High BMI is associated with lower TNF-α inhibitor serum trough levels and higher disease activity in patients with axial spondyloarthritis.

BACKGROUND: TNF-α inhibitor (TNFi) serum trough levels have previously been found to be related to disease activity in axial spondyloarthritis (axSpA). However, most research regarding serum trough levels has been conducted in patients who only recently started TNFi therapy. Therefore, our objective was to explore TNFi serum trough level measurements in relation to disease activity and BMI in the total axSpA population in daily clinical practice, also including patients on long-term TNFi therapy. METHODS: Consecutive patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort were approached for a TNFi serum trough level measurement during their regular outpatient visit at the UMCG. Spearman's correlation coefficient was used to analyse the relation of serum trough levels with disease activity and BMI. Logistic regression was performed to analyse the relation between therapeutic drug levels and disease activity, corrected for potential confounders, including BMI. RESULTS: Thirty-four patients on adalimumab and 21 patients on etanercept were included. Mean age was 45 ± 12 years, 47% were male, median BMI was 26.4 (IQR 23.9-32.5) and median treatment duration was 41 months (range 2-126). According to definitions of Sanquin, 47% of patients had therapeutic serum trough levels. No significant correlations were found between TNFi levels and disease activity (ASDAS-CRP: adalimumab: ρ = -0.16, p = 0.39; etanercept: ρ = -0.29, p = 0.20). TNFi levels were moderately correlated with BMI (adalimumab: ρ = -0.48, p = 0.004; etanercept: ρ = -0.50, p = 0.021). Patients with active disease (ASDAS ≥ 2.1) showed higher BMI than patients with inactive disease (median 29.7 vs. 24.6, p = 0.015). In multivariable regression analyses, BMI was identified as the only confounder for the relationship between therapeutic drug levels and ASDAS. CONCLUSION: In this cross-sectional, observational study of axSpA patients mainly on long-term treatment with TNFi, higher BMI was significantly associated with lower adalimumab and etanercept serum trough levels and higher disease activity.

An Update Review of Biosimilars of Adalimumab in Psoriasis - Bioequivalence and Interchangeability.

Biologic drugs have revolutionized the treatment of psoriasis and other rheumatological diseases. In recent years, many biosimilar agents that are highly similar in structure and function to their originator products have been developed, including the tumor necrosis factor-alpha antagonist adalimumab. The considerably lower cost of these products has greatly cut the economic burden of the patients and increased the accessibility of biologic therapies worldwide. The US Food and Drug Administration and/or the European Medicines Agency have approved eight biosimilars of adalimumab (ABP 501/BI 695501/SB5/GP2017/FKB327/MSB11022/PF-06410293/CT-P17) for the treatment of psoriasis, and others are under review. Given that these agents showed pharmacokinetic, efficacy, safety, and immunogenicity profiles comparable to those of the originator, adalimumab biosimilars were licensed for all indications approved for reference adalimumab based on extrapolation; however, some of the equivalence studies were only conducted in one or two disease populations. This review discusses the bioequivalence of adalimumab biosimilars as demonstrated by various clinical trials, the extrapolation of indications, guidance and policies of the EU and US on interchangeability (nonmedical switching/automatic substitution) between biosimilars and originators, and the real-life practices of switching from reference adalimumab to the respective biosimilars. Further data from real-world studies and post-marketing analyses are needed better to address the efficacy and safety of the transition strategy.

[Placental transfer of monoclonal antibodies: The example of anti-TNF alpha drugs]. / Le passage placentaire des anticorps monoclonaux : exemple des anti-TNF alpha.

Anti-TNF alpha monoclonal antibodies are used in the treatment of chronic inflammatory diseases, which commonly affect women of childbearing age. Due to their similar structure to native immunoglobulins, the evaluation of their placental transfer by a pharmacological approach of the mechanisms involved is an interesting source of information, useful to the risk-benefit assessment of drugs in pregnant women.

Factors associated with reduced infliximab exposure in the treatment of pediatric autoimmune disorders: a cross-sectional prospective convenience sampling study.

