Project description:A semiphysiologically based pharmacokinetic (semi-PBPK) population model was used to evaluate the influence of enterohepatic recycling and protein binding, as well as the effect of genetic variability in CYP1A2, CYP2C19, and ABCG2, on the large interindividual variability of teriflunomide (active metabolite) concentrations following leflunomide administration in rheumatoid arthritis (RA) patients. The model was developed with total and free teriflunomide concentrations determined in RA patients taking leflunomide, as well as mean teriflunomide concentrations following the administration of leflunomide or teriflunomide extracted from the literature. Once developed, the 15-compartment model was able to predict total and free teriflunomide concentrations and was used to screen demographic and genotypic covariates, of which only fat-free mass and liver function (ALT) improved prediction. This approach effectively evaluated the effects of multiple covariates on both total and free teriflunomide concentrations, which have only been explored previously through simplistic one-compartment models for total teriflunomide.
Project description:Rational selection of disease modifying anti-rheumatic drugs in the treatment of rheumatoid arthritis (RA) has many potential advantages, including rapid disease control, reduced long-term disability and reduced overall cost to the healthcare system. Inter-individual genetic differences are particularly attractive as markers to predict efficacy and toxicity, as they can be determined rapidly prior to drug selection. The aims of this study, therefore, were to investigate the association between differences in genes associated with the metabolism, clearance and efficacy of leflunomide with its cessation in a group of rheumatoid arthritis patients who were treated with an intensive contemporary, treat-to-target approach.This retrospective cohort study identified all individuals who received leflunomide and were enrolled in the Early Arthritis inception cohort at the Royal Adelaide Hospital between 2001 and July 2011. Inclusion criteria were age (>18) and a diagnosis of rheumatoid arthritis. Patients were excluded if a DNA sample was not available, if they withdrew from the cohort or if clinical data were insufficient. Subjects were followed for 12 months or until either another disease modifying antirheumatic drug was added or leflunomide was ceased. The following single nucleotide polymorphisms (SNPs) were determined: CYP2C19*2 (rs4244285), CYP2C19*17 (rs12248560), ABCG2 421C>A (rs2231142), CYP1A2*1F (rs762551) and DHODH 19C>A (rs3213422). The effects of variables on cessation were assessed with Cox Proportional Hazard models.Thirty-three of 78 (42.3%) patients ceased leflunomide due to side effects. A linear trend between cytochrome P450 2C19 (CYP2C19) phenotype and leflunomide cessation was observed, with poor and intermediate metabolizers ceasing more frequently (adjusted Hazard Ratio = 0.432 for each incremental change in phenotype, 95% CI 0.237 to 0.790, P = 0.006). Previously observed associations between cytochrome P450 1A2 (CYP1A2) and dihydro-orotate dehydrogenase (DHODH) genotype and toxicity were not apparent, but there was a trend for ATP-binding cassette sub-family G member 2 (ABCG2) genotype to be associated with cessation due to diarrhea.CYP2C19 phenotype was associated with cessation due to toxicity, and since CYP2C19 intermediate and poor metabolizers have lower teriflunomide concentrations, it is likely that they have a particularly poor risk:benefit ratio when using this drug.
Project description:IntroductionWe identified silent liver fibrosis in patients with rheumatoid arthritis (RA) using transient elastography, and investigated medication that correlated with abnormal liver stiffness measurement (LSM) values.MethodsWe consecutively enrolled 105 patients with RA taking methotrexate over 24 weeks with normal liver functions and no history of underlying chronic liver disease. Blood tests were performed, and body mass index and metabolic syndrome were assessed. We checked LSM values, and adopted 5.3 kPa as the cutoff for abnormal LSM values. The cumulative doses of medications including methotrexate, leflunomide, sulfasalazine, hydroxychloroquine, prednisolone, meloxicam, and celecoxib were calculated.ResultsThe median age of patients (20 men and 85 women) was 52.4 years. The median LSM value was 4.7 kPa and 24 (22.9%) patients had abnormal LSM values. Gamma-glutamyltranspeptidase levels and the cumulative doses of leflunomide and prednisolone significantly correlated with LSM values (P<0.05). The cumulative dose of leflunomide, but not methotrexate, was significantly higher in patients with abnormal LSM values than that in patients with normal LSM values (P = 0.008). When RA patients receiving leflunomide plus methotrexate were classified into two groups according to the optimal cutoff cumulative dose of leflunomide (19,170 mg), abnormal LSM values were more frequently identified in patients with high cumulative dose of leflunomide (odds ratio, 12.750; P<0.001).ConclusionsThe cumulative dose of leflunomide was the only independent predictor of abnormal LSM values in patients with RA who had received methotrexate for more than six months.
