to gefitinib therapy in non-small-cell lung cancer patients

BACKGROUND

MET amplification has been detected in approximately 20% of non-small-cell lung cancer patients (NSCLC) with epidermal growth factor receptor (EGFR) mutations progressing after an initial response to tyrosine kinase inhibitor (TKI) therapy.

PATIENTS AND METHODS

We analyzed MET gene copy number using FISH in two related NSCLC cell lines, one sensitive (HCC827) and one resistant (HCC827 GR6) to gefitinib therapy and in two different NSCLC patient populations: 24 never smokers or EGFR FISH-positive patients treated with gefitinib (ONCOBELL cohort) and 182 surgically resected NSCLC not exposed to anti-EGFR agents.

RESULTS

HCC827 GR6-resistant cell line displayed MET amplification, with a mean MET copy number >12, while sensitive HCC827 cell line had a mean MET copy number of 4. In the ONCOBELL cohort, no patient had gene amplification and MET gene copy number was not associated with outcome to gefitinib therapy. Among the surgically resected patients, MET was amplified in 12 cases (7.3%) and only four (2.4%) had a higher MET copy number than the resistant HCC827 GR6 cell line.

CONCLUSIONS

MET gene amplification is a rare event in patients with advanced NSCLC. The development of anti-MET therapeutic strategies should be focused on patients with acquired EGFR-TKI resistance.

Pemetrexed plus carboplatin in elderly patients with malignant pleural mesothelioma: combined analysis of two phase II trials

The incidence of malignant pleural mesothelioma (MPM) in elderly patients is increasing. In this study, pooled data from two phase II trials of pemetrexed and carboplatin (PC) as first-line therapy were retrospectively analysed for comparisons between age groups. Patients received pemetrexed 500 mg m(-2) and carboplatin AUC 5 mg ml(-1) min(-1) intravenously every 21 days with standard vitamin supplementation. Elderly patients were defined as those >or=70 years old. A total of 178 patients with an ECOG performance status of or=70 years (27%). Grade 3-4 haematological toxicity was slightly worse in >or=70 vs <70-year-old patients, with neutropenia observed in 25.0 vs 13.8% (P=0.11), anaemia in 20.8 vs 6.9% (P=0.01) and thrombocytopenia in 14.6 vs 8.5% (P=0.26). Non-haematological toxicity was mild and similar in the two groups. No significant difference was observed in terms of overall disease control (60.4 vs 66.9%, P=0.47), time to progression (7.2 vs 7.5 months, P=0.42) and survival (10.7 vs 13.9 months, P=0.12). Apart from slightly worse haematological toxicity, there was no significant difference in outcome or toxicity between age groups. The PC regimen is effective and well tolerated in selected elderly patients with MPM.

Role of cMET expression in non-small-cell lung cancer patients treated with EGFR tyrosine kinase inhibitors

BACKGROUND

Approximately 10% of unselected non-small-cell lung cancer (NSCLC) patients responded to the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. However, resistance mechanisms are not well understood. We evaluated several potential biological markers of intrinsic EGFR-TKIs-resistance in NSCLC.

MATERIALS AND METHODS

pAKT, pERK, cSRC, E-cadherin, cMET[pY1003], cMET[pY1230/1234/1235], and cMET[pY1349] immunohistochemistry, cMET FISH analysis, and EGFR-, KRAS-, and cMET mutation analysis were carried out on tumor samples from 51 gefitinib-treated NSCLC patients. Biological parameters and survival end points were compared by univariate and multivariate analyses. cMET expression was also investigated in two additional series of patients. The in vitro antiproliferative activity of gefitinib alone or in combination with hepatocyte growth factor and the cMET antibody DN-30 was assessed in NSCLC cells.

RESULTS

EGFR19 deletion and pAKT expression were significantly associated with response (P < 0.0001) and longer time to progression (TTP) (P = 0.007), respectively. Strong cMET[pY1003] membrane immunoreactivity was expressed in 6% of 149 tumors analyzed and was significantly associated with progressive disease (P = 0.019) and shorter TTP (P = 0.041). In vitro, the DN-30 combination synergistically (CI < 1) enhanced gefitinib-induced growth inhibition in all cMET[pY1003]-expressing cell lines studied.

