Recent Progress in JAK Inhibitors for the Treatment of Rheumatoid Arthritis

Immune pathogenesis of idiopathic granulomatous mastitis: from etiology toward therapeutic approaches

Idiopathic granulomatous mastitis (IGM) is a noncancerous, chronic inflammatory disorder of breast with unknown causes, posing significant challenges to the quality of life due to its high refractoriness and local aggressiveness. The typical symptoms of this disease involve skin redness, a firm and tender breast mass and mastalgia; others may include swelling, fistula, abscess (often without fever), nipple retraction, and peau d'orange appearance. IGM often mimics breast abscesses or malignancies, particularly inflammatory breast cancer, and is characterized by absent standardized treatment options, inconsistent patient response and unknown mechanism. Definite diagnosis of this disease relies on core needle biopsy and histopathological examination. The prevailing etiological theory suggests that IGM is an autoimmune disease, as some patients respond well to steroid treatment. Additionally, the presence of concurrent erythema nodosum or other autoimmune conditions supports the autoimmune nature of the disease. Based on current knowledge, this review aims to elucidate the autoimmune-favored features of IGM and explore its potential etiologies. Furthermore, we discuss the immune-mediated pathogenesis of IGM using existing research and propose immunotherapeutic strategies for managing this condition.

STA-21 regulates Th-17/Treg balance and synovial fibroblasts functions in rheumatoid arthritis

JAK/STAT signaling pathway plays a significant role in cytokines and growth factors signaling involved in the pathogenesis of rheumatoid arthritis (RA). STAT3 is a major downstream signaling mediator of important pro-inflammatory cytokines involved in Th-17 cell differentiation playing a significant role in regulating Th-17/ Treg balance and the development of autoimmune diseases, especially RA. Studies also have reported the role of the STAT3 pathway in inflammatory and destructive functions of synovial fibroblasts (SFs) in RA. STA-21 is a small molecule inhibitor that can inhibit STAT3 activation impairing the expression of STAT3 target genes. In this study, we tested whether a STAT3 inhibitor, STA-21, can alter Th-17/Treg balance and SF functions in RA. Peripheral blood mononuclear cells (PBMC) and SFs were isolated from 34 RA patients undergoing orthopedic surgery and 15 healthy controls to investigate in vitro effects of STA-21. The main assays were MTT assay, PI staining, reverse transcription-PCR (RT-PCR), flow cytometric analysis, and ELISA. Results showed that STA-21 reduced the proportion of Th-17 cells and the expression of STAT3 target genes, RORγt, IL-21, and IL-23R involved in Th-17 cells differentiation while it conversely increased the proportion of Treg cells, which theoretically may result in suppression of inflammation. We found that STAT3 activation and its target gene expression increased in RA-SFs. In addition, results showed that STA-21 can reduce the expression of STAT3 target genes related to cell proliferation, apoptosis, and inflammation leading to a decrease in proliferation and conversely increase in apoptosis of RA-SFs. Overall, our findings provide evidence that STA-21 can reduce inflammatory immune processes conducted by T cells and RA-SFs in RA, suggesting that this compound is a suitable option for clinical studies in RA.

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.

Protective effect of fustin against adjuvant-induced arthritis through the restoration of proinflammatory response and oxidative stress

Rheumatoid arthritis causes irreparable damage to joints. The present research sought to check fustin's anti-arthritic efficacy against the complete Freund's adjuvant-induced arthritis paradigm in animals by altering the inflammatory response. In the rats, complete Freund's adjuvant was used to trigger arthritis and they received fustin at 50 and 100 mg/kg for 21 days. At regular intervals, the hind paw volume and arthritic score were assessed. After the trial period, hematological, antioxidant, pro-inflammatory cytokines, and other biochemical parameters were estimated. Fustin-treated rats showed the down-regulation of hind paw volume, arthritic score, and altered hematological parameters (TLC, DLC (neutrophil, lymphocyte, monocyte, eosinophil, basophil)). Furthermore, fustin significantly mitigates proinflammatory cytokine (reduced interleukin, tumor necrosis factor-a (TNF-α), IL-6, IL-1β), oxidative stress (attenuated malondialdehyde (MDA), catalase (CAT), glutathione (GSH), superoxide dismutase (SOD)), attenuated production of prostaglandin E2 and myeloperoxidase (MPO) and improved nuclear factor erythroid 2-related factor (Nrf2) action. Fustin led to the benefit in arthritis-prone animals elicited by complete Freund's adjuvant via pro-inflammatory cytokine.

Clinically approved small-molecule drugs for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a persistent autoimmune ailment that is typified by the development of pannus, proliferation of synovial lining cells, microvascular neogenesis, infiltration of interstitial inflammatory cells, and destruction of cartilage and bone tissue. The disease not only imposes physical pain and economic burden on patients, but also results in a significant decline in their quality of life, rendering it a leading cause of disability. General treatment and drugs are commonly employed to alleviate the condition and symptoms of RA. Cyclooxygenase (COX), janus kinase (JAK), glucocorticoid receptor (GR) et al. have been identified as the main therapeutic targets for RA. This article provides a comprehensive review of the clinical applications and synthetic routes of 26 representative drugs for the treatment of RA, with the aim of facilitating the discovery of more effective new drugs for the treatment of this debilitating disease.

Number needed to treat and cost per responder of Janus kinase inhibitors approved for the treatment of moderate-to-severe rheumatoid arthritis in Japan

OBJECTIVE

This study evaluated the effectiveness and cost-effectiveness of baricitinib, tofacitinib, and upadacitinib regimens, compared to conventional synthetic disease-modifying antirheumatic drug (csDMARD) alone, among Japanese patients with moderate-to-severe rheumatoid arthritis (RA) inadequately responsive to csDMARD, measured in terms of number needed to treat (NNT) and cost per responder (CPR).

METHODS

Efficacy data were derived from two recent network meta-analyses among global and Japanese population. The cost perspective was that of the Japanese Health Service. Both NNT and CPR were based on disease activity score for 28 joints with C-reactive protein (DAS28-CRP) remission and American College of Rheumatology (ACR) 20/50/70 at 12 and 24 weeks.

RESULTS

Over 12 weeks, the median NNT and the median CPR to achieve DAS28-CRP remission were 4.3 and JPY 1,799,696 [USD 16,361], respectively, for upadacitinib 15 mg + csDMARD. The equivalent results were 6.0 and JPY 2,691,684 [USD 24,470] for baricitinib 4 mg + csDMARD and 5.6 and JPY 2,507,152 [USD 22,792] for tofacitinib 5 mg + csDMARD. Similar rankings were observed at 24 weeks and for other outcomes.

CONCLUSIONS

Upadacitinib 15 mg was associated with the lowest NNT and CPR among the three Janus kinase inhibitors used in treatment regimens for Japanese patients with moderate-to-severe RA inadequately responsive to csDMARD.

