Vito Guagnano

FGFR Genetic Alterations Predict for Sensitivity to NVP-BGJ398, a Selective Pan-FGFR Inhibitor

UNLABELLED Patient stratification biomarkers that enable the translation of cancer genetic knowledge into clinical use are essential for the successful and rapid development of emerging targeted anticancer therapeutics. Here, we describe the identification of patient stratification biomarkers for NVP-BGJ398, a novel and selective fibroblast growth factor receptor (FGFR) inhibitor. By intersecting genome-wide gene expression and genomic alteration data with cell line-sensitivity data across an annotated collection of cancer cell lines called the Cancer Cell Line Encyclopedia, we show that genetic alterations for FGFR family members predict for sensitivity to NVP-BGJ398. For the first time, we report oncogenic FGFR1 amplification in osteosarcoma as a potential patient selection biomarker. Furthermore, we show that cancer cell lines harboring FGF19 copy number gain at the 11q13 amplicon are sensitive to NVP-BGJ398 only when concomitant expression of β-klotho occurs. Thus, our findings provide the rationale for the clinical development of FGFR inhibitors in selected patients with cancer harboring tumors with the identified predictors of sensitivity. SIGNIFICANCE The success of a personalized medicine approach using targeted therapies ultimately depends on being able to identify the patients who will benefit the most from any given drug. To this end, we have integrated the molecular profiles for more than 500 cancer cell lines with sensitivity data for the novel anticancer drug NVP-BGJ398 and showed that FGFR genetic alterations are the most significant predictors for sensitivity. This work has ultimately endorsed the incorporation of specific patient selection biomakers in the clinical trials for NVP-BGJ398.

Discovery of NVP-BYL719 a potent and selective phosphatidylinositol-3 kinase alpha inhibitor selected for clinical evaluation.

Phosphatidylinositol-3-kinase α (PI3Kα) is a therapeutic target of high interest in anticancer drug research. On the basis of a binding model rationalizing the high selectivity and potency of a particular series of 2-aminothiazole compounds in inhibiting PI3Kα, a medicinal chemistry program has led to the discovery of the clinical candidate NVP-BYL719.

Pharmacological inhibition of fibroblast growth factor (FGF) receptor signaling ameliorates FGF23-mediated hypophosphatemic rickets

Fibroblast growth factor 23 (FGF23) is a circulating factor secreted by osteocytes that is essential for phosphate homeostasis. In kidney proximal tubular cells FGF23 inhibits phosphate reabsorption and leads to decreased synthesis and enhanced catabolism of 1,25‐dihydroxyvitamin D3 (1,25[OH]2D3). Excess levels of FGF23 cause renal phosphate wasting and suppression of circulating 1,25(OH)2D3 levels and are associated with several hereditary hypophosphatemic disorders with skeletal abnormalities, including X‐linked hypophosphatemic rickets (XLH) and autosomal recessive hypophosphatemic rickets (ARHR). Currently, therapeutic approaches to these diseases are limited to treatment with activated vitamin D analogues and phosphate supplementation, often merely resulting in partial correction of the skeletal aberrations. In this study, we evaluate the use of FGFR inhibitors for the treatment of FGF23‐mediated hypophosphatemic disorders using NVP‐BGJ398, a novel selective, pan‐specific FGFR inhibitor currently in Phase I clinical trials for cancer therapy. In two different hypophosphatemic mouse models, Hyp and Dmp1‐null mice, resembling the human diseases XLH and ARHR, we find that pharmacological inhibition of FGFRs efficiently abrogates aberrant FGF23 signaling and normalizes the hypophosphatemic and hypocalcemic conditions of these mice. Correspondingly, long‐term FGFR inhibition in Hyp mice leads to enhanced bone growth, increased mineralization, and reorganization of the disturbed growth plate structure. We therefore propose NVP‐BGJ398 treatment as a novel approach for the therapy of FGF23‐mediated hypophosphatemic diseases.

Rescue Screens with Secreted Proteins Reveal Compensatory Potential of Receptor Tyrosine Kinases in Driving Cancer Growth

The overall power of kinase inhibitors is substantially overshadowed by the acquisition of drug resistance. To address this issue, we systematically assessed the potential of secreted proteins to induce resistance to kinase inhibitors. To this end, we developed a high-throughput platform for screening a cDNA library encoding 3,432 secreted proteins in cellular assays. Using cancer cells originally dependent on either MET, FGFR2, or FGFR3, we observed a bypass of dependence through ligand-mediated activation of alternative receptor tyrosine kinases (RTK). Our findings indicate a broad and versatile potential for RTKs from the HER and FGFR families as well as MET to compensate for loss of each other. We further provide evidence that combined inhibition of simultaneously active RTKs can lead to an added anticancer effect.

Synthesis and biological evaluation of highly potent analogues of epothilones B and D

A series of new epothilone B and D analogues incorporating fused hetero-aromatic side chains have been prepared. The synthetic strategy is based on olefin 3 as the common intermediate and allows variation of the side-chain structure in a highly convergent and stereoselective manner. Epothilone analogues 1a-d and 2a-d are more potent inhibitors of cancer cell proliferation than the corresponding parent epothilones B or D.

Entry into a new class of protein kinase inhibitors by pseudo ring design.

