State of the art: approved and emerging JAK inhibitors for rheumatoid arthritis

Myasthenia gravis and five autoimmune diseases: a bidirectional Mendelian randomization study

BACKGROUND

The association between myasthenia gravis (MG) and other autoimmune diseases is well established. In this study, we aimed to investigate the causal effects between MG and five other autoimmune diseases, including autoimmune thyroid disease (AITD), multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and type 1 diabetes (T1DM).

METHODS

We conducted a bidirectional Mendelian randomization (MR) study by using seven published genome-wide association studies (GWAS), including MG (1873 patients versus 36,370 controls), AITD (autoimmune hypothyroidism) (22,997 patients versus 175,475 controls), AITD (autoimmune hyperthyroidism) (962 patients versus 172,976 controls), MS (47,429 patients versus 68,374 controls), RA (14,361 patients versus 43,923 controls), SLE (4222 patients versus 8431 controls), and T1DM (9266 patients versus 15,574 controls). We used the inverse-variance-weighted (IVW) method, weighted-median (WM) estimator, MR-Egger regression, and MR PRESSO in our analyses. We also carried out detailed sensitivity analyses for each direction using the aforementioned methods.

RESULTS

When MG was treated as the exposure, MR evidence suggested a causal relationship between MG and T1DM, SLE, AITD (both hypothyroidism and hyperthyroidism), and MS (excluding RA). Using the IVW method, we found that MG was associated with increased risk of T1DM (OR = 1.94; 95% CI, 1.16-3.26; p = 0.012), SLE (OR = 1.47; 95% CI, 1.02-2.13; p = 0.04), AITD (hypothyroidism) (OR = 1.31; 95% CI, 1.02-1.68; p = 0.039), AITD (hyperthyroidism) (OR = 1.55; 95% CI, 1.15-2.09; p = 0.004), and MS (OR = 1.46; 95% CI, 1.01-2.09; p = 0.041). When MG was treated as the outcome, MR evidence suggested that RA, T1DM, and SLE were causal factors in MG. Using the IVW method, we found that the risk of MG increased with exposure to RA (OR = 1.21; 95% CI, 1.08-1.37; p = 0.002), T1DM (OR = 1.09; 95% CI, 1.02-1.16; p = 0.006), and SLE (OR = 1.12; 95% CI, 1.02-1.23; p = 0.018).

CONCLUSIONS

This study demonstrated a causal relationship between MG and several other autoimmune diseases. Our results supported a bidirectional causal association between MG and SLE/T1DM. Our findings also provided reliable evidence that MG is associated with increased risk of AITD. Meanwhile, we also showed that RA is a possible causal driver of MG risk.

Discovery of novel dual Bruton's tyrosine kinase (BTK) and Janus kinase 3 (JAK3) inhibitors as a promising strategy for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronically systemic autoimmune disorder, which is related with various cellular signal pathways. Both BTK (Bruton's Tyrosine Kinase) and JAK3 (Janus Kinase 3) play important roles in the pathogenesis of rheumatoid arthritis. Herein, we reported the discovery of dual BTK/JAK3 inhibitors through bioisosterism and computer-aided drug design based on the structure of BTK inhibitor ibrutinib. We reported the discovery of dual BTK/JAK3 inhibitors which are based on the structure of BTK inhibitor ibrutinib via the method of bioisosterism and computer-aided drug design) Most of the target compounds exhibited moderate to strong inhibitory activities against BTK and JAK3. Among them, compound XL-12 stood out as the most promising candidate targeting BTK and JAK3 with potent inhibitory activities (IC50 = 2.0 nM and IC50 = 14.0 nM respectively). In the in vivo studies, compound XL-12 (40 mg/kg) exhibited more potent antiarthritic activity than ibrutinib (10 mg/kg) in adjuvant arthritis (AA) rat model. Furthermore, compound XL-12 (LD50 > 1600 mg/kg) exerted improved safety compared with ibrutinib (LD50 = 750 mg/kg). These results indicated that compound XL-12, the dual BTK/JAK3 inhibitor, might be a potent drug candidate for the treatment of RA.

The economic burden of biologic disease-modifying antirheumatic drugs in rheumatoid arthritis patients in the United States

BACKGROUND

Previous U.S. economic burden estimates for rheumatoid arthritis (RA) varied from $85.6 to 148.1 billion annually. However, these estimates do not reflect comparative amounts spent on RA treatment options in addition to other medical expenditures. Therefore, this study's goal was to comparatively analyze the overall economic burden of U.S. patients treated for RA using conventional disease-modifying antirheumatic drugs (DMARDs) versus TNF alpha biologic DMARDs.

RESEARCH DESIGN AND METHODS

This retrospective observational study analyzed Medical Expenditure Panel Survey Household Component data from 2016 to 2018. Healthcare utilization, total medical expenditures, and out-of-pocket expenditures were compared between RA medication groups.