Identification of TUL01101: A Novel Potent and Selective JAK1 Inhibitor for the Treatment of Rheumatoid Arthritis

Janus kinase 1 (JAK1) is a potential target for the treatment of rheumatoid arthritis (RA). In this study, the introduction of a spiro ring with a difluoro-substituted cyclopropionamide resulted in the identification of TUL01101 (compound 36) based on a triazolo[1,5-a]pyridine core of filgotinib. It showed excellent potency on JAK1 with an IC₅₀ value of 3 nM and exhibited more than 12-fold selectivity for JAK2 and TYK2. Whole blood assay also demonstrated the high activity and selectivity (37-fold for JAK2). At the same time, TUL01101 also demonstrated excellent metabolic stability and pharmacokinetics (PK) profiles were assayed in three species (mouse, rat, and dog). Moreover, it has been validated for effective activity in the treatment of RA both in collagen-induced arthritis (CIA) and adjuvant-induced arthritis (AIA) models, with low dose and low toxicity. Now, TUL01101 has progressed into phase I clinical trials.

Ultrasound response to tofacitinib in patients with rheumatoid arthritis: Data from a multicenter 24 weeks prospective study

Background

Treatment of rheumatoid arthritis (RA) should aim at full remission. Ultrasonography (US) might have an added value to clinical examination in assessing disease activity of RA. In this study we evaluated the ultrasound response, next to clinical and laboratory response, in RA patients treated with tofacitinib (TOF).

Methods

In this observational multicenter study, patients received TOF 5 mg twice daily, with or without the contemporary use of methotrexate or other conventional DMARD, for 24 weeks. All patients underwent clinical, laboratory and US examinations of 40 sites among joints and tendons. Sonographers were blinded to clinical and laboratory parameters. Data were assessed at baseline, week 2, 4, 8, 12 and 24. For each patient we used two US joint scores (Gray Scale –GS–and power Doppler –PD– score), a 0–3 semi-quantitative scale for each joint and the EULAR-OMERACT US scoring system (combined GS and PD graded from 0 to 3). Besides, we calculated a tenosynovitis scores (GS and PD) according to the OMERACT score.

Results

Fifty-two RA patients completed the 6 months period study: mean disease duration 9.97 ± 8.75 years, baseline DAS28-CRP 4.9 ± 1.2, HAQ 1.4 ± 0.7, C-reactive protein (CRP 2.25 ± 3.11 mg/dl). Baseline joint (GS, PD and combined-US) and tendon US scores (GS and PD) were 23.5 ± 18.4, 22.7 ± 19.3, 25.7 ± 20.6, 10.5 ± 11.4 and 11.0 ± 12.0, respectively. US joint and tendon scores significantly reduced as early as T1 (week 2) examination as well as at week 4, 12 and 24, as compared to baseline values (p < 0.001 for all comparisons). Improvement of joint US scores (GS, PD and US-combined) correlated at T4 examination, with the reduction of serum CRP levels (rho 0.418, p = 0.036, rho 0.495, p = 0.004 and rho 0.454, p = 0.009, respectively). We did not find any correlation between the variations of DAS28-CRP and any US scores at any visits.

Conclusion

These results provide evidence that TOF treatment leads to early (2 weeks) and persistent reduction of US signs of inflammation both at tendon and joint level comparable to clinical improvement.

Preferable outcome of Janus kinase inhibitors for a group of difficult-to-treat rheumatoid arthritis patients: from the FIRST Registry

Backgrounds

Treatment of difficult-to-treat rheumatoid arthritis (D2T RA) is one of the greatest unmet needs in rheumatology. This study aims to find out preferable treatment options for a group of D2T RA patients who are refractory to multiple biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs).

Methods

Data were obtained from patients enrolled in the FIRST Registry who started either TNF inhibitor (TNFi), interleukin-6 receptor inhibitor, cytotoxic T-lymphocyte–associated antigen-4 immunoglobulin, or Janus-kinase inhibitor (JAKi) in the period of August 2013 to December 2020. Those who failed to ≥ 2 and ≥ 3 b/tsDMARDs were categorised as D2T RA and very D2T RA (vD2T RA), respectively. Change in Clinical Disease Activity Index (CDAI) and Health Assessment Questionnaire Disability Index were compared among the groups using propensity-based inverse probability treatment weighted (IPTW) method.

Results

Of 2128 cases included, 353 were categorised as D2T RA. Among the D2T RA, 106 were identified as vD2T RA. JAKi showed a significant improvement in CDAI in the patients with D2T RA and vD2T RA, compared to IPTW-adjusted patients treated with the other 3 regimens. Latent class analysis of the trajectories of treatment response revealed that the proportion of a group of patients who showed poor response was lower among the JAKi subgroup than among those with other subgroups. This superiority of JAKi was more apparent among methotrexate- and glucocorticoid-free individuals. The hazard ratio of severe adverse events was comparable among the four treatment subgroups in both the D2T RA and b/tsDMARD-naïve groups.

Conclusions

This study compared responsiveness to different classes of b/tsDMARDs among D2T RA and vD2T RA patients who were refractory to multiple b/tsDMARDs. The results suggest JAKi is a preferable treatment choice for this type of D2T RA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02744-7.

Recent Advances in Ovarian Cancer: Therapeutic Strategies, Potential Biomarkers, and Technological Improvements

Aggressive and recurrent gynecological cancers are associated with worse prognosis and a lack of effective therapeutic response. Ovarian cancer (OC) patients are often diagnosed in advanced stages, when drug resistance, angiogenesis, relapse, and metastasis impact survival outcomes. Currently, surgical debulking, radiotherapy, and/or chemotherapy remain the mainstream treatment modalities; however, patients suffer unwanted side effects and drug resistance in the absence of targeted therapies. Hence, it is urgent to decipher the complex disease biology and identify potential biomarkers, which could greatly contribute to making an early diagnosis or predicting the response to specific therapies. This review aims to critically discuss the current therapeutic strategies for OC, novel drug-delivery systems, and potential biomarkers in the context of genetics and molecular research. It emphasizes how the understanding of disease biology is related to the advancement of technology, enabling the exploration of novel biomarkers that may be able to provide more accurate diagnosis and prognosis, which would effectively translate into targeted therapies, ultimately improving patients’ overall survival and quality of life.

