Precision Medicine With Leflunomide: Consideration of the DHODH Haplotype and Plasma Teriflunomide Concentration and Modification of Outcomes in Patients With Rheumatoid Arthritis.

OBJECTIVE: Leflunomide is a commonly used disease-modifying drug in the treatment of rheumatoid arthritis (RA). Its effects are mediated via inhibition of dihydroorotate dehydrogenase (DHODH) by its active metabolite teriflunomide, and the pharmacokinetics of teriflunomide are highly variable. Our objective was to examine the association between the DHODH haplotype and plasma teriflunomide concentration with response to leflunomide in patients with RA where leflunomide was added to an existing disease-modifying drug regimen after failure to achieve an adequate response with conventional triple therapy. METHODS: Patients with RA who were taking, or were about to initiate, leflunomide were included. Participant characteristics, including the DHODH haplotype, were determined. Up to 5 plasma samples were collected after leflunomide was initiated for assays of total and free teriflunomide concentration. Disease activity was determined via the 28-joint Disease Activity Score (DAS28). The association between DAS28 scores and patient covariates was determined by linear mixed-effects modeling. RESULTS: A total of 67 patients were included in the study. The DAS28 score after initiation of leflunomide was associated with the baseline DAS28 score (ß = 0.70, P < 0.001) and was higher in those who carried the DHODH haplotype 2 (ß = 0.56. P = 0.01) and did not carry the shared epitope (ß = 0.56, P = 0.013). As total and free plasma teriflunomide concentration increased, the DAS28 score was significantly lower (P < 0.001 and P = 0.001, respectively). When considering threshold concentrations, teriflunomide concentrations >16 mg/liter were associated with a DAS28 score that was 0.33 lower, and when free teriflunomide concentration was >35 µg/liter, the DAS28 score was 0.32 lower. CONCLUSION: Teriflunomide concentration and carriage of the DHODH haplotype 2 are associated with response to leflunomide in patients with RA, and a total plasma teriflunomide concentration of at least 16 mg/liter is needed to maximize the likelihood of response.

Coated nanostructured lipid carriers targeting the joints - An effective and safe approach for the oral management of rheumatoid arthritis.

Oral treatment of rheumatoid arthritis (RA) with the immunomodulator, leflunomide (LEF), is associated with systemic side effects namely immunosuppression and hepatotoxicity. Herein, attempts to improve LEF therapeutic outcomes via nanostructured lipid carriers (NLCs) targeting inflamed rheumatic joints were executed. LEF-NLCs coated with either chondroitin sulphate (CHS) or chitosan (CS) were around 250 nm in size with negative or positive charge, respectively. Particle coating was evidenced by TEM and FTIR analysis. NLCs generally ensured sustained release profile up to 21 days, particularly extended in coated formulations. In vivo pharmacokinetic study of LEF suspension, uncoated NLCs, CHS- and CS-coated NLCs was carried out. Following oral administration in RA-induced rat model, joint diameter, paw inflammation, liver functions were measured, in addition to histological examination of liver, kidney and joints. Results revealed improved joint healing and reduced hepatotoxicity following treatment with nanoencapsulated LEF compared to LEF suspension, whereby CHS-NLCs ensued the highest Cmax, AUC and lowest TNF-α level. The dual potential of CHS to achieve active targeting to CD44-receptor and hence maximize LEF concentration at the target site in addition to its synergistic effect in joint healing endow promises for a competent oral nanosystem for targeted drug delivery to the joints.

Systematic review and meta-analysis of the efficacy and safety of leflunomide and methotrexate in the treatment of rheumatoid arthritis / Revisión sistemática y metaanálisis de la eficacia y la seguridad de leflunomida y metotrexato en el tratamiento de la artritis reumatoide

