Reappraisal of the clinical use of leflunomide in rheumatoid arthritis and psoriatic arthritis

Prolonged, staged, and self-regulated methotrexate release coupled with ROS scavenging in an injectable hydrogel for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) remains a formidable healthcare challenge due to its chronic nature and potential for irreversible joint damage. Methotrexate (MTX) is a cornerstone treatment for RA but carries significant risks of adverse effects with repeated administration, necessitating the exploration of alternative delivery methods. Injectable hydrogels loaded with MTX for intra-articular injection present a promising solution, allowing sustained drug release directly into affected joints. However, current hydrogel systems often lack extended therapeutic periods and the ability to self-regulate drug release according to disease state. Furthermore, RA is associated with excessive production of reactive oxygen species (ROS), which exacerbates inflammation and joint damage. Herein, we developed an advanced injectable hydrogel (MPDANPs/MTX HA-PEG gel) based on "bio-orthogonal chemistry", combining hyaluronic acid and polyethylene glycol (PEG) matrices co-loaded with mesoporous polydopamine nanoparticles (MPDANPs) and MTX. MPDANPs/MTX HA-PEG gel achieved prolonged, staged, and self-regulated MTX release, coupled with ROS scavenging capabilities for enhanced therapeutic efficacy. Due to its optimized MTX release behavior and significant ROS scavenging function, MPDANPs/MTX HA-PEG gel exhibited potent anti-inflammatory effects in collagen-induced arthritis (CIA) rats following a single intra-articular injection. Our findings highlight the potential of MPDANPs/MTX HA-PEG gel as a highly effective treatment strategy for RA, offering a promising avenue for improving patient outcomes.

Leflunomide-induced cardiac injury in adult male mice and bioinformatic approach identifying Nrf2/NF-κb signaling interplay

Leflunomide (LFND) is an immunosuppressive and immunomodulatory disease-modifying antirheumatic drug (DMARD) that was approved for treating rheumatoid arthritis. LFND-induced cardiotoxicity was not fully investigated since its approval. We investigated the cardiac injury in male mice and identified the role of nuclear factor erythroid 2-related factor 2/nuclear factor-κ B (Nrf2/NF-κB) signaling. Male albino mice were assigned into five groups as control, vehicle, and LFND (2.5, 5, and 10 mg/kg). We investigated cardiac enzymes, histopathology, and the mRNA expression of Nrf2, NF-κB, BAX, and tumor necrosis factor-α (TNF-α). The bioinformatic study identified the interaction between LFND and Nrf2/NF-κB signaling; this was confirmed by amelioration in mRNA expression (0.5- to 0.34-fold decrease in Nrf2 and 2.6- to 4.61-fold increases in NF-κB genes) and increased (1.76- and 2.625-fold) serum creatine kinase (CK) and 1.38- and 2.33-fold increases in creatine kinase-MB (CK-MB). Histopathological results confirmed the dose-dependent effects of LFND on cardiac muscle structure in the form of cytoplasmic, nuclear, and vascular changes in addition to increased collagen deposits and apoptosis which were increased compared to controls especially with LFND 10 mg/kg. The current study elicits the dose-dependent cardiac injury induced by LFND administration and highlights, for the first time, dysregulation in Nrf2/NF-κB signaling.

Side-by-side comparison of published small molecule inhibitors against thapsigargin-induced store-operated Ca2+ entry in HEK293 cells

Calcium (Ca2+) is a key second messenger in eukaryotes, with store-operated Ca2+ entry (SOCE) being the main source of Ca2+ influx into non-excitable cells. ORAI1 is a highly Ca2+-selective plasma membrane channel that encodes SOCE. It is ubiquitously expressed in mammals and has been implicated in numerous diseases, including cardiovascular disease and cancer. A number of small molecules have been identified as inhibitors of SOCE with a variety of potential therapeutic uses proposed and validated in vitro and in vivo. These encompass both nonselective Ca2+ channel inhibitors and targeted selective inhibitors of SOCE. Inhibition of SOCE can be quantified both directly and indirectly with a variety of assay setups, making an accurate comparison of the activity of different SOCE inhibitors challenging. We have used a fluorescence based Ca2+ addback assay in native HEK293 cells to generate dose-response data for many published SOCE inhibitors. We were able to directly compare potency. Most compounds were validated with only minor and expected variations in potency, but some were not. This could be due to differences in assay setup relating to the mechanism of action of the inhibitors and highlights the value of a singular approach to compare these compounds, as well as the general need for biorthogonal validation of novel bioactive compounds. The compounds observed to be the most potent against SOCE in our study were: 7-azaindole 14d (12), JPIII (17), Synta-66 (6), Pyr 3 (5), GSK5503A (8), CM4620 (14) and RO2959 (7). These represent the most promising candidates for future development of SOCE inhibitors for therapeutic use.