RESULTS

Three hundred twenty-five adult RA patients experiencing 603 RA-related events, including at least one medical visit, between 2016 and 2018 were identified. Rheumatic arthritis-attributable medical expenditures among patients prescribed DMARDs were $11.4 billion. Average total medical expenditures were significantly higher for the TNF alpha biologic group $26,216.67 (95% CI: $19,502.84-$32,930.5) versus $5,388.52 (95% CI: $2,768.25-$8,008.79) for the conventional DMARD group (p<0.001).

CONCLUSIONS

RA patients receiving TNF alpha biologics experienced significantly higher total medical and out-of-pocket expenditures; however, they have experienced fewer or no occurrences of high-cost drivers of healthcare utilization compared to patients receiving conventional DMARDs.

Safety and Effectiveness of Baricitinib for Rheumatoid Arthritis in Japanese Clinical Practice: 24-Week Results of All-Case Post-Marketing Surveillance

OBJECTIVES

To assess safety and effectiveness of baricitinib treatment for rheumatoid arthritis (RA) in real-world clinical practice.

METHODS

This ongoing all-case post-marketing surveillance study (starting September 2017) includes all patients with RA treated with baricitinib in Japan. Safety and effectiveness (disease activity) were assessed for 24 weeks.

RESULTS

Safety analyses to February 2021 included 4731 patients (initial baricitinib dose: 4 mg/day, n=3058; 2 mg/day, n=1661; other, n=12); 1059 (22.38%) were ≥75 years, and 3362 (71.06%) previously received biologic therapy. Overall observational period was 1863.14 patient-years; 1174 (24.82%) patients discontinued baricitinib before Week 24, mostly for lack of effectiveness (n=478; 10.10%). Adverse events occurred in 1271 (26.87%) patients (serious: 203 [4.29%]; death: 18 [0.38%]). The incidence of herpes zoster, hepatic function disorder, and serious infection was 3.09%, 2.77%, and 1.90%, respectively. Malignancy occurred in 17 patients (0.36%) and major adverse cardiovascular events in seven patients (0.15%). Among patients with effectiveness data, at least 26.57% (Boolean) achieved remission at Week 24.

CONCLUSIONS

This large nationwide surveillance study evaluated the safety and effectiveness of 24 weeks of baricitinib for RA in real-world clinical practice. Continued surveillance of long-term safety is ongoing.

[Recent research on tofacitinib in the treatment of pediatric rheumatic diseases]

Tofacitinib is a Janus kinase inhibitor and can block the Janus kinase-signal transducer and activator of transcription signal transduction pathway and reduce the production and release of a variety of cytokines. It has great potential in the treatment of various rheumatic diseases with a rapid onset of action and can reduce corticosteroid dependence and related adverse events. The therapeutic effect of tofacitinib in adult patients has been confirmed, and it has been increasingly used in pediatric patients in recent years. This article reviews the clinical application of tofacitinib in the treatment of pediatric autoimmune diseases.

Rheumatoid arthritis and myasthenia gravis: a case-based review of the therapeutic options

Introduction

Myasthenia gravis is an autoimmune disease affecting the neuromuscular junction, often associated with other autoimmune diseases, including rheumatoid arthritis. Patients with rheumatoid arthritis present an increased prevalence of myasthenia gravis compared to the general population. While these two diseases share some therapeutic options, such as glucocorticoids, methotrexate, and rituximab, there are no guidelines for treating concomitant disease. We aim to review the available evidence and to discuss the efficacy and safety of the therapeutic options in patients with rheumatoid arthritis associated with myasthenia gravis.

Method

We described three patients with rheumatoid arthritis associated with myasthenia gravis and we performed a systematic review of the associated literature.

Results

A 48-year-old man and two women (48 and 55 years old) with concomitant diagnoses of active rheumatoid arthritis and well-controlled myasthenia gravis are described. They were treated with methotrexate, leflunomide, upadacitinib, and adalimumab. None of them experienced changes in their myasthenic symptoms. We found 9 additional cases from our literature review. Methotrexate, rituximab, upadacitinib, diphenyl sulfone, auranofin, and loxoprofen sodium did not show an impact on the seven patients with previously well-controlled myasthenia. Glucocorticoids, methotrexate, and rituximab proved effective in active myasthenia gravis and arthritis. Conflicting data emerged for Tumor-necrosis factor inhibitors.

Conclusions

Although the available evidence remains scarce, we consider glucocorticoids, methotrexate, and rituximab as safe and effective options. The role of tumor-necrosis factor inhibitors remains uncertain. Eventually, Janus Kinase inhibitors are a novel interesting option for these patients.

Key Points • To date, the only evidence on the treatment of patients with rheumatoid arthritis and concomitant myasthenia gravis derives from case reports. • Based on the review of the available case reports and on the cases we described, we consider glucocorticoids, methotrexate, and rituximab as safe and effective options, while the role of Tumor-necrosis factor inhibitors remains uncertain. • Based on the cases we described, Janus Kinase inhibitors are a novel interesting option for patients with concomitant rheumatoid arthritis and myasthenia gravis.