Objective: To assess the efficacy and side effects of methotrexate and leflunomide in patients with rheumatoid arthritis (RA) as the first disease-modifying antirheumatic drug (DMARD). Methods: We performed a systematic review and meta-analysis of clinical studies that included patients who took methotrexate, leflunomide, placebo or another DMARD for RA treatment. A systematic review yielded 1971 articles from databases; once completely reviewed, 73 trials that completed inclusion criteria were selected. In structured workshops for discussion and assessment of each article, 6 could be meta-analyzed for the primary and secondary outcomes: achievement of American College of Rheumatology (ACR) 20 and its core set components; and change of serum C-reactive protein (CRP) levels, Health Assessment Questionnaire Disability Index (HAQ-Di), liver enzyme aspartate transaminase/alanine transaminase ratio, new gastrointestinal (GI) side effects and infections. Results: A total of 1984 patients were included: 986 took leflunomide and 998 methotrexate. The probability of achieving ACR 20 had an odds ratio (OR) of 0.88 (95% confidence interval [CI] 0.74, 1.06) with a trend toward favoring methotrexate; reduction of the swollen joint count was greater for methotrexate: mean difference=0.82 (95%CI 0.24, 1.39); tender joint count, physician global assessment, HAQ-Di, and serum CRP levels revealed no significant difference between groups. Increased liver enzymes were more frequent in the leflunomide group, OR=0.38 (95%CI 0.27, 0.53), and new GI complaints were more common with methotrexate (OR=1.44; 95%CI 1.17, 1.79). There was no difference in the incidence of non-severe infections. Conclusion: Leflunomide used as the first DMARD in RA seemed to be as efficacious as methotrexate; only the reduction of swollen joint count was more marked for methotrexate. Leflunomide was linked to a greater increase in liver enzymes, but there were fewer GI complaints

Objetivo: Evaluar la eficacia y los efectos secundarios del metotrexato o la leflunomida en pacientes con AR como primer fármaco modificador de la enfermedad (FAME). Métodos: Se realizó una revisión sistemática y metaanálisis de estudios clínicos que incluyeron a pacientes que tomaron metotrexato, leflunomida, placebo u otro FAME para el tratamiento de la AR. Después de una revisión sistemática, se encontraron 1.971 artículos, una vez revisados completamente, se seleccionaron 73 ensayos que completaron los criterios de inclusión. En talleres estructurados para el debate y la evaluación de cada artículo, 6 pudieron ser metaanalizados para los resultados primarios y secundarios: logro de ACR 20 y sus componentes básicos, así como el cambio de los niveles séricos de PCR, HAQ-DI, enzimas hepáticas AST/ALT, nuevos efectos secundarios gastrointestinales (GI) e infecciones. Resultados: Se incluyó a un total de 1.984 pacientes, 986 tomaron leflunomida y 998 metotrexato. La probabilidad de alcanzar ACR 20 reveló una OR 0,88 (IC del 95%: 0,74; 1,06) con una tendencia a favorecer el metotrexato; la reducción del recuento de articulaciones inflamadas fue mayor para metotrexato: diferencia de medias (MD)=0,82 (IC del 95%: 0,24, 1,39); el recuento de articulaciones sensibles, la evaluación global de médicos, el HAQ-DI, y los niveles séricos de PCR no revelaron diferencias entre los grupos. El aumento de las enzimas hepáticas fue más frecuente en el grupo con leflunomida, OR=0,38 (IC del 95%: 0,27, 0,53) y las nuevas quejas GI fueron más frecuentes en el metotrexato, OR=1,44 (IC del 95% 1,17, 1,79). No hubo diferencias en la incidencia de infecciones no graves. Conclusión: La leflunomida utilizada como el primer FAME en la AR parece ser tan eficaz como el metotrexato; solo la reducción de las articulaciones inflamadas fue mayor para el metotrexato. La leflunomida está relacionada con una mayor elevación de las enzimas hepáticas, pero presenta menos molestias GI

Safety, Pharmacokinetics, and Pharmacogenetics of Single-Dose Teriflunomide Sodium and Leflunomide in Healthy Chinese Subjects.

