Doravirine: First Global Approval

Real-world effectiveness and tolerability of switching to doravirine-based antiretroviral therapy in people with HIV: a nationwide, matched, prospective cohort study

BACKGROUND

Currently, real-world data on doravirine are scarce. In a national prospective cohort, we assessed the effectiveness and tolerability of switching to doravirine-based antiretroviral therapy (ART) in people with HIV.

METHODS

We did a nationwide, matched, prospective cohort study of people with HIV without previous virological failure and stable for at least 12 months on non-doravirine-containing triple or dual ART switching to doravirine before Sept 1, 2020 (exposed group). Participants in the exposed group were matched 1:2 to individuals continuing stable non-doravirine-containing ART, on age, sex, HIV acquisition category, time since ART initiation, calendar time, pre-ART CD4-count, pre-ART plasma viral load (PVL) and anchor drug class before switching. The primary outcome was protocol-defined virological failure (PDVF; PVL of ≥200 copies per mL) in the intention-to-treat (ITT) population at week 104, with participants modifying their regimen or becoming lost to follow-up considered as PDVF (non-inferiority margin +5%). In contrast, in the on-treatment population, those who modified their regimen or became lost to follow-up were censored from that moment onwards. Tolerability was a secondary outcome.

FINDINGS

In total, 590 participants in the exposed group and 1180 participants in the unexposed group (of whom 55·3% used integrase strand transfer inhibitor-based regimens) were included. In the ITT analysis, PDVF occurred in 135 (22·9%) exposed participants and in 295 (25·0%) unexposed participants (risk difference -2·12%, upper limit of the one-sided 95% CI +1·40%). In the on-treatment analysis, 10 (2·2%) of 455 non-censored exposed participants and 26 (2·9%) of 885 non-censored unexposed participants had PDVF (risk difference -0·70%, upper limit of the one-sided 95% CI +0·73%). All exposed participants with a PVL of 200 copies or more per mL resuppressed without regimen modification: no confirmed virological failure (two consecutive PVLs of ≥200 copies per mL) was observed. 104 (17·6%) exposed participants and 211 (17·9%) unexposed participants modified their regimen. 73 (12.4%) exposed participants discontinued doravirine due to adverse events: abnormal dreams (1·7%) and insomnia (1·5%) were most common.

INTERPRETATION

Switching to doravirine in well suppressed people with HIV without previous virological failure was non-inferior compared with continuing non-doravirine-containing regimens after 2 years in a real-world setting.

FUNDING

None.

Fluorine in the pharmaceutical industry: Synthetic approaches and application of clinically approved fluorine-enriched anti-infectious medications

The strategic integration of fluorine atoms into anti-infectious agents has become a cornerstone in the field of medicinal chemistry, owing to the unique influence of fluorine on the chemical and biological properties of pharmaceuticals. This review examines the synthetic methodologies that enable the incorporation of fluorine into anti-infectious drugs, and the resultant clinical applications of these fluorine-enriched compounds. With a focus on clinically approved medications, the discussion extends to the molecular mechanisms. It further outlines the specific effects of fluorination, which contribute to the heightened efficacy of anti-infective therapies. By presenting a comprehensive analysis of current drugs and their developmental pathways, this review underscores the continuing evolution and significance of fluorine in advancing anti-infectious treatment options. The insights offered extend valuable guidance for future drug design and the development of next-generation anti-infectious agents.

A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

Current insights and molecular docking studies of HIV-1 reverse transcriptase inhibitors

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS), a lethal disease that is prevalent worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) data, 38.4 million people worldwide were living with HIV in 2021. Viral reverse transcriptase (RT) is an excellent target for drug intervention. Nucleoside reverse transcriptase inhibitors (NRTIs) were the first class of approved antiretroviral drugs. Later, a new type of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were approved as anti-HIV drugs. Zidovudine, didanosine, and stavudine are FDA-approved NRTIs, while nevirapine, efavirenz, and delavirdine are FDA-approved NNRTIs. Several agents are in clinical trials, including apricitabine, racivir, elvucitabine, doravirine, dapivirine, and elsulfavirine. This review addresses HIV-1 structure, replication cycle, reverse transcription, and HIV drug targets. This study focuses on NRTIs and NNRTIs, their binding sites, mechanisms of action, FDA-approved drugs and drugs in clinical trials, their resistance and adverse effects, their molecular docking studies, and highly active antiretroviral therapy (HAART).