BACKGROUND: Inadequate systemic exposure to infliximab (IFX) is associated with treatment failure. This work evaluated factors associated with reduced IFX exposure in children with autoimmune disorders requiring IFX therapy. METHODS: In this single-center cross-sectional prospective study IFX trough concentrations and anti-drug antibodies (ADAs) were measured in serum from children diagnosed with inflammatory bowel disease (IBD) (n = 73), juvenile idiopathic arthritis (JIA) (n = 16), or uveitis (n = 8) receiving maintenance IFX infusions at an outpatient infusion clinic in a tertiary academic pediatric hospital. IFX concentrations in combination with population pharmacokinetic modeling were used to estimate IFX clearance. Patient demographic and clinical data were collected by chart review and evaluated for their relationship with IFX clearance. RESULTS: IFX trough concentrations ranged from 0 to > 40 µg/mL and were 3-fold lower in children with IBD compared to children with JIA (p = 0.0002) or uveitis (p = 0.001). Children with IBD were found to receive lower IFX doses with longer dosing intervals, resulting in dose intensities (mg/kg/day) that were 2-fold lower compared to children with JIA (p = 0.0002) or uveitis (p = 0.02). Use of population pharmacokinetic analysis to normalize for variation in dosing practices demonstrated that increased IFX clearance was associated with ADA positivity (p = 0.004), male gender (p = 0.02), elevated erythrocyte sedimentation rate (ESR) (p = 0.02), elevated c-reactive protein (CRP) (p = 0.001), reduced serum albumin concentrations (p = 0.0005), and increased disease activity in JIA (p = 0.009) and IBD (p ≤ 0.08). No significant relationship between diagnosis and underlying differences in IFX clearance was observed. Multivariable analysis by covariate population pharmacokinetic modeling confirmed increased IFX clearance to be associated with anti-IFX antibody positivity, increased ESR, and reduced serum albumin concentrations. CONCLUSIONS: Enhanced IFX clearance is associated with immunogenicity and inflammatory burden across autoimmune disorders. Higher systemic IFX exposures observed in children with rheumatologic disorders are driven primarily by provider drug dose and interval selection, rather than differences in IFX pharmacokinetics across diagnoses. Despite maintenance IFX dosing at or above the standard recommended range for IBD (i.e., 5 mg/kg every 8 weeks), the dosing intensity used in the treatment of IBD is notably lower than dosing intensities used to treat JIA and uveitis, and may place some children with IBD at risk for suboptimal maintenance IFX exposures necessary for treatment response.

Pharmacokinetics, safety, and immunogenicity of HLX03, an adalimumab biosimilar, compared with reference biologic in healthy Chinese male volunteers: Results of a randomized, double-blind, parallel-controlled, phase 1 study.

The primary objective of this randomized, double-blind, parallel-controlled study (from December 2016 to October 2018) was to evaluate pharmacokinetic (PK) equivalence of adalimumab biosimilar HLX03 and reference adalimumab in healthy volunteers, and to assess safety, and immunogenicity of HLX03. The primary PK endpoints were maximum observed plasma concentration (Cmax ) and area under the concentration curve from time zero to the last quantifiable concentration (AUC0-t ). Equivalence was determined if the 90% confidence interval (CI) of geometric least square mean ratio between the two treatment groups were within the predefined range of 80%-125%. Safety and immunogenicity were monitored during the study. Healthy Chinese males (N = 220) were randomized 1:1 to receive a single subcutaneous 40 mg dose of HLX03 or China (CN)-sourced adalimumab. The ratios of the geometric mean of Cmax and AUC0-t were 102.2% and 105.7%, respectively, with corresponding 90% CIs falling in the predefined margins, which demonstrated PK equivalence between HLX03 and CN-adalimumab. The incidence of treatment-emergent adverse events (TEAEs) was similar in the two groups (73.8% and 66.0% in the HLX03 and CN-adalimumab groups, respectively). Grade 3-4 TEAEs were reported in 7.5% and 5.7% of participants, respectively. The incidences of participants with antidrug antibodies (HLX03: 96.2%; CN-adalimumab: 93.4%) or neutralizing antibodies (HLX03: 40.6%, CN-adalimumab: 41.4%) were comparable between groups. This study demonstrated PK bioequivalence between HLX03 and CN-adalimumab, with similar safety and immunogenicity profiles. These data support further clinical development of HLX03 as an adalimumab biosimilar.

