Identification of Clinical Candidate M2698, a Dual p70S6K and Akt Inhibitor, for Treatment of PAM Pathway-Altered Cancers.

Herein, we report the discovery of a novel class of quinazoline carboxamides as dual p70S6k/Akt inhibitors for the treatment of tumors driven by alterations to the PI3K/Akt/mTOR (PAM) pathway. Through the screening of in-house proprietary kinase library, 4-benzylamino-quinazoline-8-carboxylic acid amide 1 stood out, with sub-micromolar p70S6k biochemical activity, as the starting point for a structurally enabled p70S6K/Akt dual inhibitor program that led to the discovery of M2698, a dual p70S6k/Akt inhibitor. M2698 is kinase selective, possesses favorable physical, chemical, and DMPK profiles, is orally available and well tolerated, and displayed tumor control in multiple in vivo studies of PAM pathway-driven tumors.

Discovery of substituted benzamides as follicle stimulating hormone receptor allosteric modulators.

Follicle-stimulating hormone (FSH), acting on its receptor (FSHR), plays a pivotal role in the stimulation of follicular development and maturation. Multiple injections of protein formulations are used during clinical protocols for ovulation induction and for in vitro fertilization that are followed by a selection of assisted reproductive technologies. In order to increase patient convenience and compliance several research groups have searched for orally bioavailable FSH mimetics for innovative fertility medicines. We report here the discovery of a series of substituted benzamides as positive allosteric modulators (PAM) targeting FSHR. Optimization of this series has led to enhanced activity in primary rat granulosa cells, as well as remarkable selectivity against the closely related luteinizing hormone receptor (LHR) and thyroid stimulating hormone receptor (TSHR). Two modulators, 9j and 9k, showed promising in vitro and pharmacokinetic profiles.

Synthesis and biological evaluation of antifungal derivatives of enfumafungin as orally bioavailable inhibitors of ß-1,3-glucan synthase.

Orally bioavailable inhibitors of ß-(1,3)-D-glucan synthase have been pursued as new, broad-spectrum fungicidal therapies suitable for treatment in immunocompromised patients. Toward this end, a collaborative medicinal chemistry program was established based on semisynthetic derivatization of the triterpenoid glycoside natural product enfumafungin in order to optimize in vivo antifungal activity and oral absorption properties. In the course of these studies, it was hypothesized that the pharmacokinetic properties of the semisynthetic enfumafungin analog 3 could be improved by tethering the alkyl groups proximal to the basic nitrogen of the C3-aminoether side chain into an azacyclic system, so as to preclude oxidative N-demethylation. The results of this research effort are disclosed herein.

A novel series of 2-pyridyl-containing compounds as lysophosphatidic acid receptor antagonists: development of a nonhydrolyzable LPA3 receptor-selective antagonist.

A recently reported dual LPA(1)/LPA(3) receptor antagonist (1) has been modified so as to modulate the basicity, sterics, and dipole moment of the 2-pyridyl moiety. Additionally, the implications of installing nonhydrolyzable phosphate head group isosteres with regard to antagonist potency and selectivity at LPA receptors is described. This study has resulted in the development of the first nonhydrolyzable and presumably phosphatase-resistant LPA(3)-selective antagonist reported to date.

Synthesis and biological evaluation of phosphonic and thiophosphoric acid derivatives of lysophosphatidic acid.

Using an N-oleoyl ethanolamide scaffold, a series of phosphate polar head group analogues of LPA comprised of various alpha-substituted phosphonates and thiophosphates was prepared. In a broken cell GTP[gamma35S] binding assay, agonist activity was evaluated at the three LPA receptors of the endothelial differentiation gene (Edg) family. This study has resulted in the discovery of a nonhydrolyzable LPA1-selective agonist (11). Additionally, thiophosphate 19 bears an isosteric phosphate mimetic that confers agonism at the LPA1 receptor but not LPA2.

Initial structure-activity relationships of lysophosphatidic acid receptor antagonists: discovery of a high-affinity LPA1/LPA3 receptor antagonist.

A recently reported dual LPA1/LPA3 receptor antagonist (VPC12249, 1) has been modified herein so as to optimize potency and selectivity at LPA receptors. Compounds containing variation in the acyl lipid chain and linker region have been synthesized and screened for activity at individual LPA receptors. LPA1-selective (14b) and LPA3-selective (10g,m) compounds of modest potency have been discovered. Additionally, 2-pyridyl derivative 10t exhibits a Ki value of 18 nM at the LPA1 receptor and is significantly more potent than 1 at the LPA3 receptor. This paper describes the synthetic methods, biological evaluation, and structure-activity relationships (SARs) of LPA receptor antagonists.

In vitro metabolism of 2-acetylbenzothiophene: relevance to zileuton hepatotoxicity.

Zileuton, an inhibitor of 5-lipooxygenase, the initial enzyme in the leukotriene pathway, was marketed as a new treatment for asthma. This drug has been associated with liver toxicity, which has limited its clinical usefulness. We provide evidence here that the liver toxicity likely involves a sequence of biotransformations leading to 2-acetylbenzothiophene (2-ABT), which is subsequently metabolized to give a reactive intermediate(s). In vitro experiments with the human lymphoblast MCL5 cell line demonstrated that 2-ABT is cytotoxic in a P450-dependent manner. Human liver microsome (HLM) incubations with 2-ABT revealed the formation of two short-lived oxidized species, "M + 16" and "M + 32". Both of these metabolites formed adducts in the presence of GSH or NAC. Singly oxidized M + 16 adducts, from either GSH or NAC, appeared to be unstable in acidic medium and eliminated water readily to form a new compound. Authentic synthetic standards demonstrated that 2-ABT-S-oxide M1 corresponded to the M + 16 metabolite and that the S-oxide underwent nucleophilic addition with GSH and NAC to produce the singly oxidized adducts observed in HLM. The S-oxide adducts readily eliminated water to form a rearomatized 2-ABT-GSH adduct or 2-ABT-NAC adduct. Coelution experiments with the synthetic standard confirmed the structure of the eliminated 2-ABT-NAC adduct C1. LC/MS analyses of urine samples collected from rats dosed with zileuton indicate that C1 is a metabolite of zileuton formed in vivo. The in vitro and in vivo data presented here demonstrate the formation of 2-ABT from zileuton and its further bioactivation to a potentially toxic metabolite.