Phytochemical drug discovery for COVID-19 using high-resolution computational docking and machine learning assisted binder prediction

The COVID-19 pandemic has resulted in millions of deaths around the world. Multiple vaccines are in use, but there are many underserved locations that do not have adequate access to them. Variants may emerge that are highly resistant to existing vaccines, and therefore cheap and readily obtainable therapeutics are needed. Phytochemicals, or plant chemicals, can possibly be such therapeutics. Phytochemicals can be used in a polypharmacological approach, where multiple viral proteins are inhibited and escape mutations are made less likely. Finding the right phytochemicals for viral protein inhibition is challenging, but in-silico screening methods can make this a more tractable problem. In this study, we screen a wide range of natural drug products against a comprehensive set of SARS-CoV-2 proteins using a high-resolution computational workflow. This workflow consists of a structure-based virtual screening (SBVS), where an initial phytochemical library was docked against all selected protein structures. Subsequently, ligand-based virtual screening (LBVS) was employed, where chemical features of 34 lead compounds obtained from the SBVS were used to predict 53 lead compounds from a larger phytochemical library via supervised learning. A computational docking validation of the 53 predicted leads obtained from LBVS revealed that 28 of them elicit strong binding interactions with SARS-CoV-2 proteins. Thus, the inclusion of LBVS resulted in a 4-fold increase in the lead discovery rate. Of the total 62 leads, 18 showed promising pharmacokinetic properties in a computational ADME screening. Collectively, this study demonstrates the advantage of incorporating machine learning elements into a virtual screening workflow.Communicated by Ramaswamy H. Sarma.

Contemporary Medicinal Chemistry Strategies for the Discovery and Development of Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors

Currently, HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) are a major component of the highly active anti-retroviral therapy (HAART) regimen. However, the occurrence of drug-resistant strains and adverse reactions after long-term usage have inevitably compromised the clinical application of NNRTIs. Therefore, the development of novel inhibitors with distinct anti-resistance profiles and better pharmacological properties is still an enormous challenge. Herein, we summarize state-of-the-art medicinal chemistry strategies for the discovery of potent NNRTIs, such as structure-based design strategies, contemporary computer-aided drug design, covalent-binding strategies, and the application of multi-target-directed ligands. The strategies described here will facilitate the identification of promising HIV-1 NNRTIs.

Impact of HIV-1 Resistance-Associated Mutations on Susceptibility to Doravirine: Analysis of Real-World Clinical Isolates

Clinical management of human immunodeficiency virus type-1 (HIV-1) infection may be negatively impacted by either acquired or transmitted drug resistance. Here, we aim to extend our understanding of the impact of resistance-associated mutations (RAMs) on the susceptibility of clinical isolates to the nonnucleoside reverse transcriptase inhibitor (NNRTI) doravirine. Clinical isolates from people living with HIV-1 undergoing routine testing for susceptibility to doravirine and other approved NNRTIs (etravirine, rilpivirine, efavirenz, and nevirapine) were collected from August 2018 to August 2019. Susceptibility in the presence/absence of NNRTI and nucleos(t)ide reverse transcriptase inhibitor (NRTI) mutations was determined using cutoffs for relative fold change in inhibition (ratio of the 50% inhibitory concentration [IC₅₀] of patient virus compared with the IC₅₀ of a wild-type reference strain). Biological cutoffs of 3- to 15-fold change were investigated for doravirine, with preestablished cutoffs used for the other NNRTIs. Of 4,070 clinical isolates, 42.9% had ≥1 NNRTI RAM. More isolates were susceptible to doravirine (92.5-96.7%) than to etravirine (91.5%), rilpivirine (89.5%), efavirenz (81.5%), or nevirapine (77.5%). Based on a 3-fold cutoff, doravirine susceptibility was retained in 44.7-65.8% of isolates resistant to another NNRTI and 28.5% of isolates resistant to all other tested NNRTIs. The presence of NRTI RAMs, including thymidine analog mutations, was associated with doravirine hypersusceptibility in some isolates, particularly in the absence of NNRTI RAMs. These results support the favorable resistance profile of doravirine and are of particular importance given the challenge posed by both acquired and transmitted resistance.

