Tapinarof for the treatment of psoriasis

A comprehensive review of new small molecule drugs approved by the FDA in 2022: Advance and prospect

In 2022, the U.S. Food and Drug Administration approved a total of 16 marketing applications for small molecule drugs, which not only provided dominant scaffolds but also introduced novel mechanisms of action and clinical indications. The successful cases provide valuable information for optimizing efficacy and enhancing pharmacokinetic properties through strategies like macrocyclization, bioequivalent group utilization, prodrug synthesis, and conformation restriction. Therefore, gaining an in-depth understanding of the design principles and strategies underlying these drugs will greatly facilitate the development of new therapeutic agents. This review focuses on the research and development process of these newly approved small molecule drugs including drug design, structural modification, and improvement of pharmacokinetic properties to inspire future research in this field.

Spectrofluorimetric determination of tapinarof via Zn (II) complexation and assessment of its topical dosage application

Topical tapinarof is used to treat plaque psoriasis (a skin disease in which red and scaly patches form are appeared on some areas of the body). The goal of the current research is to establish a facile and rapid fluorimetric technique for tapinarof analysis. The approach relied on the reaction between the drug and zinc ion through metal complexation to produce a highly-fluorescent product. The fluorescence was further enhanced by adding sodium dodecyl sulfate, and it was observed at 542 nm following excitation at 497 nm. With a correlation coefficient of 0.9997, the association between emission intensity and tapinarof concentration was linear between 2.0 and 120 ng mL-1. 1.021 ng mL-1 was the quantitation limit while 0.366 ng mL-1 was the detection limit. The buffer type, pH and concentration, type of surfactant and concentration, and finally the diluting solvent were among the reaction conditions that were closely examined and it was found that the optimum conditions were obtained upon employing teorell-stenhagen buffer optimized at pH 6.0, 1.38 × 10-2 M SDS and distilled water as a solvent are the suitable choice. With great precision and reliability, the drug under study was quantified using this method in ointment formulations. The proposed method's level of greenness was assessed using two methodologies: the analytical greenness metric (AGREE) and the Green Analytical Procedure Index (GAPI), with good recovery results ensuring high efficiency of the proposed approach on analysis of ointment without any interference from additives and excipients.

Emerging drugs for the treatment of atopic dermatitis: a focus on phase 2 and phase 3 trials

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory skin condition that affects millions of pediatric and adult patients with well-studied impact on morbidity and quality of life. Management occurs in a stepwise fashion beginning with preventative measures before immunomodulators are introduced. However, challenges remain in treatment of moderate-to-severe atopic dermatitis that is refractory to first- and second-line treatments and there are only few topical anti-inflammatory options, especially for pediatric patients.

AREAS COVERED

New medications are required to address these gaps as lesions may persist despite treatment or patients may discontinue treatment due to actual or anticipated adverse effects of mainstay medications. Emerging research into the pathophysiology of AD and the immune system at large has provided opportunities for novel interventions aimed at stopping AD mechanisms at new checkpoints. Clinical trials for 36 agents currently in phase 2 or phase 3 are evaluated with particular focus on the studies for, B244, CBP-201, tapinarof, lebrikizumab, nemolizumab, amlitelimab, and rocatinlimab as they explore novel pathways and have some of the most promising results.

EXPERT OPINION

These clinical trials contribute to the evolution of AD treatment toward greater precision based on salient pathways with a particular focus on moderate-to-severe AD to enhance efficacy and minimize adverse effects.

Decoding Allosteric Control in Hypoxia-Inducible Factors

The mammalian family of basic helix-loop-helix-PER-ARNT-SIM (bHLH-PAS) transcription factors possess the ability to sense and respond to diverse environmental and physiological cues. These proteins all share a common structural framework, comprising a bHLH domain, two PAS domains, and transcriptional activation or repression domain. To function effectively as transcription factors, members of the family must form dimers, bringing together bHLH segments to create a functional unit that allows for DNA response element binding. The significance of bHLH-PAS family is underscored by their involvement in many major human diseases, offering potential avenues for therapeutic intervention. Notably, the clear identification of ligand-binding cavities within their PAS domains enables the development of targeted small molecules. Two examples are Belzutifan, targeting hypoxia-inducible factor (HIF)-2α, and Tapinarof, targeting the aryl hydrocarbon receptor (AHR), both of which have gained regulatory approval recently. Here, we focus on the HIF subfamily. The crystal structures of all three HIF-α proteins have been elucidated, revealing their bHLH and tandem PAS domains are used to engage their dimerization partner aryl hydrocarbon receptor nuclear translocator (ARNT, also called HIF-1β). A broad range of recent findings point to a shared allosteric modulation mechanism among these proteins, whereby small-molecules at the PAS-B domains exert direct influence over the HIF-α transcriptional functions. As our understanding of the architectural and allosteric mechanisms of bHLH-PAS proteins continues to advance, the possibility of discovering new therapeutic drugs becomes increasingly promising.

