Resistance to osimertinib in advanced EGFR-mutated NSCLC: a prospective study of molecular genotyping on tissue and liquid biopsies.

BACKGROUND: Resistance to osimertinib in advanced EGFR-mutated non-small cell lung cancer (NSCLC) constitutes a significant challenge for clinicians either in terms of molecular diagnosis and subsequent therapeutic implications. METHODS: This is a prospective single-centre study with the primary objective of characterising resistance mechanisms to osimertinib in advanced EGFR-mutated NSCLC patients treated both in first- and in second-line. Next-Generation Sequencing analysis was conducted on paired tissue biopsies and plasma samples. A concordance analysis between tissue and plasma was performed. RESULTS: Sixty-five advanced EGFR-mutated NSCLC patients treated with osimertinib in first- (n = 56) or in second-line (n = 9) were included. We managed to perform tissue and liquid biopsies in 65.5% and 89.7% of patients who experienced osimertinib progression, respectively. Acquired resistance mechanisms were identified in 80% of 25 patients with post-progression samples, with MET amplification (n = 8), EGFR C797S (n = 3), and SCLC transformation (n = 2) the most frequently identified. The mean concordance rates between tissue and plasma for the EGFR activating mutation and for the molecular resistance mechanisms were 87.5% and 22.7%, respectively. CONCLUSIONS: Resistance to osimertinib demonstrated to be highly heterogeneous, with MET amplification the main mechanism. Plasma genotyping is a relevant complementary tool which might integrate tissue analysis for the study of resistance mechanisms.

PD-L1 overexpression induces STAT signaling and promotes the secretion of pro-angiogenic cytokines in non-small cell lung cancer (NSCLC).

BACKGROUND: Monoclonal antibodies (ICI) targeting the immune checkpoint PD-1/PD-L1 alone or in combination with chemotherapy have demonstrated relevant benefits and established new standards of care in first-line treatment for advanced non-oncogene addicted non-small cell lung cancer (NSCLC). However, a relevant percentage of NSCLC patients, even with high PD-L1 expression, did not respond to ICI, highlighting the presence of intracellular resistance mechanisms that could be dependent on high PD-L1 levels. The intracellular signaling induced by PD-L1 in tumor cells and their correlation with angiogenic signaling pathways are not yet fully elucidated. METHODS: The intrinsic role of PD-L1 was initially checked in two PD-L1 overexpressing NSCLC cells by transcriptome profile and kinase array. The correlation of PD-L1 with VEGF, PECAM-1, and angiogenesis was evaluated in a cohort of advanced NSCLC patients. The secreted cytokines involved in tumor angiogenesis were assessed by Luminex assay and their effect on Huvec migration by a non-contact co-culture system. RESULTS: PD-L1 overexpressing cells modulated pathways involved in tumor inflammation and JAK-STAT signaling. In NSCLC patients, PD-L1 expression was correlated with high tumor intra-vasculature. When challenged with PBMC, PD-L1 overexpressing cells produced higher levels of pro-angiogenic factors compared to parental cells, as a consequence of STAT signaling activation. This increased production of cytokines involved in tumor angiogenesis largely stimulated Huvec migration. Finally, the addition of the anti-antiangiogenic agent nintedanib significantly reduced the spread of Huvec cells when exposed to high levels of pro-angiogenic factors. CONCLUSIONS: In this study, we reported that high PD-L1 modulates STAT signaling in the presence of PBMC and induces pro-angiogenic factor secretion. This could enforce the role of PD-L1 as a crucial regulator of the tumor microenvironment stimulating tumor progression, both as an inhibitor of T-cell activity and as a promoter of tumor angiogenesis.

The value of disease-free survival (DFS) and osimertinib in adjuvant non-small-cell lung cancer (NSCLC): an international Delphi consensus report.