Targeting of Janus Kinases Limits Pro-Inflammatory but Also Immunosuppressive Circuits in the Crosstalk between Synovial Fibroblasts and Lymphocytes

Crosstalk between synovial fibroblasts (SF) and immune cells plays a central role in the development of rheumatoid arthritis (RA). Janus kinase inhibitors (JAKi) have proven efficacy in the treatment of RA, although clinical responses are heterogeneous. Currently, little is known regarding how JAKi affect pro- and anti-inflammatory circuits in the bidirectional interplay between SF and immune cells. Here, we examined the effects of tofacitinib, baricitinib and upadacitinib on crosstalk between SF and T or B lymphocytes in vitro and compared them with those of biologic disease modifying anti-rheumatic drugs (bDMARDs). JAKi dose-dependently suppressed cytokine secretion of T helper (Th) cells and decreased interleukin (IL)-6 and matrix metalloproteinase (MMP)3 secretion of SF stimulated by Th cells. Importantly, JAK inhibition attenuated the enhanced memory response of chronically stimulated SF. Vice versa, JAKi reduced the indoleamine-2,3-dioxygenase (IDO)1-mediated suppression of T cell-proliferation by SF. Remarkably, certain bDMARDs were as efficient as JAKi in suppressing the IL-6 and MMP3 secretion of SF stimulated by Th (adalimumab, secukinumab) or B cells (canakinumab) and combining bDMARDs with JAKi had synergistic effects. In conclusion, JAKi limit pro-inflammatory circuits in the crosstalk between SF and lymphocytes; however, they also weaken the immunosuppressive functions of SF. Both effects were dose-dependent and may contribute to heterogeneity in clinical response to treatment.

Patient- and physician-reported outcomes from two phase 3 randomized studies (RAJ3 and RAJ4) of peficitinib (ASP015K) in Asian patients with rheumatoid arthritis

BACKGROUND

Peficitinib (ASP015K), a novel oral Janus kinase inhibitor, has demonstrated efficacy and safety in the treatment of patients with rheumatoid arthritis (RA). This study evaluated the effect of peficitinib on patient- and physician-reported outcomes in Asian patients with RA and an inadequate response to prior disease-modifying antirheumatic drugs (DMARDs).

METHODS

Patients from two randomized, placebo-controlled, double-blind, phase 3 trials (RAJ3 and RAJ4) received once-daily peficitinib 100 mg, peficitinib 150 mg, or placebo, alone or in combination with DMARDs (RAJ3), or in combination with methotrexate (RAJ4). Mean changes in Work Productivity and Activity Impairment (WPAI) questionnaire domain scores from baseline, and percentages of patients achieving minimal clinically important differences (MCIDs) for patient- and physician-reported outcomes (WPAI, Health Assessment Questionnaire - Disability Index [HAQ-DI], and Subject's Global Assessment of Pain [SGAP]), and Physician's Global Assessment of disease activity (PGA) were evaluated at weeks 4, 8, 12, and 12/early termination (ET).

RESULTS

Data from 1025 patients were analyzed. At week 12/ET in both studies, patients who received peficitinib 100 mg or 150 mg reported significantly improved WPAI domain scores from baseline (except for absenteeism in RAJ4) compared with placebo (both doses, p<0.05). A higher proportion of peficitinib- versus placebo-treated patients achieved MCID in WPAI, HAQ-DI, SGAP, and PGA in studies RAJ3 and RAJ4. Significant differences with peficitinib versus placebo were evident in both studies as early as week 4 in HAQ-DI (peficitinib 150 mg only), SGAP, and PGA, and week 8 in WPAI loss of work productivity and daily activity impairment. At week 12/ET, significantly higher proportions of patients receiving peficitinib versus placebo achieved MCID in HAQ-DI, SGAP, PGA, and WPAI domains of presenteeism (RAJ3 only), loss of work productivity (RAJ3 only), and daily activity impairment (p<0.05 for all comparisons).

CONCLUSIONS

Peficitinib 100 mg or 150 mg administered daily over 12 weeks resulted in clinically meaningful improvements in outcomes that are important to RA patients, including pain, physical function, and work productivity and activity. These observations were reinforced through similar improvements in physicians' rating of disease activity.

TRIAL REGISTRATION

RAJ3: ClinicalTrials.gov, NCT02308163 , registered 4 December 2014. RAJ4: ClinicalTrials.gov, NCT02305849 , registered 3 December 2014.

Efficacy and safety of jakinibs in rheumatoid arthritis: a systematic review and meta-analysis

OBJECTIVES

To assess the efficacy and safety of jakinibs for the treatment of active rheumatoid arthritis (RA) in patients with an inadequate response or intolerance to conventional synthetic or biologic disease-modifying antirheumatic drugs (DMARDs).

METHODS

A systematic search was conducted in PubMed, Embase, and the Cochrane Library. Randomized placebo-controlled trials (RCTs) of jakinibs in RA patients were eligible. The effective outcome was RA improvement to reach an American College of Rheumatology 20%/50%/70% (ACR20/50/70) response rate at weeks 12 and 24 after treatment. The safety outcomes included treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), and discontinuations due to adverse events, infections, and serious infections.

RESULTS

Twenty-eight randomized, double-blind, controlled trials including 14,500 patients were included. At both weeks 12 and 24, the pooled analysis suggested effective treatment with jakinibs, represented as an increased clinical response of ACR20, ACR50, and ACR70. Subgroup analysis based on different types of jakinibs demonstrated that only peficitinib treatment had no impact on the clinical response of ACR50 or ACR70 at week 12. Jakinibs were associated with an increased incidence of infections at week 12 and TEAEs and infections at week 24. No increase in the risk of SAEs, discontinuations due to adverse events, or serious infections was observed in comparisons between treatment with jakinibs and treatment with placebo in these patients.

CONCLUSIONS

Jakinibs are efficacious and well tolerated in RA patients up to 24 weeks, although they are associated with an increased risk of infectious complications. Key Points • ACR20/50/70 in patients treated with jakinibs was significantly higher than those in patients treated with placebo. • No difference in ACR50/70 was observed in patients with RA treated with peficitinib and placebo. • Jakinibs are beneficial and well tolerated in RA treatment.

Managing Osteoporosis and Joint Damage in Patients with Rheumatoid Arthritis: An Overview

In rheumatoid arthritis, a representative systemic autoimmune disease, immune abnormality and accompanying persistent synovitis cause bone and cartilage destruction and systemic osteoporosis. Biologics targeting tumor necrosis factor, which plays a central role in the inflammatory process, and Janus kinase inhibitors have been introduced in the treatment of rheumatoid arthritis, making clinical remission a realistic treatment goal. These drugs can prevent structural damage to bone and cartilage. In addition, osteoporosis, caused by factors such as menopause, aging, immobility, and glucocorticoid use, can be treated with bisphosphonates and the anti-receptor activator of the nuclear factor-κB ligand antibody. An imbalance in the immune system in rheumatoid arthritis induces an imbalance in bone metabolism. However, osteoporosis and bone and cartilage destruction occur through totally different mechanisms. Understanding the mechanisms underlying osteoporosis and joint destruction in rheumatoid arthritis leads to improved care and the development of new treatments.

Therapeutic Advances in Diabetes, Autoimmune, and Neurological Diseases

Since 2015, 170 small molecules, 60 antibody-based entities, 12 peptides, and 15 gene- or cell-therapies have been approved by FDA for diverse disease indications. Recent advancement in medicine is facilitated by identification of new targets and mechanisms of actions, advancement in discovery and development platforms, and the emergence of novel technologies. Early disease detection, precision intervention, and personalized treatments have revolutionized patient care in the last decade. In this review, we provide a comprehensive overview of current and emerging therapeutic modalities developed in the recent years. We focus on nine diseases in three major therapeutics areas, diabetes, autoimmune, and neurological disorders. The pathogenesis of each disease at physiological and molecular levels is discussed and recently approved drugs as well as drugs in the clinic are presented.

