Empowering Voices: Inspiring Women in Medicinal Chemistry.

As we celebrate International Women's Day 2024 with the theme "Inspire Inclusion", the women of the ACS Medicinal Chemistry Division (MEDI) want to foster a sense of belonging, relevance, and empowerment by sharing uplifting stories of what inspired them to become medicinal chemists. In this editorial, we are featuring female medicinal chemistry scientists to provide role models, encouragement, and inspiration to others. We asked women medicinal chemists to contribute a brief paragraph about what inspired them to become medicinal chemists or what inspires them today as medicinal chemists. The responses and contributions highlight their passions and motivations, such as their love of the sciences and their drive to improve human health by contributing to basic research and creating lifesaving drugs.

Empowering Voices: Inspiring Women in Medicinal Chemistry.

As we celebrate International Women's Day 2024 with the theme "Inspire Inclusion", the women of the ACS Medicinal Chemistry Division (MEDI) want to foster a sense of belonging, relevance, and empowerment by sharing uplifting stories of what inspired them to become medicinal chemists. In this editorial, we are featuring female medicinal chemistry scientists to provide role models, encouragement, and inspiration to others. We asked women medicinal chemists to contribute a brief paragraph about what inspired them to become medicinal chemists or what inspires them today as medicinal chemists. The responses and contributions highlight their passions and motivations, such as their love of the sciences and their drive to improve human health by contributing to basic research and creating lifesaving drugs.

Small-molecule inhibition of kinesin KIF18A reveals a mitotic vulnerability enriched in chromosomally unstable cancers.

Chromosomal instability (CIN) is a hallmark of cancer, caused by persistent errors in chromosome segregation during mitosis. Aggressive cancers like high-grade serous ovarian cancer (HGSOC) and triple-negative breast cancer (TNBC) have a high frequency of CIN and TP53 mutations. Here, we show that inhibitors of the KIF18A motor protein activate the mitotic checkpoint and selectively kill chromosomally unstable cancer cells. Sensitivity to KIF18A inhibition is enriched in TP53-mutant HGSOC and TNBC cell lines with CIN features, including in a subset of CCNE1-amplified, CDK4-CDK6-inhibitor-resistant and BRCA1-altered cell line models. Our KIF18A inhibitors have minimal detrimental effects on human bone marrow cells in culture, distinct from other anti-mitotic agents. In mice, inhibition of KIF18A leads to robust anti-cancer effects with tumor regression observed in human HGSOC and TNBC models at well-tolerated doses. Collectively, our results provide a rational therapeutic strategy for selective targeting of CIN cancers via KIF18A inhibition.

Targeting the Mitotic Kinesin KIF18A in Chromosomally Unstable Cancers: Hit Optimization Toward an In Vivo Chemical Probe.

Chromosomal instability (CIN) is a hallmark of cancer that results from errors in chromosome segregation during mitosis. Targeting of CIN-associated vulnerabilities is an emerging therapeutic strategy in drug development. KIF18A, a mitotic kinesin, has been shown to play a role in maintaining bipolar spindle integrity and promotes viability of CIN cancer cells. To explore the potential of KIF18A, a series of inhibitors was identified. Optimization of an initial hit led to the discovery of analogues that could be used as chemical probes to interrogate the role of KIF18A inhibition. Compounds 23 and 24 caused significant mitotic arrest in vivo, which was sustained for 24 h. This would be followed by cell death either in mitosis or in the subsequent interphase. Furthermore, photoaffinity labeling experiments reveal that this series of inhibitors binds at the interface of KIF18A and tubulin. This study represents the first disclosure of KIF18A inhibitors with in vivo activity.

Discovery of a Covalent Inhibitor of KRASG12C (AMG 510) for the Treatment of Solid Tumors.

KRASG12C has emerged as a promising target in the treatment of solid tumors. Covalent inhibitors targeting the mutant cysteine-12 residue have been shown to disrupt signaling by this long-"undruggable" target; however clinically viable inhibitors have yet to be identified. Here, we report efforts to exploit a cryptic pocket (H95/Y96/Q99) we identified in KRASG12C to identify inhibitors suitable for clinical development. Structure-based design efforts leading to the identification of a novel quinazolinone scaffold are described, along with optimization efforts that overcame a configurational stability issue arising from restricted rotation about an axially chiral biaryl bond. Biopharmaceutical optimization of the resulting leads culminated in the identification of AMG 510, a highly potent, selective, and well-tolerated KRASG12C inhibitor currently in phase I clinical trials (NCT03600883).

Small Molecule Disruptors of the Glucokinase-Glucokinase Regulatory Protein Interaction: 5. A Novel Aryl Sulfone Series, Optimization Through Conformational Analysis.

The glucokinase-glucokinase regulatory protein (GK-GKRP) complex plays an important role in controlling glucose homeostasis in the liver. We have recently disclosed a series of arylpiperazines as in vitro and in vivo disruptors of the GK-GKRP complex with efficacy in rodent models of type 2 diabetes mellitus (T2DM). Herein, we describe a new class of aryl sulfones as disruptors of the GK-GKRP complex, where the central piperazine scaffold has been replaced by an aromatic group. Conformational analysis and exploration of the structure-activity relationships of this new class of compounds led to the identification of potent GK-GKRP disruptors. Further optimization of this novel series delivered thiazole sulfone 93, which was able to disrupt the GK-GKRP interaction in vitro and in vivo and, by doing so, increases cytoplasmic levels of unbound GK.

