Leflunomide in the treatment of rheumatoid arthritis

Gold-thiol-beaded albumin nanoparticles for chemo-combined pulsatile plasmonic laser therapy of Rheumatoid arthritis in rat model

Rheumatoid arthritis (RA) is a chronic inflammatory immune disease that causes synovial membrane inflammation and destruction of articular cartilage. Traditionally, methotrexate is a first-line drug for RA treatment. However, its therapeutic benefits are insufficient. Pulsatile Plasmonic laser therapy (PPLT) has recently emerged as a localized and new-generation intervention for RA. This investigation reports the development of nanoGold-thiol-beaded albumin nanoparticles containing Leflunomide (GTBA-NP-L; 54 nm, PDI: 0.15 and entrapment efficiency: >90 %) for treating RA in an arthritic rat model. Upon irradiation of the plasmonic laser, the nanoGold component of GTBA-NP-L showed a local thermogenic effect (1.5 W/cm2 for 5 mins: ∼45 °C). This local thermal effect enhances drug release (1.5-fold) while co-delivering heat and antiarthritic leflunomide at inflamed RA joints site. In vitro and in vivo studies demonstrated significant antiarthritic effects of GTBA-NP-L, accompanied by reduced inflammatory stress in lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells and antigen-induced arthritis (AIA) rat model. GTBA-NP-L treatment significantly reduced the cell viability (49.66 ± 2.46 %), apoptosis (83.36 ± 4.30 %), cell cycle arrest (38.28 ± 2.85 %), ROS and Nitrite stress levels (178.92 ± 19.79 %), and suppressed pro-inflammatory cytokines (TNF-α: 4.81, IL-6: 3.07 and IL-1β: 4.46-fold). In the arthritic rat, GTBA-NP-L treatment reduced inflammation, paw edema (1.89-fold), pain perception (45-48 %), and impacted hematological (Hb and RBCs: 12-15 %, WBCs: 30-32 %), serological (RF: 50-54 %, CRP: 40-47 %), and radiological parameters. Conclusively, the study demonstrates that the chemo-combined Pulsatile Plasmonic laser therapy showed superior efficacy as compared to individual treatments, suggesting GTBA-NP-L as a potential therapeutic candidate for rheumatoid arthritis.

The Selective Oral Immunomodulator Vidofludimus in Patients with Active Rheumatoid Arthritis: Safety Results from the COMPONENT Study

INTRODUCTION

The dihydroorotate dehydrogenase (DHODH) inhibitors leflunomide and teriflunomide are immunomodulatory agents approved to treat rheumatoid arthritis (RA) and multiple sclerosis, respectively, and are actively being investigated as therapeutic agents for other immune-related diseases; however, both structurally related compounds have a number of potentially serious adverse effects. Vidofludimus, a new selective second-generation DHODH inhibitor, is chemically distinct from leflunomide/teriflunomide and appears to exhibit a distinct safety profile.

OBJECTIVE

The aim of the COMPONENT study was to assess the efficacy, safety, and pharmacokinetics of vidofludimus in the treatment of patients with active RA on a background therapy of methotrexate. This report focuses solely on the safety results of the COMPONENT trial.

METHODS

Patients received once-daily oral vidofludimus (N = 122) or placebo (N = 119) along with their standard of care methotrexate treatment for 13 weeks. Efficacy endpoints were assessed. Safety parameters were monitored throughout treatment and at follow-up. Plasma concentrations of vidofludimus were measured.

RESULTS

The primary efficacy endpoint, American College of Rheumatology 20 (ACR₂₀) responder rate at 13 weeks, demonstrated numerical superiority in the treatment group compared with placebo; however, it did not reach statistical significance. Nonetheless, the COMPONENT study yielded important safety and pharmacokinetic data that could provide important information regarding the use of vidofludimus in other clinical trials, not only for RA but also for other autoimmune diseases. A safety profile for vidofludimus similar to placebo was obtained in this RA patient population. This includes similar rates of the adverse events of diarrhea, alopecia, neutropenia, and elevated liver enzymes, all of which are known drug-related adverse events reported for leflunomide and teriflunomide. A potential pharmacokinetic interaction between vidofludimus and methotrexate was observed.

CONCLUSIONS

Vidofludimus demonstrated a positive safety profile, making it a promising candidate for the treatment of a variety of immune-related diseases.

TRIAL REGISTRATIONS

ClinicalTrials.gov identifier: NCT01010581.

Mitochondrial fusion exploits a therapeutic vulnerability of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) requires mitochondrial oxidative phosphorylation (OXPHOS) to fuel its growth, however, broadly inhibiting this pathway might also disrupt essential mitochondrial functions in normal tissues. PDAC cells exhibit abnormally fragmented mitochondria that are essential to its oncogenicity, but it was unclear if this mitochondrial feature was a valid therapeutic target. Here, we present evidence that normalizing the fragmented mitochondria of pancreatic cancer via the process of mitochondrial fusion reduces OXPHOS, which correlates with suppressed tumor growth and improved survival in preclinical models. Mitochondrial fusion was achieved by genetic or pharmacologic inhibition of dynamin related protein-1 (Drp1) or through overexpression of mitofusin-2 (Mfn2). Notably, we found that oral leflunomide, an FDA-approved arthritis drug, promoted a two-fold increase in Mfn2 expression in tumors and was repurposed as a chemotherapeutic agent, improving the median survival of mice with spontaneous tumors by 50% compared to vehicle. We found that the chief tumor suppressive mechanism of mitochondrial fusion was enhanced mitophagy, which proportionally reduced mitochondrial mass and ATP production. These data suggest that mitochondrial fusion is a specific and druggable regulator of pancreatic cancer growth that could be rapidly translated to the clinic.