Efficacy and safety of upadacitinib in Japanese patients with rheumatoid arthritis (SELECT-SUNRISE): a placebo-controlled phase IIb/III study

Objective

To evaluate upadacitinib efficacy and safety dose response in Japanese patients with active RA and an inadequate response to conventional synthetic DMARDs (csDMARDs).

Methods

This was a multicentre, phase IIb/III, dose-ranging study conducted in Japan, in which patients on previously stable csDMARDs were randomized to receive upadacitinib 7.5, 15 or 30 mg once daily or matching placebo for a 12-week double-blind period. The primary endpoint was a 20% improvement in ACR criteria (ACR20) response at week 12 using non-responder imputation. Key secondary endpoints included ACR50, ACR70 and 28-joint DAS with CRP (DAS28-CRP) remission and low disease activity. Adverse events were also assessed.

Results

Of 197 patients treated, 187 completed the double-blind period. At week 12, more patients receiving upadacitinib 7.5, 15 or 30 mg vs placebo met the ACR20 response (75.5%, 83.7%, 80.0% vs 42.9%; P < 0.001), with significant differences observed as early as week 1. Stringent responses, including ACR50, ACR70 and DAS28-CRP <2.6, were achieved by significantly higher proportions of patients on upadacitinib than placebo and by numerically higher proportions on upadacitinib 15 or 30 mg vs upadacitinib 7.5 mg. Adverse events and infections (serious infections, opportunistic infections and herpes zoster) were more common with upadacitinib vs placebo and numerically highest with upadacitinib 30 mg. There were no venous thromboembolic events reported.

Conclusion

Efficacy of upadacitinib was demonstrated in this population of Japanese patients with RA and an inadequate response to csDMARDs. Safety and tolerability were consistent with other upadacitinib RA studies. The 15 mg dose of upadacitinib showed the most favourable benefit–risk profile.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT02720523.

Activity Prediction of Small Molecule Inhibitors for Antirheumatoid Arthritis Targets Based on Artificial Intelligence

Rheumatoid arthritis (RA) is a chronic autoimmune disease, which is compared to "immortal cancer" in industry. Currently, SYK, BTK, and JAK are the three major targets of protein tyrosine kinase for this disease. According to existing research, marketed and research drugs for RA are mostly based on single target, which limits their efficacy. Therefore, designing multitarget or dual-target inhibitors provide new insights for the treatment of RA regarding of the specific association between SYK, BTK, and JAK from two signal transduction pathways. In this study, machine learning (XGBoost, SVM) and deep learning (DNN) models were combined for the first time to build a powerful integrated model for SYK, BTK, and JAK. The predictive power of the integrated model was proved to be superior to that of a single classifier. In order to accurately assess the generalization ability of the integrated model, comprehensive similarity analysis was performed on the training and the test set, and the prediction accuracy of the integrated model was specifically analyzed under different similarity thresholds. External validation was conducted using single-target and dual-target inhibitors, respectively. Results showed that our model not only obtained a high recall rate (97%) in single-target prediction, but also achieved a favorable yield (54.4%) in dual-target prediction. Furthermore, by clustering dual-target inhibitors, the prediction performance of model in various classes were proved, evaluating the applicability domain of the model in the dual-target drug screening. In summary, the integrated model proposed is promising to screen dual-target inhibitors of SYK/JAK or BTK/JAK as RA drugs, which is beneficial for the clinical treatment of rheumatoid arthritis.

Review article: experimental therapies in autoimmune hepatitis

BACKGROUND

Current therapeutic options for autoimmune hepatitis (AIH) are limited by adverse events associated with corticosteroids and thiopurines and the limited evidence base for second- and third-line treatment options. Furthermore, current treatment approaches require long-term exposure of patients to pharmacological agents. There have been significant advances in the understanding of the mechanisms underpinning autoimmunity and an expansion in the available therapeutic agents for suppressing autoimmune responses or potentially restoring self-tolerance.

AIM

To review the mechanisms and evidence for experimental therapies that are being actively explored in the management of AIH.

METHODS

We have reviewed the literature relating to a range of novel therapeutic immunomodulatory treatment strategies and drugs.

RESULTS

Drugs which block B cell-activating factor of the tumour necrosis factor family (BAFF) and tumour necrosis factor α are currently in clinical trials for the treatment of AIH. Experimental therapies and technologies to increase immune tolerance, such as pre-implantation factor and regulatory T cell therapies, are undergoing development for application in autoimmune disorders. There is also evidence for targeting inflammatory pathways to control other autoimmune conditions, such as blockade of IL1 and IL6 and Janus-associated kinase (JAK) inhibitors.

CONCLUSIONS

With the range of tools available to clinicians and patients increasing, it is likely that the therapeutic landscape of AIH will change over the coming years and treatment approaches offering lower corticosteroid use and aiming to restore immune self-tolerance should be sought.

Pharmacokinetics, Safety, and Tolerability of Single- and Multiple-Dose Once-Daily Baricitinib in Healthy Chinese Subjects: A Randomized Placebo-Controlled Study

The objective of this phase 1 study was to evaluate the pharmacokinetics, safety, and tolerability of baricitinib after single and multiple doses in healthy Chinese adults. Eligible subjects received a once‐daily dose of baricitinib 2, 4, or 10 mg or placebo on day 1 (single dose) and days 4 through 10 for 7 consecutive days (multiple doses). Plasma pharmacokinetic samples were collected up to 48 hours after dosing on days 1 and 10, with predose samples collected before dosing on day 1 and days 4 through 10. Safety and tolerability were also assessed. Baricitinib was rapidly absorbed, reaching peak plasma concentrations within 0.5 to 1 hour (median). Plasma concentrations declined rapidly following the attainment of peak concentrations, with a mean terminal half‐life of 5.7 to 7.3 hours. Steady‐state plasma concentrations of baricitinib were achieved after the second day of once‐daily dosing, with minimal accumulation of baricitinib in plasma (up to 10% increase in area under the plasma concentration–time curve). Single‐ and multiple‐dose mean values for area under the plasma concentration–time curve from time zero to infinity and maximum plasma concentration appeared to increase in an approximately dose‐proportional manner across the dose range. Single and multiple oral doses of once‐daily baricitinib up to 10 mg were well tolerated by healthy Chinese subjects.