BACKGROUND: Teriflunomide sodium, a novel derivative of leflunomide, was developed to treat systemic lupus erythematosus. OBJECTIVE: The objectives of this trial were to study the safety, pharmacokinetics, and pharmacogenetics of teriflunomide sodium in healthy Chinese subjects in order to support its accelerated development. METHODS: A clinical study was designed as a single-dose, randomized, parallel, open-label study. Healthy volunteers were randomly assigned to take teriflunomide sodium 10 mg or leflunomide 10 mg. Eligible healthy volunteers were monitored over a 98-day observation period. Blood and urine samples were collected and analyzed for teriflunomide and its metabolite concentrations, and ABCG2 and CYP2C9 genotypes were detected. The safety profile was also collected. RESULTS: All adverse events were mild in intensity, and all subjects completed this trial without any other treatment. After a single administration of teriflunomide sodium and leflunomide, teriflunomide maximal concentrations were 1.32 ± 0.341 mg/L and 0.718 ± 0.169 mg/L, and area under the concentration-time curve from time zero to infinity (AUC∞) was 423 ± 229 mg·h/L and 303 ± 159 mg·h/L, respectively. Overall, teriflunomide AUC∞ in ABCG2 34A/A mutants was 70.4% lower than in wild-type ABCG2 34G/G after administration of teriflunomide sodium. In addition, after administration of leflunomide, teriflunomide AUC∞ in ABCG2 34A/A mutants was 30.0% lower than in subjects carrying ABCG2 34G/G. CONCLUSIONS: Teriflunomide sodium was generally safe and well tolerated in healthy Chinese subjects. The relative bioavailability of teriflunomide between teriflunomide sodium and leflunomide after a single dose administration was approximately 150%. Additionally, ABCG2 34G>A was found to significantly affect teriflunomide pharmacokinetics, which suggested ABCG2 34G>A may be a significant influencing factor. CLINICAL TRIAL REGISTRATION: This study was registered at the China National Medical Products Administration ( http://www.nmpa.gov.cn ; registration number 2014L01935), and also at the China platform for registry and publicity of drug clinical trials ( http://www.chinadrugtrials.org.cn ; registration number CTR20150314).

Development of a simple HPLC-MS/MS method to simultaneously determine teriflunomide and its metabolite in human plasma and urine: Application to clinical pharmacokinetic study of teriflunomide sodium and leflunomide.

A simple high-performance liquid chromatography coupled with tandem mass spectrometry method was developed and fully validated to simultaneously determine teriflunomide (TER) and its metabolite 4-trifluoro-methylaniline oxanilic acid (4-TMOA) in human plasma and urine. Merely 50 µL plasma and 20 µL urine were employed in sample preparation using protein precipitation and direct dilution method, respectively. An Agilent Zorbax eclipse plus C18 column was selected to achieve rapid separation for TER and 4-TMOA within 3 min. Electrospray ionization under multiple reaction monitoring was used to monitor the ion transitions for TER (m/z 269.0 → 159.9), 4-TMOA (m/z 231.9 → 160.0), internal standard teriflunomide-d4 (m/z 273.0 → 164.0) and 2-amino-4-trifluoromethyl benzoic acid (m/z 203.8 → 120.1), operating in the negative ion mode. This method proved to have better accuracy and precision over concentration range of 10-5000 ng/mL in plasma as well as 10-10,000 ng/mL in urine. After a full validation, this method was successfully applied in a pharmacokinetic study of teriflunomide sodium and leflunomide in Chinese healthy volunteers.

LC-MS/MS Method for the Quantification of the Leflunomide Metabolite, Teriflunomide, in Human Serum/Plasma.

Leflunomide is a prodrug that is metabolized to the active metabolite, teriflunomide (A77 1726), to inhibit the enzyme dihydroorotate dehydrogenase and decrease the synthesis of pyrimidine nucleotides for DNA and RNA synthesis. Teriflunomide is primarily used for the treatment of rheumatoid arthritis and multiple sclerosis.A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated to quantify the drug teriflunomide over a concentration range of 5 ng/mL-200 µg/mL in serum or plasma. The calibration curve was divided into two separate overlapping regions of the analytical measurement range, with a high curve and a low curve range. Samples are first analyzed using the high-range calibration curve after a 100-fold dilution of the sample extract. Samples falling below the upper curve region are evaluated again without dilution and quantified, if possible, against the low curve calibration standards. This method can be used to support therapeutic drug monitoring of patients that are administered with leflunomide therapy.