Brian Michael Mathes

The Potent BACE1 Inhibitor LY2886721 Elicits Robust Central Aβ Pharmacodynamic Responses in Mice, Dogs, and Humans

BACE1 is a key protease controlling the formation of amyloid β, a peptide hypothesized to play a significant role in the pathogenesis of Alzheimers disease (AD). Therefore, the development of potent and selective inhibitors of BACE1 has been a focus of many drug discovery efforts in academia and industry. Herein, we report the nonclinical and early clinical development of LY2886721, a BACE1 active site inhibitor that reached phase 2 clinical trials in AD. LY2886721 has high selectivity against key off-target proteases, which efficiently translates in vitro activity into robust in vivo amyloid β lowering in nonclinical animal models. Similar potent and persistent amyloid β lowering was observed in plasma and lumbar CSF when single and multiple doses of LY2886721 were administered to healthy human subjects. Collectively, these data add support for BACE1 inhibition as an effective means of amyloid lowering and as an attractive target for potential disease modification therapy in AD.

A general method for the preparation of 2,3,5-trisubstituted-furo[3,2-b]pyridines

Abstract The preparation of 2,3,5-trisubstituted-furo[3,2- b ]pyridines via a Pd(0)-catalyzed intramolecular cyclization of methyl 4-(6-chloro-2-iodopyridin-3-yloxy)-substituted-butenoates 9a – f is described. This approach was both efficient and general, and provided the highly functionalized heterocyclic ring system in high yield. Among the several examples provided is the preparation of 3-[2-( N , N -dimethylamino)ethyl]-5-(4-fluorobenzoyl)amino-2-methylfuro[3,2- b ]pyridine 4 , a selective 5-HT 1F receptor agonist.

GluK1 antagonists from 6-(tetrazolyl)phenyl decahydroisoquinoline derivatives: in vitro profile and in vivo analgesic efficacy.

We have explored the decahydroisoquinoline scaffold, bearing a phenyl tetrazole, as GluK1 antagonists with potential as oral analgesics. We have established the optimal linker atom between decahydroisoquinoline and phenyl rings and demonstrated an improvement of both the affinity for the GluK1 receptor and the selectivity against the related GluA2 receptor with proper phenyl substitution. In this Letter, we also disclose in vivo data that led to the discovery of LY545694·HCl, a compound with oral efficacy in two persistent pain models.

Abstract 4973: Discovery of LY3214996, a selective and novel ERK1/2 inhibitor with potent antitumor activities in cancer models with MAPK pathway alterations

The RAS/MAPK pathway is dysregulated in approximately 30% of human cancers, and the extracellular-signal-regulated kinases (ERK1 and ERK2) serves as key central nodes within this pathway. The feasibility and clinical impact of targeting the RAS/MAPK pathway has been demonstrated by the therapeutic success of BRAF and MEK inhibitors in BRAF V600E/K metastatic melanoma. However, resistance develops frequently through reactivation of the pathway. Therefore, simultaneous targeting of multiple effectors such as RAF, MEK and ERK in this pathway, offers a potential for enhanced efficacy while delaying and overcoming resistance. LY3214996 is a highly selective inhibitor of ERK1 and ERK2, with IC50 of 5 nM for both enzymes in biochemical assays. It potently inhibits cellular phospho-RSK1 in BRAF and RAS mutant cancer cell lines. In an unbiased tumor cell panel sensitivity profiling for inhibition of cell proliferation, tumor cells with MAPK pathway alterations including BRAF, NRAS or KRAS mutation are generally sensitivity to LY3214996. In tumor xenograft models, LY3214996 inhibits PD biomarker phospho-p90RSK1 in tumors and the PD effects are correlated with compound exposures and anti-tumor activities. LY3214996 shows either similar or superior anti-tumor activity as compared to other published ERK inhibitors in BRAF or RAS mutant cell lines and xenograft models. Oral administration of single-agent LY3214996 significantly inhibits tumor growth in vivo and is well tolerated in BRAF or NRAS mutant melanoma, BRAF or KRAS mutant colorectal, lung and pancreatic cancer xenografts or PDX models. Therefore, LY3214996 can be tailored for treatment of cancers with MAPK pathway alteration. In addition, LY3214996 has anti-tumor activity in a vemurafenib-resistant A375 melanoma xenograft model due to MAPK reactivation, may have potential for treatment of melanoma patients who have failed BRAF therapies. More importantly, LY3214996 can be combined with investigational and approved agents in preclinical models, particularly KRAS mutant models. Combination treatment of LY3214996 and CDK4/6 inhibitor abemaciclib was well tolerated and results in potent tumor growth inhibition or regression in multiple in vivo cancer models, including KRAS mutant colorectal and non-small cell lung cancers. Here, we first report the preclinical characterization of LY3214996, a novel small molecule ERK1/2 inhibitor currently in Phase I clinical trials in patients with advanced and metastatic cancers (NCT02857270). Citation Format: Shripad V. Bhagwat, William T. McMillen, Shufen Cai, Baohui Zhao, Matthew Whitesell, Lisa Kindler, Robert S. Flack, Wenjuan Wu, Karen Huss, Bryan Anderson, Xiu-Juan Yuan, Susan Jaken, Denis McCann, Brian Mathes, Andrew J. Dropsey, Jason Manro, Jennie Walgren, Eunice Yuen, Xueqian Gong, Michael J. Rodriguez, Jianping Huang, Ramon V. Tiu, Sajan Joseph, Sheng-Bin Peng. Discovery of LY3214996, a selective and novel ERK1/2 inhibitor with potent antitumor activities in cancer models with MAPK pathway alterations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4973. doi:10.1158/1538-7445.AM2017-4973

