Molecular Modeling Insights into Upadacitinib Selectivity upon Binding to JAK Protein Family

Structure-guided design of potent JAK1-selective inhibitors based on 4-amino-7H-pyrrolo[2,3-d]pyrimidine with anti-inflammatory efficacy

In a continuous effort to develop Janus kinase 1 (JAK1)-selective inhibitors, a novel series of 4-amino-7H-pyrrolo[2,3-d]pyrimidine derivatives bearing the piperidinyl fragment were designed and synthesized according to a combination strategy. Through enzymatic assessments, the superior compound 12a with an IC50 value of 12.6 nM against JAK1 was identified and a 10.7-fold selectivity index over JAK2 was achieved. It was indicated that 12a displayed considerable effect in inhibiting the pro-inflammatory NO generated from lipopolysaccharide (LPS)-induced RAW264.7 macrophages, while on normal RAW264.7 cells, 12a exerted a weak cytotoxicity effect (IC50 = 143.3 μM). Furthermore, H&E stain assay demonstrated the conspicuous capacity of 12a to suppress CCl4-induced hepatic fibrosis levels in a dose-dependent manner in vivo. The binding model of 12a ideally reflects the excellent activity of JAK1 over the homologous kinase JAK2. Overall, 12a, a JAK1-selective inhibitor, exhibited potential for liver fibrosis and inflammatory diseases.

Upadacitinib sustained-release tablets for the treatment of chronic refractory gouty arthritis: a case report and literature review

Background

Gouty arthritis (GA) is a crystal-related joint disease caused by the deposition of monosodium urate (MSU) crystals, directly associated with hyperuricemia resulting from purine metabolism disorder and/or reduced uric acid excretion. Acute attacks of typical gouty arthritis are generally relieved through the clinical use of NSAIDs, colchicine, or glucocorticoids. However, managing patients with chronic refractory gout poses challenges due to complications such as multiple tophi, gouty nephropathy, diabetes, and gastrointestinal bleeding. While there have been numerous studies on gout in recent years, research specifically regarding chronic refractory gout remains limited. The management of such cases still faces several unresolved issues, including recurrent disease flare-ups and poor patient compliance leading to inadequate drug utilization and increased risk of side effects. In this report, we present a case of successful improvement in chronic refractory gouty arthritis using the biologic agent upadacitinib sustained-release tablets.

Case presentation

Our case report involves a 53 years-old Asian patient with recurrent gouty arthritis who had a history of over 20 years without regular treatment, presenting with tophi and an increasing number of painful episodes. During hospitalization, various analgesics and anti-inflammatory drugs provided inadequate relief, requiring the use of steroids to alleviate symptoms. However, tapering off steroids proved challenging. We decided to add upadacitinib sustained-release tablets to the treatment regimen, which ultimately improved the patient's condition. After 6 months of follow-up, the patient has not experienced any further acute pain episodes.

Conclusion

This case highlights the potential therapeutic effect of upadacitinib sustained-release tablets during the acute phase of chronic refractory gouty arthritis.

Efficacy and Risk Stratification of Janus Kinase Inhibitors in the Treatment of Moderate-to-Severe Atopic Dermatitis

Recently, 3 oral Janus kinase (JAK) inhibitors-abrocitinib, baricitinib, and upadacitinib-were approved in many regions around the world for the treatment of moderate-severe atopic dermatitis (AD). These JAK inhibitors generally have rapid onset of action and short half-life. Higher doses of abrocitinib and upadactinib even demonstrated superior efficacy to dupilumab. However, JAK inhibitors can be associated with rare serious and potentially life-threatening adverse events. Heterogeneity in study designs and lack of head-to-head studies make safety comparison between JAK inhibitors difficult. Dose reduction and patient selection are the most important considerations for risk mitigation. This narrative review examines the efficacy data for abrocitinib, baricitinib, and upadacitinib from large phase III double-blinded randomized controlled trials in AD and discusses risk stratification for oral JAK inhibitors in AD patients.

