Relugolix: First Global Approval

Abnormal uterine bleeding: The well-known and the hidden face

Abnormal uterine bleeding (AUB) is a bleeding from the uterine corpus that is abnormal in regularity, volume, frequency or duration. It encompasses heavy menstrual bleeding, irregular menstrual bleeding and intermenstrual bleeding, which are common symptoms among women of reproductive age, impacting their overall well-being. Menstruation involves interactions between endometrial epithelial and stromal cells, immune cell influx, and changes in endometrial vasculature. These events resemble an inflammatory response with increased vessel permeability, tissue breakdown, and the arrival of innate immune cells. However, the mechanisms of menstrual cessation are poorly understood. AUB can be related to structural causes (polyp, adenomyosis, leiomyoma, malignancy/hyperplasia) and nonstructural conditions (coagulopathy, ovulatory dysfunction, endometrial, iatrogenic). While transvaginal ultrasound is the primary method for the screening of intracavitary lesions, saline infusion sonohysterography is more accurate to detect endometrial polyps and submucous leiomyomas, while hysteroscopy with biopsy remains the reference method for a definitive diagnosis. The main goals in managing AUB are addressing and correcting the underlying primary cause, if possible, and establishing a regular bleeding pattern or amenorrhea, which can be done with antifibrinolytic agents, progestins, gonadotropin-releasing hormone agonists and antagonists, or surgical interventions, each one with specific indications and limitations. Further research is necessary to assess the effectiveness and the long-term effects of various medical and surgical treatments. Meanwhile, the availability of diagnostic methods such as transvaginal ultrasound and hysteroscopy and the universal distribution of medical treatments for AUB should be prioritized by policymakers to minimize the diagnostic and treatment delay and thus reduce the risk of AUB-related anemia and the need of hysterectomy.

Experimental and new investigational drugs for the treatment of uterine fibroids

INTRODUCTION

Uterine fibroids, the most prevalent benign tumors among reproductive-age women, pose treatment challenges that range from surgical interventions to medical therapies for symptom control. Progestins and estroprogestins effectively manage uterine bleeding by suppressing dysfunctional endometrium over fibroids. While GnRH agonists represent a crucial milestone in symptom treatment, their prolonged use results in menopausal-like symptoms and irreversible bone mineral density loss. Advancements in understanding fibroid pathophysiology have prompted the exploration of new compounds to overcome current therapy limitations.

AREAS COVERED

This manuscript offers an updated overview of investigational drugs for symptomatic uterine fibroids.

EXPERT OPINION

Despite ulipristal acetate's well-established efficacy as a selective progesterone receptor modulator (SPRM) in fibroid treatment, its prescription has declined due to the rare but severe risk of liver damage. Oral GnRH antagonists, like elagolix, relugolix, and linzagolix, with their novel pharmacodynamic properties, are gaining traction in fibroid management, inducing a dose-dependent reduction in circulating sex hormone levels. Ongoing research on natural compounds, such as vitamin D and epigallocatechin gallate (EGCG), presents emerging options for treating uterine fibroids. This evolving landscape reflects the ongoing efforts to improve therapeutic outcomes for individuals with symptomatic uterine fibroids.

Oral GnRH Antagonists in Combination with Estradiol and Norethindrone Acetate for Pain Relief Associated with Endometriosis: A Review of Evidence of a Novel Class of Hormonal Agents

Current medical treatment options for endometriosis associated pains are inadequate. Evidence on effects of nonsteroidal anti-inflammatory drugs is scarce. Around one third of patients are not responsive to oral contraceptives or progestins due to progesterone resistance. Gonadotropin-releasing hormone (GnRH) agonists can only be used for a short duration because of associated side effects. Oral GnRH antagonists, including elagolix, relugolix, and linzagolix allow oral administration, induce dose dependent reduction of estradiol levels, do not cause initial flare up of endometriosis symptoms, and allow the fast return of ovarian function and menstruation after discontinuation. Elagolix at a low dose of 150 mg once daily, or the higher dose of 200 mg twice daily, significantly increased the proportion of women achieving clinically meaningful decline of dysmenorrhea, noncyclic pelvic pain, and dyspareunia. Relugolix at an oral dose of 40 mg/day results in improvement in different forms of endometriosis related pelvic pain, with an efficacy and side effect profile similar to that of GnRH agonists. Adding 1 mg of estradiol and 0.5 mg of norethindrone to 40 mg of relugolix (relugolix combination therapy) allows extension of treatment to 24 weeks with maintained efficacy and an improved side effect profile. Linzagolix, in a dose of 75 mg/day, can be used alone to treat endometriosis associated pain. For severe pelvic pain and dyspareunia, linzagolix can be used in a high dose of 200 mg/day with hormonal add-back therapy to preserve bone health.