Small Molecule Inhibitors in the Treatment of Rheumatoid Arthritis and Beyond: Latest Updates and Potential Strategy for Fighting COVID-19

The development of biological disease-modifying antirheumatic drugs (bDMARDs) and target synthetic DMARDs (tsDMARDs), also known as small molecule inhibitors, represent a breakthrough in rheumatoid arthritis (RA) treatment. The tsDMARDs are a large family of small molecules targeting mostly the several types of kinases, which are essential in downstream signaling of pro-inflammatory molecules. This review highlights current challenges associated with the treatment of RA using small molecule inhibitors targeting intracellular JAKs/MAPKs/NF-κB/SYK-BTK signaling pathways. Indeed, we have provided the latest update on development of small molecule inhibitors, their clinical efficacy and safety as a strategy for RA treatment. On the other hand, we have highlighted the risk and adverse effects of tsDMARDs administration including, among others, infections and thromboembolism. Therefore, performance of blood tests or viral infection screening should be recommended before the tsDMARDs administration. Interestingly, recent events of SARS-CoV-2 outbreak have demonstrated the potential use of small molecule inhibitors not only in RA treatment, but also in fighting COVID-19 via blocking the viral entry, preventing of hyperimmune activation and reducing cytokine storm. Thus, small molecule inhibitors, targeting wide range of pro-inflammatory singling pathways, may find wider implications not only for the management of RA but also in the controlling of COVID-19.

Role of JAK-STAT signaling in the pathogenic behavior of fibroblast-like synoviocytes in rheumatoid arthritis: Effect of the novel JAK inhibitor peficitinib

Rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLS) play a crucial role in the pathogenesis of RA. RA-FLS display passive pro-inflammatory responses and self-directed aggressive responses, such as pro-inflammatory mediator production, reduced apoptosis and formation of a thickened synovial lining. Evidence suggests a role for Janus kinase (JAK)-signal transducer and transcriptional activator (STAT) signaling in the passive response but the aggressive behavior of RA-FLS is poorly understood. The pharmacologic effects of the novel JAK inhibitor, peficitinib, on cytokine-induced intracellular signaling and self-directed aggressive behavior of RA-FLS (e.g., increased expression of apoptosis-resistant genes and sodium nitroprusside-induced apoptosis) were investigated and compared with approved JAK inhibitors. RA-FLS assembly to form a lining-like structure and pro-inflammatory mediator production was investigated in three-dimensional (3D)-micromass culture. Peficitinib inhibited STAT3 phosphorylation in RA-FLS following induction by interferon (IFN)-α2b, IFN-γ, interleukin (IL)-6, oncostatin M, and leukemia inhibitory factor in a concentration-related manner, and was comparable to approved JAK inhibitors, tofacitinib and baricitinib. Peficitinib and tofacitinib suppressed autocrine phosphorylation of STAT3 and expression of apoptosis-resistant genes, and promoted cell death. In 3D-micromass culture, peficitinib reduced multi-layered RA-FLS cells to a thin monolayer, an effect less pronounced with tofacitinib. Both compounds attenuated production of vascular endothelial growth factor-A, matrix metalloproteinases, IL-6 and tumor necrosis factor superfamily-11. This study confirmed the pathogenic role of uncontrolled JAK-STAT signaling in the aggressive and passive responses of RA-FLS that are critical for RA progression. The novel JAK inhibitor peficitinib suppressed the pro-inflammatory behavior of RA-FLS, accelerated cell death and abrogated thickening of the synovium.

Pharmacokinetics and Safety of a Single Oral Dose of Peficitinib (ASP015K) in Japanese Subjects with Normal and Impaired Renal Function

BACKGROUND AND OBJECTIVE

This study measured and compared the exposure and safety of peficitinib (ASP015K), a novel oral Janus kinase inhibitor, in subjects with normal and impaired renal function after a single oral, clinically relevant peficitinib dose.

METHODS

This was an open-label, parallel-group study conducted at two centres in Japan. Subjects with normal and mildly, moderately, or severely impaired renal function received a single oral dose of peficitinib (one 150 mg tablet) under fasting conditions in a hospital setting. Blood samples were collected prior to administration and up to 72 h post-dose for pharmacokinetic assessment. Safety was assessed up to 7 days post-dose.

RESULTS

Peficitinib plasma concentration-time profiles were similar between those with normal and impaired renal function. In subjects with impaired renal function, area under the plasma concentration-time curve and maximum concentration were 0.8- to 1.1-fold those in subjects with no impairment. Two subjects (one in the normal group and one in the mildly impaired group) each experienced a treatment-emergent adverse event (TEAE). There were no serious TEAEs, deaths or TEAEs leading to treatment withdrawal.

CONCLUSIONS

Peficitinib exposure and TEAEs were similar in subjects with and without renal impairment after a single oral 150 mg dose. Based on these findings, it is not expected that peficitinib dose adjustment will be required in clinical practice, according to the degree of renal impairment. CLINICALTRIALS.

GOV IDENTIFIER

NCT02603497.

[Biologicals and small molecules for rheumatoid arthritis]

In recent years tremendous progress has been made in the therapeutic management of rheumatoid arthritis. Rheumatologists now have a large armamentarium of highly efficient drugs with different mechanisms of action at their disposal. These new drugs consist of biologicals (biological disease-modifying antirheumatic drugs, bDMARDs) as well as targeted synthetic DMARDs (tsDMARD). A common feature of these new drugs for treatment of rheumatoid arthritis is that the molecular target of the drug is known, which is not the case for conventional DMARDs. With the help of the new drugs, the therapeutic goal of inducing remission in patients with rheumatoid arthritis has become reality for many patients. Nevertheless, there is still a significant proportion of patients who do not adequately respond to all available drugs, leaving room for still further improvement. This review gives a short overview on the currently available and effective substances for the treatment of rheumatoid arthritis.

Safety and effectiveness of peficitinib (ASP015K) in patients with rheumatoid arthritis: interim data (22.7 months mean peficitinib treatment) from a long-term, open-label extension study in Japan, Korea, and Taiwan

BACKGROUND

Peficitinib (ASP015K), a novel oral Janus kinase inhibitor, has demonstrated efficacy and safety for the treatment of rheumatoid arthritis (RA) in randomized, controlled trials of up to 52 weeks' duration. However, safety and effectiveness after long-term treatment have not been assessed.

METHODS

This was an interim analysis of an ongoing open-label, multicenter extension study in RA patients who completed phase 2b (RAJ1; 12 weeks) and phase 3 (RAJ3 and RAJ4; 52 weeks) peficitinib studies in Asia (mainly Japan). Eligible patients (n = 843) received oral peficitinib once daily (100 mg, or 50 mg for patients transferring from RAJ1). The peficitinib dose could be increased (up to 150 mg) or reduced (to 50 mg) at the discretion of the investigator. Efficacy variables assessed included American College of Rheumatology (ACR) response rates, ACR components, and disease activity score in 28 joints based on C-reactive protein (DAS28-CRP).