Discovery of selective N-[3-(1-methyl-piperidine-4-carbonyl)-phenyl]-benzamide-based 5-HT1F receptor agonists: Evolution from bicyclic to monocyclic cores

Preclinical experiments and clinical observations suggest the potential effectiveness of selective 5-HT1F receptor agonists in migraine. Identifying compounds with enhanced selectivity is crucial to assess its therapeutic value. Replacement of the indole nucleus in 2 (LY334370) with a monocyclic phenyl ketone moiety generated potent and more selective 5-HT1F receptor agonists. Focused SAR studies around this central phenyl ring demonstrated that the electrostatic and steric interactions of the substituent with both the amide CONH group and the ketone CO group play pivotal roles in affecting the adopted conformation and thus the 5-HT1F receptor selectivity. Computational studies confirmed the observed results and provide a useful tool in the understanding of the conformational requirements for 5-HT1F receptor agonist activity and selectivity. Through this effort, the 2-F-phenyl and N-2-pyridyl series were also identified as potent and selective 5-HT1F receptor agonists.

GluK1 antagonists from 6-(carboxy)phenyl decahydroisoquinoline derivatives. SAR and evaluation of a prodrug strategy for oral efficacy in pain models

The synthesis and structure-activity relationship of decahydroisoquinoline derivatives with various benzoic acid substitutions as GluK1 antagonists are described. Potent and selective antagonists were selected for a tailored prodrug approach in order to facilitate the evaluation of the new compounds in pain models after oral administration. Several diester prodrugs allowed for acceptable amino acid exposure and moderate efficacy in vivo.

Abstract 3231: Identifying high quality, potent and selective pyrimidinylthienopyrrolone inhibitors of ERK1/2 kinase: LY3214996

The ERK/MAPK pathway plays a central role in the regulation of critical cellular processes and is activated in more than 30% of human cancers. While targeting upstream nodes with RAF and MEK inhibitors has proven effective clinically, resistance frequently develops through reactivation of the pathway. ERK inhibitors have the potential to address resistance caused by ERK reactivation. Herein, a potent, selective small molecule ERK1/2 inhibitor is described. LY3214996 possesses an optimal balance of potency (hERK1 IC50 5 nM, hERK2 IC50 5nM, pRSK IC50 0.43 µM), solubility (FaSSIF solubility at pH 6.5 0.133 µM), PK properties (dog, AUCoral 23800 nM*hr, CL 12.1 mL/min/kg, bioavailability 75.4%), IVTI (TED50 =16 mg/kg pRSK1) and demonstrated significant in vivo efficacy in several human cancer xenograft models. LY3214996 is currently undergoing early clinical evaluation. Citation Format: Gaiying Zhao, William T. McMillen, Shufen Cai, Baohui Zhao, Matthew Whitesell, Wenjuan Wu, Karen Huss, Bryan Anderson, Xiu-Juan Yuan, Susan Jaken, Lisa Kindler, Robert S. Flack, Denis McCann, Brian Mathes, Andrew J. Dropsey, Jennie Walgren, Eunice Yuen, Jason Manro, Xueqian Gong, Guillermo Cortez, Johnathan McLean, Michael J. Rodriguez, Ramon V. Tiu, Shripad V. Bhagwat, Sajan Joseph. Identifying high quality, potent and selective pyrimidinylthienopyrrolone inhibitors of ERK1/2 kinase: LY3214996 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3231. doi:10.1158/1538-7445.AM2017-3231