BACKGROUND: Rates of disease recurrence and death following surgery remain high in early-stage non-small-cell lung cancer (NSCLC), despite adjuvant treatment and curative intent. Recently, osimertinib showed overwhelming evidence for disease-free survival (DFS), as demonstrated by an overall reduction in the risk of disease recurrence or death in the adjuvant setting of 80% versus control in the ADAURA study (stage IB-IIIA; hazard ratio 0.20; 99.12% confidence interval 0.14-0.30; P < 0.001). However, due to the early unblinding of ADAURA and lack of mature overall survival data, there is a need to qualitatively confirm consensus on the clinical and patient relevance of DFS. MATERIALS AND METHODS: We conducted a modified Delphi panel study consisting of two rounds of surveys, followed by a consensus meeting. An international panel of experts in the field of NSCLC and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) (n = 13) was asked to rate agreement and comment on a list of pre-defined statements covering key consensus gaps. Statements were eliminated or updated between surveys, depending on the level of agreement. A final list of agreed-upon statements was drafted in the consensus meeting. RESULTS: Consensus was reached on 32 qualitative statements, with topics including unmet needs in early-stage NSCLC, the value of DFS, and the value of osimertinib. Crucially, DFS was agreed to be a clinically and patient-relevant endpoint in adjuvant NSCLC. The relevance of DFS was found to relate to the ability of an adjuvant therapy, such as osimertinib, to keep patients in the clinically valuable curative intent setting, while preventing the burden associated with distant and locoregional recurrence, and progressive disease. CONCLUSIONS: Addressing the need for measures that reflect clinical benefit is essential to continue improving outcomes for NSCLC patients. To that end, this work provides a qualitative framework for clinicians to consider the clinical and patient relevance of DFS in adjuvant NSCLC and the benefit demonstrated in ADAURA thus far.

The lung immuno-oncology prognostic score (LIPS-3): a prognostic classification of patients receiving first-line pembrolizumab for PD-L1 ≥ 50% advanced non-small-cell lung cancer.

BACKGROUND: To stratify the prognosis of patients with programmed cell death-ligand 1 (PD-L1) ≥ 50% advanced non-small-cell lung cancer (aNSCLC) treated with first-line immunotherapy. METHODS: Baseline clinical prognostic factors, the neutrophil-to-lymphocyte ratio (NLR), PD-L1 tumour cell expression level, lactate dehydrogenase (LDH) and their combination were investigated by a retrospective analysis of 784 patients divided between statistically powered training (n = 201) and validation (n = 583) cohorts. Cut-offs were explored by receiver operating characteristic (ROC) curves and a risk model built with validated independent factors by multivariate analysis. RESULTS: NLR < 4 was a significant prognostic factor in both cohorts (P < 0.001). It represented 53% of patients in the validation cohort, with 1-year overall survival (OS) of 76.6% versus 44.8% with NLR > 4, in the validation series. The addition of PD-L1 ≥ 80% (21% of patients) or LDH < 252 U/l (25%) to NLR < 4 did not result in better 1-year OS (of 72.6% and 74.1%, respectively, in the validation cohort). Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 [P < 0.001, hazard ratio (HR) 2.04], pretreatment steroids (P < 0.001, HR 1.67) and NLR < 4 (P < 0.001, HR 2.29) resulted in independent prognostic factors. A risk model with these three factors, namely, the lung immuno-oncology prognostic score (LIPS)-3, accurately stratified three OS risk-validated categories of patients: favourable (0 risk factors, 40%, 1-year OS of 78.2% in the whole series), intermediate (1 or 2 risk factors, 54%, 1-year OS 53.8%) and poor (>2 risk factors, 5%, 1-year OS 10.7%) prognosis. CONCLUSIONS: We advocate the use of LIPS-3 as an easy-to-assess and inexpensive adjuvant prognostic tool for patients with PD-L1 ≥ 50% aNSCLC.

Soluble PD-L1 and Circulating CD8+PD-1+ and NK Cells Enclose a Prognostic and Predictive Immune Effector Score in Immunotherapy Treated NSCLC patients.