FDA-approved heterocyclic molecules for cancer treatment: Synthesis, dosage, mechanism of action and their adverse effect

As the incorporation of heterocycles increases the physical characteristics and biological activity of pharmacological molecules, heterocyclic scaffolds are commonly discovered as common cores in a wide spectrum of biologically active drugs. In the contemporary context, many heterocycles have arisen, playing vital roles in diverse pharmaceutical compounds that benefit humanity. Over 85 % of FDA-approved medication molecules contain heterocycles, and most importantly, numerous heterocyclic medicinal molecules indicate potential benefits against a range: of malignancies. The unique flexibility and dynamic core scaffold of these compounds have aided anticancer research. These medications are used to treat cancer patients by targeting particular genes, enzymes, and receptors. Aside from the drugs that are now on the market, numerous forms are being researched for their potential anti-cancer activity. Here in this review, we classified some molecules and biologically active heterocycles containing anticancer medicinal moieties approved by the FDA between 2019 and 2021 based on their use in various forms of cancer. We will focus on those that are suitable for cancer treatment, as well as the essential biochemical mechanisms of action, biological targets, synthetic methods, and inherent limiting considerations in their use.

Early biochemical outcomes following neoadjuvant/adjuvant relugolix with stereotactic body radiation therapy for intermediate to high risk prostate cancer

Introduction

Injectable GnRH receptor agonists have been shown to improve cancer control when combined with radiotherapy. Prostate SBRT offers an abbreviated treatment course with comparable efficacy to conventionally fractionated radiotherapy. Relugolix is a new oral GnRH receptor antagonist which achieves rapid, sustained testosterone suppression. This prospective study sought to evaluate early testosterone suppression and PSA response following relugolix and SBRT for intermediate to high prostate cancer.

Methods

Relugolix was initiated at least 2 months prior to SBRT. Interventions to improve adherence were not utilized. PSA and total testosterone levels were obtained prior to and 1-4 months post SBRT. Profound castration was defined as serum testosterone ≤ 20 ng/dL. Early PSA nadir was defined as the lowest PSA value within 4 months of completion of SBRT. Per prior trials, we examined the percentage of patients who achieved PSA level of ≤ 0.5 ng/mL and ≤ 0.2 ng/mL during the first 4 months post SBRT.

Results

Between July 2021 and January 2023, 52 men were treated at Georgetown with relugolix (4-6 months) and SBRT (36.25-40 Gy in 5 fractions) per an institutional protocol (IRB 12-1775). Median age was 71 years. 26.9% of patients were African American and 28.8% were obese (BMI ≥30 kg/m2). The median pretreatment PSA was 9.1 ng/ml. 67% of patients were ≥ Grade Group 3. 44 patients were intermediate- and 8 were high-risk. Patients initiated relugolix at a median of 3.6 months prior to SBRT with a median duration of 6.2 total months. 92.3% of patients achieved profound castration during relugolix treatment. Poor drug adherence was observed in 2 patients. A third patient chose to discontinue relugolix due to side effects. By post-SBRT month 4, 87.2% and 74.4% of patients achieved PSA levels ≤ 0.5 ng/ml and ≤ 0.2 ng/ml, respectively.

Discussion

Relugolix combined with SBRT allows for high rates of profound castration with low early PSA nadirs. We observed a 96% testosterone suppresion rate without the utilization of scheduled cues/reminders. This finding supports the notion that patients with localized prostate cancer can consistently and successfully follow an oral ADT protocol without daily reminders. Given relugolix's potential benefits over injectable GnRH receptor agonists, its usage may be preferred in specific patient populations (fear of needles, prior cardiovascular events). Future studies should focus on boundaries to adherence in specific underserved populations.

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.