Per-ARNT-Sim (PAS) Domains in Basic Helix-Loop-Helix (bHLH)-PAS Transcription Factors and Coactivators: Structures and Mechanisms

PAS domains are ubiquitous in biology. They perform critically important roles in sensing and transducing a wide variety of environmental signals, and through their ability to bind small-molecule ligands, have emerged as targets for therapeutic intervention. Here, we discuss our current understanding of PAS domain structure and function in the context of basic helix-loop-helix (bHLH)-PAS transcription factors and coactivators. Unlike the bHLH-PAS domains of transcription factors, those of the steroid receptor coactivator (SRC) family are poorly characterized. Recent progress for this family and for the broader bHLH-PAS proteins suggest that these domains are ripe for deeper structural and functional studies.

Microbial metabolites as modulators of host physiology

The gut microbiota is increasingly recognised as a key player in influencing human health and changes in the gut microbiota have been strongly linked with many non-communicable conditions in humans such as type 2 diabetes, obesity and cardiovascular disease. However, characterising the molecular mechanisms that underpin these associations remains an important challenge for researchers. The gut microbiota is a complex microbial community that acts as a metabolic interface to transform ingested food (and other xenobiotics) into metabolites that are detected in the host faeces, urine and blood. Many of these metabolites are only produced by microbes and there is accumulating evidence to suggest that these microbe-specific metabolites do act as effectors to influence human physiology. For example, the gut microbiota can digest dietary complex polysaccharides (such as fibre) into short-chain fatty acids (SCFA) such as acetate, propionate and butyrate that have a pervasive role in host physiology from nutrition to immune function. In this review we will outline our current understanding of the role of some key microbial metabolites, such as SCFA, indole and bile acids, in human health. Whilst many studies linking microbial metabolites with human health are correlative we will try to highlight examples where genetic evidence is available to support a specific role for a microbial metabolite in host health and well-being.

Developed and Validated for the Estimation of Tapinarof in Topical Formulation and Active Pharmaceutical Ingredients

BACKGROUND

Its broad applicability and capacity to separate numerous components in a single chromatographic run led to the initial recognition of reversed-phase (RP)-HPLC as an analytical technique.

OBJECTIVE

The objective of this study was to create a straightforward and reliable method for accurately and precisely measuring the amount of tapinarof in both the topical formulation and the active pharmaceutical ingredient. Additionally, a robust HPLC assay was developed specifically for analyzing the topical formulation.

METHODS

In this study, chromatographic analysis was conducted using a Kromosil C18 column with dimensions of 250 × 4.6 mm and a particle size of 5 microns. The mobile phase consisted of a phosphate buffer and methanol in a ratio of 100:900 (v/v). The flow rate was set at 1.0 mL/min, with an injection volume of 10 µL and a run time of 6 min using isocratic elution. UV detection was performed at a wavelength of 313 nm, and the temperature was maintained at 30°C. The analysis showed well-separated peaks with a high number of theoretical plates, a low tailing factor, and consistent retention time. Validation of the method was conducted, and all validation parameters were found to be within the acceptable limits.

RESULTS

A method that is simple, accurate, and precise has been developed to estimate the amount of tapinarof in a topical formulation and active pharmaceutical ingredient. The optimized method involved the use of a column temperature set at 30°C, 90% methanol as the mobile phase, and a flow rate of 1.0 mL/min. The retention time for tapinarof was determined to be 2.88 min. The method exhibited linearity in the concentration range of 5 to 30 µg/mL (with an R2 value greater than 0.999) for tapinarof.

CONCLUSION

The topical formulated cream and active pharmaceutical ingredient showed more than 90% dissolution within 5 min. The method developed in this study utilized photo diode array (PDA) for peak integrity and purity confirmation, making it suitable for the quantification of tapinarof in both topical formulations and active pharmaceutical ingredients.

HIGHLIGHTS

The method was validated and can be recommended for routine analysis in QC laboratories.

The roles of T cells in psoriasis

Psoriasis is a recurring inflammatory skin condition characterized by scaly, red patches on the skin. It affects approximately 3% of the US population and is associated with histological changes such as epidermal hyperplasia, increased blood vessel proliferation, and infiltration of leukocytes into the skin's dermis. T cells, which are classified into various subtypes, have been found to play significant roles in immune-mediated diseases, particularly psoriasis. This paper provides a review of the different T lymphocyte subtypes and their functions in psoriasis, as well as an overview of targeted therapies for treating psoriasis.