Pharmacokinetic equivalence of CT-P17 to high-concentration (100 mg/ml) reference adalimumab: A randomized phase I study in healthy subjects.

This study aimed to demonstrate pharmacokinetic (PK) equivalence of a single dose of the proposed adalimumab biosimilar CT-P17 to United States-licensed adalimumab (US-adalimumab) and European Union-approved adalimumab (EU-adalimumab). This double-blind, parallel-group, phase I trial (clinicaltrials.gov NCT03970824) was conducted at 10 hospitals (Republic of Korea), in which healthy subjects (1:1:1) were randomized to receive a single 40 mg (100 mg/ml) subcutaneous injection of CT-P17, US-adalimumab, or EU-adalimumab. Primary end points were PK equivalence in terms of: area under the concentration-time curve from time zero to infinity (AUC0-inf ); AUC from time zero to the last quantifiable concentration (AUC0-last ); and maximum serum concentration (Cmax ). PK equivalence was concluded if 90% confidence intervals (CIs) for percent ratios of geometric least squares means (GLSMs) for pairwise comparisons were within the equivalence margin of 80-125%. Additional PK end points, safety, and immunogenicity were evaluated. Of the 312 subjects who were randomized (103 CT-P17; 103 US-adalimumab; 106 EU-adalimumab), 308 subjects received study drug. AUC0-inf , AUC0-last , and Cmax were equivalent among CT-P17, US-adalimumab, and EU-adalimumab, because 90% CIs for the ratios of GLSMs were within the 80-125% equivalence margin for each pairwise comparison. Secondary PK end points, safety, and immunogenicity were similar between treatment groups. In conclusion, PK equivalence for single-dose administration of CT-P17, EU-adalimumab, and US-adalimumab was demonstrated in healthy adults. Safety and immunogenicity profiles were comparable between treatment groups and consistent with previous reports for adalimumab biosimilars.

Safety and tolerability of a humanized rabbit monoclonal antibody (SSS07) in healthy adults: Randomized double-blind placebo-controlled single ascending dose trial.

BACKGROUND/OBJECTIVE: SSS07, a humanized rabbit monoclonal antibody, can selectively block human tumor necrosis factor-α (TNF-α). The objective of this study was to assess the safety, tolerability, and relative immunogenicity of SSS07 after multiple single subcutaneous (SC) doses in healthy volunteers. METHODS: A total of 71 healthy volunteers were randomized to six sequential ascending-dose groups (5, 15, 30, 50, 75, and 100 mg), and except for the 100 mg group that only had one subject who received a placebo, all of the other groups included two placebo-control subjects. Safety, tolerability, and immunogenicity were assessed by physical examinations, vital signs, electrocardiography (ECG), clinical laboratory tests, and plasma anti-drug antibody (ADA) over 28 days for each group. Their concentrations of TNF-α were also analyzed. Only after safety and tolerance were determined in the lower-dose groups was the next dose group initiated. The dose increments did not exceed 100 mg. RESULTS: No serious adverse events or dose-limited toxicity (DLT) were observed, so 100 mg was defined as the maximum tolerated dose (MTD). Overall, 71 AEs and 59 treatment-related adverse events (TRAEs) were reported in 36 (60.0%) and 30 (50.0%) volunteers, respectively, who received SSS07. All AEs and TRAEs were mild or moderate and expected based on previous results with similar types of drugs, without new safety concerns. Except for infections and administration site reactions, the frequency and intensity of the other TRAEs were similar for SSS07 and placebo. No severe acute immune reactions occurred. The lower dose's immunogenicity was stronger than the higher doses. The highest ADA titer was observed 3 to 6 months after administration. CONCLUSION: SSS07 was generally safe and well tolerated in healthy Chinese volunteers. Higher immunogenicity was observed at low SSS07 concentration levels. The infections and administration site conditions might have been related to the immunogenicity and the degree of inhibition of TNF-α. However, the existence of ADA did not appear to affect the safety of the subjects throughout the follow-up period. These findings could support further investigations of treatments with humanized monoclonal antibodies.