Physiological and Pharmacological overview of the Gonadotropin Releasing Hormone

Gonadotropin-releasing Hormone (GnRH) is a decapeptide responsible for the control of the reproductive functions. It shows C- and N-terminal aminoacid modifications and two other distinct isoforms have been so far identified. The biological effects of GnRH are mediated by binding to high-affinity G-protein couple receptors (GnRHR), showing characteristic very short C tail. In mammals, including humans, GnRH-producing neurons originate in the embryonic nasal compartment and during early embryogenesis they undergo rapid migration towards the hypothalamus; the increasing knowledge of such mechanisms improved diagnostic and therapeutic approaches to infertility. The pharmacological use of GnRH, or its synthetic peptide and non-peptide agonists or antagonists, provides a valid tool for reproductive disorders and assisted reproduction technology (ART). The presence of GnRHR in several organs and tissues indicates additional functions of the peptide. The identification of a GnRH/GnRHR system in the human endometrium, ovary, and prostate has extended the functions of the peptide to the physiology and tumor transformation of such tissues. Likely, the activity of a GnRH/GnRHR system at the level of the hippocampus, as well as its decreased expression in mice brain aging, raised interest in its possible involvement in neurogenesis and neuronal functions. In conclusion, GnRH/GnRHR appears to be a fascinating biological system that exerts several possibly integrated pleiotropic actions in the complex control of reproductive functions, tumor growth, neurogenesis, and neuroprotection. This review aims to provide an overview of the physiology of GnRH and the pharmacological applications of its synthetic analogs in the management of reproductive and non-reproductive diseases.

The pyridazine heterocycle in molecular recognition and drug discovery

The pyridazine ring is endowed with unique physicochemical properties, characterized by weak basicity, a high dipole moment that subtends π-π stacking interactions and robust, dual hydrogen-bonding capacity that can be of importance in drug-target interactions. These properties contribute to unique applications in molecular recognition while the inherent polarity, low cytochrome P450 inhibitory effects and potential to reduce interaction of a molecule with the cardiac hERG potassium channel add additional value in drug discovery and development. The recent approvals of the gonadotropin-releasing hormone receptor antagonist relugolix (24) and the allosteric tyrosine kinase 2 inhibitor deucravacitinib (25) represent the first examples of FDA-approved drugs that incorporate a pyridazine ring. In this review, the properties of the pyridazine ring are summarized in comparison to the other azines and its potential in drug discovery is illustrated through vignettes that explore applications that take advantage of the inherent physicochemical properties as an approach to solving challenges associated with candidate optimization.

Graphical Abstract

Profile of Linzagolix in the Management of Endometriosis, Including Design, Development and Potential Place in Therapy: A Narrative Review

Estrogens play a critical role in the pathogenesis of endometriosis and it is logical to assume that lowering estradiol levels with oral gonadotropin-releasing hormone (GnRH) antagonists may prove effective, especially in women who fail to respond to progestogens. Indeed, due to progesterone resistance, oral contraceptives and progestogens work well in two-thirds of women suffering from endometriosis, but are ineffective in 33% of women. Oral GnRH antagonists have therefore been evaluated for management of premenopausal women with endometriosis-associated pelvic pain. The first publication on these drugs reported the efficacy of elagolix. The present paper is a narrative review of linzagolix, which is an orally administered GnRH receptor antagonist with low pharmacokinetic/pharmacodynamic variability. It binds to and blocks the GnRH receptor in the pituitary gland, resulting in a dose-dependent drop in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) production. This reduction in LH and FSH levels in turn leads to a dose-dependent decline in estrogen. Phase 2 and 3 trials are reviewed and discussed here. There is a place for GnRH antagonists in the management of symptomatic endometriosis, and linzagolix with or without add-back therapy (ABT) is one option that can be used at low doses, avoiding the need for ABT, which is contraindicated in some patients.

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease on the background of progesterone resistance. Increased estrogen production, low estrogen metabolization, and altered estrogen receptors (ERs) expression contribute to the hyperestrogenic milieu within endometriotic lesions. Since estrogens play a crucial role in the pathogenesis of the disease, inhibition of estrogen production is one of the main targets of available and emerging drugs.

AREAS COVERED

Firstly, we described the molecular alterations responsible for estrogen dependence. Secondly, we reviewed available and emerging treatments that interfere, through central (gonadotropin-releasing hormone analogs (GnRH-a), GnRH antagonists) or local mechanisms (aromatase inhibitors (AIs), inhibitors of steroid sulfatase (STS) and hydroxysteroid dehydrogenase type 1 (17β-HSD1)), with estrogen dependence. Finally, we focused on emerging treatments targeting ERs (selective estrogen receptor modulators (SERMs), estrogen receptors agonists, and antagonists).

EXPERT OPINION

Available treatments interfering with estrogen pathways exert a contraceptive effect, have hypoestrogenic side effects, and cannot prevent or definitively treat the disease. Preclinical and animal studies are focusing on emerging drugs targeting ERs in order to overcome limitations of available treatments. These treatments may represent a promising option, as they may produce a more specific inhibition of disease activity within endometriotic implants, avoiding prolonged hypoestrogenic status and limiting systemic side effects.