CONCLUSIONS

Activated cMET[pY1003] appears to be a marker of primary gefitinib resistance in NSCLC patients. cMET may be a target in treatment of NSCLC.

Src as a potential therapeutic target in non-small-cell lung cancer

Lung cancer is the most common cause of cancer-related death, with non-small-cell lung cancer (NSCLC) accounting for 80%-85% of all cases. Although survival rates are reasonably good for patients diagnosed with very early disease, the majority of patients present with advanced disease. For these patients, palliation and improvements in quality of life are the primary goals of therapy. Although chemotherapeutic agents remain the cornerstone of first-line therapy, these agents have limited use in patients who have relapsed and have metastatic disease. Therefore, new strategies are required to improve survival and quality of life in this setting. With the substantial advances in our understanding of tumour biology, it has been possible to identify signalling pathways involved in mediating tumour growth and progression. These pathways offer targets for new biological agents such as small molecule inhibitors and monoclonal antibodies. One such target is Src, a tyrosine kinase that is involved in multiple aspects of tumorigenesis including proliferation, migration and angiogenesis. Increased levels of Src expression have been found in a range of cancers, especially breast, colorectal, prostate and lung. Preliminary preclinical data and pharmacodynamic data suggest that Src inhibition is a viable therapeutic option in the treatment of advanced NSCLC.

Activated c-Met[pY1003]: A potential marker of intrinsic resistance and therapy target to restore sensitivity to gefitinib

7624

Background: Epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR-TKIs) show anti-tumor activity in only 10% of Caucasian non-small cell lung cancer (NSCLC) patients. Aim of this study was to evaluate several biological parameters potentially related to EGFR, including c-Met activation, as potential markers of intrinsic resistance to EGFR-TKIs in NSCLC. Methods: P-Akt, p-Erk, c-Src, E-Cadherin, c-Met[pY1003] and c-Met[pY1230/1234/1235] status was immunohistochemically determined on a tissue micro-array of tumor samples from 51 NSCLC patients treated with gefitinib. EGFR, k-ras, and c-Met mutation analysis was also carried out. A panel of NSCLC cell lines expressing c-Met[pY1003] were treated with gefitinib (0.01–100μ M) alone or in combination with hepatocyte growth factor (40 ng/ml) and the c-Met-agonistic antibody DN-30 (80 μg/ml) for 72 hours in 0.5% FCS medium. Drug interaction between gefitinib and DN-30 was assessed, at a non-constant concentration ratio, using the combination index (CI) method. Results: There was no association between p-Erk, c-Src, E-Cadherin, c-Met[pY1230/1234/1235], and k-ras status and response or survival. EGFR exon 19 deletion and p-Akt nuclear staining were significantly associated with response (P<0.0001; Fisher's exact test) and longer time to progression (TTP) (P=0.007; log-rank test), respectively. High c-Met[pY1003] membrane staining was significantly associated with progressive disease (P=0.019; Fisher's exact test) and shorter TTP (P=0.0416; log-rank test), but not with survival. Multivariate analysis confirmed a significant relationship between c-Met[pY1003] and increased risk of disease progression (HR=2.464, 95% CI 1.293–4.696, P=0.006). No c-Met mutations were found. In vitro, the combination with DN- 30 synergistically (CI<1) enhanced gefitinib-induced growth inhibition in all c-Met[pY1003]-expressing NSCLC cells studied (H460, SW1573, A549 and H292). Conclusions: Activation of c-MET may be a biological marker of intrinsic resistance to gefitinib in NSCLC patients, and combined inhibition of c-Met and EGFR may be a suitable therapeutic approach in patients with activated c-Met[pY1003] tumors.

No significant financial relationships to disclose.