Efficacy of leflunomide in the treatment of palindromic rheumatism

OBJECTIVE

The goal of treatment in palindromic rheumatism (PR) is to control the attacks and prevent disease evolution to chronic arthritis. Conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) including antimalarial and methotrexate cannot control attacks in all patients.

METHODS

In this retrospective study, we assessed the efficacy of leflunomide in patients with PR who had an inadequate response to DMARDs. In this study, patients who had a diagnosis of PR and were treated with leflunomide because of active disease despite treatment with csDMARDs for at least 6 months were included. Remission was defined as no attacks for 3 months and prednisolone dose ≤5 mg/d. Leflunomide treatment failure was defined as failure to achieve remission, the need to add other DMARDs for controlling attacks and disease progression to chronic arthritis during treatment with leflunomide.

RESULTS

Ten cases with active disease despite treatment with hydroxychloroquine and methotrexate and low-dose prednisolone treated with leflunomide were included in the study. During the 12.6 ± 7.5 months of treatment with leflunomide, the frequency of attacks significantly decreased. Complete and partial remission were achieved in 90% of patients.

CONCLUSION

Our results indicate that leflunomide controls PR attacks and it might be a new option for patients with PR.

Updated therapies for the management of Psoriatic Arthritis

Psoriatic arthritis (PsA) is a large volume of our clinical practice and its management can be challenging. Traditional DMARDs have been used over last six decades and observational studies have substantiated an effective use of many of these drugs. However, in last two decades use of anti-TNF agents has brought a new dimension in treatment of PsA and in many other autoimmune diseases. Regulatory role of the Th17 cells and its cytokines in the pathogenesis of PsA has successfully paved the foundations of anti-IL antibody based therapies in PsA. Newer therapies targeting the IL-23/IL-17 cytokines and its signaling proteins are now in development and bringing new promises for management of PsA. Herein, we provide an overview of the landscape of drug therapies, including IL-17, IL-12/23, IL-23 inhibitors, and janus kinase (JAK) inhibitors, as well as those in development, such as RORγt inhibitors, anti-NGF agents, mTOR inhibitors and T cell ion-channel blockers.

Effectiveness of maintenance therapy with methotrexate compared with leflunomide for patients with RA having achieved disease control with both these drugs: results of a predefined sub-analysis of CareRA, a pragmatic RCT

INTRODUCTION/OBJECTIVES

Evidence regarding the effectiveness of step-down strategies for patients with well-controlled early rheumatoid arthritis (RA) on a combination of methotrexate (MTX) and leflunomide (LEF) is currently lacking.

METHOD

The Care in early RA (CareRA) trial is a 2-year randomized pragmatic trial comparing different remission induction strategies in treatment-naïve patients with early RA. For this study, we included participants who achieved low disease activity (LDA) (DAS28-CRP ≤ 3.2) between 40 to 52 weeks after starting a combination of MTX, LEF, and a prednisone bridging scheme followed by a treat-to-target approach. Patients were re-randomized to a maintenance monotherapy of either MTX 15 mg weekly or LEF 20 mg daily. Remission rates (DAS28-CRP < 2.6) at week 65 counted from re-randomization, as well as drug retention rates and safety during the 65 weeks of follow-up, were compared.

RESULTS

Remission rates at week 65 after re-randomization were numerically higher in patients assigned to MTX (29/32; 90.6%) compared with patients on LEF (20/27; 74.1%) (p = 0.091). Of patients assigned to MTX, 60% (19/32) maintained LDA while continuing their assigned monotherapy until week 65 after re-randomization versus 44% (12/27) in the LEF group (p = 0.25). Patients re-randomized to MTX were more frequently in LDA measured by Clinical Disease Activity Index (32/32; 100%) compared with patients on LEF (23/27; 85.2%) (p = 0.024) 65 weeks after re-randomization. According to survival analyses, the probability of maintaining MTX monotherapy was higher (81%) than maintaining LEF monotherapy (55%) for 65 weeks (p = 0.025) after re-randomization. Safety analysis after re-randomization showed a good safety profile in both groups.

CONCLUSION

MTX monotherapy seems not significantly more efficacious as maintenance treatment compared with LEF monotherapy but has a better retention rate and is well tolerated in early RA patients in LDA after combination therapy with both.

TRIAL REGISTRATION

Clinical trials NCT01172639 Key points • Methotrexate should be preferred over leflunomide as maintenance therapy after an initial intensive combination of these two drugs. • Methotrexate shows a better retention rate to leflunomide as maintenance therapy in this context.