Pharmacogenetics of trough serum anti-TNF levels in paediatric inflammatory bowel disease.

AIMS: Identifying DNA variants associated with trough serum anti-tumour necrosis factor (TNF) levels could predict response to treatment in inflammatory bowel disease (IBD). To date, no specific studies have been performed in children. The aim of this study was to identify genetic variants associated with trough serum anti-TNF levels and whether these variants are differential markers for infliximab and adalimumab. METHODS: We included 154 children (age < 18 years) from 17 hospitals who had been diagnosed with IBD and actively treated with infliximab or adalimumab. Twenty-one polymorphisms were genotyped using real-time PCR. Trough serum anti-TNF levels were measured using enzyme-linked immunosorbent assay (ELISA). The association between DNA polymorphisms and the therapeutic range or the absolute values of anti-TNF drugs was analysed by Fisher exact test, student's t-test and logistic regression. RESULTS: The variants rs5030728 (TLR4) and rs11465996 (LY96) were associated with subtherapeutic infliximab levels. rs1816702 (TLR2) was associated with supratherapeutic levels and rs3397 (TNFRSF1B) with subtherapeutic levels of adalimumab (P < .05). In addition, rs1816702 (TLR2) and rs2569190 (CD14) were associated with absolute values of trough serum adalimumab, and rs2569190 (CD14) was associated with absolute values of trough serum adalimumab and infliximab (P < .05). CONCLUSION: Genotyping of these DNA variants before starting treatment may help to select the best anti-TNF drug in paediatric patients. The SNP rs1816702 is the most promising marker for tailoring the anti-TNF regimen in children with IBD. For the first time, DNA variants are associated with trough serum anti-TNF levels.

A Randomized, Double-Blind, Parallel-Group, Phase 1 Clinical Trial Comparing the Pharmacokinetic, Safety, and Immunogenicity of the Biosimilar HS016 and the Originator Adalimumab in Chinese Healthy Male Subjects.

A comparison of the immunogenicity, safety, and pharmacokinetic properties of HS016 and its originator, adalimumab, was conducted in Chinese healthy male subjects. This was a phase 1 single-center, randomized, parallel-group double-blind clinical trial. Chinese healthy male subjects (1:1) allocated to HS016 and adalimumab groups were treated with single subcutaneous injections (40 mg/0.8 mL). The pharmacokinetic equivalence of HS016 and adalimumab was assessed by (1) the area under the plasma concentration-time curve (AUC) from time 0 to the last detectable drug concentration (AUC0-t ), (2) the AUC from time 0 extrapolated to infinity (AUC0-∞ ), and (3) the maximum plasma concentration (Cmax ). Other pharmacokinetic parameters (time to Cmax , apparent clearance, and half-life), safety, and immunogenicity were also evaluated. A total of 136 subjects were randomly divided into HS016 (n = 68) or adalimumab (n = 68) groups. The geometric means of AUC0-t , AUC0-∞ , and Cmax were similar for HS016 and adalimumab. The 90%CIs of AUC0-t (87.2% to 106.1%), AUC0-∞ (87.4% to 108.4%), and Cmax (98.6% to 113.6%) were all within the prespecified bioequivalence criteria (80% to 125%). The incidence of treatment-emergent adverse events (TEAEs) was similar in both groups, with most TEAEs being mild; only 3 (4.4%) subjects in the HS016 group experienced moderate TEAEs. No significant differences in the time to Cmax , apparent clearance, half-life, and immunogenicity were detected. The pharmacokinetic profile of HS016 was equivalent to that of the originator, adalimumab, with similar safety and immunogenicity profiles. HS016 may be considered for assessment in the treatment of patients with ankylosing spondylitis.

