Effectiveness and safety of nivolumab in patients with advanced melanoma: A multicenter, observational study.

This retrospective observational study aimed to determine the effectiveness, safety and patterns of the use of nivolumab in patients with advanced melanoma in real-world clinical practice in France using data from a Temporary Authorization for Use Program (ATU). Data were collected from patients with unresectable or metastatic melanoma enrolled in a French national database (Réseau pour la Recherche et l'Investigation Clinique sur le Mélanome: Ric-Mel) and treated with nivolumab during the ATU program (12 September 2014 to 31 August 2015). The primary objectives of the study were to evaluate the effect of patient characteristics on clinical response and overall survival (OS). Among 400 included patients (median age 66 years), the majority (83%) received nivolumab as second- or subsequent-line therapy. The median durations of progression-free survival and OS were 3.3 and 14.1 months, respectively, and 31.6% of patients achieved an objective response with a median duration of 20.1 months (range: 0-34.7). The safety profile of nivolumab was manageable and consistent with those of previous clinical trials, with an incidence of grade 3-5 adverse events of 13.8%. The safety and effectiveness of nivolumab in patients with advanced melanoma in real-world clinical practice in France were in line with the data reported in the Phase 3 trials CheckMate 066 and 037 of nivolumab in this patient population.

Medullary thyroid carcinoma arises in the absence of prolactin signaling.

Prolactin, a pituitary hormone, exerts pleiotropic effects in various cells. These effects are mediated by a membrane receptor highly expressed in many tissues. To analyze prolactin effects on the thyroid gland, we first identified prolactin receptor (PRLR) mRNAs by in situ hybridization. To further evaluate the physiologic relevance of PRLR actions in the thyroid in vivo, we used PRLR knockout mice. Whereas the histologic structure of thyroid of PRLR-null mice was not disturbed, we show that T4 levels are lower in null animals (13.63 +/- 2.98 versus 10.78 +/- 2.25 pmol/L in null mice), confirming that prolactin participates in the control of thyroid metabolism. To further investigate thyroid effects in mice, we measured body temperature and thyroid-stimulating hormone in young and adult male and/or female PRLR-null mice and their normal siblings. Surprisingly, in null animals, we saw medullary thyroid carcinoma (MTC) arising from parafollicular C cells producing calcitonin. The incidence of these carcinomas attained 41% in PRLR-null mice, whereas this malignant tumor occurs sporadically or as a component of the familial cancer syndrome in humans. This finding suggests that PRLR-null mice could represent a valuable animal model for MTC, which could be compared with existing MTC models. These observations suggest a possible link between the appearance of this carcinoma and the absence of prolactin signaling.

A recurrent neomorphic mutation in MYOD1 defines a clinically aggressive subset of embryonal rhabdomyosarcoma associated with PI3K-AKT pathway mutations.

Rhabdomyosarcoma, a cancer of skeletal muscle lineage, is the most common soft-tissue sarcoma in children. Major subtypes of rhabdomyosarcoma include alveolar (ARMS) and embryonal (ERMS) tumors. Whereas ARMS tumors typically contain translocations generating PAX3-FOXO1 or PAX7-FOXO1 fusions that block terminal myogenic differentiation, no functionally comparable genetic event has been found in ERMS tumors. Here we report the discovery, through whole-exome sequencing, of a recurrent somatic mutation encoding p.Leu122Arg in the myogenic transcription factor MYOD1 in a distinct subset of ERMS tumors with poor outcomes that also often contain mutations altering PI3K-AKT pathway components. Previous mutagenesis studies had shown that MYOD1 with a p.Leu122Arg substitution can block wild-type MYOD1 function and bind to MYC consensus sequences, suggesting a possible switch from differentiation to proliferation. Our functional data now confirm this prediction. Thus, MYOD1 p.Leu122Arg defines a subset of rhabdomyosarcomas eligible for high-risk protocols and the development of targeted therapeutics.

Oncogene mutation profiling of pediatric solid tumors reveals significant subsets of embryonal rhabdomyosarcoma and neuroblastoma with mutated genes in growth signaling pathways.

PURPOSE: In contrast to the numerous broad screens for oncogene mutations in adult cancers, few such screens have been conducted in pediatric solid tumors. To identify novel mutations and potential therapeutic targets in pediatric cancers, we conducted a high-throughput Sequenom-based analysis in large sets of several major pediatric solid cancers, including neuroblastoma, Ewing sarcoma, rhabdomyosarcoma (RMS), and desmoplastic small round cell tumor (DSRCT). EXPERIMENTAL DESIGN: We designed a highly multiplexed Sequenom-based assay to interrogate 275 recurrent mutations across 29 genes. Genomic DNA was extracted from 192 neuroblastoma, 75 Ewing sarcoma, 89 RMS, and 24 DSRCT samples. All mutations were verified by Sanger sequencing. RESULTS: Mutations were identified in 13% of neuroblastoma samples, 4% of Ewing sarcoma samples, 21.1% of RMS samples, and no DSRCT samples. ALK mutations were present in 10.4% of neuroblastoma samples. The remainder of neuroblastoma mutations involved the BRAF, RAS, and MAP2K1 genes and were absent in samples harboring ALK mutations. Mutations were more common in embryonal RMS (ERMS) samples (28.3%) than alveolar RMS (3.5%). In addition to previously identified RAS and FGFR4 mutations, we report for the first time PIK3CA and CTNNB1 (ß-catenin) mutations in 5% and 3.3% of ERMS, respectively. CONCLUSIONS: In ERMS, Ewing sarcoma, and neuroblastoma, we identified novel occurrences of several oncogene mutations recognized as drivers in other cancers. Overall, neuroblastoma and ERMS contain significant subsets of cases with nonoverlapping mutated genes in growth signaling pathways. Tumor profiling can identify a subset of pediatric solid tumor patients as candidates for kinase inhibitors or RAS-targeted therapies.

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/ß, 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 RET(C634W) 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-ß2. 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.

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.