RESULTS

Results up to May 2018 are summarized. Mean peficitinib duration of exposure was 22.7 months and the maximum dose was 100 mg in most (66.5%) patients. ACR responses were maintained during the extension study, with ACR20/50/70 response rates of 71.6%, 52.1%, and 34.7% at week 0 and 78.9%, 61.4%, and 42.7% at end of treatment, respectively. ACR components and DAS28-CRP showed improvements from baselines of the preceding studies and continued to show improvements during the extension study. Treatment-emergent adverse events (TEAEs) were reported in 757/843 (89.8%) patients, the most common being nasopharyngitis (39.7%) and herpes zoster (11.7%). The majority of TEAEs were severity grade 1/2. Drug-related TEAEs leading to permanent study drug discontinuation occurred in 55/843 (6.5%) patients. Regarding AEs of special interest, the incidence per 100 patient-years of serious infections was 2.3 (95% CI 1.6 - 3.1), herpes zoster-related disease 6.8 (95% CI, 5.6 - 8.3), and malignancies 1.1 (95% CI, 0.7 - 1.8). One death from diffuse large B cell lymphoma during the study and one death from uterine sarcoma after the study were considered probably and possibly related to study drug, respectively.

CONCLUSIONS

The effectiveness of peficitinib was maintained or improved during long-term administration and treatment up to 6 years was well tolerated in Asian patients with RA.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01638013, registered retrospectively 11 July 2012.

Molecular modeling studies of pyrrolo[2,3-d]pyrimidin-4-amine derivatives as JAK1 inhibitors based on 3D-QSAR, molecular docking, molecular dynamics (MD) and MM-PBSA calculations

Rheumatoid Arthritis (RA) is an autoimmune disease caused by overproduction of pro-inflammatory cytokines. Janus Kinases (JAKs) mediate cytokines signaling through the Janus Kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways. Clinical studies have shown that Janus kinase 1 (JAK1) mediated signaling plays a key role in synovial response in rheumatoid arthritis. Hence, the inhibition JAK1 is considered as an important therapeutic route for treatment of rheumatoid arthritis. In this study, we have performed three-dimensional quantitative structure-activity relationship (3 D-QSAR), molecular docking, molecular dynamics (MD) and free energy calculations on a series of pyrrolo[2,3-d]pyrimidin-4-amine JAK1 inhibitors. Molecular docking studies of the compounds 03, 13, 36 and 49 with JAK1 were performed to study the binding interactions. The binding conformations of the compounds from docking studies were selected based on binding energy and H-bond interactions and were used as initial structure for MD simulations. Using 3 D-QSAR techniques, a ligand-based comparative molecular field analysis (CoMFA) model (q² = 0.5, r² = 0.96) and a receptor-based CoMFA model (q² = 0.78, r² = 0.98) were developed. Analysis of the MD results of the most active compound (compound 49) with JAK1 showed the formation of H-bond interactions with residues Glu957, Leu959 and Gly887 and water-mediated H-bond interaction with Gly887 and His885. Based on the contour map analyses of the receptor-based CoMFA, a design strategy was proposed and was used for designing new JAK1 inhibitors. Four of the designed compounds (D57, D58, D98 and D99) showed predicted activity values (pIC₅₀> 8.8) greater than the most active compound for JAK1. MM-PBSA based free energy calculations indicated that the designed compounds were able to form stable binding with JAK1 primarily through electrostatic interactions and van der Waal interactions. Collectively, the outcome of this study can be used to further the progress of JAK1 inhibition for the treatment of rheumatoid arthritis. Communicated by Ramaswamy H. Sarma.

The role of JAK/STAT signaling pathway and its inhibitors in diseases

The JAK/STAT signaling pathway is an universally expressed intracellular signal transduction pathway and involved in many crucial biological processes, including cell proliferation, differentiation, apoptosis, and immune regulation. It provides a direct mechanism for extracellular factors-regulated gene expression. Current researches on this pathway have been focusing on the inflammatory and neoplastic diseases and related drug. The mechanism of JAK/STAT signaling is relatively simple. However, the biological consequences of the pathway are complicated due to its crosstalk with other signaling pathways. In addition, there is increasing evidence indicates that the persistent activation of JAK/STAT signaling pathway is closely related to many immune and inflammatory diseases, yet the specific mechanism remains unclear. Therefore, it is necessary to study the detailed mechanisms of JAK/STAT signaling in disease formation to provide critical reference for clinical treatments of the diseases. In this review, we focus on the structure of JAKs and STATs, the JAK/STAT signaling pathway and its negative regulators, the associated diseases, and the JAK inhibitors for the clinical therapy.

Population Pharmacokinetics of Upadacitinib in Healthy Subjects and Subjects with Rheumatoid Arthritis: Analyses of Phase I and II Clinical Trials

Background and Objectives

Upadacitinib is a janus kinase (JAK) 1 inhibitor being developed for the treatment of rheumatoid arthritis (RA) and other inflammatory diseases. This work characterized upadacitinib population pharmacokinetics in healthy subjects and RA patients and the effects of covariates on upadacitinib exposure.

Methods

Upadacitinib plasma concentrations (n = 6399) from 107 healthy subjects and 466 RA patients from three phase I and two 12-week RA phase IIb trials (1–48 mg immediate-release doses across studies) were analyzed using non-linear mixed-effects modeling. The models were qualified using bootstrap and stochastic simulations.

Results

A two-compartment model with first-order absorption and elimination described upadacitinib pharmacokinetics. Estimates (95% bootstrap confidence interval) for upadacitinib oral clearance, steady-state volume of distribution, absorption lag time, and mean absorption time were 39.7 (37.8–41.5) L/h, 210 (196–231) L, 0.48 (0.47–0.49) h, and 0.08 (0.04–0.12) h, respectively, for a typical healthy male. Matching on other covariates, a 16 and 32% higher upadacitinib area under the concentration–time curve (AUC) was estimated for females relative to males, and for subjects with RA relative to healthy volunteers, respectively. Subjects with RA with mild or moderate renal impairment were estimated to have 16 and 32% higher upadacitinib AUC, respectively, compared with subjects with RA with normal renal function. Upadacitinib clearance was not correlated with body weight.

Conclusions

Upadacitinib pharmacokinetics follow dose-proportional, bi-exponential disposition. A slightly lower upadacitinib clearance is estimated in subjects with RA than in healthy volunteers, consistent with observations for other JAK inhibitors. Other covariates (weight, sex, mild or moderate renal impairment) are not associated with clinically relevant effects on upadacitinib exposure.

Trial Registration

ClinicalTrials.gov (https://clinicaltrials.gov/) identifiers: NCT01741493, NCT02066389, and NCT01960855.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-017-0605-6) contains supplementary material, which is available to authorized users.