Synthesis and clinical application of small-molecule inhibitors of Janus kinase

Janus kinase (JAK) plays a crucial role in intracellular signaling pathways, particularly in cytokine-mediated signal transduction, making them attractive therapeutic targets for a wide range of diseases, including autoimmune disorders, myeloproliferative neoplasms, and inflammatory conditions. The review provides a comprehensive overview of the development and therapeutic potential of small-molecule inhibitors targeting JAK family of proteins in various clinical trials. It also discusses the mechanisms of action, specificity, and selectivity of these inhibitors, shedding light on the challenges associated with achieving target selectivity while minimizing off-target effects. Moreover, the review offers insights into the clinical applications of JAK inhibitors, summarizing the ongoing clinical trials and the Food and Drug Administration (FDA)-approved JAK inhibitors currently available for various diseases. Overall, this review provides a thorough examination of the synthesis and clinical use of typical small-molecule JAK inhibitors in different clinical stages and offers a bright future for the development of novel small-molecule JAK inhibitors.

A review: FDA-approved fluorine-containing small molecules from 2015 to 2022

Fluorine-containing small molecules have occupied a special position in drug discovery research. The successful clinical use of fluorinated corticosteroids in the 1950s and fluoroquinolones in the 1980s led to an ever-increasing number of approved fluorinated compounds over the last 50 years. They have shown various biological properties such as antitumor, antimicrobial, and anti-inflammatory activities. Fluoro-pharmaceuticals have been considered a strong and practical tool in the rational drug design approach due to their benefits from potency and ADME (absorption, distribution, metabolism, and excretion) points of view. Herein, approved fluorinated drugs from 2015 to 2022 were reviewed.

Crucial safety issues on Janus kinase inhibitors in rheumatoid arthritis might be associated with the lack of LDL-cholesterol management: a reasoned literature analysis

This point of view explores the safety concerns of Janus kinase inhibitors (JAK-Is), used in treating rheumatoid arthritis (RA) and other rheumatologic conditions. Increasing evidence shows that JAK-Is may elevate the risk of venous thromboembolism (VTE), especially pulmonary embolism. This fact has prompted the European Medicines Agency to advise cautious use of these drugs in patients over 65, smokers, and those at risk of cardiovascular issues or cancer. The paper analyses the evidence on the association between VTE risk and RA and whether different JAK-Is pose different risks. It also probes the link between VTE, lipids, and JAK inhibition, noting that JAK-Is can alter HDL and LDL levels. On the other hand, some evidence indicates that tighter LDL-cholesterol control could mitigate VTE risk, particularly pulmonary embolism. Moreover, data from trials show little attention to treating this main cardiovascular and VTE risk factor in rheumatological patients. Although the lipid paradox theory emphasizes the U-shaped relationship between LDL cholesterol and cardiovascular risk in patients with RA, uncontrolled levels of clinically relevant LDL cholesterol remain closely linked to cardiovascular and VTE risk. In conclusion, high-potency statins could help to manage the increased cardiovascular and VTE risk concomitant to JAK-Is treatment in rheumatologic patients without depriving them of the best therapeutic choice and, in addition, reducing the inherent risk associated with the disease.

Current application status and structure-activity relationship of selective and non-selective JAK inhibitors in diseases

JAK kinase includes four family members: JAK1, JAK2, JAK3, and TYK2. It forms the JAK-STAT pathway with signal transmitters and activators of subscription (STAT). This pathway is one of the main mechanisms by which many cytokine receptors transduce intracellular signals, it is associated with the occurrence of various immune, inflammatory, and tumor diseases. JAK inhibitors block the signal transduction of the JAK-STAT pathway by targeting JAK kinase. Based on whether they target multiple subtypes of JAK kinase, JAK inhibitors are categorized into pan-JAK inhibitors and selective JAK inhibitors. Compared with pan JAK inhibitors, selective JAK inhibitors are associated with a specific member, thus more targeted in therapy, with improved efficacy and reduced side effects. Currently, a number of JAK inhibitors have been approval for disease treatment. This review summarized the current application status of JAK inhibitors that have been marketed, advances of JAK inhibitors currently in phase Ш clinical trials, and the structure-activity relationship of them, with an intention to provide references for the development of novel JAK inhibitors.

