Sophie Broutin

Body Composition Variation and Impact of Low Skeletal Muscle Mass in Patients With Advanced Medullary Thyroid Carcinoma Treated With Vandetanib: Results From a Placebo-Controlled Study

OBJECTIVES Vandetanib was approved by the U.S. Food and Drug Association for the treatment of advanced medullary thyroid cancer (MTC). Because body weight (BW) loss is observed in MTC and because low skeletal muscle mass (SM) is associated with drug toxicity, this study assessed effects of vandetanib on SM and adipose tissue (AT) and explored the association between SM, toxicity, and serum concentration of vandetanib. METHODS Thirty-three patients with MTC received vandetanib (n = 23) or placebo (n = 10) in the ZETA study. Visceral AT (VAT), sc AT (SAT), and SM were assessed with computed tomography imaging by measuring tissue cross-sectional areas (square centimers per square meter). Dose-limiting toxicities (DLTs) were prospectively recorded. RESULTS Early at 3 months, compared with placebo group who lost BW, muscle, and SAT, patients treated with vandetanib gained 1.5 kg BW (P = 0.02), 1.3 cm(2)/m(2) (∼0.7 kg) of SM (P = 0.009), and 4.5 cm(2)/m(2) (∼0.5 kg) of SAT (P = 0.004) and gained more VAT, 5.1 cm(2)/m(2) (∼0.7 kg) (P = 0.02). Patients with DLT had lower SM index (37.2 vs 44.3 cm(2)/m(2), P = 0.003) and a higher vandetanib serum concentration (1091 vs 739 ng/mL, P = 0.03). Patients with SM index <43.1 cm(2)/m(2) had a higher probability of DLT (73% vs 14%, P = 0.004) and a higher vandetanib serum concentration (1037 vs 745 ng/mL, P = 0.04). Patients with the highest compared with the intermediate and lower levels of vandetanib serum concentration experienced more DLT, respectively, 78% vs 40% vs 20% (P = 0.04). CONCLUSIONS Muscle and adipose tissues are restored after only 3 months of vandetanib treatment. Patients with low muscle mass had high vandetanib serum concentration and high incidence of toxicities.

AG-221, a First-in-Class Therapy Targeting Acute Myeloid Leukemia Harboring Oncogenic IDH2 Mutations.

Somatic gain-of-function mutations in isocitrate dehydrogenases (IDH) 1 and 2 are found in multiple hematologic and solid tumors, leading to accumulation of the oncometabolite (R)-2-hydroxyglutarate (2HG). 2HG competitively inhibits α-ketoglutarate-dependent dioxygenases, including histone demethylases and methylcytosine dioxygenases of the TET family, causing epigenetic dysregulation and a block in cellular differentiation. In vitro studies have provided proof of concept for mutant IDH inhibition as a therapeutic approach. We report the discovery and characterization of AG-221, an orally available, selective, potent inhibitor of the mutant IDH2 enzyme. AG-221 suppressed 2HG production and induced cellular differentiation in primary human IDH2 mutation-positive acute myeloid leukemia (AML) cells ex vivo and in xenograft mouse models. AG-221 also provided a statistically significant survival benefit in an aggressive IDH2R140Q-mutant AML xenograft mouse model. These findings supported initiation of the ongoing clinical trials of AG-221 in patients with IDH2 mutation-positive advanced hematologic malignancies.Significance: Mutations in IDH1/2 are identified in approximately 20% of patients with AML and contribute to leukemia via a block in hematopoietic cell differentiation. We have shown that the targeted inhibitor AG-221 suppresses the mutant IDH2 enzyme in multiple preclinical models and induces differentiation of malignant blasts, supporting its clinical development. Cancer Discov; 7(5); 478-93. ©2017 AACR.See related commentary by Thomas and Majeti, p. 459See related article by Shih et al., p. 494This article is highlighted in the In This Issue feature, p. 443.

Identification of soluble candidate biomarkers of therapeutic response to sunitinib in Medullary Thyroid Carcinoma in preclinical models.