Peficitinib Inhibits the Chemotactic Activity of Monocytes via Proinflammatory Cytokine Production in Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Background: This study was performed to examine the effects of the Janus kinase (JAK) inhibitor peficitinib on fibroblast-like synoviocytes (FLS) obtained from patients with rheumatoid arthritis (RA). Methods: To examine the expression of JAK1, JAK2, and JAK3 in RA synovial tissue (ST) and FLS, immunohistochemistry was performed. We investigated the effects of peficitinib on interleukin 6 and IL-6 receptor responses in RA FLS. Phosphorylation of STAT was determined by western blot. To examine the functional analysis of peficitinib, we performed a proliferation and chemotaxis assays with FLS using THP-1 and peripheral blood mononuclear cells (PBMC). The inflammatory mediator expression of FLS was estimated by enzyme-linked immunosorbent assay. Results: JAK1, JAK2, and JAK3 were expressed in RA STs and FLS. Phosphorylation of STAT1, STAT3, and STAT5 in RA FLS was suppressed by peficitinib in a concentration-dependent manner. Peficitinib-treated RA FLS-conditioned medium reduced THP-1 and PBMC migration (p < 0.05) and proliferation of RA FLS (p < 0.05). Peficitinib suppressed the secretion of MCP-1/CCL2 in the RA FLS supernatant (p < 0.05). Conclusion: Peficitinib suppressed the JAK-STAT pathway in RA FLS and also suppressed monocyte chemotaxis and proliferation of FLS through inhibition of inflammatory cytokines.

Impact of Janus kinase inhibitors on risk of cardiovascular events in patients with rheumatoid arthritis: systematic review and meta-analysis of randomised controlled trials

Objectives

To investigate the effect of Janus kinase inhibitors (Jakinibs) on cardiovascular risk in adult patients with rheumatoid arthritis (RA) via a meta-analysis of randomised controlled trials (RCTs).

Methods

PubMed, Embase and Cochrane library were thoroughly searched for RCTs reporting safety issues in patients with RA receiving Jakinibs, from inception to October 2018. The primary and secondary outcomes were all cardiovascular events (CVEs) and major adverse cardiovascular events (MACEs)/venous thromboembolism events (VTEs). OR and 95% CI were calculated using the Mantel-Haenszel fixed-effect method.

Results

26 RCTs randomising 11 799 patients were included. No significant difference was observed regarding all CVEs risk following Jakinibs usage in general (OR 1.04 (0.61 to 1.76), p = 0.89), tofacitinib (OR 0.63 (0.26 to 1.54), p = 0.31), baricitinib (OR 1.21 (0.51 to 2.83), p = 0.66), upadacitinib (OR 3.29 (0.59 to 18.44), p = 0.18), peficitinib (OR 0.43 (0.07 to 2.54), p = 0.35) or decernotinib (OR 1.12 (0.13 to 10.11), p = 0.92). Likewise, there was no significant difference for Jakinibs treatment overall regarding occurrence of MACEs (OR 0.80 (0.36 to 1.75), p = 0.57) or VTEs (OR 1.16 (0.48 to 2.81), p = 0.74). Dose-dependent impact of Jakinibs on the risks of all CVEs, MACEs and VTEs was not observed in tofacitinib (5 mg vs 10 mg), upadacitinib (15 mg vs 30 mg), whereas baricitinib at 2 mg was found to be safer than 4 mg in all CVEs incidence (OR 0.19 (0.04 to 0.88), p = 0.03).

Conclusion

The existing evidence from RCTs indicated no significant change in cardiovascular risk for Jakinib-treated patients with RA in a short-term perspective, but postmarketing data are sorely needed to ascertain their cardiovascular safety, especially at the higher dose, due to increased risk of thromboembolism events for both tofacitinib and baricitinib at higher dosage.

Baricitinib for the treatment of rheumatoid arthritis and systemic lupus erythematosus: a 2019 update

Introduction: JAK, which constitutively binds to some cytokine receptors, plays an important role in cytokine signaling. While JAK is comprised of JAK1, JAK2, JAK3, and Tyk2, more than 40 types of cytokines transmit signals through JAK. Baricitinib is reported to be highly effective in the treatment of rheumatoid arthritis (RA) and is the second drug launched as a JAK inhibitor for RA. Area covered: We provide an overview of the mechanisms of action of baricitinib and its clinical implications in RA and other autoimmune diseases based on recent reports. This review outlines the mechanisms of action of baricitinib on human immune cells, the results of Phase III trials for RA, and the results of Phase II trials on SLE. Expert opinion: Baricitinib has potential to fine-tune various immune networks through a variety of mechanisms. Precision medicine is required in order to achieve maximum effects of targeted synthetic DMARDs including baricitinib and biological DMARDs in the future.

Baricitinib induces LDL-C and HDL-C increases in rheumatoid arthritis: a meta-analysis of randomized controlled trials

Background

Baricitinib, an oral-administrated selective inhibitor of the JAK1 and JAK2, is recently approved for rheumatoid arthritis (RA) treatment. With the aim to provide some insights on the clinical safety, the current study mainly focused on the effect of baricitinib on low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels and cardiovascular risk.

Methods

The net change scores [least squares mean (LSM) and mean change] of LDL-C and HDL-C levels from baseline with the comparison of baricitinib versus placebo were pooled, respectively. Risk rations (RR) of major cardiovascular events (MACEs) and differences of cardiovascular risk scores at the end of treatment across groups were compared.

Results

Six trials with randomized 3552 patients were finally included in summary analysis. Results showed that baricitinib significantly increased LDL-C levels, the net mean change was 13.15 mg/dl with 95% CI 8.89~17.42 (I² = 0) and the net LSM was 11.94 mg/dl with 95% CI 7.52~16.37 (I² = 84%). HDL-C also increased obviously with the net LSM change was 7.19 mg/dl (95% CI, 6.05~8.33, I² = 47%) and net mean change was 5.40 mg/dl (95% CI, 3.07~7.74, I² = 10%). Subgroup and meta-regression analysis demonstrated baricitinib induced LDL-C and HDL-C increases in a dose-response manner. However, both the pooled RRs of MACEs and differences of cardiovascular risk scores were not statistically significant across groups.

Conclusion

This study confirmed that baricitinib induced a stable dose-response increase in LDL-C and HDL-C levels. Since the causality association between altered lipids and cardiovascular risk was not identified yet, this issue cannot be completely dismissed. Future research is needed to fully dissect the implications of these lipid changes.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-0994-7) contains supplementary material, which is available to authorized users.

The role of the JAK/STAT signal pathway in rheumatoid arthritis

Proinflammatory cytokine activation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal transduction pathway is a critical event in the pathogenesis and progression of rheumatoid arthritis. Under normal conditions, JAK/STAT signaling reflects the influence of negative regulators of JAK/STAT, exemplified by the suppressor of cytokine signaling and protein inhibitor of activated STAT. However, in rheumatoid arthritis (RA) both of these regulators are dysfunctional. Thus, continuous activation of JAK/STAT signaling in RA synovial joints results in the elevated level of matrix metalloproteinase gene expression, increased frequency of apoptotic chondrocytes and most prominently 'apoptosis resistance' in the inflamed synovial tissue. Tofacitinib, a JAK small molecule inhibitor, with selectivity for JAK2/JAK3 was approved by the United States Food and Drug Administration (US FDA) for the therapy of RA. Importantly, tofacitinib has demonstrated significant clinical efficacy for RA in the post-US FDA-approval surveillance period. Of note, the success of tofacitinib has spurred the development of JAK1, JAK2 and other JAK3-selective small molecule inhibitors, some of which have also entered the clinical setting, whereas other JAK inhibitors are currently being evaluated in RA clinical trials.

Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials

OBJECTIVES

To evaluate efficacy/safety of baricitinib for rheumatoid arthritis (RA) in Japanese subpopulations from four phase 3 studies, and assess whether results in these subpopulations are consistent with the overall study populations.

METHODS

Subgroup analyses (394 patients) of four phase 3 randomized controlled trials: RA-BEGIN [no or limited treatment with disease-modifying antirheumatic drugs (DMARDs)], RA-BEAM [inadequate response (IR) to methotrexate], RA-BUILD [IR to conventional synthetic DMARDs (csDMARDs)], and RA-BEACON (IR to tumor necrosis factor inhibitors receiving csDMARDs).

RESULTS

For American College of Rheumatology 20% improvement (ACR20) response rate, Japanese patients receiving baricitinib 4-mg showed similar improvement compared to methotrexate at Week 24 (72 versus 69%; RA-BEGIN), and greater improvement compared with placebo at Week 12 (67 versus 34%; RA-BEAM). Japanese patients receiving baricitinib 4-mg also showed greater improvement compared with placebo at Week 12 in RA-BUILD and RA-BEACON. Across all studies, baricitinib was well-tolerated, with no deaths and one malignancy. In RA-BEGIN and RA-BEAM, herpes zoster rates were higher for Japanese patients than for overall populations; all events were mild/moderate.

CONCLUSION

Data for baricitinib, with/without methotrexate, in Japanese subpopulations across all stages of the RA treatment continuum accord with the efficacy/safety profile in overall study populations. Baricitinib appears to be similarly effective in Japanese patients.

Linking energy sensing to suppression of JAK-STAT signalling: A potential route for repurposing AMPK activators?

Exaggerated Janus kinase-signal transducer and activator of transcription (JAK-STAT) signalling is key to the pathogenesis of pro-inflammatory disorders, such as rheumatoid arthritis and cardiovascular diseases. Mutational activation of JAKs is also responsible for several haematological malignancies, including myeloproliferative neoplasms and acute lymphoblastic leukaemia. Accumulating evidence links adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), an energy sensor and regulator of organismal and cellular metabolism, with the suppression of immune and inflammatory processes. Recent studies have shown that activation of AMPK can limit JAK-STAT-dependent signalling pathways via several mechanisms. These novel findings support AMPK activation as a strategy for management of an array of disorders characterised by hyper-activation of the JAK-STAT pathway. This review discusses the pivotal role of JAK-STAT signalling in a range of disorders and how both established clinically used and novel AMPK activators might be used to treat these conditions.

Janus Kinase Inhibitors for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a disease where the immune system attacks the linings of the joints, resulting in joint pain, stiffness, swelling, and destruction. Although many products are available for the treatment of RA, limitations such as adverse reactions and tolerance greatly affect adherence. Many of the current biologic disease-modifying antirheumatic drugs on the market are injectables, leaving a void to be filled for a product that can be taken orally. The most advanced of these approaches, the Janus kinase (JAK) inhibitors, are oral drugs that have not only made a breakthrough in RA, but also other skin conditions.

Two new drugs for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease that causes inflammation and destruction of the joints.^1-3 It can also affect the eyes, the heart and the lungs and is associated with significant disability and increased mortality. RA is estimated to affect just under 1% of the population aged over 16 years, equating to more than 400,000 people in the UK.⁴ ▼Baricitinib (Olumiant) and ▼tofacitinib (Xeljanz) were launched in the UK in April 2017 and represent a new therapeutic class of medicines known as targeted synthetic disease modifying antirheumatic drugs.^5,6 Here, we review the evidence for the safety and effectiveness of these new oral agents.

Thymosin β4 in rheumatoid arthritis: Friend or foe

Rheumatoid arthritis (RA) has characteristic pannus tissues, which show tumor-like growth of the synovium through chronic joint inflammation. The synovium is highly penetrated by various immune cells, and the synovial lining becomes hyperplastic due to increased numbers of macrophage-like and fibroblast-like synoviocytes. Thus, a resultant hypoxic condition stimulates the expression of inflammation-related genes in various cells, in particular, vascular endothelial growth factor. Thymosin β4 (Tβ4), a 5-kDa protein, is known to play a significant role in various biological activities, such as actin sequestering, cell motility, migration, inflammation, and damage repair. Recent studies have provided evidence that Tβ4 may have a role in RA pathogenesis. The Tβ4 level has been shown to increase significantly in the joint fluid and serum of RA patients. However, whether Tβ4 stimulates or inhibits activation of RA immune responses remains to be determined. In the present study, we discuss the logical and clinical justifications for Tβ4 as a potential target for RA therapeutics.

Novel therapies for immune-mediated inflammatory diseases: What can we learn from their use in rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus, psoriasis, Crohn's disease and ulcerative colitis?

The past three decades have witnessed remarkable advances in our ability to target specific elements of the immune and inflammatory response, fuelled by advances in both biotechnology and disease knowledge. As well as providing superior treatments for immune-mediated inflammatory diseases (IMIDs), such therapies also offer unrivalled opportunities to study the underlying immunopathological basis of these conditions.In this review, we explore recent approaches to the treatment of IMIDs and the insights to pathobiology that they provide. We review novel biologic agents targeting the T-helper 17 axis, including therapies directed towards interleukin (IL)-17 (secukinumab, ixekizumab, bimekizumab), IL-17R (brodalumab), IL-12/23p40 (ustekinumab, briakinumab) and IL-23p19 (guselkumab, tildrakizumab, brazikumab, risankizumab, mirikizumab). We also present an overview of biologics active against type I and II interferons, including sifalumumab, rontalizumab, anifrolumab and fontolizumab. Emerging strategies to interfere with cellular adhesion processes involved in lymphocyte recruitment are discussed, including both integrin blockade (natalizumab, vedolizumab, etrolizumab) and sphingosine-1-phosphate receptor inhibition (fingolimod, ozanimod). We summarise the development and recent application of Janus kinase (JAK) inhibitors in the treatment of IMIDs, including first-generation pan-JAK inhibitors (tofacitinib, baricitinib, ruxolitinib, peficitinib) and second-generation selective JAK inhibitors (decernotinib, filgotinib, upadacitinib). New biologics targeting B-cells (including ocrelizumab, veltuzumab, tabalumab and atacicept) and the development of novel strategies for regulatory T-cell modulation (including low-dose IL-2 therapy and Tregitopes) are also discussed. Finally, we explore recent biotechnological advances such as the development of bispecific antibodies (ABT-122, COVA322), and their application to the treatment of IMIDs.