Novel pharmacological therapies for the treatment of endometriosis

INTRODUCTION

Endometriosis is a chronic, estrogen-dependent, inflammatory disease associated with pelvic pain, infertility, impaired sexual function, and psychological suffering. Therefore, tailored patient management appears of primary importance to address specific issues and identify the appropriate treatment for each woman. Over the years, abundant research has been carried out with the objective to find new therapeutic approaches for this multifaceted disease.

AREAS COVERED

This narrative review aims to present the latest advances in the pharmacological management of endometriosis. In particular, the potential role of GnRH antagonists, selective progesterone receptor modulators (SPRMs), and selective estrogen receptors modulators (SERMs) will be discussed. We performed a literature search in PubMed and Embase, and selected the best quality evidence, giving preference to the most recent and definitive original articles and reviews.

EXPERT OPINION

Medical therapy represents the cornerstone of endometriosis management, although few advances have been made in the last decade. Most studies have focused on the evaluation of the efficacy and safety of GnRH antagonists (plus add-back therapy in cases of prolonged treatment), which should be used as second-line treatment options in selected cases (i.e. non-responders to first-line treatments). Further studies are needed to identify the ideal treatment for women with endometriosis.

Relugolix in the management of prostate cancer

INTRODUCTION

Relugolix is the first oral gonadotrophin-releasing hormone (GnRH) receptor antagonist. Based on the phase III HERO trial results, relugolix received Food and Drug Administration approval for adult patients with advanced prostate cancer (PCa).

AREAS COVERED

: We provide an overview of the preclinical and clinical development of relugolix and its role in the current treatment landscape of PCa.

EXPERT OPINION

Relugolix leads to rapid inhibition of testicular production of testosterone and its rapid recovery upon discontinuation. In the HERO trial, relugolix was associated with a superior cardiovascular safety profile compared to GnRH agonists. These attributes make relugolix a promising therapy for patients with pre-existing cardiovascular co-morbidities, those pursuing intermittent androgen deprivation therapy, and those who desire rapid testosterone recovery during "off-treatment" periods. In the HERO trial, very few patients received concomitant enzalutamide (n=17, 2.7%) or docetaxel (n<10, 1.3%). Safety of relugolix has not been established in combination with many androgen-receptor-axis targeted therapies (e.g. abiraterone, apalutamide), cabazitaxel, or lutetium Lu 177 vipivotide tetraxetan, which precludes its use in combination with these agents. In addition, being an oral drug, relugolix may also be associated with challenges of affordability, adherence, and compliance in this predominantly elderly population.

FDA-Approved Small Molecule Compounds as Drugs for Solid Cancers from Early 2011 to the End of 2021

Solid cancers are the most common types of cancers diagnosed globally and comprise a large number of deaths each year. The main challenge currently in drug development for tumors raised from solid organs is to find more selective compounds, which exploit specific molecular targets. In this work, the small molecule drugs registered by the Food and Drug Administration (FDA) for solid cancers treatment between 2011 and 2022 were identified and analyzed by investigating a type of therapy they are used for, as well as their structures and mechanisms of action. On average, 4 new small molecule agents were introduced each year, with a few exceptions, for a total of 62 new drug approvals. A total of 50 of all FDA-approved drugs have also been authorized for use in the European Union by the European Medicines Agency (EMA). Our analysis indicates that many more anticancer molecules show a selective mode of action, i.e., 49 targeted agents, 5 hormone therapies and 3 radiopharmaceuticals, compared to less specific cytostatic action, i.e., 5 chemotherapeutic agents. It should be emphasized that new medications are indicated for use mainly for monotherapy and less for a combination or adjuvant therapies. The comprehensive data presented in this review can serve for further design and development of more specific targeted agents in clinical usage for solid tumors.

An evaluation of relugolix/estradiol/norethindrone acetate for the treatment of heavy menstrual bleeding associated with uterine fibroids in premenopausal women

INTRODUCTION

Uterine Fibroids (UFs) are the most predominant benign tumor in women who are coming of reproductive age, and causes intense economic load priced in billions of US dollars. Historically, surgery has been the main definitive treatment, albeit less attractive nowadays, especially for women with future fertility plans. Therefore, studies to explore the pharmacological treatment options are increasing especially as those that are currently available are limited for short-term use only.