Project description:In agreement with EULAR recommendations, a DMARD in combination with a biotherapy is the reference treatment because of the superior long-term clinical and radiographic outcomes. Methotrexate (MTX) is the cornerstone of combination therapy but is in some cases contra-indicated or poorly tolerated. This observational study aimed to compare the effectiveness and safety of TCZ in combination with either MTX or leflunomide (LEF) in the treatment of patients with active rheumatoid arthritis (RA) and an inadequate response to one or more DMARDs and/or biological agents in a real-world setting.We performed an ambispective review of 91 patients with active RA who were routinely treated with TCZ plus MTX or LEF. A comparative study between the two combinations of treatment was performed at 6 months of follow-up considering 3 outcomes: improvement of RA disease activity, evolution of functional disability, and tolerability and side effect profile.Of the 91 patients, 62 received TCZ with MTX and 29 received TCZ with LEF. Eighty-one patients were followed for 6 months, and the remaining 10 patients discontinued treatment due to serious adverse events. At baseline, there were no significant differences between the groups in terms of the main clinical and laboratory data or in the number of previous DMARDs and biological agents used. At 6 months, there were no significant differences between the combinations in terms of disease activity and functional disability. Serious adverse events occurred in 11% and 10% of the patients treated in combination with MTX and LEF, respectively.Our preliminary data support the argument that LEF is an effective and safe (equivalent) alternative to MTX for combination treatment with TCZ.
Project description:Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by progressive bone erosion. Leflunomide is originally developed to suppress inflammation via its metabolite A77 1726 to attenuate bone erosion. However, distinctive responsiveness to Leflunomide is observed among RA individuals. Here we show that Leflunomide exerts immunosuppression but limited efficacy in RA individuals distinguished by higher serum C-reactive protein (CRPHigher, CRPH), whereas the others with satisfactory responsiveness to Leflunomide show lower CRP (CRPLower, CRPL). CRP inhibition decreases bone erosion in arthritic rats. Besides the immunomodulation via A77 1726, Leflunomide itself induces AHR-ARNT interaction to inhibit hepatic CRP production and attenuate bone erosion in CRPL arthritic rats. Nevertheless, high CRP in CRPH rats upregulates HIF1?, which competes with AHR for ARNT association and interferes Leflunomide-AHR-CRP signaling. Hepatocyte-specific HIF1? deletion or a HIF1? inhibitor Acriflavine re-activates Leflunomide-AHR-CRP signaling to inhibit bone erosion. This study presents a precision medicine-based therapeutic strategy for RA.
Project description:ObjectiveTo investigate the efficacy and safety of rituximab + LEF in patients with RA.MethodsIn this investigator-initiated, randomized, double-blind, placebo-controlled phase 3 trial, patients with an inadequate response to LEF who had failed one or more DMARD were randomly assigned 2:1 to i.v. rituximab 1000 mg or placebo on day 1 and 15 plus ongoing oral LEF. The primary efficacy outcome was the difference between ≥50% improvement in ACR criteria (ACR50 response) rates at week 24 (P ≤ 0.025). Secondary endpoints included ACR20/70 responses, ACR50 responses at earlier timepoints and adverse event (AE) rates. The planned sample size was not achieved due to events beyond the investigators' control.ResultsBetween 13 August 2010 and 28 January 2015, 140 patients received rituximab (n = 93) or placebo (n = 47) plus ongoing LEF. Rituximab + LEF resulted in an increase in the ACR50 response rate that was significant at week 16 (32 vs 15%; P = 0.020), but not week 24 (27 vs 15%; P = 0.081), the primary endpoint. Significant differences favouring the rituximab + LEF arm were observed in some secondary endpoints, including ACR20 rates from weeks 12 to 24. The rituximab and placebo arms had similar AE rates (71 vs 70%), but the rituximab arm had a higher rate of serious AEs (SAEs 20 vs 2%), primarily infections and musculoskeletal disorders.ConclusionThe primary endpoint was not reached, but rituximab + LEF demonstrated clinical benefits vs LEF in secondary endpoints. Although generally well tolerated, the combination was associated with additional SAEs and requires monitoring.Trial registrationEudraCT: 2009-015950-39; ClinicalTrials.gov: NCT01244958.