The role for JAK inhibitors in the treatment of immune-mediated rheumatic and related conditions

JAK inhibitors (JAKIs) are a new class of targeted therapy that have entered clinical practice for the treatment of immune-mediated rheumatic conditions. JAKIs can block the signaling activity of a variety of proinflammatory cytokines and therefore have the potential to mediate therapeutic benefits across a wide range of immune-mediated conditions. Several JAKIs are licensed, and many more are undergoing clinical trials. Here we provide a narrative review of the current and upcoming JAKIs for adult immune-mediated rheumatic and related conditions, with a specific focus on efficacy in rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, psoriasis, and inflammatory bowel disease. The overall safety profile of JAKIs appears largely comparable to that of existing biologic cytokine-targeting agents, particularly, TNF inhibitors, apart from risk of herpes zoster, which is increased for JAKIs. Importantly however, unresolved safety concerns remain, particularly relating to increased venous thromboembolism.

Efficacy of Long-Term Treatment with Once-Daily Baricitinib 2 mg in Patients with Active Rheumatoid Arthritis: Post Hoc Analysis of Two 24-Week, Phase III, Randomized, Controlled Studies and One Long-Term Extension Study

INTRODUCTION

To evaluate long-term efficacy of once-daily baricitinib 2 mg in patients with active rheumatoid arthritis who had an inadequate response (IR) to conventional synthetic disease-modifying antirheumatic drugs (csDMARD) or biologic DMARDs (bDMARD).

METHODS

Data from patients treated with baricitinib 2 mg daily in two 24-week, phase III studies, RA-BUILD (csDMARD-IR; NCT01721057) and RA-BEACON (bDMARD-IR; NCT01721044), and one long-term extension study (RA-BEYOND; NCT01885078), were analyzed (120 weeks). The main outcomes were achievement of low-disease activity (LDA; Simple Disease Activity Index [SDAI] ≤ 11), clinical remission (SDAI ≤ 3.3), Health Assessment Questionnaire Disability Index (HAQ-DI) ≤ 0.5 and improvement from baseline of ≥ 0.22, and safety. Analysis populations included (1) all patients and (2) never-rescued patients. Completer and non-responder imputation (NRI) analyses were conducted on each population.

RESULTS

In RA-BUILD, 684 were randomized (229 to baricitinib 2 mg, 180 of whom completed RA-BUILD and entered RA-BEYOND). In RA-BEACON, 527 were randomized (174 to baricitinib 2 mg, 117 of whom completed RA-BEACON and entered RA-BEYOND). In RA-BUILD-BEYOND, 85.1% (63/74, completer) and 27.5% (63/229, NRI) of csDMARD-IR patients treated with baricitinib 2 mg achieved SDAI LDA; 40.5% (30/74, completer) and 13.1% (30/229, NRI) were in SDAI remission; 62.2% (46/74, completer) and 20.1% (46/229, NRI) had HAQ-DI ≤ 0.5 and 81.1% (60/74, completer); and 26.2% (60/229, NRI) achieved ≥ 0.22 change from baseline at week 120. In RA-BEACON-BEYOND, 86.5% (32/37, completer) and 18.4% (32/174, NRI) of bDMARD-IR patients treated with baricitinib 2 mg achieved SDAI LDA; 24.3% (9/37, completer) and 5.2% (9/174, NRI) were in SDAI remission; 50.0% (19/38, completer) and 10.9% (19/174, NRI) had HAQ-DI ≤ 0.5; and 73.7% (28/38, completer) and 16.1% (28/174, NRI) achieved ≥ 0.22 change from baseline at week 120. Rates of adverse events of special interest were consistent with previous reports.

CONCLUSIONS

Long-term treatment with baricitinib 2 mg demonstrated efficacy for up to 120 weeks and was well tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01721057, NCT01721044, and NCT01885078.

Clinical Aspects of Janus Kinase (JAK) Inhibitors in the Cardiovascular System in Patients with Rheumatoid Arthritis

Janus kinase (JAK) inhibitors, a novel class of targeted synthetic disease-modifying antirheumatic drugs (DMARDs), have shown their safety and efficacy in rheumatoid arthritis (RA) and are being intensively tested in other autoimmune and inflammatory disorders. Targeting several cytokines with a single small compound leads to blocking the physiological response of hundreds of genes, thereby providing the background to stabilize the immune response. Unfortunately, blocking many cytokines with a single drug may also bring some negative consequences. In this review, we focused on the activity of JAK inhibitors in the cardiovascular system of patients with RA. Special emphasis was put on the modification of heart performance, progression of atherosclerosis, lipid profile disturbance, and risk of thromboembolic complications. We also discussed potential pathophysiological mechanisms that may be responsible for such JAK inhibitor-associated side effects.