AREAS COVERED

This drug evaluation features the clinical results from previous and ongoing studies of relugolix, in combination with the add back therapy of estradiol (E2) and norethindrone acetate (NETA), as a novel, orally administered, nonpeptide antagonist of gonadotropin-releasing hormone (GnRH) for the management of heavy menstrual bleeding (HMB) in premenopausal women with UFs.

EXPERT OPINION

The combination of relugolix/E2/NETA is an encouraging, well-tolerated and noninvasive pharmacological option for UFs patients. Relugolix induced a concentration-dependent decrease in HMB. However, it should be used with hormonal add-back therapy (E2+ NETA) to avoid induced hypoestrogenic side effects, importantly bone mineral density loss. Moreover, symptoms will likely resume shortly after the termination of the relugolix combination administration.

The novel oral gonadotropin‐releasing hormone receptor antagonist relugolix is a new option for controlled ovarian stimulation cycles

Purpose

Relugolix is an oral gonadotropin‐releasing hormone antagonist (GnRHant), which was first introduced in 2019. This study investigated the effects of the conventional injectable GnRHant formulation and this new oral GnRHant formulation on controlled ovarian stimulation (COS) cycles.

Methods

Relugolix was administered in 126 cycles and conventional GnRHant injection was administered in 658 cycles (controls). The follicle stimulation was performed by an antagonist method, and for final oocyte maturation, recombinant human chorionic gonadotropin (rHCG), or gonadotropin‐releasing hormone agonist (GnRHa), or both (dual trigger) were selected. The number of retrieved oocytes was counted and then they were evaluated for subsequent development up to cleavage stage.

Results

The number of retrieved oocytes which was the primary outcome of this research was affected by the combination of GnRHant type and the final oocyte maturation agent. The combination of relugolix and a GnRHa trigger showed a significantly lower number of retrieved oocytes (p < 0.001) than the other combinations.

Conclusions

Relugolix is a new option for COS cycles, but should be carefully combined with the final maturation agent.

Clinical trial approval

This study was conducted after approval by the Medical Corporation Sankeikai Institutional Ethics Committee (approval number: 2019‐34).

Administering Docetaxel for Metastatic Hormone-Sensitive Prostate Cancer 1-6 Days Compared to More Than 14 Days after the Start of LHRH Agonist Is Associated with Better Clinical Outcomes Due to Androgen Flare

Simple Summary

Hormonal therapy with long-acting luteinizing hormone-releasing hormone (LHRH) for metastatic hormone-sensitive prostate cancer (MHSPC) results initially in testosterone flare followed by testosterone deprivation. Docetaxel is a chemotherapy that is effective against prostate cancer and specifically targets cells during cell division by stabilizing the mitotic spindle, which results in “mitotic catastrophe” and death of the dividing cancer cells. Combining LHRH and docetaxel was proved to be superior to LHRH treatment alone. Here, we show that simply by providing the first dose of docetaxel during testosterone flare, which occurs 1–6 days after LHRH initiation, patients could have better clinical outcomes, as testosterone drives specifically prostate cells into mitosis, priming them to cell kill by docetaxel.

Abstract

Docetaxel, when given at the beginning of androgen deprivation therapy (ADT) for patients with metastatic hormone-sensitive prostate cancer (MHSPC), results in significantly longer overall survival than ADT alone. We aimed to investigate if the delivery of the first dose of docetaxel during the testosterone flare associated with LHRH initiation results in better clinical outcomes, as testosterone induces mitosis of prostate cancer cells, and docetaxel specifically targets cells in mitosis. We analyzed data from the CHAARTED trial which randomized MHSPC patients to ADT alone or ADT plus docetaxel. We included only patients treated with LHRH agonist and docetaxel (n = 379). The only cutoff that resulted in differences in treatment outcomes was between patients who started docetaxel 1–6 days (n = 18) compared to more than 14 days from LHRH initiation (n = 297). Actuarial median overall survival was 72 versus 57 months (p = 0.2); progression-free survival was 49 versus 17 months (p = 0.06), and freedom from castrate-resistant prostate cancer was 51 versus 18 months (p = 0.04) for patients who started docetaxel 1–6 days compared to more than 14 days from LHRH initiation, respectively. Administering docetaxel 1–6 days from the initiation of LHRH agonist for patients with MHSPC could be associated with improved clinical outcomes.

GnRH Antagonists with or without Add-Back Therapy: A New Alternative in the Management of Endometriosis?

