Abstract CT083: A pivotal randomized phase II study of anetumab ravtansine or vinorelbine in patients with advanced or metastatic pleural mesothelioma after progression on platinum/pemetrexed-based chemotherapy (NCT02610140)

Background: Mesothelioma is a rare but aggressive cancer with a 5-year survival rate less than 10%. Mesothelin is a protein normally present on mesothelial cells and overexpressed in the majority of mesotheliomas. Anetumab ravtansine (BAY 94-9343) is a novel fully human anti-mesothelin IgG1 antibody conjugated to ravtansine, an antitubulin cytotoxic agent. In a phase I study, anetumab ravtansine at 6.5 mg/kg on a q3w IV schedule was well tolerated and showed encouraging durable tumor responses in patients with previously treated mesothelioma.

Design: A randomized, open-label, active-controlled, 2-arm, multicenter, phase II trial to evaluate the efficacy and safety of anetumab ravtansine at 6.5 mg Q3W versus vinorelbine 30 mg/m2 QW in patients with advanced or metastatic malignant pleural mesothelioma overexpressing mesothelin and who have progressed on first-line platinum/pemetrexed-based chemotherapy.

Objectives: The primary objective is to test the superiority of anetumab ravtansine monotherapy over vinorelbine in progression-free survival (PFS). The secondary objectives of this study include overall survival, patient-reported outcomes (PRO), tumor response, and safety. Exploratory objectives include immunogenicity of anetumab ravtansine, pharmacokinetics, and biomarkers of response.

Methods: Biomarker sampling will be performed on all patients to measure tumor mesothelin expression levels at prescreening. Biomarker-positive patients with moderate (2+) and/or strong (3+) level in at least 30% of tumor cells will be randomized and start study treatment following progression after 1st line treatment of platinum/pemetrexed (with or without bevacizumab).

Approximately 183 patients meeting eligibility criteria will berandomized in a 2:1 ratio to receive anetumab ravtansine or vinorelbine. Randomization will be stratified by geographic region (Rest of World v. Asia) and time to progression on 1st line treatment (? 6 months vs < 6 months). The primary endpoint, PFS per modified RECIST criteria for metastatic pleural mesothelioma per central review, will be tested using a log-rank test stratified by randomization strata, with 1-sided significance level 0.0125. The primary analysis will occur after approximately 117 PFS events. Assuming true median PFS of 3.6 months under vinorelbine treatment, the primary hypothesis test is designed to detect a 100% prolongation of true PFS (median 7.2 months) with 90% power. Novel study methods include a grading system for AEs of special interest and the PRO instrument.

Results: This trial is open and currently accruing patients.

Citation Format: Raffit Hassan, John J. Nemunaitis, Jan P. van Meerbeeck, Ross Jennens, George R. Blumenschein, Jr, Dean A. Fennell, Hedy L. Kindler, Silvia Novello, Cem Elbi, Annette Walter, Danila Serpico, Emma Fountain, Sandra Vingerhoedt, Christine Brown, Jonathan Siegel, Barrett H. Childs. A pivotal randomized phase II study of anetumab ravtansine or vinorelbine in patients with advanced or metastatic pleural mesothelioma after progression on platinum/pemetrexed-based chemotherapy (NCT02610140). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT083.

Thymoma and thymic carcinomas

Thymomas (Ts) and thymic carcinomas (TCs) are rare tumours of the mediastinum with an incidence rate of 1.7/million per year in Europe. Histological classification is based on rate of non-malignant-appearing thymic epithelial cells and proportions of lymphocytes (A, AB, B1, B2, B3, and C), while staging system concerns localisation of the involved areas. Surgery is the mainstay of treatment with a 10-year survival of 80%, 78%, 75%, and 42% for stages I, II, III and IV, respectively, with an R0 resection. Radiotherapy has a role in selected cases (stage III patients or R1-2 residual) and platinum-based chemotherapy remains the standard of care for patients with advanced disease. A multimodality approach would be advisable when surgery is not recommended. Since molecular aberrations are poorly understood and few responses are reported, targeted therapies are yet being studied. In this review, we describe key aspects of clinical management for Ts and TCs.