Design, synthesis, and antiviral evaluation of novel piperidine-substituted arylpyrimidines as HIV-1 NNRTIs by exploring the hydrophobic channel of NNIBP

Herein, alkenylpiperidine and alkynylpiperidine moieties were introduced into the left wing of DAPYs (diarylpyrimidines) to explore the new site of the NNIBP (non-nucleoside inhibitor binding pocket) protein-solvent interface region via the structure-based drug design strategy. All the synthesized compounds displayed nanomolar to submicromolar activity against WT (wild-type) HIV-1. Among all, compound FT1 (EC₅₀ = 19 nM) was found to be the most active molecule, which is better than NVP (EC₅₀ = 0.10 μM). In addition, most of the compounds displayed micromolar activity against K103N and E138K mutant strains, while FT1 (EC_50(K103N) = 50 nM, EC_50(E138K) = 0.19 µM) still has the most effective activity. The molecular dynamics simulation studies revealed that the presence of pyridine moiety of FT1 was essential and played a significant role in its binding with RT (reverse transcriptase).

Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate (TDF) Versus Efavirenz/Emtricitabine/TDF in Treatment-naive Adults With Human Immunodeficiency Virus Type 1 Infection: Week 96 Results of the Randomized, Double-blind, Phase 3 DRIVE-AHEAD Noninferiority Trial

Background

Doravirine (DOR) is a nonnucleoside reverse-transcriptase inhibitor. In the phase 3 DRIVE-AHEAD trial in treatment-naive adults with human immunodeficiency virus type 1 (HIV-1) infection, DOR demonstrated noninferior efficacy compared with efavirenz (EFV) and superior profiles for neuropsychiatric tolerability and lipids at 48 weeks. We present data through week 96.

Methods

DRIVE-AHEAD is a phase 3, multicenter, double-blind, noninferiority trial in antiretroviral treatment-naive adults with HIV-1 RNA ≥1000 copies/mL. Participants were randomized to a daily fixed-dose tablet of DOR (100 mg), lamivudine (3TC; 300 mg) and tenofovir disoproxil fumarate (TDF; 300 mg) (DOR/3TC/TDF) or EFV (600 mg), emtricitabine (FTC; 200 mg) and TDF (300 mg) (EFV/FTC/TDF). The efficacy end point of interest at week 96 was the proportion of participants with HIV-1 RNA levels <50 copies/mL (Food and Drug Administration Snapshot Approach) with a predefined noninferiority margin of 10% to support week 48 results. Safety end points of interest included prespecified neuropsychiatric adverse events and the mean change in fasting lipids at week 96.

Results

Of 734 participants randomized, 728 received study drugs and were included in analyses. At week 96, HIV-1 RNA <50 copies/mL was achieved by 77.5% of DOR/3TC/TDF vs 73.6% of EFV/FTC/TDF participants, with a treatment difference of 3.8% (95% confidence interval, –2.4% to 10%). Virologic failure rates were low and similar across treatment arms, with no additional resistance to DOR observed between weeks 48 and 96. Prespecified neuropsychiatric adverse events and rash were less frequent in DOR/3TC/TDF than in EFV/FTC/TDF participants through week 96. At week 96, fasting low-density lipoprotein cholesterol and non–high-density lipoprotein cholesterol (HDL-C) levels increased in the EFV/FTC/TDF group but not in the DOR/3TC/TDF group; the mean changes from baseline in total cholesterol/HDL-C ratio were similar.

Clinical Trials Registration

NCT02403674.

Trends and strategies to combat viral infections: A review on FDA approved antiviral drugs

The infectious microscopic viruses invade living cells to reproduce themselves, and causes chronic infections such as HIV/AIDS, hepatitis B and C, flu, etc. in humans which may lead to death if not treated. Different strategies have been utilized to develop new and superior antiviral drugs to counter the viral infections. The FDA approval of HIV nucleoside reverse transcriptase inhibitor, zidovudine in 1987 boosted the development of antiviral agents against different viruses. Currently, there are a number of combination drugs developed against various viral infections to arrest the activity of same or different viral macromolecules at multiple stages of its life cycle; among which majority are targeted to interfere with the replication of viral genome. Besides these, other type of antiviral molecules includes entry inhibitors, integrase inhibitors, protease inhibitors, interferons, immunomodulators, etc. The antiviral drugs can be toxic to human cells, particularly in case of administration of combination drugs, and on the other hand viruses can grow resistant to the antiviral drugs. Furthermore, emergence of new viruses like Ebola, coronaviruses (SARS-CoV, SARS-CoV-2) emphasizes the need for more innovative strategies to develop better antiviral drugs to fight the existing and the emerging viral infections. Hence, we reviewed the strategic enhancements in developing antiviral drugs for the treatment of different viral infections over the years.