Purpose: Medullary thyroid carcinoma (MTC), an aggressive rare tumor due to activating mutations in the proto-oncogene RET, requires new therapeutic strategies. Sunitinib, a potent inhibitor of RET, VEGF receptor (VEGFR)-1, VEGFR-2, VEGFR-3, and platelet-derived growth factor receptor (PDGFR)α/β, has been reported as clinically effective in some patients with advanced MTC. In this study, we examine molecular mechanisms of action of sunitinib and identify candidate soluble biomarkers of response. Experimental Design: Both in vitro and in vivo assays, using the human TT RETC634W MTC cell line, were done to assess the activity of sunitinib. Kinetic microarray studies were used to analyze molecular pathways modified by sunitinib and to identify candidate biomarkers that were subsequently investigated in the serum of patients. Results: Sunitinib displayed antiproliferative and antiangiogenic activities and inhibited RET autophosphorylation and activation of downstream signaling pathways. We showed that sunitinib treatment induced major changes in the expression of genes involved in tissue invasion and metastasis including vimentin (VIM), urokinase plasminogen (PLAU), tenascin-C (TN-C), SPARC, and CD44. Analyzing downregulated genes, we identified those encoding secreted proteins and, among them, interleukin (IL)-8 was found to be modulated in the serum of xenografted mice under sunitinib treatment. Furthermore, we demonstrated that metastatic MTC patients presented increased serum levels of IL-8 and TGF-β2. Conclusions: Experimental models confirm the clinical efficacy of sunitinib observed in a few studies. Molecular pathways revealed by genomic signatures underline the impact of sunitinib on tissue invasion. Selected soluble candidate biomarkers could be of value for monitoring sunitinib response in metastatic MTC patients. Clin Cancer Res; 17(7); 2044–54. ©2011 AACR.

Aggressive inherited and sporadic medullary thyroid carcinomas display similar oncogenic pathways

RET oncogene mutations are found in familial medullary thyroid carcinomas (MTC) and in one-third of sporadic cases. Oncogenic mechanisms involved in non-RET mutated sporadic MTC remain unclear. To study alterations associated with the development of both inherited and sporadic MTC, pangenomic DNA microarrays were used to analyze the transcriptome of 13 MTCs (four familial and nine sporadic). By using an ANOVA test, a list of 173 gene sequences with at least a twofold change expression was obtained. A subset of differentially expressed genes was controlled by real-time quantitative PCR and immunohistochemistry on a larger collection of MTCs. The expression pattern of those genes allowed us to distinguish two groups of sporadic tumors. The first group displays an expression profile similar to that expressed by inherited RET634 tumors. The second presents an expression profile close to that displayed by inherited RET918 tumors and includes tumors from patients with distant metastases. It is characterized by the overexpression of genes involved in proliferation and invasion (PTN, ESM1, and CEACAM6) or matrix remodeling (COL1A1, COL1A2, and FAP). Interestingly, RET918 tumors showed overexpression of the PTN gene, encoding pleiotrophin, a protein associated with metastasis. Using a MTC cell line, silencing of RET induced the inhibition of PTN gene expression. Overall, our results suggest that familial MTC and sporadic MTC could activate similar oncogenic pathways.

The IDH2 R172K mutation associated with angioimmunoblastic T-cell lymphoma produces 2HG in T cells and impacts lymphoid development.

Significance Mutations in isocitrate dehydrogenase (IDH)1 and IDH2 contribute to malignant progression by producing the oncometabolite 2HG. In myeloid disorders, mutations at three positions in these genes are commonly observed, but in angioimmunoblastic T-cell lymphoma (AITL), IDH mutations are restricted to IDH2 arginine (R) 172. The complex microenvironment of AITL, where malignant T cells comprise a minority of the tumor, has made it difficult to evaluate the role of this mutation. Here, we provide clinical data showing that mutant IDH2 expression is restricted to malignant T cells and that 2HG may be a useful biomarker in AITL. In addition, using conditional knock-in mouse models, we find that only mutations at IDH2 R172 produce significant quantities of 2HG in lymphoid cells and alter lymphoid development. Oncogenic isocitrate dehydrogenase (IDH)1 and IDH2 mutations at three hotspot arginine residues cause an enzymatic gain of function that leads to the production and accumulation of the metabolite 2-hydroxyglutarate (2HG), which contributes to the development of a number of malignancies. In the hematopoietic system, mutations in IDH1 at arginine (R) 132 and in IDH2 at R140 and R172 are commonly observed in acute myeloid leukemia, and elevated 2HG is observed in cells and serum. However, in angioimmunoblastic T-cell lymphoma (AITL), mutations are almost exclusively restricted to IDH2 R172, and levels of 2HG have not been comprehensively measured. In this study, we investigate the expression pattern of mutant IDH2 in the AITL tumor microenvironment and measure levels of 2HG in tissue and serum of AITL patients. We find that mutant IDH2 expression is restricted to the malignant T-cell component of AITL, and that 2HG is elevated in tumor tissue and serum of patients. We also investigate the differences between the three hotspot mutation sites in IDH1 and IDH2 using conditional knock-in mouse models. These studies show that in the lymphoid system, mutations in IDH2 at R172 produce high levels of 2HG compared with mutations at the other two sites and that lymphoid development is impaired in these animals. These data provide evidence that IDH2 R172 mutations may be the only variants present in AITL because of their capacity to produce significant amounts of the oncometabolite 2HG in the cell of origin of this disease.

