Discovery of the thieno[2,3-d]pyrimidine-2,4-dione derivative 21a: A potent and orally bioavailable gonadotropin-releasing hormone receptor antagonist

Transfer of the Oral Gonadotropin-Releasing Hormone Receptor Antagonist Relugolix Into Breast Milk of Healthy Lactating Women

Relugolix is an oral gonadotropin-releasing hormone receptor antagonist that suppresses sex steroid hormones and is approved as monotherapy for prostate cancer and as a fixed-dose combination with estradiol/norethindrone for the treatment of endometriosis and uterine fibroids. The aim of this postmarketing study was to determine the pharmacokinetics and quantify the amount of relugolix excreted into breast milk of healthy lactating women. Following a single, oral dose of 40 mg relugolix, breast milk was sampled over 120 h. Pharmacokinetic parameters were determined, including the cumulative amount of relugolix excreted into breast milk to derive the total infant dose. The safety and tolerability of relugolix were also assessed. Eight healthy lactating women were enrolled and completed the study per protocol. Relugolix was safe and well tolerated based on adverse events and other safety data. It was excreted into breast milk with a median time to peak concentration (tmax) of 5.81 h and a geometric mean peak concentration (Cmax) of 15.7 ng/mL, similar to corresponding plasma data from previous clinical studies. The mean cumulative amount of relugolix excreted was 0.0051 mg over 24 h and 0.0067 mg over 120 h, corresponding to 0.0128% and 0.0167% of the maternal dose, respectively. The body weight-adjusted relative daily infant dose of approximately 0.25% suggests a 400-fold lower newborn than maternal relugolix exposure. Relevant effects of relugolix on the breastfed child appear unlikely given its limited excretion into breast milk of lactating women but cannot be fully excluded in the absence of infant safety data.

Advances in structural identification of some thieno[2,3-d]pyrimidine scaffolds as antitumor molecules: Synthetic approaches and control programmed cancer cell death potential

Thieno[2,3-d]pyrimidine fragment is not only bioistostere to quinazoline ring but also to purines which exist in nucleic acids responsible for several key biological processes of the living cells, thus it is of a great interest for many researchers. Thieno[2,3-d]pyrimidine ring has become an important scaffold for different compounds with versatile pharmacological activities including anticancer. These compounds exert their anticancer activity through variant mechanisms of action; one of these is the induction of different programmed cell death types as apoptosis and necroptosis which is an effective approach for cancer treatment. This review highlights the different synthetic approaches of recent thieno[2,3-d]pyrimidine analogs along with their anticancer significance through induction of apoptotic or necroptotic cell death with illustration of the structure-activity relationship (SAR).

Relugolix for the treatment of prostate cancer

INTRODUCTION

Androgen deprivation therapy consists of the cornerstone of prostate cancer medical treatment. Until recently, castration of hypothalamus-hypophysis-gonadal axial was based on injectable medical agents. A few years ago, a novel per os administered GnRH antagonist was approved leading testosterone to castration level. Relugolix was approved by FDA in 2020, and it is the first per os administered GnRH antagonist. The present study is a literature review of the efficacy, safety and clinical perspectives of relugolix.

AREAS COVERED

A literature narrative review was conducted using PubMed/MEDLINE, Scopus, and the Cochrane library. Studies written in English language, considering efficacy, safety and cost-effectiveness of relugolix compared with other androgen deprivation therapies were included in the review.

EXPERT OPINION

Recent studies have examined efficacy of relugolix revealing a testosterone suppression percentage of 78.4% after 48 weeks from treatment initiation. Moreover, relugolix has been associated with less major cardiovascular events as well as better rate of testosterone recovery after treatment completion compared with the GnRH agonists. However, there is no head-to-head trial comparing relugolix with injectable GnRH antagonists, so far. As a result, a trial comparing the methods of antagonists' administration should be performed in the future.

A decade's overview of 2-aminothiophenes and their fused analogs as promising anticancer agents

Over the past decades, cancer has been a challenging domain for medicinal chemists as it is an international health concern. In association, small molecules such as 2-aminothiophenes and their derivatives showed significant antitumor activity through variable modes of action. Therefore, this article aims to review the advances regarding these core scaffolds over the past 10 years, where 2-aminothiophenes and their fused analogs are classified and discussed according to their biological activity and mode of action, in the interest of boosting new design pathways for medicinal chemists to develop targeted antitumor candidates.

G protein-coupled receptors (GPCRs): advances in structures, mechanisms, and drug discovery

G protein-coupled receptors (GPCRs), the largest family of human membrane proteins and an important class of drug targets, play a role in maintaining numerous physiological processes. Agonist or antagonist, orthosteric effects or allosteric effects, and biased signaling or balanced signaling, characterize the complexity of GPCR dynamic features. In this study, we first review the structural advancements, activation mechanisms, and functional diversity of GPCRs. We then focus on GPCR drug discovery by revealing the detailed drug-target interactions and the underlying mechanisms of orthosteric drugs approved by the US Food and Drug Administration in the past five years. Particularly, an up-to-date analysis is performed on available GPCR structures complexed with synthetic small-molecule allosteric modulators to elucidate key receptor-ligand interactions and allosteric mechanisms. Finally, we highlight how the widespread GPCR-druggable allosteric sites can guide structure- or mechanism-based drug design and propose prospects of designing bitopic ligands for the future therapeutic potential of targeting this receptor family.

Synthesis and evaluation of piperazinotriazoles. Discovery of a potent and orally bioavailable neurokinin-3 receptor inhibitor

The neurokinin-3 receptor (NK3R) is one of three receptors that recognize neurokinins. The finding that pharmacological blockade of neurokinin B (NKB) signaling with an oral NK3R antagonist can significantly improve hot flash symptoms independent of any hormonal effect fits strongly suggest that NK3R is a viable drug target and that drugs targeting this receptor could be novel pharmacotherapies. Currently no NK3R ligands have been approved for the treatment of human disorders. Herein, we designed and synthesized a series of novel imidazolepiperazine derivatives (16a-16x, 20a-20f, 29a-29m) and performed molecular docking to confirm the design, among which the target compound 16x exhibited promising inhibitory activity against NK3R (IC₅₀ = 430.60 nM) with excellent membrane permeability (Papp, A-B = 37.6 × 10^-6 cm/s, ER < 1) and oral bioavailability (F% = 93.6%). Our in vivo studies demonstrated that 16x was orally active, efficacious, and well-tolerated in ovariectomy (OVX) model to suppress blood luteinizing hormone levels, which suggests that 16x is a viable lead compound for further optimization and development.

Synthesis of 3-(Pyridin-2-yl)quinazolin-2,4(1H,3H)-diones via Annulation of Anthranilic Esters with N-pyridyl Ureas

A new route for the synthesis of quinazolin-2,4(1H,3H)-diones and thieno [2,3-d]pyrimidine-2,4(1H,3H)-diones substituted by pyridyl/quinolinyl moiety in position 3 has been developed. The proposed method concluded in an annulation of substituted anthranilic esters or 2-aminothiophene-3-carboxylates with 1,1-dimethyl-3-(pyridin-2-yl) ureas. The process consists of the formation of N-aryl-N'-pyridyl ureas followed by their cyclocondensation into the corresponding fused heterocycles. The reaction does not require the use of metal catalysts and proceeds with moderate to good yields (up to 89%). The scope of the method is more than 30 examples, including compounds with both electron-withdrawing and electron-donating groups, as well as diverse functionalities. At the same time, strong electron-acceptor substituents in the pyridine ring of the starting ureas reduce the product yield or even prevent the cyclocondensation step. The reaction can be easily scaled to gram quantities.