Insights into the FDA 2018 New Drug Approvals

OBJECTIVE

The Center of Drug Evaluation and Research (CDER) in the food and drug administration (FDA) approves new drugs every year. This review discusses the novel drugs of the FDA in 2018, with emphasis on the breakthrough drugs, the milestones in the approved list, and drugs with the highest expected sales in 2024.

METHODS

The following scientific search engines were surveyed for the clinical trials of the drugs approved by the FDA in 2018: Pubmed, Springer link, ScienceDirect, Scopus, Wiley online library, Taylor and Francis, and Google Scholar. The total forecast sales were compared based on information from the Cortellis database, EvaluatePharma, and Nature Biobusiness Briefs.

RESULTS

The 2018 year was full of good news for the drug market in the USA, with 59 new drug approvals by the FDA, which is the highest number of approvals in the last twenty years. The oncology and the antimicrobial drugs represent almost 50% of the new list, which gives hope to cancer patients and subjects with infectious diseases. In the 2018 FDA list, a number of drugs are expected to exceed 1$ billion dollars of sales by 2024.

CONCLUSION

The new drugs approved by the FDA in 2018 have been reviewed. This year showed the highest number of new drug approvals in the last two decades. Among the 59 drugs approved in 2018, 14 drugs are considered breakthroughs, which revive hope for many poorly managed diseases. The list also contains 19 drugs that are first in class and 43 that were given priority reviews.

Analysis and Molecular Determinants of HIV RNase H Cleavage Specificity at the PPT/U3 Junction

HIV reverse transcriptases (RTs) convert viral genomic RNA into double-stranded DNA. During reverse transcription, polypurine tracts (PPTs) resilient to RNase H cleavage are used as primers for plus-strand DNA synthesis. Nonnucleoside RT inhibitors (NNRTIs) can interfere with the initiation of plus-strand DNA synthesis by enhancing PPT removal, while HIV RT connection subdomain mutations N348I and N348I/T369I mitigate this effect by altering RNase H cleavage specificity. Now, we demonstrate that among approved nonnucleoside RT inhibitors (NNRTIs), nevirapine and doravirine show the largest effects. The combination N348I/T369I in HIV-1_BH10 RT has a dominant effect on the RNase H cleavage specificity at the PPT/U3 site. Biochemical studies showed that wild-type HIV-1 and HIV-2 RTs were able to process efficiently and accurately all tested HIV PPT sequences. However, the cleavage accuracy at the PPT/U3 junction shown by the HIV-2_EHO RT was further improved after substituting the sequence YQEPFKNLKT of HIV-1_BH10 RT (positions 342–351) for the equivalent residues of the HIV-2 enzyme (HQGDKILKV). Our results highlight the role of β-sheets 17 and 18 and their connecting loop (residues 342–350) in the connection subdomain of the large subunit, in determining the RNase H cleavage window of HIV RTs.

Antiviral Classification

Over the past 60 years, more than 100 antiviral drugs or their combinations have been approved for clinical use. Antiviral drugs can be classified according to their chemical nature (e.g., small-molecules, peptides, biologics) or mechanisms of drug actions against specific viral proteins (e.g., polymerase inhibitors, protease inhibitors, glycoprotein inhibitors). This article provides an overview of antiviral classifications in 10 important human viruses: hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), variola virus (human smallpox), varicella zoster virus (VZV), influenza virus, respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The crosstalk between antiretrovirals pharmacology and HIV drug resistance

INTRODUCTION

The clinical development of antiretroviral drugs has been followed by a rapid and concomitant development of HIV drug resistance. The development and spread of HIV drug resistance is due on the one hand to the within-host intrinsic HIV evolutionary rate and on the other to the wide use of low genetic barrier antiretrovirals.

AREAS COVERED

We searched PubMed and Embase on 31 January 2020, for studies reporting antiretroviral resistance and pharmacology. In this review, we assessed the molecular target and mechanism of drug resistance development of the different antiretroviral classes focusing on the currently approved antiretroviral drugs. Then, we assessed the main pharmacokinetic/pharmacodynamic of the antiretrovirals. Finally, we retraced the history of antiretroviral treatment and its interconnection with antiretroviral worldwide resistance development both in , and middle-income countries in the perspective of 90-90-90 World Health Organization target.