Calcipotriol and Betamethasone Dipropionate Cream Based on PAD Technology for the Treatment of Plaque Psoriasis: A Narrative Review

Topical treatment plays a crucial role in psoriasis management, with non-adherence being a major barrier to treatment success. The fixed-dose combination of calcipotriol (CAL) and betamethasone dipropionate (BDP) represents the first-line choice in topical psoriasis treatment. A CAL/BDP cream based on polyaphron dispersion (PAD) Technology has emerged as a novel formulation for a more convenient topical treatment of psoriasis. This article aims to summarize the most relevant published evidence about CAL/BDP PAD-cream and its underlying PAD Technology. The PAD Technology enables CAL and BDP stability in an aqueous cream through a multimolecular shell structure, as well as it increases the penetration of both active ingredients into the epidermis and dermis. This technology also demonstrated to increase the cosmetic acceptability and to provide the desirable sensory properties for a topical psoriasis treatment. Two phase III clinical trials have been conducted so far with CAL/BDP PAD-cream. Findings from both trials revealed high efficacy with a fast onset of action, a favourable safety and tolerability profile and convenience for CAL/BDP PAD-cream compared to CAL/BDP gel. In the trial including patients with psoriasis affecting the scalp (MC2-01-C7), results support the use of CAL/BDP PAD-cream in scalp psoriasis. An anchored matching-adjusted indirect comparison (MAIC) was conducted to compare CAL/BDP PAD-cream and CAL/BDP foam, as both products had been previously compared to CAL/BDP gel. CAL/BDP PAD-cream and CAL/BDP foam showed equivalent efficacy and quality of life at their recommended treatment duration, whereas greater treatment satisfaction for CAL/BDP PAD-cream was found after one week of treatment. Overall, the high patient acceptability and treatment satisfaction observed with CAL/BDP PAD-cream in clinical trials may lead to improved adherence and hence higher efficacy in clinical practice.

The Current Advancement in Psoriasis

The study on psoriasis disease helps improve the condition and treatment options day by day in dermatology. In the current scenario, research is ongoing to make the best interventions possible for managing the disease. Psoriasis is one of the most common dermatological conditions wherein chronic inflammation of the skin occurs, characterized by the formation of a rash with scaly, itchy patches over the body surface. The condition is mainly related to the immune system wherein epidermal hyperplasia occurs with infiltration of immune cells. Many factors can trigger psoriasis. Environmental, emotional, hereditary, and personal habits are responsible for the conditions. The current research helps to gain a complete understanding, and the basic knowledge of the state with recent advancements in treatment strategies and characteristic features can also be studied. The main aim is to know the disease's primary root cause and management. It involves the main sites of the body. The most commonly affected parts are the scalp, trunks, knees, elbow, and ankle. It is a chronic long-term disease. Sometimes it may be painful. Itching, bleeding, and disturbed sleep patterns are common symptoms. Most commonly involves the upper epidermal surface. The prevalence of the condition has been increased as it is associated with other comorbidities. The main focus of the treatment is to restrict skin cell multiplication and remove scaly surfaces. This review discusses the advancement in the treatment, its initiation, progression, current symptoms, and disease development. The study also includes basic knowledge about the types of psoriatic disease with its specific features and mechanisms.

Efficacy of Apremilast Gels in Mouse Model of Imiquimod-Induced Psoriasis Skin Inflammation

Apremilast (APM) is a novel drug for the treatment of psoriasis and psoriatic arthritis. APM is a phosphodiesterase 4 (PDE4) inhibitor, raising intracellular cAMP levels and thereby decreasing the inflammatory response by modulating the expression of TNF-α, IL-17, IL-23, and other inflammatory cytokines. The goal of this study is to develop APM gels as a new pharmaceutical formulation for the treatment of topical psoriasis. APM was solubilized in Transcutol-P and incorporated into Pluronic F127, Sepigel, and carbomer bases at different proportions. All formulations were characterized physiochemically. A biopharmaceutical study (release profile) was performed, and ex vivo permeation was evaluated using a human skin model. A toxicity assay was carried out on the HaCaT cell line. A mouse model of imiquimod-induced psoriasis skin inflammation was carried out to determine its efficacy by histological analysis, RNA extraction, and RT-qPCR assays. APM gel formulations showed good physicochemical characteristics and a sustained release profile. There was no permeation of any gel measured through human skin, indicating a high retained amount of APM on the skin. Cell viability was greater than 80% at most dilution concentrations. APM gels treated the psoriasis mouse model, and it shows a reduction in the proinflammatory cytokines (IL-8, IL-17A, IL-17F, and IL-23). APM gels could be a new approach for the treatment of topical psoriasis.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2022