To evaluate the effectiveness of a new class of medical drugs, namely oral gonadotropin-releasing hormone (GnRH) antagonists, in the management of premenopausal women with endometriosis-associated pelvic pain. We reviewed the most relevant papers (n = 27) on the efficacy of new medical alternatives (oral GnRH antagonists) as therapy for endometriosis. We first briefly summarized the concept of progesterone resistance and established that oral contraceptives and progestogens work well in two-thirds of women suffering from endometriosis. Since clinical evidence shows that estrogens play a critical role in the pathogenesis of the disease, lowering their levels with oral GnRH antagonists may well prove effective, especially in women who fail to respond to progestogens. There is a need for reliable long-term oral treatment capable of managing endometriosis symptoms, taking into consideration both the main symptoms and phenotype of the disease. Published studies reviewed and discussed here confirm the efficacy of GnRH antagonists. There is a place for GnRH antagonists in the management of symptomatic endometriosis. Novel algorithms that take into account the different phenotypes are proposed.

New FDA oncology small molecule drugs approvals in 2020: Mechanism of action and clinical applications

In 2020, fifty-three new drugs, including forty small-molecules (thirty-six new chemical entities and four new diagnostic agents) and thirteen biologic drugs were approved by the U.S. Food and Drug Administration (FDA). This year, small-molecules continue to play a role in innovative treatments representing around 75% of all drugs accepted by FDA. The dominant therapeutic area was oncology, accounting for twenty-three new approvals, including thirteen new chemical entities, four new diagnostic agents, and thirteen biologic drugs. Recognizing the importance of small-molecules on cancer treatment, this review aims to provide an overview regarding the clinical applications and mechanism of action of the thirteen new small-molecules (excluding new diagnostic agents) approved by FDA in 2020.

Small-Molecule Anti-Cancer Drugs From 2016 to 2020: Synthesis and Clinical Application

Malignant tumors have become a significant public health problem that severely threatens human health. Drug-targeting therapy is essential for tumor therapy, along with surgery and radiotherapy. Of the 378 novel drugs approved over the past five years, those for oncological therapy remains at the top (25%). These drugs are used to treat patients with various cancers by acting on corresponding targets, such as EGFR, JAK, BTK, IDH, and FLT3. This review examines anti-tumor agents approved between 2016 and 2020, classifying them according to indication (such as lung cancer, leukemia, breast cancer, and myeloma). These drugs are reviewed according to their route of administration, first-in-class designation, approval dates, and expedited review categories. Furthermore, this paper summarizes the targets and modes of action of the approved anti-tumor drugs while systematically discussing their synthetic routes for medicinal chemistry or industrial use, which will benefit next-generation drug discovery.

Recent Development and Future Prospects of Molecular Targeted Therapy in Prostate Cancer

Prostate cancer (PC) is a rapidly increasing ailment worldwide. The previous decade has observed a rapid advancement in PC therapies that was evident from the number of FDA approvals during this phase. Androgen deprivation therapies (ADT) have traditionally remained a mainstay for the management of PCs, but the past decade has experienced the emergence of newer classes of drugs that can be used with or without the administration of ADT. FDA approved poly (ADP-ribose) polymerase inhibitors (PARPi), such as olaparib and rucaparib, after successful clinical trials against gene-mutated metastatic castration-resistant prostate cancer. Furthermore, drugs like apalutamide, darolutamide, and enzalutamide with an androgen-targeted mechanism of action have manifested superior results in non-metastatic castration-resistant prostate cancer (nmCRPC), metastatic castration-sensitive prostate cancer (mCSPC), and metastatic castration-resistant prostate cancer (mCRPC), respectively, with or without previously administered docetaxel. Relugolix, an oral gonadotropin-releasing hormone antagonist, and a combination of abiraterone acetate plus prednisone were also approved by FDA after a successful trial in advanced PC and mCRPC, respectively. This review aims to analyze the FDA-approved agents in PC during the last decade and provide a summary of their clinical trials. It also presents an overview of the ongoing progress of prospective molecules still under trial.