EXPERT OPINION

Drug resistance development is an invariably evolutionary driven phenomenon, which challenge the 90-90-90 target. In high-income countries, the antiretroviral drug resistance seems to be stable since the last decade. On the contrary, multi-intervention strategies comprehensive of broad availability of high genetic barrier regimens should be implemented in resource-limited setting to curb the rise of drug resistance.

The New NNRTI ACC007 Combined with Lamivudine and Tenofovir Disoproxil Fumarate Show Synergy Anti-HIV Activity In Vitro

BACKGROUND

Acquired immunodeficiency syndrome can hardly be cured currently and people with human immunodeficiency virus (HIV) need lifelong treatment that may result in the emergence of drug resistance which leads to failed treatment. Thus, the development of new anti- HIV drugs and new treatment regimens are necessary.

OBJECTIVE

The aim of this study is to analyze the combined anti-HIV activity of tenofovir disoproxil fumarate, lamivudine and ACC007, a new non-nucleoside reverse transcriptase inhibitor.

METHODS

The antiviral activity of tenofovir disoproxil fumarate, lamivudine and ACC007 alone or in combination against different HIV-1 strains was determined by the detection of HIV-1 p24 level through enzyme-linked immunosorbent assay.

RESULT

ACC007 showed EC50 of nanomolar range (from 3.03 nM to 252.59 nM) against all HIV-1 strains used in this study except the HIV-1A17, with EC50 of 1.57 μM. The combined antiviral activity of ACC007, lamivudine and tenofovir disoproxil fumarate showed synergy antiviral activity against all HIV-1 strains used in this study. The three-drug combination showed moderate synergism against HIV-1A17, HIV-14755-5, HIV-1K103N and HIV-1V106M, with a combination index value ranging from 0.71 to 0.87, and showed synergism against the other HIV-1 strains with combination index value from 0.35 to 0.67. The combination with ACC007 significantly increases the dose reduction index value of lamivudine and tenofovir disoproxil fumarate, compared with two-drug combination.

CONCLUSION

ACC007 exhibits potent antiviral activity alone or with 3TC and TDF, and exerts synergistic effect against all HIV strains used in our investigation in vitro.

Current Computational Approaches for the Development of Anti-HIV Inhibitors: An Overview

BACKGROUND

Today, HIV-1 infection has become an extensive problem to public health and a greater challenge to all working researchers throughout the world. Since the beginning of HIV-1 virus, several antiviral therapeutic agents have been developed at various stages to combat HIV-1 infection. But, many of antiviral drugs are on the platform of drug resistance and toxicology issues, needs an urgent constructive investigation for the development of productive and protective therapeutics to make an improvement of individual life suffering with viral infection. As developing a novel agent is very costly, challenging and time taking route in the recent times.

METHODS

The review summarized about the modern approaches of computational aided drug discovery to developing a novel inhibitor within a short period of time and less cost.

RESULTS

The outcome suggests on the premise of reported information that the computational drug discovery is a powerful technology to design a defensive and fruitful therapeutic agents to combat HIV-1 infection and recover the lifespan of suffering one.

CONCLUSION

Based on survey of the reported information, we concluded that the current computational approaches is highly supportive in the progress of drug discovery and controlling the viral infection.

Non-Nucleoside Reverse Transcriptase Inhibitors Join Forces with Integrase Inhibitors to Combat HIV

In the treatment of acquired immune deficiency syndrome (AIDS), the diarylpyrimidine (DAPY) analogs etravirine (ETR) and rilpivirine (RPV) have been widely effective against human immunodeficiency virus (HIV) variants that are resistant to other non-nucleoside reverse transcriptase inhibitors (NNRTIs). With non-inferior or improved efficacy, better safety profiles, and lower doses or pill burdens than other NNRTIs in the clinic, combination therapies including either of these two drugs have led to higher adherence than other NNRTI-containing treatments. In a separate development, HIV integrase strand transfer inhibitors (INSTIs) have shown efficacy in treating AIDS, including raltegravir (RAL), elvitegravir (EVG), cabotegravir (CAB), bictegravir (BIC), and dolutegravir (DTG). Of these, DTG and BIC perform better against a wide range of resistance mutations than other INSTIs. Nevertheless, drug-resistant combinations of mutations have begun to emerge against all DAPYs and INSTIs, attributable in part to non-adherence. New dual therapies that may promote better adherence combine ETR or RPV with an INSTI and have been safer and non-inferior to more traditional triple-drug treatments. Long-acting dual- and triple-therapies combining ETR or RPV with INSTIs are under study and may further improve adherence. Here, highly resistant emergent mutations and efficacy data on these novel treatments are reviewed. Overall, ETR or RPV, in combination with INSTIs, may be treatments of choice as long-term maintenance therapies that optimize efficacy, adherence, and safety.