Available evidence and new biological perspectives on medical treatment of advanced thymic epithelial tumors

Thymic epithelial tumors (TETs) are rare primary mediastinal tumors arising from thymic epithelium. Their rarity and complexity hinder investigations of their causes and therapy development. Here, we summarize the existing knowledge regarding medical treatment of these tumors, and thoroughly review the known genetic aberrations associated with TETs and the present status of potential biological treatments. Epidermal growth factor receptor (EGFR), stem-cell factor receptor, insulin-like growth factor-1 receptor (IGF1R), and vascular endothelial growth factors (VEGF-A, VEGF-B, and VEGF-2) are overexpressed in TETs. EGFR overexpression in TETs is associated with higher stage, and IGF1R overexpression has poor prognostic value. Data indicate that anti-IGF1R monoclonal antibodies, and inhibitors of angiogenesis, somatostatin receptors, histone deacetylase, mammalian target of rapamycin, and cyclin-dependent kinases may be active against TETs. Continued investigations in this field could lead to advancement of targeted and biological therapies for TETs.

microRNAs in breast cancer development and treatment

microRNAs (herein after miRNAs) represent a recently uncovered class of small and endogenous non-coding RNAs. miRNAs play a well conserved and crucial role in normal biological processes, such as cell differentiation, proliferation and apoptosis through a complicated gene regulation networking. The recent rise of interest in miRNAs in cancer research is ascribed to the breakthrough of their role in many pathological processes, including malignant transformation. miRNAs signatures have been clearly defined for certain types of cancer, with correlation to tumor aggressiveness, therapy response and patient outcome. Furthermore, the use of miRNAs as therapeutic targets for cancer is currently under investigation. The aim of this review is to focus on the role of miRNAs in breast cancer development and to summarize the evidence for their potential diagnostic and therapeutic applications in clinical practice.

Fasting glucose and treatment outcome in breast and colorectal cancer patients treated with targeted agents: results from a historic cohort

BACKGROUND

We investigated pretreatment fasting glucose as a predictor of patients' important outcomes in breast and colorectal cancers undergoing targeted therapies.

PATIENTS AND METHODS

In a historic cohort of 202 breast and 218 colorectal cancers treated with targeted agents from 1998 to 2009, we used the Kaplan-Meier method and the log-rank test to estimate survival through tertiles of fasting glucose and the Cox proportional hazards model for multivariate analysis stratified by primary site of cancer and including gender, age and body mass index.

RESULTS

The median follow-up was 20 months (1-128). At 60 months, 65% of patients in the lowest tertile of fasting glucose did not experiment disease progression compared with 34% in the highest tertile (P=0.001). Seventy-six percent of females in the lowest tertile showed no progression compared with 49% in the top tertiles (P=0.015). In multivariate analysis, fasting glucose was a significant predictor of time to disease progression only in breast cancer patients in the first tertile compared with the third (P=0.017).

CONCLUSIONS

We found evidence of a predictive role of pretreatment fasting glucose in the development of resistance in breast cancer patients treated with targeted agents. Prospective studies are warranted to confirm our findings.

Molecular profiling of patients with colorectal cancer and matched targeted therapy in phase I clinical trials

Clinical experience increasingly suggests that molecular prescreening and biomarker enrichment strategies in phase I trials with targeted therapies will improve the outcomes of patients with cancer. In keeping with the exigencies of a personalized oncology program, tumors from patients with advanced chemorefractory colorectal cancer were analyzed for specific aberrations (KRAS/BRAF/PIK3CA mutations, PTEN and pMET expression). Patients were subsequently offered phase I trials with matched targeted agents (MTA) directed at the identified anomalies. During 2010 and 2011, tumor molecular analysis was conducted in 254 patients: KRAS mutations (80 of 254, 31.5%), BRAF mutations (24 of 196, 12.2%), PIK3CA mutations (15 of 114, 13.2%), KRAS and PIK3CA mutations (9 of 114, 7.9%), low PTEN expression (97 of 183, 53.0%), and high pMET expression (38 of 64, 59.4%). In total, 68 patients received 82 different MTAs: phosphoinositide 3-kinase (PI3K) pathway inhibitor (if PIK3CA mutation, n = 10; or low PTEN, n = 32), PI3K pathway inhibitor plus MEK inhibitor (if KRAS mutation, n = 10; or BRAF mutation, n = 1), second-generation anti-EGF receptor monoclonal antibodies (if wild-type KRAS, n = 11), anti-hepatocyte growth factor monoclonal antibody (if high pMET, n = 10), mTOR inhibitor plus anti-insulin-like growth factor-1 receptor monoclonal antibody (if low PTEN, n = 5), and BRAF inhibitor (if BRAF mutation, n = 3). Median time-to-treatment failure on MTA was 7.9 versus 16.3 weeks for their prior systemic antitumor therapy (P < 0.001). Partial response was seen in 1 patient [1.2%, PI3K inhibitor with PIK3CA mutation] and stable disease >16 weeks in 10 cases (12.2%). These results suggest that matching chemorefractory patients with colorectal cancer with targeted agents in phase I trials based on the current molecular profile does not confer a significant clinical benefit.