Optimization of potency and pharmacokinetic properties of tetrahydroisoquinoline transient receptor potential melastatin 8 (TRPM8) antagonists.

Transient receptor potential melastatin 8 (TRPM8) is a nonselective cation channel expressed in a subpopulation of sensory neurons in the peripheral nervous system. TRPM8 is the predominant mammalian cold temperature thermosensor and is activated by cold temperatures ranging from 8 to 25 °C and cooling compounds such as menthol or icilin. TRPM8 antagonists are being pursued as potential therapeutics for treatment of pain and bladder disorders. This manuscript outlines new developments in the SAR of a lead series of 1,2,3,4-tetrahydroisoquinoline derivatives with emphasis on strategies to improve pharmacokinetic properties and potency. Selected compounds were profiled in two TRPM8 target-specific in vivo coverage models in rats (the icilin-induced wet dog shake model and the cold pressor test). Compound 45 demonstrated robust efficacy in both pharmacodynamic models with ED90 values <3 mg/kg.

Selective class I phosphoinositide 3-kinase inhibitors: optimization of a series of pyridyltriazines leading to the identification of a clinical candidate, AMG 511.

The phosphoinositide 3-kinase family catalyzes the phosphorylation of phosphatidylinositol-4,5-diphosphate to phosphatidylinositol-3,4,5-triphosphate, a secondary messenger which plays a critical role in important cellular functions such as metabolism, cell growth, and cell survival. Our efforts to identify potent, efficacious, and orally available phosphatidylinositol 3-kinase (PI3K) inhibitors as potential cancer therapeutics have resulted in the discovery of 4-(2-((6-methoxypyridin-3-yl)amino)-5-((4-(methylsulfonyl)piperazin-1-yl)methyl)pyridin-3-yl)-6-methyl-1,3,5-triazin-2-amine (1). In this paper, we describe the optimization of compound 1, which led to the design and synthesis of pyridyltriazine 31, a potent pan inhibitor of class I PI3Ks with a superior pharmacokinetic profile. Compound 31 was shown to potently block the targeted PI3K pathway in a mouse liver pharmacodynamic model and inhibit tumor growth in a U87 malignant glioma glioblastoma xenograft model. On the basis of its excellent in vivo efficacy and pharmacokinetic profile, compound 31 was selected for further evaluation as a clinical candidate and was designated AMG 511.

Structure-based design of a novel series of potent, selective inhibitors of the class I phosphatidylinositol 3-kinases.

A highly selective series of inhibitors of the class I phosphatidylinositol 3-kinases (PI3Ks) has been designed and synthesized. Starting from the dual PI3K/mTOR inhibitor 5, a structure-based approach was used to improve potency and selectivity, resulting in the identification of 54 as a potent inhibitor of the class I PI3Ks with excellent selectivity over mTOR, related phosphatidylinositol kinases, and a broad panel of protein kinases. Compound 54 demonstrated a robust PD-PK relationship inhibiting the PI3K/Akt pathway in vivo in a mouse model, and it potently inhibited tumor growth in a U-87 MG xenograft model with an activated PI3K/Akt pathway.

Fused piperidines as a novel class of potent and orally available transient receptor potential melastatin type 8 (TRPM8) antagonists.

The transient receptor potential melastatin type 8 (TRPM8) is a nonselective cation channel primarily expressed in a subpopulation of sensory neurons that can be activated by a wide range of stimuli, including menthol, icilin, and cold temperatures (<25 °C). Antagonism of TRPM8 is currently under investigation as a new approach for the treatment of pain. As a result of our screening efforts, we identified tetrahydrothienopyridine 4 as an inhibitor of icilin-induced calcium influx in CHO cells expressing recombinant rat TRPM8. Exploration of the structure-activity relationships of 4 led to the identification of a potent and orally bioavailable TRPM8 antagonist, tetrahydroisoquinoline 87. Compound 87 demonstrated target coverage in vivo after oral administration in a rat pharmacodynamic model measuring the prevention of icilin-induced wet-dog shakes (WDS).

Design of a new peptidomimetic agonist for the melanocortin receptors based on the solution structure of the peptide ligand, Ac-Nle-cyclo[Asp-Pro-DPhe-Arg-Trp-Lys]-NH(2).

The solution structure of a potent melanocortin receptor agonist, Ac-Nle-cyclo[Asp-Pro-DPhe-Arg-Trp-Lys]-NH(2) (1) was calculated using distance restraints determined from 1H NMR spectroscopy. Eight of the lowest energy conformations from this study were used to identify non-peptide cores that mimic the spatial arrangement of the critical tripeptide region, DPhe-Arg-Trp, found in 1. From these studies, compound 2a, containing the cis-cyclohexyl core, was identified as a functional agonist of the melanocortin-4 receptor (MC4R) with an IC(50) and EC(50) below 10 nM. Compound 2a also showed 36- and 7-fold selectivity over MC3R and MC1R, respectively, in the binding assays. Subtle changes in cyclohexane stereochemistry and removal of functional groups led to analogues with lower affinity for the MC receptors.

Structure-activity relationship of (1-aryl-2-piperazinylethyl)piperazines: antagonists for the AGRP/melanocortin receptor binding.

Agouti-related protein (AGRP) is an endogenous antagonist of the melanocortin action.(1) In the hypothalamus, melanocortin peptide agonists act as satiety-inducing factors that mediate their action through the melanocortin-4 receptor (MC4R) whereas AGRP is an opposing orexigenic agent. Novel inhibitors of the AGRP/MC4 binding based on (piperazinylethyl)piperazines were prepared, and their structure-activity relationship was established.