INTRODUCTION: Upfront criteria to foresee immune checkpoint inhibitors (ICIs) efficacy are far from being identified. Thus, we integrated blood descriptors of pro-inflammatory/immunosuppressive or effective anti-tumor response to non-invasively define predictive immune profiles in ICI-treated advanced non-small cell lung cancer (NSCLC). METHODS: Peripheral blood (PB) was prospectively collected at baseline from 109 consecutive NSCLC patients undergoing ICIs as first or more line treatment. Soluble PD-L1 (sPD-L1) (immunoassay), CD8+PD-1+ and NK (FACS) cells were assessed and interlaced to generate an Immune effector Score (IeffS). Lung Immune Prognostic Index (LIPI) was computed by LDH levels and derived Neutrophil-to-Lymphocyte Ratio (dNLR). All these parameters were correlated with survival outcome and treatment response. RESULTS: High sPD-L1 and low CD8+PD-1+ and NK number had negative impact on PFS (P < 0.001), OS (P < 0.01) and ICI-response (P < 0.05). Thus, sPD-L1high, CD8+PD-1+low and NKlow were considered as risk factors encompassing IeffS, whose prognostic power outperformed that of individual features and slightly exceeded that of LIPI. Accordingly, the absence of these risk factors portrayed a favorable IeffS characterizing patients with significantly (P < 0.001) prolonged PFS (median NR vs 2.3 months) and OS (median NR vs 4.1) and greater benefit from ICIs (P < 0.01). We then combined each risk parameter composing IeffS and LIPI (LDHhigh, dNLRhigh), thus defining three distinct prognostic classes. A remarkable impact of IeffS-LIPI integration was documented on survival outcome (PFS, HR = 4.61; 95%CI = 2.32-9.18; P < 0.001; OS, HR=4.03; 95%CI=1.91-8.67; P < 0.001) and ICI-response (AUC=0.90, 95%CI=0.81-0.97, P < 0.001). CONCLUSION: Composite risk models based on blood parameters featuring the tumor-host interaction might provide accurate prognostic scores able to predict ICI benefit in NSCLC patients.

Osimertinib beyond disease progression in T790M EGFR-positive NSCLC patients: a multicenter study of clinicians' attitudes.

BACKGROUND: In most cases, T790M EGFR-positive NSCLC patients receiving osimertinib developed "non-drugable" progression, as the patients with common EGFR-sensitizing mutations were treated with first-line osimertinib. In both settings, chemotherapy represents the standard treatment and local ablative treatments (LATs) are potential useful options in the case of oligo-progression. METHODS: We conducted a study on "post-progression" (pp) outcomes of T790M EGFR-positive NSCLC patients treated with osimertinib, according to the therapeutic strategy applied: osimertinib beyond progression (± LATs), "switched therapies" or best supportive care only (BSC). RESULTS: 144 consecutive patients were evaluated: 53 (36.8%) did not received post-progression treatments (BSC), while 91 (63.2%) patients received at least 1 subsequent treatment; 50 patients (54.9%) received osimertinib beyond disease progression [19 (20.9%) of them with adjunctive LATs] and 41 (45.1%) a switched therapy. Median ppPFS (progression-free survival) and median ppOS (overall survival) of patients who received osimertinib beyond progression vs. switched therapies were 6.4 months vs. 4.7 months, respectively [HR 0.57 (95% CI 0.35-0.92), p = 0.0239] and 11.3 months vs 7.8 months, respectively [HR 0.57 (95% CI 0.33-0.98), p = 0.0446]. Among patients who received osimertinib beyond progression with and without LATs median ppPFS was 6.4 months and 5.7 months, respectively [HR 0.90 (95% CI 0.68-1.18), p = 0.4560], while median ppOS was 20.2 months and 9.9 months, respectively [HR 0.73 (95% CI 0.52-1.03), p = 0.0748]. At the univariate analysis, the only factor significantly related to the ppPFS was the therapeutic strategy in favor of osimertinib beyond progression (± LATs). Moreover, the only variable which was significantly related to ppOS at the multivariate analysis was osimertinib beyond progression (± LATs). CONCLUSION: Our study confirmed that in clinical practice, in case of "non-druggable" disease progression, maintaining osimertinib beyond progression (with adjunctive LATs) is an effective option.

Real-world outcomes according to treatment strategies in ALK-rearranged non-small-cell lung cancer (NSCLC) patients: an Italian retrospective study.