Pharmaceutical, clinical, and resistance information on doravirine, a novel non-nucleoside reverse transcriptase inhibitor for the treatment of HIV-1 infection

As part of a combined antiretroviral regimen, doravirine is safe and effective at suppressing viral replication in both treatment-naive and treatment-experienced adults living with human immunodeficiency virus (HIV)-1 who have no history of drug resistance against doravirine. In virologically suppressed individuals switching to a combination of doravirine, lamivudine, and tenofovir disoproxil fumarate, no resistance was found after 48 weeks. In treatment-naive individuals, rare cases (<2%) of emergent drug resistance have been reported, often involving the development of substitutions at position V106. From these few clinical cases, it is inferred that cross-resistance with other non-nucleoside reverse transcriptase inhibitors (NNRTIs) should be limited. In contrast, the use of doravirine as a second NNRTI should be evaluated on a case-by-case basis in the presence of pre-existing resistance. Importantly, doravirine remains active against K103N viruses in vitro, and limited clinical evidence suggests this to be the case in patients as well. Since K103N is by far the most prevalent (<70%) NNRTI substitution found in clinical practice, resistance against doravirine-based antiretroviral therapies is expected to be rare, even for treatment-experienced individuals. This review summarizes chemical, pharmacological, and clinical information about doravirine with an emphasis on drug resistance. The efficacy results from an early phase clinical trial evaluating doravirine in combination with islatravir are also provided.

Fluorine-Containing Drugs Approved by the FDA in 2018

Over the last two decades, fluorine substitution has become one of the essential structural traits in modern pharmaceuticals. Thus, about half of the most successful drugs (blockbuster drugs) contain fluorine atoms. In this review, we profile 17 fluorine-containing drugs approved by the food and drug administration (FDA) in 2018. The newly approved pharmaceuticals feature several types of aromatic F and CF₃ , as well as aliphatic (CF₂ ) substitution, offering advances in the treatment of various diseases, including cancer, HIV, malarial and smallpox infections.

Iridium-Catalyzed Silylation of C-H Bonds in Unactivated Arenes: A Sterically Encumbered Phenanthroline Ligand Accelerates Catalysis

We report a new system for the silylation of aryl C-H bonds. The combination of [Ir(cod)(OMe)]₂ and 2,9-Me₂-phenanthroline (2,9-Me₂-phen) catalyzes the silylation of arenes at lower temperatures and with faster rates than those reported previously, when the hydrogen byproduct is removed, and with high functional group tolerance and regioselectivity. Inhibition of reactions by the H₂ byproduct is shown to limit the silylation of aryl C-H bonds in the presence of the most active catalysts, thereby masking their high activity. Analysis of initial rates uncovered the high reactivity of the catalyst containing the sterically hindered 2,9-Me₂-phen ligand but accompanying rapid inhibition by hydrogen. With this catalyst, under a flow of nitrogen to remove hydrogen, electron-rich arenes, including those containing sensitive functional groups, undergo silylation in high yield for the first time, and arenes that underwent silylation with prior catalysts react over much shorter times with lower catalyst loadings. The synthetic value of this methodology is demonstrated by the preparation of key intermediates in the synthesis of medicinally important compounds in concise sequences comprising silylation and functionalization. Mechanistic studies demonstrate that the cleavage of the aryl C-H bond is reversible and that the higher rates observed with the 2,9-Me₂-phen ligand are due to a more thermodynamically favorable oxidative addition of aryl C-H bonds.

Recent Advances in the Design and Development of Non-nucleoside Reverse Transcriptase Inhibitor Scaffolds

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have always been an important part of the anti-HIV-1 combination therapy known as combination antiretroviral therapy (cART) since 1996. The use of NNRTIs for about 22 years has led to some mutations in the residues that compose the reverse transcriptase active site, resulting in the emergence of drug-resistant viruses. Thus, the search for new potent NNRTIs with an improved safety profile and activity against drug-resistant HIV strains is indispensable, and many hit and lead NNRTIs have been discovered in the last decade. This review provides an overview of the development in this field from 2013 to August 2018.