Project description:ObjectiveAlthough Leflunomide (LEF) is effective in treating rheumatoid arthritis (RA), there are still a considerable number of patients who respond poorly to LEF treatment. Till date, few LEF efficacy-predicting biomarkers have been identified. Herein, we explored and developed a DNA methylation-based predictive model for LEF-treated RA patient prognosis.MethodsTwo hundred forty-five RA patients were prospectively enrolled from four participating study centers. A whole-genome DNA methylation profiling was conducted to identify LEF-related response signatures via comparison of 40 samples using Illumina 850k methylation arrays. Furthermore, differentially methylated positions (DMPs) were validated in the 245 RA patients using a targeted bisulfite sequencing assay. Lastly, prognostic models were developed, which included clinical characteristics and DMPs scores, for the prediction of LEF treatment response using machine learning algorithms.ResultsWe recognized a seven-DMP signature consisting of cg17330251, cg19814518, cg20124410, cg21109666, cg22572476, cg23403192, and cg24432675, which was effective in predicting RA patient's LEF response status. In the five machine learning algorithms, the support vector machine (SVM) algorithm provided the best predictive model, with the largest discriminative ability, accuracy, and stability. Lastly, the AUC of the complex model(the 7-DMP scores with the lymphocyte and the diagnostic age) was higher than the simple model (the seven-DMP signature, AUC:0.74 vs 0.73 in the test set).ConclusionIn conclusion, we constructed a prognostic model integrating a 7-DMP scores with the clinical patient profile to predict responses to LEF treatment. Our model will be able to effectively guide clinicians in determining whether a patient is LEF treatment sensitive or not.
Project description:To identify susceptibility genes concerning copy number variations (CNVs) in rheumatoid arthritis (RA), a case-control genome-wide CNV analyses was carried out by Roche Nimblegen array-based CGH. In this study, 15 RA patients and 1 control (Non-RA) were included.
Project description:In the last few decades, strategies for the management of rheumatoid arthritis (RA) have been increasingly oriented toward more comprehensive control of the disease, taking into account even RA extra-articular manifestations, comorbidities, and the patient's perception about the disease. The need for improving the shared decision-making process suggested by European League Against Rheumatism recommendations is leading to an increasing interest in the role of patient-reported outcomes (PROs) beside the usual more objective criteria for defining clinical response based on disease-activity composite indices. Measurement of such PROs as pain or fatigue may be significantly influenced by mood disorders often complicating RA, the pathogenesis of which is deeply interconnected with phlogistic processes mediated by proinflammatory cytokines. IL6 is a pleiotropic mediator involved in neuroendocrine and neuropsychological processes, besides its well known effects on immune, cardiovascular, and metabolic systems. Therefore, there is a growing body of evidence about the efficacy of IL6 blockade in PRO improvement in RA patients. Sarilumab is a monoclonal antibody binding both soluble and membrane-bound IL6R?, inhibiting the IL6-mediated signaling pathway with favorable efficacy and safety profile. This review analyzes the importance of PROs in strategies for the management of RA and the pathogenic mechanisms linking IL6 with the patient's perception of the disease. Moreover, the main findings from sarilumab randomized controlled trials are summarized in detail, emphasizing the potential role of this IL6 blocker in the holistic treatment of RA.
Project description:AimLeflunomide is a disease-modifying antirheumatic drug used in therapy for rheumatoid arthritis (RA). Previous studies indicated that oestrogens and androgens may affect the response to leflunomide in RA patients. The synthesis of androgens is regulated by cytochrome CYB5A. The aim of this study was to examine the association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.MethodsThe study included 111 women diagnosed with RA. Leflunomide was administered in monotherapy at a dose of 20 mg/day. All patients underwent a monthly evaluation for 12 months after the initiation of treatment with leflunomide.ResultsAfter 12 months of therapy, the changes in individual disease activity parameters, such as: DAS28, ESR, CRP and VAS, were not statistically significantly different between rs1790834 genotypes in the Kruskal-Wallis test.ConclusionsThe results of our study suggest lack of statistically significant association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.