A pyrimidin-4-yl-urea motif forming a pseudo ring by intramolecular hydrogen bonding has been designed to mimic the pyrido[2,3-d]pyrimidin-7-one core structure of a well-established class of protein kinase inhibitors. Potent inhibition of a number of protein kinases was obtained with the first prototype compound synthesized to probe the design concept.

Fibroblast growth factor receptors as novel therapeutic targets in SNF5-deleted malignant rhabdoid tumors.

Malignant rhabdoid tumors (MRTs) are aggressive pediatric cancers arising in brain, kidney and soft tissues, which are characterized by loss of the tumor suppressor SNF5/SMARCB1. MRTs are poorly responsive to chemotherapy and thus a high unmet clinical need exists for novel therapies for MRT patients. SNF5 is a core subunit of the SWI/SNF chromatin remodeling complex which affects gene expression by nucleosome remodeling. Here, we report that loss of SNF5 function correlates with increased expression of fibroblast growth factor receptors (FGFRs) in MRT cell lines and primary tumors and that re-expression of SNF5 in MRT cells causes a marked repression of FGFR expression. Conversely, siRNA-mediated impairment of SWI/SNF function leads to elevated levels of FGFR2 in human fibroblasts. In vivo, treatment with NVP-BGJ398, a selective FGFR inhibitor, blocks progression of a murine MRT model. Hence, we identify FGFR signaling as an aberrantly activated oncogenic pathway in MRTs and propose pharmacological inhibition of FGFRs as a potential novel clinical therapy for MRTs.

Discovery of a novel class of highly potent inhibitors of the p53-MDM2 interaction by structure-based design starting from a conformational argument.

The p53-MDM2 interaction is an anticancer drug target under investigation in the clinic. Our compound NVP-CGM097 is one of the small molecule inhibitors of this protein-protein interaction currently evaluated in cancer patients. As part of our effort to identify new classes of p53-MDM2 inhibitors that could lead to additional clinical candidates, we report here the design of highly potent inhibitors having a pyrazolopyrrolidinone core structure. The conception of these new inhibitors originated in a consideration on the MDM2 bound conformation of the dihydroisoquinolinone class of inhibitors to which NVP-CGM097 belongs. This work forms the foundation of the discovery of HDM201, a second generation p53-MDM2 inhibitor that recently entered phase I clinical trial.

Optimisation of a 5-[3-phenyl-(2-cyclic-ether)-methyl-ether]-4-aminopyrrolopyrimidine series of IGF-1R inhibitors

Taking the pyrrolopyrimidine derived IGF-1R inhibitor NVP-AEW541 as the starting point, the benzyl ether back-pocket binding moiety was replaced with a series of 2-cyclic ether methyl ethers leading to the identification of novel achiral [2.2.1]-bicyclic ether methyl ether containing analogues with improved IGF-1R activities and kinase selectivities. Further exploration of the series, including a fluorine scan of the 5-phenyl substituent, and optimisation of the sugar-pocket binding moiety identified compound 33 containing (S)-2-tetrahydrofuran methyl ether 6-fluorophenyl ether back-pocket, and cis-N-Ac-Pip sugar-pocket binding groups. Compound 33 showed improved selectivity and pharmacokinetics compared to NVP-AEW541, and produced comparable in vivo efficacy to linsitinib in inhibiting the growth of an IGF-1R dependent tumour xenograft model in the mouse.

Abstract 1239: NVP-HDM201: Biochemical and biophysical profile of a novel highly potent and selective PPI inhibitor of p53-Mdm2

An effective strategy to restore p53 activity in cancer cells containing wild type p53 is to inhibit the Mdm2-p53 protein-protein interaction (PPI). NVP-HDM201 is a novel PPI inhibitor currently under evaluation in a Phase I clinical trial. It binds to the p53 binding-site of the Mdm2 protein, disrupting the interaction of the two proteins and leading to the activation of the p53 pathway. NVP-HDM201 belongs to a novel chemical series with a distinct biophysical and biochemical profile. Affinity constant of NVP-HDM201 for Mdm2 is in the picomolar range, with a selectivity ratio greater than a 10000-fold vs. Mdm4. Analysis of its binding mode provides evidence for a distinct set of critical interactions between the small molecule and its target, as compared with our other Mdm2 inhibitor NVP-CGM097, and explains as to why NVP-HDM201 binds equally to human, mouse, rat and dog Mdm2. Characterization of its binding kinetics indicates that the optimized interactions of NVP-HDM201 with Mdm2 protein are responsible for the increased stabilization of the complex resulting in high potency against Mdm2. This feature, together with favorable physicochemical and drug-like properties, supported the selection of NVP-HDM201 for clinical development. Citation Format: Therese Stachyra-Valat, Frederic Baysang, Anne-Cecile D’Alessandro, Erdmann Dirk, Pascal Furet, Vito Guagnano, Joerg Kallen, Lukas Leder, Robert Mah, Keiichi Masuya, Stefan Stutz, Andrea Vaupel, Francesco Hofmann, Patrick Chene, Sebastien Jeay, Philipp Holzer. NVP-HDM201: Biochemical and biophysical profile of a novel highly potent and selective PPI inhibitor of p53-Mdm2. [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 1239.