PURPOSE: Anaplastic lymphoma kinase (ALK) rearrangement confers sensitivity to ALK inhibitors (ALKis) in non-small-cell lung cancer (NSCLC). Although several drugs provided an impressive outcome benefit, the most effective sequential strategy is still unknown. We describe outcomes of real-life patients according to the treatment strategy received. PATIENTS: We retrospectively collected 290 ALK rearranged advanced NSCLC diagnosed between 2011 and 2017 in 23 Italian institutions. RESULTS: After a median follow-up of 26 months, PFS for crizotinib and a new generation ALKis were 9.4 [CI 95% 7.9-11.2] and 11.1 months [CI 95% 9.2-13.8], respectively, while TTF were 10.2 [CI 95% 8.5-12.6] and 11.9 months [CI 95% 9.7-17.4], respectively, being consistent across the different settings. The composed outcomes (the sum of PFS or TTF) in patients treated with crizotinib followed by a new generation ALKis were 27.8 months [CI 95% 24.3-33.7] in PFS and 30.4 months [CI 95% 24.7-34.9] in TTF. The median OS from the diagnosis of advanced disease was 39 months [CI 95% 31.8-54.5]. Patients receiving crizotinib followed by a new generation ALKis showed a higher median OS [57 months (CI 95% 42.0-73.8)] compared to those that did not receive crizotinib [38 months (CI 95% 18.6-NR)] and those who performed only crizotinib as target agent [15 months (CI 95% 11.3-34.0)] (P < 0.0001). CONCLUSION: The sequential administration of crizotinib and a new generation ALKis provided a remarkable clinical benefit in this real-life population, being an interesting option to consider in selected patients.

L718Q mutant EGFR escapes covalent inhibition by stabilizing a non-reactive conformation of the lung cancer drug osimertinib.

Osimertinib is a third-generation inhibitor approved for the treatment of non-small cell lung cancer. It overcomes resistance to first-generation inhibitors by incorporating an acrylamide group which alkylates Cys797 of EGFR T790M. The mutation of a residue in the P-loop (L718Q) was shown to cause resistance to osimertinib, but the molecular mechanism of this process is unknown. Here, we investigated the inhibitory process for EGFR T790M (susceptible to osimertinib) and EGFR T790M/L718Q (resistant to osimertinib), by modelling the chemical step (i.e., alkylation of Cys797) using QM/MM simulations and the recognition step by MD simulations coupled with free-energy calculations. The calculations indicate that L718Q has a negligible impact on both the activation energy for Cys797 alkylation and the free-energy of binding for the formation of the non-covalent complex. The results show that Gln718 affects the conformational space of the EGFR-osimertinib complex, stabilizing a conformation of acrylamide which prevents reaction with Cys797.

Primary resistance to osimertinib due to SCLC transformation: Issue of T790M determination on liquid re-biopsy.

OBJECTIVES: EGFR T790M mutation is the most common mechanism of resistance to first-/second-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) and could be overcome by third-generation EGFR-TKIs, such as osimertinib. Liquid biopsy, a non-invasive technique used to test the presence of the resistant mutation, may help avoiding tissue re-biopsy. However, analysing only circulating-free DNA, information about other less frequent and coexisting resistance mechanisms may remain unrevealed. MATERIALS AND METHODS: All patients reported in this series participated in the ASTRIS trial, a real world treatment study testing the efficacy of osimertinib (80mg os die) in advanced T790M-positive NSCLC progressed to prior EGFR-TKI. Patients were considered eligible to osimertinib if T790M positive on tissue or plasma samples. In our patients, EGFR molecular testing on blood sample was conducted with digital droplet PCR (ddPCR). RESULTS: We report our experience of five patients treated with osimertinib after T790M detection on liquid biopsy that presented a disease progression at first tumor assessment mediated by SCLC transformation, as evidenced at tissue re-biopsies. All patients showed low ratio T790M/activating mutation in the blood before osimertinib (lower than 0.03). For three patients, EGFR mutational analysis was T790M-negative when re-assessed by using a less sensitive method (therascreen®) on the same liquid biopsy sample analysed by ddPCR before osimertinib therapy. CONCLUSION: Although liquid biopsy is a relevant tool to diagnose T790M presence in NSCLC patients resistant to EGFR-TKI, in case of a low ratio T790M/activating mutation, tissue biopsy should be considered to exclude the presence of SCLC transformation and/or other concomitant resistance mechanisms.