DNA methylation profile predicts survival of patients with resected malignant pleural mesothelioma (MPM)

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Background: Methylation in different tumor suppressor genes is among the most frequent alterations reported in MPM patients (pts). DNA methylation increases upon immortalization and transformation of human mesothelial cells, and demethylating agents were found to have some activity in MPM. In this study we analysed the methylation status of the promoter region of four candidate genes in MPM: p15INK4BINK4B, p16INK4AINK4A, RASSF1A and NORE1A. Methods: Samples of 79 consecutive MPM pts who underwent surgical procedures (41 extrapleural pneumonectomy (EPP), 32 partial pleurectomy, 6 diagnostic biopsy) at our Institution from 1997 to 2005 were analyzed. DNA was isolated from each paraffin-embedded MPM; the methylation status of the four genes was evaluated by a methylation-specific PCR method (MSP). Correlations between methylation status, clinico-pathological parameters (including proliferation index) and overall survival (OS) were examined in all pts and in the EPP subgroup. Proliferation index was evaluated as percentage of nuclear immunoreactivity/10 high-power field using a mouse monoclonal antibody anti-human Ki-67, clone MIB-1 (DAKO Corporation, Carpinteria, CA). Results: The MSP analysis documented gene promoter methylation in at least one gene in 30 cases (38%). The methylation frequency of each gene was: p15INK4B 15 cases (19%), p16INK4A 9 (11.4%), RASSF1A 16 (20.2%), Nore1A 4 (5.1%). Of the 30 methylated MPMs, 18 (60%) showed only one methylated gene, 10 (33.3%) were methylated in two genes and 2 (6.7%) in three. Methylation in at least one gene was associated to a higher proliferation index (P=0.058, ANOVA), but not to OS, in the whole study population. In pts treated with EPP, the 22 methylated cases showed a trend to a worst OS in comparison to 19 unmethylated cases (median OS 16 months vs 35 months, P=0.066, HR=2.01, 95% CI 0.94–4.30, Cox regression), independently by histology and nodal status. Conclusions: In pts treated with EPP, the methylation profile of p15INK4BINK4B, p16INK4AINK4A, RASSF1A and NORE1A appeared to be an independent prognostic factor for OS. The methylation status was correlated to proliferation rate, indicating a potential role of these oncosuppressor genes in the neoplastic progression of MPM.

No significant financial relationships to disclose.

EGFR overexpression in malignant pleural mesothelioma. An immunohistochemical and molecular study with clinico-pathological correlations

The epidermal growth factor receptor (EGFR) is overexpressed in many epithelial malignancies, against which some antitumoral drugs have been developed. There is a lack of information as to EGFR expression in malignant pleural mesothelioma (MPM), an aggressive and fatal cancer poorly responsive to current oncological treatments. Our aim was to: (a) compare EGFR immunohistochemical expression with mRNA levels measured by real time PCR; (b) assess the relationships between EGFR expression and clinico-pathological data including survival; (c) analyze the EGFR mutations. We developed an immunohistochemical method of EGFR evaluation based on the number of immunoreactive cells and staining intensity in 61 MPMs. EGFR immunoreactivity was documented in 34/61 (55.7%) cases. A significant correlation between EGFR protein and mRNA levels (p = 0.0077) was found, demonstrating the reliability of our quantification method of EGFR membrane expression. Radically resected patients (p = 0.005) and those with epithelial histotype (p = 0.048) showed an increased survival. No statistical correlation between EGFR immunoreactivity and patients survival was observed. No EGFR mutation was documented. This study documents EGFR overexpression in MPM at the protein and the transcriptional levels; it proposes a reliable method for EGFR expression evaluation in MPM. EGFR levels are not associated with clinico-pathological features of patients, including survival.

