Stefan Stutz

Structure-based design of aliskiren, a novel orally effective renin inhibitor

Hypertension is a major risk factor for cardiovascular diseases such as stroke, myocardial infarction, and heart failure, the leading causes of death in the Western world. Inhibitors of the renin-angiotensin system (RAS) have proven to be successful treatments for hypertension. As renin specifically catalyses the rate-limiting step of the RAS, it represents the optimal target for RAS inhibition. Several peptide-like renin inhibitors have been synthesized previously, but poor pharmacokinetic properties meant that these compounds were not clinically useful. We employed a combination of molecular modelling and crystallographic structure analysis to design renin inhibitors lacking the extended peptide-like backbone of earlier inhibitors, for improved pharmacokinetic properties. This led to the discovery of aliskiren, a highly potent and selective inhibitor of human renin in vitro, and in vivo; once-daily oral doses of aliskiren inhibit renin and lower blood pressure in sodium-depleted marmosets and hypertensive human patients. Aliskiren represents the first in a novel class of renin inhibitors with the potential for treatment of hypertension and related cardiovascular diseases.

Structure-based drug design: the discovery of novel nonpeptide orally active inhibitors of human renin

BACKGROUND The aspartic proteinase renin plays an important physiological role in the regulation of blood pressure. It catalyses the first step in the conversion of angiotensinogen to the hormone angiotensin II. In the past, potent peptide inhibitors of renin have been developed, but none of these compounds has made it to the end of clinical trials. Our primary aim was to develop novel nonpeptide inhibitors. Based on the available structural information concerning renin-substrate interactions, we synthesized inhibitors in which the peptide portion was replaced by lipophilic moieties that interact with the large hydrophobic S1/S3-binding pocket in renin. RESULTS Crystal structure analysis of renin-inhibitor complexes combined with computational methods were employed in the medicinal-chemistry optimisation process. Structure analysis revealed that the newly designed inhibitors bind as predicted to the S1/S3 pocket. In addition, however, these compounds interact with a hitherto unrecognised large, distinct, sub-pocket of the enzyme that extends from the S3-binding site towards the hydrophobic core of the enzyme. Binding to this S3(sp) sub-pocket was essential for high binding affinity. This unprecedented binding mode guided the drug-design process in which the mostly hydrophobic interactions within subsite S3(sp) were optimised. CONCLUSIONS Our design approach led to compounds with high in vitro affinity and specificity for renin, favourable bioavailability and excellent oral efficacy in lowering blood pressure in primates. These renin inhibitors are therefore potential therapeutic agents for the treatment of hypertension and related cardiovascular diseases.

A convergent synthesis approach towards CGP60536B, a non-peptide orally potent renin inhibitor, via an enantiomerically pure ketolactone intermediate

We report a convergent synthesis of the potent orally active non-peptide renin inhibitor CGP60536B. The key reaction employs the coupling of the enantiopure Grignard species derived from chloride 13 with the diastereomerically pure γ-lactone 9b. The stereoselective reduction of the resulting ketone 14b has been thoroughly investigated.

Discovery of a Dihydroisoquinolinone Derivative (NVP-CGM097): A Highly Potent and Selective MDM2 Inhibitor Undergoing Phase 1 Clinical Trials in p53wt Tumors

As a result of our efforts to discover novel p53:MDM2 protein-protein interaction inhibitors useful for treating cancer, the potent and selective MDM2 inhibitor NVP-CGM097 (1) with an excellent in vivo profile was selected as a clinical candidate and is currently in phase 1 clinical development. This article provides an overview of the discovery of this new clinical p53:MDM2 inhibitor. The following aspects are addressed: mechanism of action, scientific rationale, binding mode, medicinal chemistry, pharmacokinetic and pharmacodynamic properties, and in vivo pharmacology/toxicology in preclinical species.

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.

Biphenyl derivatives as novel dual NK1/NK2-receptor antagonists

In a continuation of our efforts to simplify the structure of our neurokinin antagonists, a series of substituted biphenyl derivatives has been prepared. Several compounds exhibit potent affinities for both the NK(1) receptor (<10nM) and for the NK(2) receptor (<50 nM). Details on the design, synthesis, biological activities, SAR and conformational analysis of this new class of dual NK(1)/NK(2) receptor antagonists are presented.