ALK-positive adenocarcinoma of the lung expressing neuroendocrine markers and presenting as a "pituitary adenoma".

We report an ALK-rearranged adenocarcinoma of the lung presenting as a pituitary metastasis, clinically simulating a pituitary adenoma. The patient, a 50 year-old, former-smoking woman was admitted with a Parinaud's syndrome characterized by progressive oculomotor impairment of visual verticality, bitemporal hemianopsia and nystagmus. Imaging studies showed a sellar tumor and the biopsy revealed a TTF-1 and napsin positive lung adenocarcinoma strongly expressing synaptophysin and CD56, also harboring ALK rearrangement. A subsequent CT scan disclosed the primary lung mass of the left upper lobe. The patient progressed after 4 cycles of cisplatin/pemetrexed as first line treatment, but showed a partial response and a significant clinical benefit from the combination of ceritinib and nivolumab in a phase Ib trial. Despite its central nervous system tropism, ALK-rearranged adenocarcinoma manifesting with pituitary gland involvement was never reported. Second generation ALK inhibitors seem the best therapeutic strategy.

The Third Italian Consensus Conference for Malignant Pleural Mesothelioma: State of the art and recommendations.

Malignant Pleural Mesothelioma (MPM) remains a relevant public health issue, and asbestos exposure is the most relevant risk factor. The incidence has considerably and constantly increased over the past two decades in the industrialized countries and is expected to peak in 2020-2025. In Italy, a standardized-rate incidence in 2011 among men was 3.5 and 1.25 per 100,000 in men and women, respectively, and wide differences are noted among different geographic areas. The disease remains challenging in terms of diagnosis, staging and treatment and an optimal strategy has not yet been clearly defined. The Third Italian Multidisciplinary Consensus Conference on Malignant Pleural Mesothelioma was held in Bari (Italy) in January 30-31, 2015. This Consensus has provided updated recommendations on the MPM management for health institutions, clinicians and patients.

Risk of recurrent venous thromboembolism and major hemorrhage in cancer-associated incidental pulmonary embolism among treated and untreated patients: a pooled analysis of 926 patients.

UNLABELLED: ESSENTIALS: We performed a pooled analysis of 926 patients with cancer-associated incidental pulmonary embolism (IPE). Vitamin K antagonists (VKA) are associated with a higher risk of major hemorrhage. Recurrence risk is comparable after subsegmental and more proximally localized IPE. Our results support low molecular weight heparins over VKA and similar management of subsegmental IPE. BACKGROUND: Incidental pulmonary embolism (IPE) is defined as pulmonary embolism (PE) diagnosed on computed tomography scanning not performed for suspected PE. IPE has been estimated to occur in 3.1% of all cancer patients and is a growing challenge for clinicians and patients. Nevertheless, knowledge about the treatment and prognosis of cancer-associated IPE is scarce. We aimed to provide the best available evidence on IPE management. METHODS: Incidence rates of symptomatic recurrent venous thromboembolism (VTE), major hemorrhage, and mortality during 6-month follow-up were pooled using individual patient data from studies identified by a systematic literature search. Subgroup analyses based on cancer stage, thrombus localization, and management were performed. RESULTS: In 926 cancer patients with IPE from 11 cohorts, weighted pooled 6-month risks of recurrent VTE, major hemorrhage and mortality were 5.8% (95% confidence interval [CI] 3.7-8.3%), 4.7% (95% CI 3.0-6.8%), and 37% (95% CI 28-47%). VTE recurrence risk was comparable under low molecular weight heparins (LMWH) and vitamin K antagonists (VKAs) (6.2% vs. 6.4%; hazard ratio [HR] 0.9; 95% CI 0.3-3.1), while 12% in untreated patients (HR 2.6; 95% CI 0.91-7.3). Risk of major hemorrhage was higher under VKAs than under LMWH (13% vs. 3.9%; HR 3.9; 95% CI 1.6-10). VTE recurrence risk was comparable in patients with an subsegmental IPE and those with a more proximally localized IPE (HR 1.1; 95% CI 0.50-2.4). CONCLUSION: These results support the current recommendation to anticoagulate cancer-associated IPE with LMWH and argue against different management of subsegmental IPE.