While new drug approvals by the U.S. Food and Drug Administration (FDA) had remained stable or even increased in the first 2 years of the COVID-19 pandemic, the 37 newly approved drugs in 2022 are considerably less than the 53 and 50 new drugs approved in 2020 and 2021, respectively, and less than the rolling 10-year average of 43. As in previous years of this annual review, we assign these new drugs to one of three levels of innovation: first drug against a condition ("first-in-indication"), first drug using a novel molecular mechanism ("first-in-class"), and "next-in-class," i.e., a drug using an already exploited molecular mechanism. We identify two "first-in-indication" (ganaxolon and teplizumab), 20 (54%) "first-in-class," and 17 (46%) "next-in-class" drugs. By treatment area, rare diseases and cancer drugs were once again the most prevalent (partly overlapping) therapeutic areas. Other continuing trends were the use of accelerated regulatory approval pathways and the reliance on biopharmaceuticals (biologics).

Topical roflumilast for the treatment of psoriasis

INTRODUCTION

New non-steroidal topical agents are needed for the treatment of psoriasis. Roflumilast cream 0.3% is a once daily phosphodiesterase-4 inhibitor that was recently approved by the FDA for the treatment of plaque psoriasis in adolescents and adults. It is indicated for use on all body surfaces including intertriginous areas.

AREAS COVERED

In this review, we summarize the current knowledge about roflumilast cream for the treatment of psoriasis, highlighting its efficacy and safety profile from published clinical trials. Roflumilast's mechanism of action and pharmacokinetic profile are also discussed.

EXPERT OPINION

Positive results were reported across trials with 48% of patients treated with roflumilast achieving an Investigator Global Assessment score of clear or almost clear at 8 weeks in phase III studies. Most adverse events were mild or moderate in severity and few application-site reactions were reported among participants. Unique advantages of the cream are its success in treating intertriginous areas and its ability to reduce symptoms of itch, results of which may significantly improve quality of life for patients. In the future, real-world data and active comparator trials with existing non-steroidal agents are needed to better understand roflumilast's place in the current treatment landscape.

First Use of Tapinarof Monotherapy for Seborrhoeic Dermatitis: A Case Report

Abstract is missing (Short communication)

Novel Aryl Hydrocarbon Receptor Agonists for Treating Psoriasis

Provided herein are aryl hydrocarbon receptor agonists, pharmaceutical compositions, use of such compounds in treating immune-mediated diseases, in particular, psoriasis, and processes for preparing such compounds.

Novel AHR Agonists for Treating Psoriasis

Described herein are aryl hydrocarbon receptor agonists, their pharmaceutical compositions, the use of such compounds in treating immune-mediated diseases, in particular psoriasis, and processes for preparing such compounds.

Natural Plant Extract - Loganin: A Hypothesis for Psoriasis Treatment Through Inhibiting Oxidative Stress and Equilibrating Immunity via Regulation of Macrophage Polarization

Psoriasis, a chronic immune-mediated inflammatory skin disease, influences approximately 2-3% of the world's population. At present, the etiology of psoriasis remains unclear and there is still no causal treatment available. Recent studies indicate that oxidative stress (OS) and T cells dysregulation may participate in the pathogenesis of psoriasis, among which M1-dominant macrophage polarization is a crucial contributor. Macrophages mainly polarize into two different subsets, ie, classically activated macrophage (M1) and alternatively activated macrophage (M2). M1 polarization tends to exacerbate psoriasis via producing substantial reactive oxygen species (ROS) and inflammatory mediators, to encourage OS invasion and T cells dysregulation. Thus, targeting M1 polarization can be a possible therapeutic alternative for psoriasis. Loganin, belonging to iridoid glycosides, is a pharmaceutically active ingredient originated from Cornus officinalis, exerting multiple biological activities, eg, immunomodulation, antioxidation, anti-inflammation, etc. More importantly, it could effectively suppress M1 polarization, thereby arresting OS aggression and T cells' dysregulation. Numerous studies have confirmed that loganin is quite reliable for diseases treatment via suppressing M1 polarization. Nevertheless, reports about loganin treating psoriasis have seldom appeared so far. Accordingly, we hold a hypothesis that loganin would availably manage psoriasis through preventing M1 polarization. Data from previous studies guarantee the potential of loganin in control of psoriasis.