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 1798: Mechanistic study of NVP-CGM097: a potent, selective and species specific inhibitor of p53-Mdm2

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA 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-CGM097 is a novel PPI inhibitor under evaluation in a Phase I clinical trial. It binds to the p53 binding-site of the Mdm2 protein, disrupting the interaction between both proteins, leading to an activation of the p53 pathway. The main biophysical and biochemical inhibitory characteristics of NVP-CGM097 are presented here. These include an affinity constant for Mdm2 in the nanomolar range and a selectivity of 3 orders of magnitude vs. Mdm4. The binding kinetics of NVP-CGM097 to Mdm2 are characterized by a high association rate constant (Kon =37 x 106 M-1.s-1) and a moderate dissociation rate constant (Koff =0.071 s-1). Additionally, NVP-CGM097 exhibits an 8-fold greater affinity for Mdm2 over Nutlin-3 due to a longer residence time of the Mdm2-inhibitor complex. Moreover, biochemical studies have revealed the species specificity of NVP-CGM097 with human Mdm2 being inhibited more strongly than the dog, mouse or rat forms of the protein. This was confirmed in cellular assays where NVP-CGM097 treatment resulted in induction of p53 target gene expression (p21, PUMA and Mdm2) only in human, but not in dog, mouse or rat cell lines. Citation Format: Therese Valat, Keiichi Masuya, Frederic Baysang, Genevieve Albrecht, Nicole Buschmann, Dirk Erdmann, Pascal Furet, Tobias Gabriel, Francois Gessier, Francesco Hofmann, Philipp Holzer, Joerg Kallen, Carole Pissot-Solderman, Stefan Stutz, Patrick Chene, Sebastien Jeay. Mechanistic study of NVP-CGM097: a potent, selective and species specific inhibitor of p53-Mdm2. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1798. doi:10.1158/1538-7445.AM2014-1798

Abstract 1797: Discovery of NVP-CGM097, a highly potent and optimized small molecule inhibitor of Mdm2 under evaluation in a Phase I clinical trial

Activation of p53 by blocking the p53-Mdm2 interaction using non-peptidic small-molecule inhibitors is being pursued as a promising cancer therapeutic strategy. In the present study, we show the identification of NVP-CGM097, a novel, highly optimized, and selective inhibitor of the p53-Mdm2 interaction. NVP-CGM097 binds to human Mdm2 protein with a Ki value of 1.3 nM, activates p53 in human cells and induces robust p53-dependent cell cycle arrest and apoptosis in human p53 wild-type tumor cells. Its activity and selectivity has been tested and confirmed across a large panel of cancer cell lines from the Cancer Cell Line Encyclopedia. Importantly, NVP-CGM097 displays desirable pharmacokinetic and pharmacodynamic profiles in animals together with excellent oral bioavailability, which triggers rapid and sustained activation of p53-dependent pharmacodynamic biomarkers resulting in tumor regression in multiple xenografted models of p53 wild-type human cancer. The validation and understanding of its mechanism of action, the overall favorable drug-like properties and the characterization of its on-target toxicological profile in preclinical species strongly supported the initiation of Phase I clinical trials with NVP-CGM097 in pre-selected patients with p53 wild-type tumors. Citation Format: Sebastien Jeay, Joerg Berghausen, Nicole Buschmann, Patrick Chene, Robert Cozens, Dirk Erdmann, Stephane Ferretti, Pascal Furet, Tobias Gabriel, Francois Gessier, Diana Graus-Porta, Francesco Hofmann, Philipp Holzer, Moriko Ito, Edgar Jacoby, Michael Jensen, Joerg Kallen, Marc Lang, Joanna Lisztwan, Masato Murakami, Carole Pissot-Soldermann, Stephan Ruetz, Caroline Rynn, Dario Sterker, Stefan Stutz, Therese Valat, Marion Wiesmann, Keiichi Masuya. Discovery of NVP-CGM097, a highly potent and optimized small molecule inhibitor of Mdm2 under evaluation in a Phase I clinical trial. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1797. doi:10.1158/1538-7445.AM2014-1797

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.