Abstract The NCI Experimental Therapeutics Program (NExT) is making available two new smaller (3.5K) screening libraries suitable for academic investigator HTS drug discovery programs. The NExT program is a partnership between NCI's Division of Cancer Treatment and Diagnosis (DCTD) and the Center for Cancer Research (CCR). NExT consolidates NCI's anticancer drug discovery and development resources with the goal of maintaining a robust and balanced therapeutics pipeline. It encompasses tasks from new target validation through Phase III clinical trial evaluation. The Program is designed to streamline development and testing of promising new anticancer drugs and to expedite their delivery to the bedside. As part of the Program to support HTS drug discovery, NCI has previously offered academic oncology investigators access to our full 83K NExT Diversity Library in single-use, 384-well plate format. The set was designed to identify lead small molecules for drug discovery programs. We are now making available 2 smaller pre-plated subsets of this library, the NExT Diversity 3500 and NExT Diversity 3500 SAR, for when screening the full set is not appropriate. Each library contains 3,500 compounds: NExT Diversity 3500 is a diverse sampling across the entire 83K library while the NExT Diversity 3500 SAR is designed to facilitate rapid SAR follow-up by sampling only those compounds that have at least 5 close neighbors in the 83K library. The new libraries were designed by initially filtering the full NExT Diversity Library for undesirable compounds such as PAINS. Both atom-pair based 2D pharmacophore fingerprints and ECFP6 topological fingerprints from ChemAxon were then employed to generate the two non-overlapping subset libraries. The NExT screening libraries are provided as a resource to academic oncology investigators through the NExT Program (see NExT Resources: http://next.cancer.gov/). The design details and physiochemical characteristics of the two new sets, NExT Diversity 3500 and NExT 3500 SAR, and procedures and criteria for accessing this resource are presented along with several other screening sets available through the Developmental Therapeutics Program (DTP). Citation Format: Raj N. Misra, Michael Eckert, Christian Laggner. New NCI experimental therapeutics program (NExT) small molecule libraries for academic investigator hts projects. [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 1350.

1314 Carcinoma of the prostate (CaP) is the 2 nd leading cause of cancer-related death in men in the United States. Androgen ablation via surgical or chemical castration or by treatment with an antiandrogen is currently the treatment of choice for advanced CaP. Although this therapy initially shows an 80-90% response rate, approximately 50% of patients progress to fatal androgen independent CaP (AI-CaP) after about 18 months of treatment. Recent advances in the field have shown that reactivation of the androgen receptor (AR) signaling pathway is the root cause for the development of AI-CaP. The identification of the role of the AR in AI-CaP suggests that new agents that act at the level of the AR may be effective in the treatment of this disease. Here will be presented structure-based design efforts to identify novel chemotypes that show potent binding to, and antagonism of, the AR. In particular, a series of [2.2.1]-oxobicyclic imide-based AR antagonists showed great promise and the structure activity relationships (SAR) of this novel series will be presented in detail. All new analogs were screened via whole cell competitive binding and transactivation assays in MB-MDA-453 cells to generate in vitro SAR around the wild-type AR. Promising leads from these in vitro assays were then screened through an immature rat prostate weight PK/PD model (IRPW, PO, QD x 4 days). Analogs showing optimal PK and PD effects in the IRPW were then tested in the human cancer xenograft model CWR22, implanted in nude mice. These approaches resulted in the identification of BMS-641988 as a development candidate for the treatment of advanced CaP.

ChemMedChemVolume 3, Issue 7 p. 1135-1135 Book Review Inhibitors of Cyclin-dependent Kinases as Antitumor Agents. Edited by Paul J. Smith and Eddy W. Yue. Raj N. Misra Dr., Raj N. Misra Dr. National Institutes of Health, Maryland (USA)Search for more papers by this author Raj N. Misra Dr., Raj N. Misra Dr. National Institutes of Health, Maryland (USA)Search for more papers by this author First published: 10 July 2008 https://doi.org/10.1002/cmdc.200800165Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume3, Issue7July 14, 2008Pages 1135-1135 RelatedInformation

A novel series of 17beta-hydroxysteroid dehydrogenase type 3 (17beta-HSD3) inhibitors has been identified. These inhibitors, based on a dibenzazocine core, exhibited picomolar to low nanomolar inhibition of 17beta-HSD3 in cell-free enzymatic as well as in cell-based transcriptional reporter assays.

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N-Acyl-2-aminothiazoles with nonaromatic acyl side chains containing a basic amine were found to be potent, selective inhibitors of CDK2/cycE which exhibit antitumor activity in mice. In particular, compound 21 {N-[5-[[[5-(1,1-dimethylethyl)-2-oxazolyl]methyl]thio]-2-thiazolyl]-4-piperidinecarboxamide, BMS-387032}, has been identified as an ATP-competitive and CDK2-selective inhibitor which has been selected to enter Phase 1 human clinical trials as an antitumor agent. In a cell-free enzyme assay, 21 showed a CDK2/cycE IC50 = 48 nM and was 10- and 20-fold selective over CDK1/cycB and CDK4/cycD, respectively. It was also highly selective over a panel of 12 unrelated kinases. Antiproliferative activity was established in an A2780 cellular cytotoxicity assay in which 21 showed an IC50 = 95 nM. Metabolism and pharmacokinetic studies showed that 21 exhibited a plasma half-life of 5-7 h in three species and moderately low protein binding in both mouse (69%) and human (63%) serum. Dosed orally to mouse, rat, and dog, 21 showed 100%, 31%, and 28% bioavailability, respectively. As an antitumor agent in mice, 21 administered at its maximum-tolerated dose exhibited a clearly superior efficacy profile when compared to flavopiridol in both an ip/ip P388 murine tumor model and in a sc/ip A2780 human ovarian carcinoma xenograft model.

N-Aryl aminothiazoles 6-9 were prepared from 2-bromothiazole 5 and found to be CDK inhibitors. In cells they act as potent cytotoxic agents. Selectivity for CDK1, CDK2, and CDK4 was dependent of the nature of the N-aryl group and distinct from the CDK2 selective N-acyl analogues. The N-2-pyridyl analogues 7 and 19 showed pan CDK inhibitory activity. Elaborated analogues 19 and 23 exhibited anticancer activity in mice against P388 murine leukemia. The solid-state structure of 7 bound to CDK2 shows a similar binding mode to the N-acyl analogues. (C) 2004 Elsevier Ltd. All rights reserved.

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Structure-activity studies of 1H-pyrazolo[3,4-b]pyridine 1 have resulted in the discovery of potent CDK1/CDK2 selective inhibitor 21h, BMS-265246 (CDK1/cycB IC(50)=6 nM, CDK2/cycE IC(50)=9 nM). The 2,6-difluorophenyl substitution was critical for potent inhibitory activity. A solid state structure of 21j, a close di-fluoro analogue, bound to CDK2 shows the inhibitor resides coincident with the ATP purine binding site and forms important H-bonds with Leu83 on the protein backbone.

1H-Pyrazolo[3,4-b]pyridine 3 (SQ-67563) has been shown to be a potent, selective inhibitor of CDK1/CDK2 in vitro. In cells 3 acts as a cytotoxic agent with the ability to block cell cycle progression and/or induce apoptosis. The solid state structure of 3 bound to CDK2 shows 3 resides coincident with the ATP purine binding site and forms important H-bonding interactions with Leu83 on the protein backbone.