Endometriosis and Medical Therapy: From Progestogens to Progesterone Resistance to GnRH Antagonists: A Review

Background: The first objective of this review was to present, based on recent literature, the most frequently applied medical options (oral contraceptive pills (OCPs) and progestogens) for the management of symptomatic endometriosis, and evaluate their effectiveness in treating premenopausal women with endometriosis-associated pelvic pain, dysmenorrhea, non-menstrual pelvic pain and dyspareunia. The second objective was to review the concept of progesterone resistance and newly available treatment options. Methods: We reviewed the most relevant papers (n = 73) on the efficacy of OCPs and progestogens as medical therapy for endometriosis, as well as those on progesterone resistance and new medical alternatives (oral gonadotropin-releasing hormone (GnRH) antagonist). Eleven papers, essentially reviews, were selected and scrutinized from among 94 papers discussing the concept of progesterone resistance. Results: Having reviewed the most significant papers, we can confirm that OCPs and progestogens are effective in two-thirds of women suffering from endometriosis, but that other options are required in case of failure (in one-third of women due to progesterone resistance) or intolerance to these compounds. It is clear that there is a need for effective long-term oral treatment capable of managing endometriosis symptoms, while mitigating the impact of side effects. Biochemical, histological and clinical evidence show that estrogens play a critical role in the pathogenesis of endometriosis, so lowering levels of circulating estrogens should be considered an effective medical approach. The efficacy of three oral GnRH antagonists is discussed on the basis of published studies. Conclusion: There is a place for GnRH antagonists in the management of symptomatic endometriosis and clinical trials should be conducted, taking into account the different phenotypes in order to propose novel algorithms.

New drug approvals for 2020: Synthesis and clinical applications

53 New drugs including 38 chemical entities and 15 biologics were approved by the U.S. Food and Drug Administration during 2020. Among the marketed drugs, 34 new small molecule drugs and 4 new diagnostic agents with privileged structures and novel clinical applications represent as promising leads for the development of new drugs with the similar indications and improved therapeutic efficacy. This review is mainly focused on the clinical applications and synthetic methods of 34 small-molecule drugs newly approved by the FDA in 2020.

Structure of the human gonadotropin-releasing hormone receptor GnRH1R reveals an unusual ligand binding mode

Gonadotrophin-releasing hormone (GnRH), also known as luteinizing hormone-releasing hormone, is the main regulator of the reproductive system, acting on gonadotropic cells by binding to the GnRH1 receptor (GnRH1R). The GnRH-GnRH1R system is a promising therapeutic target for maintaining reproductive function; to date, a number of ligands targeting GnRH1R for disease treatment are available on the market. Here, we report the crystal structure of GnRH1R bound to the small-molecule drug elagolix at 2.8 Å resolution. The structure reveals an interesting N-terminus that could co-occupy the enlarged orthosteric binding site together with elagolix. The unusual ligand binding mode was further investigated by structural analyses, functional assays and molecular docking studies. On the other hand, because of the unique characteristic of lacking a cytoplasmic C-terminal helix, GnRH1R exhibits different microswitch structural features from other class A GPCRs. In summary, this study provides insight into the ligand binding mode of GnRH1R and offers an atomic framework for rational drug design.

Relugolix for the treatment of uterine fibroids

INTRODUCTION

Uterine fibroids (UF) are benign tumors common in premenopausal women, with strong impact on the health-care systems. For many years, surgery represented the only therapy for symptomatic fibroids. However, clinicians are observing a switch from surgery to noninvasive methods; in particular, medical treatment has been shown to be efficacious in obtaining a bleeding reduction and in ameliorating patient conditions.

AREAS COVERED

The authors review the current options available for the treatment of women with UF, with a special focus on the newest one, relugolix. It is an orally active non-peptide Gonadotropin-releasing hormone (GnRH)-receptor antagonist recently licensed for women with symptomatic fibroids. Relugolix is a well-tolerated safe drug; it is effective in inducing a dose-dependent decrease in menstrual blood loss, with faster reduction of heavy menstrual bleeding (HMB) and a greater shrinkage in fibroid volume compared to the current standard of GnRH agonist treatment.

EXPERT OPINION

Relugolix is a promising drug for the non-surgical treatment of women with UF. To date, the only published data come from a well-selected Japanese female population study while results from worldwide ongoing studies are ongoing in order to confirm the efficacy of this GnRH agonist receptor.