Molecular profiling of patients (pts) with colorectal cancer (CRC) and matched targeted therapy (MTA) in phase I clinical trials

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Background: Molecular prescreening and biomarker enrichment strategies in Phase 1 trials with targeted therapies are anticipated to improve the outcomes of affected pts. Methods: As part of our personalized oncology program, tumors from pts with advanced chemorefractory CRC were analyzed for specific molecular aberrations (KRAS/ BRAF/ PIK3CA mutations [mut], PTEN and pMET expression) at the Vall d'Hebron Molecular Pathology and Genomics Labs. Those whose tumors were found to have a dysregulation were offered a Phase 1 trial with MTA. Results: During 2010 and 2011, tumor molecular analysis was performed in 254 pts: KRAS mut (80/254, 31.5%), BRAF mut (24/196, 12.2%), PIK3CA mut (15/114, 13.2%), KRAS+PIK3CA mut (9/114, 7.9%), PTEN low (97/183, 53.0% - HSCORE<50; 45/183, 24.6% - PTEN null), KRAS mut + PTEN low (38/138, 20.8%), pMET high (38/64, 59.4% with HSCORE>30). In total, 68 pts (median, age 63 yrs; prior therapies 3), received 82 different matched therapies. Type of MTA: PI3K pathway inh (if PIK3CA mut, n=10; or PTEN low, n=32), MEK+PI3K pathway inh (if KRAS mut, n=10; or BRAF mut, n=1), second-generation anti-EGFR mAbs (if KRAS wild-type, n=11), anti-HGF mAb (if pMET high, n=10), mTOR inh + anti-IGFR-1R mAb (if PTEN low, n=5) and BRAF inh (if BRAF mut, n=3). Median time to treatment failure (TTF) with MTA was 7.9 weeks (CI95%:7.6-8.1) vs. 16.3 weeks (CI95%:13.9-18.7) for their prior systemic antitumor therapy (p<0.001). If prior therapy non-standard (according to NCCN guidelines, n=39), TTF with MTA 7.9 weeks (CI95%:6.8-8.9) vs. TTF with prior therapy 8.7 weeks (CI95%:7.3-10.1). If an approved standard regimen (n=43), TTF with MTA 7.9 weeks (CI95%:7.6-8.1) vs. TTF with prior therapy 21.9 weeks (CI95%:15.0-28.7). Partial response was seen in one pt (1.2%, PI3K inh with PIK3CA mut) and stable disease > 16 weeks in 10 cases (12.2%). Clinical benefit, defined as a TTF ratio ≥ 1.3 (TTF on MTA/ TTF on prior therapy), was seen with 15.9% of the therapies (13/82). Conclusions: Preliminary results suggest that matching chemorefractory CRC patients with targeted agents in early clinical trials based on the current molecular profile does not result in longer TTF compared to their prior therapy.

Is Hypogammaglobulinemia a Constant Feature in Good's Syndrome?

Thymomas are rare tumors, which can be associated to a variety of paraneoplastic syndromes, including a fatal hypogammaglobulinemia, namely Good's Syndrome (GS). Although the combination of thymoma and hypogammaglobulinemia is regarded as sufficient for diagnosis of Good's syndrome, some thymoma patients with a clear clinical picture of immunodeficiency present normal levels of immunoglobulins. We describe the case of a patient, with a 20-year history of thymoma, who underwent several operations and lines of chemotherapy, and suffered from recurrent infections, including one rare skin infection from Pseudoallescheria boydii. The patient constantly presented normal levels of gammaglobulins.