Analysis of epidermal growth factor receptor expression as a predictive factor for response to gefitinib ('Iressa', ZD1839) in non-small-cell lung cancer

Gefitinib ('Iressa', ZD1839) is an orally active epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that has demonstrated antitumour activity and favourable tolerability in Phase II studies. We investigated whether EGFR expression levels could predict for response to gefitinib in patients with advanced non-small-cell lung cancer (NSCLC), who received gefitinib (250 mg day(-1)) as part of a worldwide compassionate-use programme. Tissue samples were analysed by immunohistochemistry to assess membrane EGFR immunoreactivity. Of 147 patients enrolled in our institution, 50 patients were evaluable for assessment of both clinical response and EGFR expression. The objective tumour response rate was 10% and disease control was achieved in 50% of patients. Although high EGFR expression was more common in squamous-cell carcinomas than adenocarcinomas, all objective responses were observed in patients with adenocarcinoma. Response and disease control with gefitinib were not associated with high EGFR expression. Overall, median survival was 4 months, and the 1-year survival rate was 18%. Strong EGFR staining correlated with shorter survival time for all patients. Gefitinib demonstrated promising clinical activity in this group of patients with NSCLC. These results have also shown that EGFR expression is not a significant predictive factor for response to gefitinib.

Activity of a specific inhibitor, gefitinib (Iressa™, ZD1839), of epidermal growth factor receptor in refractory non-small-cell lung cancer

BACKGROUND

Gefitinib (Iressa(TM), ZD1839) is an orally active, selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. Phase I studies showed that it is well tolerated, with evidence of tumor regression in patients with advanced non-small-cell lung cancer (NSCLC). Therefore, we aimed to assess the antitumor activity and tolerability of gefitinib in a series of patients with previously treated, advanced NSCLC, as a part of a compassionate use program.

PATIENTS AND METHODS

To be eligible, all patients were required to have histologically or cytologically proven advanced or metastatic NSCLC, prior chemotherapy with at least one cisplatin-containing chemotherapy regimen or contraindication to cytotoxic drugs, Eastern Cooperative Oncology Group performance status < or =2, and adequate hematological, renal and hepatic parameters. All patients provided signed informed consent. Patient re-evaluation was performed every 4-6 weeks.

RESULTS

Seventy-three consecutive patients were enrolled. Response rate, including complete and partial response, was 9.6%; an additional 43.8% of patients achieved stable disease, for an overall disease control of 53.4%. EGFR1 status was evaluated by immunocytochemistry in 25 patients. According to EGFR1 immunoreactivity all responses were observed with medium/strong imunoreactivity while three out of four responses were observed in high expressive patients. Median survival for all patients was 4 months while it reached 6 months for patients with disease control. The 1-year survival rate was 13.1% for the entire series and 23.2% for patients with disease control. Non-hematological toxicity was generally mild.

CONCLUSION

Gefitinib has promising activity with a good toxicity profile in patients with progressive NSCLC who have received one or two prior chemotherapy regimens. A possible relationship within response and EGFR1 expression is suggested.

Irinotecan and raltitrexed: an active combination in advanced colorectal cancer

BACKGROUND

Irinotecan and raltitrexed are active agents in metastatic colorectal cancer. Preclinical findings suggest a remarkable synergistic activity between the two drugs and the feasibility of this association has been shown in a recent phase I study. The aim of our phase II trial was to assess the efficacy and tolerability of the combination of irinotecan and raltitrexed in patients with metastatic colorectal cancer untreated with chemotherapy.

PATIENTS AND METHODS

From June 1998 to February 2000, 46 patients were enrolled. Patients received irinotecan 350 mg/m(2) on day 1 and raltitrexed 2.6 mg/m(2) on day 2, every 3 weeks, for up to nine courses. Tumour assessment was performed every three cycles.

RESULTS

A total of 223 cycles of chemotherapy, with a median number of six (range 1-9) courses per patient, was administered. According to intention-to-treat analysis, the overall response rate was 46% (95% confidence interval 31% to 61%). The median duration of response was 21 weeks (range 11-> or =101), the median time to progression 27 weeks (range 1-> or =116), and the median overall survival 57 weeks (range 1-> or =130). The main toxicities were diarrhoea, with National Cancer Institute common toxicity criteria grade 3/4 in 26% of patients, grade 3/4 neutropenia in 20%, grade 3 nausea-vomiting in 13%, grade 3 asthenia in 11% and grade 3/4 transaminase elevation in 4%.

CONCLUSIONS

Results achieved with irinotecan and raltitrexed show that this regimen is active, despite 'not-negligible' toxicity, and may represent a useful regimen for specific subgroups of colorectal cancer patients.