Mitochondrial dysfunction induced by leflunomide and its active metabolite

Leflunomide, an anti-inflammatory drug used for the treatment of rheumatoid arthritis, has been marked with a black box warning regarding an increased risk of liver injury. The active metabolite of leflunomide, A771726, which also carries a boxed warning about potential hepatotoxicity, has been marketed as teriflunomide for the treatment of relapsing multiple sclerosis. Thus far, however, the mechanism of liver injury associated with the two drugs has remained elusive. In this study, cytotoxicity assays showed that ATP depletion and subsequent LDH release were induced in a time- and concentration-dependent manner by leflunomide in HepG2 cells, and to a lesser extent, by A77 1726. The decline of cellular ATP levels caused by leflunomide was dramatically exacerbated when galactose was substituted for glucose as the sugar source, indicating a potential mitochondrial liability of leflunomide. By measuring the activities of immuno-captured mitochondrial oxidative phosphorylation (OXPHOS) complexes, we found that leflunomide and A77 1726 preferentially targeted complex V (F₁F_O ATP synthase), with IC₅₀ values of 35.0 and 63.7 μM, respectively. Bongkrekic acid, a mitochondrial permeability transition pore blocker that targets adenine nucleotide translocase, profoundly attenuated mitochondrial membrane depolarization, ATP depletion, and LDH leakage induced by leflunomide and A77 1726. Substantial alterations of mitochondrial function at the transcript level were observed in leflunomide-treated HepG2 cells, whereas the effects of A77 1726 on the cellular transcriptome were much less profound. Our results suggest that mitochondrial dysfunction may be implicated in the hepatotoxicity associated with leflunomide and A77 1726, with the former exhibiting higher toxicity potency.

Effect of ABCG2 genotypes on the pharmacokinetics of A771726, an active metabolite of prodrug leflunomide, and association of A771726 exposure with serum uric acid level

OBJECTIVE

It has been reported that leflunomide and its active metabolite, A771726, are substrates of the ABCG2 (BCRP) transporter in vitro. Recent genome-wide association studies have shown that ABCG2 transporter modulates serum uric acid (UA) levels. We explored the role of ABCG2 genotypes in the pharmacokinetics of A771726 and the relationship between serum UA levels and pharmacokinetics of A771726 in healthy participants.

METHODS

Twenty-four healthy individuals were recruited and genotyped for ABCG2. After administration of a single dose of 20 mg leflunomide, plasma concentrations of A771726 were measured. Serum UA levels were measured just before medication, and ABCG2 c.421C>A and c.34G> A polymorphism were genotyped.

RESULTS

ABCG2 c.421C>A but not c.34G>A substantially influenced the pharmacokinetics of A771726. A771726 C(max) was 30% higher, area under the concentration-time curve (AUC) 83% larger, and oral clearance (CL/F) 41% lower in c.421C>A carriers than in noncarriers. Serum UA levels were also higher in carriers than in noncarriers and exhibited a strong and positive correlation with A771726 AUC (Spearman r = 0.6746, P = 0.0003), but a negative correlation was observed with A771726 CL/F (Spearman r = -0.6616, P = 0.0004).

CONCLUSION

ABCG2 c.421C>A but not c.34G>A polymorphism appears to be a major determinant of interindividual variability in A771726 disposition. Additionally, serum UA levels exhibited a strong correlation with exposure to A771726.

Effect of ABCG2 genotypes on the pharmacokinetics of A771726, an active metabolite of prodrug leflunomide, and association of A771726 exposure with serum uric acid level

OBJECTIVE

It has been reported that leflunomide and its active metabolite, A771726, are substrates of the ABCG2 (BCRP) transporter in vitro. Recent genome-wide association studies have shown that ABCG2 transporter modulates serum uric acid (UA) levels. We explored the role of ABCG2 genotypes in the pharmacokinetics of A771726 and the relationship between serum UA levels and pharmacokinetics of A771726 in healthy participants.

METHODS

Twenty-four healthy individuals were recruited and genotyped for ABCG2. After administration of a single dose of 20 mg leflunomide, plasma concentrations of A771726 were measured. Serum UA levels were measured just before medication, and ABCG2 c.421C>A and c.34G> A polymorphism were genotyped.

RESULTS

ABCG2 c.421C>A but not c.34G>A substantially influenced the pharmacokinetics of A771726. A771726 C(max) was 30% higher, area under the concentration-time curve (AUC) 83% larger, and oral clearance (CL/F) 41% lower in c.421C>A carriers than in noncarriers. Serum UA levels were also higher in carriers than in noncarriers and exhibited a strong and positive correlation with A771726 AUC (Spearman r = 0.6746, P = 0.0003), but a negative correlation was observed with A771726 CL/F (Spearman r = -0.6616, P = 0.0004).