Herpes Simplex Viruses Whose Replication Can Be Deliberately Controlled as Candidate Vaccines

Over the last few years, we have been evaluating a novel paradigm for immunization using viruses or virus-based vectors. Safety is provided not by attenuation or inactivation of vaccine viruses, but by the introduction into the viral genomes of genetic mechanisms that allow for stringent, deliberate spatial and temporal control of virus replication. The resulting replication-competent controlled viruses (RCCVs) can be activated to undergo one or, if desired, several rounds of efficient replication at the inoculation site, but are nonreplicating in the absence of activation. Extrapolating from observations that attenuated replicating viruses are better immunogens than replication-defective or inactivated viruses, it was hypothesized that RCCVs that replicate with wild-type-like efficiency when activated will be even better immunogens. The vigorous replication of the RCCVs should also render heterologous antigens expressed from them highly immunogenic. RCCVs for administration to skin sites or mucosal membranes were constructed using a virulent wild-type HSV-1 strain as the backbone. The recombinants are activated by a localized heat treatment to the inoculation site in the presence of a small-molecule regulator (SMR). Derivatives expressing influenza virus antigens were also prepared. Immunization/challenge experiments in mouse models revealed that the activated RCCVs induced far better protective immune responses against themselves as well as against the heterologous antigens they express than unactivated RCCVs or a replication-defective HSV-1 strain. Neutralizing antibody and proliferation responses mirrored these findings. We believe that the data obtained so far warrant further research to explore the possibility of developing effective RCCV-based vaccines directed to herpetic diseases and/or diseases caused by other pathogens.

Endometriosis and pain in the adolescent- striking early to limit suffering: A narrative review

Endometriosis, a condition in which uterine tissue grows outside the uterus, is a debilitating disease, affecting millions of women and costing the United States approximately $78 billion annually in pain- related disability. It is also the leading cause of chronic pelvic pain (CPP), which is often unresponsive to existing treatments. Adolescent women with the disease are at particular risk as there are often significant diagnostic delays, which in turn can exacerbate pain. Research and treatment guidelines for adolescents with endometriosis are largely based on studies for adult women due to the limited number of studies focusing on adolescents. The current paper critically reviews the literature as it pertains to endometriosis pathophysiology, mechanisms contributing to CPP, and treatment implications and recommendations with a focus on gaps related to adolescents.

Clinical Utility Of Elagolix As An Oral Treatment For Women With Uterine Fibroids: A Short Report On The Emerging Efficacy Data

Uterine fibroids (UFs) are the most common gynaecological benign disease. Even though often asymptomatic, UFs can worsen women’s health and their quality of life, causing heavy bleeding and anaemia, pelvic discomfort and reduced fertility. Surgical treatment of UFs could be limited by its invasiveness and the desire to preserve fertility. Thus, effective medical therapies for the management of this condition are needed. Common drugs used to control bleeding, such us hormonal contraceptive or levonorgestrel-releasing intrauterine system, have no effect on fibroids volume. Among other more efficient treatments, the gonadotropin-releasing hormone (GnRH) agonist or the selective progesterone-receptor modulators have a non-neutral safety profile; thus, they are used for limited periods or for cyclic treatments. Elagolix is a potent, orally bioavailable, non-peptide GnRH antagonist that acts by a competitive block of the GnRH receptor. The biological effect is a dose-dependent inhibition of gonadal axis, without a total suppression of estradiol concentrations. For this reason, even though comparative studies between elagolix and GnRH agonists have not been performed, elagolix has been associated with a better profile of adverse events. Recently, elagolix received US FDA approval for the treatment of moderate to severe pain caused by endometriosis. Several clinical trials assessed the efficacy of elagolix for the treatment of heavy bleeding caused by UFs and the definitive results of Phase III studies are expected. Available data on elagolix and UFs showed that the drug, with or without low-dose hormone add-back therapy, is able to significantly reduce menstrual blood loss, lead to amenorrhea and improve haemoglobin concentrations in the majority of participants in comparison with placebo. The safety and tolerability profile appeared generally acceptable. The concomitant use of add-back therapy can prevent bone loss due to the hypoestrogenic effect and can improve safety during elagolix treatment.

Clinical evaluation of the oral gonadotropin-releasing hormone-antagonist elagolix for the management of endometriosis-associated pain

Endometriosis is an estrogen-dependent chronic inflammatory disease associated with pelvic pain symptoms that are often severe, mainly dysmenorrhea, nonmenstrual pelvic pain and dyspareunia. This condition is also associated with peripheral and central sensitization. The current medical treatment options for endometriosis-associated pain are limited. Recently, the US FDA approved the novel, oral, nonpeptide gonadotropin-releasing hormone antagonist elagolix for the management of moderate to severe endometriosis-associated pain. Elagolix produces dose-dependent estrogen suppression, from partial suppression at lower doses to nearly full suppression at higher doses. This review article summarizes the current understanding of the pathophysiology of endometriosis, with a focus on the role of estrogen and the mechanisms of pain symptoms, and reviews the clinical development of elagolix in women with endometriosis-associated pain.