Advances of the small molecule drugs regulating fibroblast-like synovial proliferation for rheumatoid arthritis

Rheumatoid arthritis (RA) is a type of chronic autoimmune and inflammatory disease. In the pathological process of RA, the alteration of fibroblast-like synoviocyte (FLS) and its related factors is the main influence in the clinic and fundamental research. In RA, FLS exhibits a uniquely aggressive phenotype, leading to synovial hyperplasia, destruction of the cartilage and bone, and a pro-inflammatory environment in the synovial tissue for perpetuation and progression. Evidently, it is a highly promising way to target the pathological function of FLS for new anti-RA drugs. Based on this, we summed up the pathological mechanism of RA-FLS and reviewed the recent progress of small molecule drugs, including the synthetic small molecule compounds and natural products targeting RA-FLS. In the end, there were some views for further action. Compared with MAPK and NF-κB signaling pathways, the JAK/STAT signaling pathway has great potential for research as targets. A small number of synthetic small molecule compounds have entered the clinic to treat RA and are often used in combination with other drugs. Meanwhile, most natural products are currently in the experimental stage, not the clinical trial stage, such as triptolide. There is an urgent need to unremittingly develop new agents for RA.

Modern drug discovery for inflammatory bowel disease: The role of computational methods

Inflammatory bowel diseases (IBDs) comprising ulcerative colitis, Crohn’s disease and microscopic colitis are characterized by chronic inflammation of the gastrointestinal tract. IBD has spread around the world and is becoming more prevalent at an alarming rate in developing countries whose societies have become more westernized. Cell therapy, intestinal microecology, apheresis therapy, exosome therapy and small molecules are emerging therapeutic options for IBD. Currently, it is thought that low-molecular-mass substances with good oral bio-availability and the ability to permeate the cell membrane to regulate the action of elements of the inflammatory signaling pathway are effective therapeutic options for the treatment of IBD. Several small molecule inhibitors are being developed as a promising alternative for IBD therapy. The use of highly efficient and time-saving techniques, such as computational methods, is still a viable option for the development of these small molecule drugs. The computer-aided (in silico) discovery approach is one drug development technique that has mostly proven efficacy. Computational approaches when combined with traditional drug development methodology dramatically boost the likelihood of drug discovery in a sustainable and cost-effective manner. This review focuses on the modern drug discovery approaches for the design of novel IBD drugs with an emphasis on the role of computational methods. Some computational approaches to IBD genomic studies, target identification, and virtual screening for the discovery of new drugs and in the repurposing of existing drugs are discussed.

Identification of Potent and Selective JAK1 Lead Compounds Through Ligand-Based Drug Design Approaches

JAK1 plays a significant role in the intracellular signaling by interacting with cytokine receptors in different types of cells and is linked to the pathogenesis of various cancers and in the pathology of the immune system. In this study, ligand-based pharmacophore modeling combined with virtual screening and molecular docking methods was incorporated to identify the potent and selective lead compounds for JAK1. Initially, the ligand-based pharmacophore models were generated using a set of 52 JAK1 inhibitors named C-2 methyl/hydroxyethyl imidazopyrrolopyridines derivatives. Twenty-seven pharmacophore models with five and six pharmacophore features were generated and validated using potency and selectivity validation methods. During potency validation, the Guner-Henry score was calculated to check the accuracy of the generated models, whereas in selectivity validation, the pharmacophore models that are capable of identifying selective JAK1 inhibitors were evaluated. Based on the validation results, the best pharmacophore models ADHRRR, DDHRRR, DDRRR, DPRRR, DHRRR, ADRRR, DDHRR, and ADPRR were selected and taken for virtual screening against the Maybridge, Asinex, Chemdiv, Enamine, Lifechemicals, and Zinc database to identify the new molecules with novel scaffold that can bind to JAK1. A total of 4,265 hits were identified from screening and checked for acceptable drug-like properties. A total of 2,856 hits were selected after ADME predictions and taken for Glide molecular docking to assess the accurate binding modes of the lead candidates. Ninety molecules were shortlisted based on binding energy and H-bond interactions with the important residues of JAK1. The docking results were authenticated by calculating binding free energy for protein–ligand complexes using the MM-GBSA calculation and induced fit docking methods. Subsequently, the cross-docking approach was carried out to recognize the selective JAK1 lead compounds. Finally, top five lead compounds that were potent and selective against JAK1 were selected and validated using molecular dynamics simulation. Besides, the density functional theory study was also carried out for the selected leads. Through various computational studies, we observed good potency and selectivity of these lead compounds when compared with the drug ruxolitinib. Compounds such as T5923555 and T5923531 were found to be the best and can be further validated using in vitro and in vivo methods.