Elshabacy F, Tayel M, Elwakd M, Mortada M, H.Elshahaly M, Mohannad N, A. Kader R, Hassan SZ, A. Elbakry S, Refaat S. Clinical Efficacy and Safety of Leflunomide in Egyptian Patients with Active Rheumatoid Arthritis: CLEAR Interim Results

Background:

Worldwide, leflunomide is a commonly used Disease-Modifying Anti-Rheumatic Drugs (DMARDs). It can be used as a monotherapy or in combination with other DMARDs to inhibit the production of inflammatory cells and accordingly reduce inflammation.

Objectives:

CLEAR is a multi-centric study that aims to assess the clinical efficacy and safety of leflunomide as first-line and/or add-on therapy to other DMARDs with or without steroids in Egyptian patients with active Rheumatoid Arthritis (RA).

Methods:

Egyptian patients with active RA for whom leflunomide was prescribed at physicians’ discretion were observed for 12 weeks. Clinical Disease Activity Index (CDAI) score, and Health Assessment Questionnaire Disability Index (HAQ-DI) score were acquired thrice during this period. This study was registered on clinicaltrials.gov (NCT03599986).

Results:

Interim analysis of the data collected from 337 patients (in 21 centers) showed a statistically significant decrease in the mean total CDAI score throughout the first 12 weeks of treatment (p<0.001); as the mean ±SD score decreased from 36.60 ±14.90 at baseline to reach 16.16 ±9.84 at week 12 (% reduction: 61.16 ±14.36). A statistically significant decrease (p<0.001) was also observed in HAQ-DI, as the mean ±SD score decreased from 1.46 ±0.69 at baseline to reach 0.67 ±0.54 at week 12 (% reduction: 56.11 ±27.59).

Conclusion:

Results of the interim analysis suggest that treatment of Egyptian patients with active RA with leflunomide (as first-line and/or add-on therapy to other DMARDs with or without steroids) for 12 weeks may be effective in terms of CDAI score and HAQ-DI score reduction and may offer an alternative for patients who experienced resistance, inadequate response or intolerance to other DMARDs.

Evaluation of WO2013076170: the use of a dihydroorotate dehydrogenase inhibitor for the treatment of psoriasis

Inhibition of dihydroorotate dehydrogenase (DHODH) modulates pyrimidine biosynthesis. Effective inhibitors are immunomodulatory drugs clinically useful in the treatment of diseases such as rheumatoid arthritis, psoriatic arthritis and multiple sclerosis. There is limited evidence of their potential utility in treating psoriasis. This patent application claims topical formulations of the non-hepatotoxic DHODH inhibitor 2-[(3,5-difluoro-3'-methoxy-1,1'-biphenyl-4-yl)amino]nicotinic acid for use in the treatment of psoriasis. This inhibitor had previously been claimed to be useful in treating various autoimmune disease.

Randomized trial of oral teriflunomide for relapsing multiple sclerosis

BACKGROUND

Teriflunomide is a new oral disease-modifying therapy for relapsing forms of multiple sclerosis.

METHODS

We concluded a randomized trial involving 1088 patients with multiple sclerosis, 18 to 55 years of age, with a score of 0 to 5.5 on the Expanded Disability Status Scale and at least one relapse in the previous year or at least two relapses in the previous 2 years. Patients were randomly assigned (in a 1:1:1 ratio) to placebo, 7 mg of teriflunomide, or 14 mg of teriflunomide once daily for 108 weeks. The primary end point was the annualized relapse rate, and the key secondary end point was confirmed progression of disability for at least 12 weeks.

RESULTS

Teriflunomide reduced the annualized relapse rate (0.54 for placebo vs. 0.37 for teriflunomide at either 7 or 14 mg), with relative risk reductions of 31.2% and 31.5%, respectively (P<0.001 for both comparisons with placebo). The proportion of patients with confirmed disability progression was 27.3% with placebo, 21.7% with teriflunomide at 7 mg (P=0.08), and 20.2% with teriflunomide at 14 mg (P=0.03). Both teriflunomide doses were superior to placebo on a range of end points measured by magnetic resonance imaging (MRI). Diarrhea, nausea, and hair thinning were more common with teriflunomide than with placebo. The incidence of elevated alanine aminotransferase levels (≥1 times the upper limit of the normal range) was higher with teriflunomide at 7 mg and 14 mg (54.0% and 57.3%, respectively) than with placebo (35.9%); the incidence of levels that were at least 3 times the upper limit of the normal range was similar in the lower- and higher-dose teriflunomide groups and the placebo group (6.3%, 6.7%, and 6.7%, respectively). Serious infections were reported in 1.6%, 2.5%, and 2.2% of patients in the three groups, respectively. No deaths occurred.

CONCLUSIONS

Teriflunomide significantly reduced relapse rates, disability progression (at the higher dose), and MRI evidence of disease activity, as compared with placebo. (Funded by Sanofi-Aventis; TEMSO ClinicalTrials.gov number, NCT00134563.).