Insights into significance of combined inhibition of MEK and m-TOR signalling output in KRAS mutant non-small-cell lung cancer

Background:We aimed to understand the dependence of MEK and m-TOR inhibition in EGFRWT/ALKnon-rearranged NSCLC cell lines.Methods:In a panel of KRASM and KRASWT NSCLC cell lines, we determined growth inhibition (GI) following maximal reduction in p-ERK and p-S6RP caused by trametinib (MEK inhibitor) and AZD2014 (m-TOR inhibitor), respectively.Results:GI caused by maximal m-TOR inhibition was significantly greater than GI caused by maximal MEK inhibition in the cell line panel (52% vs 18%, P<10−4). There was no significant difference in GI caused by maximal m-TOR compared with maximal m-TOR+MEK inhibition. However, GI caused by the combination was significantly greater in the KRASM cell lines (79% vs 61%, P=0.017).Conclusions:m-TOR inhibition was more critical to GI than MEK inhibition in EGFRWT/ALKnon-rearranged NSCLC cells. The combination of MEK and m-TOR inhibition was most effective in KRASM cells.

Individualized Pazopanib Dosing—Letter

We have read with interest the recent article by Verheijen and colleagues ([1][1]) reporting the feasibility of the individualization of pazopanib dosing, based on therapeutic drug monitoring of steady-state trough plasma concentrations ( C ss trough). The authors should be congratulated for this

Abstract 5343: The effect of horizontal and vertical inhibition of nodes within the MAPK and PI3K-AKT pathways in NSCLC models

Introduction and Aims Efficacy of targeted anticancer drugs is limited by de novo resistances related to cross talk within and between complex signal transduction networks. Rational combinatorial targeted therapies are one of the main solutions to increase activity or overcome resistance. We aimed to investigate the effects of inhibiting different nodes within the MAPK pathway (RAF and MEK) and PI3K-AKT pathway (PI3K, AKT and m-TORC1/2) either alone or in different combinations, on cell growth in a panel of KRAS mutant and KRAS wt NSCLC cell lines. Material & Methods We used dabrafenib, trametinib, GDC-0941, MK2206 and AZD2014 to inhibit RAF, MEK, PI3K, AKT and m-TORC1/2 respectively. Inhibition of signalling output in MEK, PI3K, AKT and m-TORC1/2 was assessed by maximal reduction of p-ERK, p-AKT (Thr308), p-AKT (Ser473) and p-S6 by trametinib, GDC-0941, MK2206 and AZD2014 respectively. In keeping with its mechanism of action, maximal induction of p-MEK was considered as inhibition of RAF by dabrafenib in the cell line panel (none had mutations in BRAF). Quantification of phosphoproteins was done using MesoScale Discovery ELISA. Using concentrations of drugs shown to inhibiting signalling though these nodes, the effects of inhibiting the nodes alone or in combination on cell growth was studied using WST-1 assays. The NSCLC cell line panel included KRAS wild-type (H522; H1838; H1651) or KRAS mutant (A-549; Calu-6; H23) cells. Results The concentration range of dabrafenib, trametinib, GDC-0941, MK2206 and AZD2014 to inhibit RAF, MEK, PI3K, AKT and m-TORC1/2 related to the different cell lines was [40-1000 nM], [40-200 nM], [1000 - 10 000 nM], >50 000 nM, and [500-1500 nM] respectively. The degree of growth inhibition following inhibition of an individual node varied between 5% and 75%. Highest inhibitions of cell proliferation by drugs alone were obtained with PI3K-AKT pathways compared to the MAPK pathway inhibitors for 6/6 cell lines. Drug combinations improved inhibition of cell proliferation in all cell lines. In 3/3 KRAS mutant cells, best combinations included MEK inhibitor and any other of the PI3K-AKT pathway as compared to inhibition of different nodes within the PI3K-AKT or MAPK pathways. In 3/3 KRAS wt cell lines, vertical combinations within the PI3K-AKT pathway induced highest inhibitions of cell proliferation compared to vertical combinations within the MAPK pathway or horizontal combinations between the PI3K-AKT and MAPK pathways. Discussion/Conclusions In the cell line panel tested, KRAS mutant cell lines were more sensitive to horizontal combinations than vertical combinations with the MAPK and PI3K-AKT pathways. KRAS wt cells were more sensitive to vertical combinations within the PI3K-AKT pathway. This preclinical study has clinical implications while planning combinations of targeted agents to treat NSCLC. Citation Format: Sophie Broutin, Adam Stewart, Parames Thavasu, Angelo Paci, Jean-Michel Bidart, Udai Banerji. The effect of horizontal and vertical inhibition of nodes within the MAPK and PI3K-AKT pathways in NSCLC models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5343. doi:10.1158/1538-7445.AM2015-5343