CONCLUSION

ABCG2 c.421C>A but not c.34G>A polymorphism appears to be a major determinant of interindividual variability in A771726 disposition. Additionally, serum UA levels exhibited a strong correlation with exposure to A771726.

Investigation of the influence of CYP1A2 and CYP2C19 genetic polymorphism on 2-Cyano-3-hydroxy-N-[4-(trifluoromethyl)phenyl]-2-butenamide (A77 1726) pharmacokinetics in leflunomide-treated patients with rheumatoid arthritis

Leflunomide is a disease-modifying antirheumatic drug used for the treatment of rheumatoid arthritis (RA). Cytochromes P450, mainly CYP1A2 and CYP2C19, may be involved in the transformation of leflunomide to leflunomide metabolite (A77 1726, 2-cyano-3-hydroxy-N-[4-(trifluoromethyl)phenyl]-2-butenamide). The aim of this study was to investigate whether genetic polymorphisms in CYP1A2 and CYP2C19 influence leflunomide pharmacokinetics, treatment response, and the occurrence of adverse drug reactions (ADRs). The study included 67 patients with RA and 4 patients with polyarthritis resembling RA and psoriasis treated with leflunomide. A77 1726 steady-state plasma concentrations were determined by validated high-performance liquid chromatography with UV detection. A population pharmacokinetic model was developed to estimate the oral clearance (CL/F) and volume of distribution (V/F). A genotyping approach was used to determine C-163A, C-729T, and T-739G in the CYP1A2 gene as well as single nucleotide polymorphisms that characterize CYP2C19*2, *3, *4, and *17 alleles. A large interindividual variability in trough A77 1726 steady-state plasma concentrations was observed (from 1.9 to 156.9 mg/l). A77 1726 CL/F was 71% higher in carriers of the CYP2C19*2 allele compared with noncarriers. The A77 1726 average steady-state plasma concentration was associated with the treatment response. Patients with a greater decrease in C-reactive protein (CRP) had higher average steady-state plasma A77 1726 concentrations: 49.7 +/- 39.0 mg/l in patients with DeltaCRP of more than 8.5 mg/l compared with 24.8 +/- 13.7 mg/l in patients with DeltaCRP of Collapse

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Aniline Compounds/pharmacokinetics
• Aniline Compounds/therapeutic use
• Antirheumatic Agents/pharmacokinetics
• Antirheumatic Agents/therapeutic use
• Arthritis, Rheumatoid/blood
• Arthritis, Rheumatoid/drug therapy
• Arthritis, Rheumatoid/metabolism
• Aryl Hydrocarbon Hydroxylases/genetics
• Aryl Hydrocarbon Hydroxylases/physiology
• Crotonates
• Cytochrome P-450 CYP1A2/genetics
• Cytochrome P-450 CYP1A2/physiology
• Cytochrome P-450 CYP2C19
• Female
• Humans
• Hydroxybutyrates/pharmacokinetics
• Hydroxybutyrates/therapeutic use
• Isoxazoles/pharmacokinetics
• Isoxazoles/therapeutic use
• Leflunomide
• Male
• Middle Aged
• Nitriles
• Polymorphism, Genetic
• Synovial Membrane
• Toluidines

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Affiliation(s)

Petra Bohanec Grabar Faculty of Medicine, Institute of Biochemistry, University of Ljubljana, 1000 Ljubljana, Slovenia
Iztok Grabnar
Blaz Rozman
Dusan Logar
Matija Tomsic
Dasa Suput
Tina Trdan
Lucija Peterlin Masic
Ales Mrhar
Vita Dolzan

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Genetic polymorphism of CYP1A2 and the toxicity of leflunomide treatment in rheumatoid arthritis patients

OBJECTIVE

Leflunomide is a disease-modifying antirheumatic drug used for treating rheumatoid arthritis (RA). In vitro studies demonstrated that cytochromes P450 (CYPs), mainly CYP1A2 and CYP2C19, might be involved in leflunomide activation. The aim of our study was to investigate whether genetic polymorphisms of CYP1A2, CYP2C19, and CYP2C9 influence leflunomide toxicity.

METHODS

A genotyping approach was used to determine CYP1A2*1F, CYP2C19*2, CYP2C19*17, CYP2C9*2, and CYP2C9*3 alleles in 105 RA patients.

RESULTS

Leflunomide treatment was well tolerated by 62 patients, whereas 43 patients discontinued the treatment within the first year due to toxicity. Patients with CYP1A2*1F CC genotype had a 9.7-fold higher risk for overall leflunomide-induced toxicity than did the carriers of CYP1A2*1F A allele [P = 0.002, odds ratio = 9.708, 95% confidence interval = 2.276-41.403]. No significant association between the CYP2C19 and CYP2C9 genotypes and the leflunomide toxicity was observed.

CONCLUSION

Our results suggest that the CYP1A2*1F allele may be associated with leflunomide toxicity in RA patients.