Targeting the MET gene for the treatment of non-small-cell lung cancer.

Recently, a better understanding of the specific mechanisms of oncogene addiction has led to the development of antitumor strategies aimed at blocking these abnormalities in different malignancies, including lung cancer. These abnormalities trigger constitutive activation of tyrosine kinase receptors (RTKs) involved in fundamental cell mechanisms such as proliferation, survival, differentiation and migration, and consequently the aberrant signaling of RTKs leads to cancer growth and survival. The inhibition of aberrant RTKs and downstream signaling pathways has opened the door to the targeted therapy era. In non-small-cell lung cancer (NSCLC), molecular research has allowed the discrimination of different aberrant RTKs in lung cancer tumorigenesis and progression, and thus the identification of several targetable oncogenic drivers. Following the development of small molecules (gefitinib/erlotinib and crizotinib) able to reversibly inhibit the epidermal growth factor receptor (EGFR) and signaling pathways mediated by anaplastic lymphoma kinase (ALK), respectively, the MET signaling pathway has also been recognized as a potential target. Moreover, according to current knowledge, MET could be considered both as a secondary oncogenic mechanism and as a prognostic factor. Several therapeutic strategies for inhibiting activated hepatocyte growth factor receptor (HGFR) and the subsequent downstream signaling transduction have been improved in order to block tumor growth. This review will focus on the MET pathway and its role in resistance to EGFR TK (tyrosine kinase) inhibitors, the different strategies of its inhibition, and the potential approaches to overcoming acquired resistance.

Grading the neuroendocrine tumors of the lung: an evidence-based proposal.

Lung neuroendocrine tumors are catalogued in four categories by the World Health Organization (WHO 2004) classification. Its reproducibility and prognostic efficacy was disputed. The WHO 2010 classification of digestive neuroendocrine neoplasms is based on Ki67 proliferation assessment and proved prognostically effective. This study aims at comparing these two classifications and at defining a prognostic grading system for lung neuroendocrine tumors. The study included 399 patients who underwent surgery and with at least 1 year follow-up between 1989 and 2011. Data on 21 variables were collected, and performance of grading systems and their components was compared by Cox regression and multivariable analyses. All statistical tests were two-sided. At Cox analysis, WHO 2004 stratified patients into three major groups with statistically significant survival difference (typical carcinoid vs atypical carcinoid (AC), P=0.021; AC vs large-cell/small-cell lung neuroendocrine carcinomas, P<0.001). Optimal discrimination in three groups was observed by Ki67% (Ki67% cutoffs: G1 <4, G2 4-<25, G3 ≥25; G1 vs G2, P=0.021; and G2 vs G3, P≤0.001), mitotic count (G1 ≤2, G2 >2-47, G3 >47; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001), and presence of necrosis (G1 absent, G2 <10% of sample, G3 >10% of sample; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001) at uni and multivariable analyses. The combination of these three variables resulted in a simple and effective grading system. A three-tiers grading system based on Ki67 index, mitotic count, and necrosis with cutoffs specifically generated for lung neuroendocrine tumors is prognostically effective and accurate.

MET and ALK as targets for the treatment of NSCLC.

Cell proliferation, survival, differentiation, migration and metabolism are some of the fundamental cellular processes tightly controlled by the activity of tyrosine-kinase receptors (RTKs). The aberrant signaling of RTKs contributes to cancer growth and survival and has become important target for therapeutic approaches. Well-characterized kinase molecular target in lung cancer, in particular in non-small cell lung cancer (NSCLC), is the activated epidermal growth factor receptor (EGFR) pathway. More recently, the oncogenic role of other two tyrosine-kinases, the hepatocyte growth factor receptor (MET) and the anaplastic lymphoma kinase (ALK), has been recognized. Many different therapeutic strategies have been investigated with the goal to inhibit these receptors, subsequent downstream signaling cascades and arrest tumor growth. This review will discuss the MET and ALK pathways, the different strategies of their inhibition and the potential approaches to overcome acquired resistance to kinase inhibitors in these two genes.

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.