First case report of intrathecal panitumumab for treatment of meningeal carcinomatousis in an EGFR mutant lung adenocarcinoma patient

Intrathecal (IT) chemotherapy has been the mainstay treatment for patients with meningeal carcinomatosis (MC) but the prognosis of MC remains disastrous and most patients expire before 6 months [1]. Recently IT administration of trastuzumab, an IgG1 anti-HER2 monoclonal antibody (mAbs), has been tested with signs of efficacy in HER2 positive breast cancer patients [2–5]. We report here the first case of IT panitumumab, a human recombinant IgG2 kappa mAbs that binds specifically to EGFR, for a patient with MC derived from an EGFR exon 19 mutant lung adenocarcinoma.

Mutational profiling of isolated myeloid sarcomas and utility of serum 2HG as biomarker of IDH1/2 mutations

Myeloid sarcoma (MS) is an extramedullary tumor mass consisting of myeloid blasts with or without maturation. MS may precede a characterized acute myeloid leukemia (AML) or can be present as an isolated tumor. Prognosis of isolated MS is typically poor despite the use of high-dose chemotherapy [1]. As isolated MS are frequently misdiagnosed for a solid tumor or lymphoma at diagnosis, molecular characterization of MS is not routinely performed, and tailored therapies based on molecular risk stratification in MS patients remained unused. Like in AML, cytogenetic abnormalities are found in around 50% of MS and mutations in NPM1 and FLT3 genes are the most frequent molecular lesions reported so far in MS [1–3]. A next-generation sequencing (NGS) assay including 21 genes in a series of 6 MS cases recently detected lesions in a broad spectrum of AML and myelodysplastic syndrome (MDS)-associated genes critical for epigenetic (TET2, DNMT3A, IDH2, ASXL1, EZH2), splicing (SF3B1), transcription (RUNX1, WT1), tumor suppression (TP53), or signaling (KIT, N-RAS) regulation [4]. To further characterize the mutational landscape of isolated MS, we analyzed gene mutations in cases of isolated MS using an NGS panel of 32 genes recurrently mutated in myeloid malignancies. Samples were obtained from 14 consecutive patients with histologically proven isolated de novo MS collected in 3 French centers between 2004 and 2016. Clinical and pathology data are summarized in Table 1. Conventional karyotype on MS sample was normal in the single patient with available data. Genomic DNA (gDNA) was extracted from frozen MS samples (n= 8) or formalin-fixed paraffin-embedded (FFPE) tissue samples (n = 6) and assessed for mutations in 32 genes (ASXL1, BCOR, BCORL1, CALR, CBL, CSF3R, DNMT3A, ETV6, EZH2, FLT3-TKD, GATA2, IDH1, IDH2, JAK2, KIT, KRAS, MPL, NPM1, NRAS, PHF6, PTPN11, RIT1, RUNX1, SETBP1, SF3B1, SRSF2, STAG2, TET2, TP53, U2AF1, WT1, and ZRSR2). FLT3 internal tandem duplication (FLT3-ITD) mutations were investigated by fluorescent PCR and fragment analysis. NPM1, ASXL1 (including c.1934dupG; p.G646WfsX12), SRSF2, and IDH1/2 variants were confirmed by Sanger sequencing (cf Supplemental Methods). Overall, 11/14 (79%) patients presented at least 1 mutation in the selected genes. Our results are consistent with the reported high frequency of NPM1 mutation in MS (7/14) [2–4]. A FLT3-ITD mutation was identified in only 2 out of 10 patients in our cohort, contrasting with the higher frequency in previously reported cases [2, 4]. Mutations in These authors contributed equally: Christophe Willekens, Aline Renneville.