A Phase I, Randomized, Double-Blind, Single-Dose, Parallel-Group Study to compare Pharmacokinetic Similarity, Safety, and Immunogenicity Between BAT2506 and Golimumab in Healthy Chinese Male Subjects.

Background: To compare the pharmacokinetic (PK) profile, safety, and immunogenicity between golimumab and the biosimilar BAT2506 in healthy Chinese male subjects. Research design and methods: A total of 180 healthy male subjects were recruited for this randomized, double-blinded, single-dose, parallel study. They received 50 mg BAT2506 or golimumab (1:1 ratio) by single subcutaneous injection. The evaluation index included maximum plasma concentration (Cmax), area under the plasma concentration-time curve (AUC0-t, AUC0-∞), safety, and immunogenicity. Results: The results showed that the 90% confidence interval (CI) of the geometric mean ratio (GMR) of BAT2506 to reference drug (golimumab) for Cmax, AUC0-∞ and AUC0-t were 99.26% (90.59-108.76%), 102.06% (93.31%-111.64%), and 102.05% (93.51-111.38%), respectively. All 90% CIs were within the range of 80-125% range, which is the limitation of the equivalence margin. Furthermore, similarity of treatment-emergent adverse events was also found between the two drugs. A total of 14 subjects (7.8%) developed anti-drug antibody after administration. Conclusions: Our study confirmed the PK similarity between BAT2506 and golimumab, and showed good tolerance of BAT2506 in healthy subjects. There were no differences in safety and immunogenicity between the two drugs. Therefore, BAT2506 meets the criteria for biosimilarity to golimumab. Trial registration: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT04152759).

Therapeutic Drug Monitoring of Tumor Necrosis Factor Antagonists in Crohn Disease: A Theoretical Construct to Apply Pharmacokinetics and Guidelines to Clinical Practice.

Therapeutic drug monitoring (TDM) is the measurement of drug and antidrug antibody concentrations in individuals to guide treatment decisions. In patients with Crohn disease (CD), TDM, used either reactively or proactively, is emerging as a valuable tool for optimization of tumor necrosis factor (TNF) antagonist therapy. Reactive TDM is carried out in response to treatment failure, whereas proactive TDM involves the periodic monitoring of patients responding to TNF antagonist therapy to allow treatment optimization. In patients with CD, most of the available data for TDM relate to the first-to-market TNF antagonist infliximab and, to a lesser extent, to adalimumab and certolizumab pegol. Several gastroenterology associations, including the American Gastroenterology Association, have endorsed the use of reactive TDM in patients with active CD. However, fewer recommendations currently exist for the use of proactive TDM, although several new prospective randomized controlled trials evaluating proactive TDM strategies have been published. In this review, the current evidence for reactive and proactive TDM is discussed, and a proactive treatment algorithm for certolizumab pegol based on previously published threshold concentrations is proposed.

Metabolic, pharmacokinetic, and toxicological issues of biologic therapies currently used in the treatment of hidradenitis suppurativa.

INTRODUCTION: Hidradenitis suppurativa is a chronic, relapsing, debilitating inflammatory dermatologic disease of the terminal hair follicles at intertriginous sites clinically characterized by painful inflammatory nodules, abscesses, draining sinus tracts, and dermal fibrosis. The management of hidradenitis suppurativa is a challenge and usually consists of both medical and surgical approaches, which must often be combined for best outcome. The introduction of biological therapies, specifically TNFα-inhibitors such as adalimumab, has profoundly changed the therapeutic armamentarium of the disease. AREAS COVERED: The PubMed database was searched using combinations of the following keywords: hidradentis suppurativa, biologic therapy, TNF-α inhibitors, adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, adverse effects, pharmacodynamics, pharmacology, adverse events, pharmacokinetics, drug interaction. This article reviews and updates the chemistry, pharmacokinetics, mechanism of action, adverse effects, drug interactions of on-label and off-label use of TNF-α inhibitors in HS. EXPERT OPINION: Biologic agents, particularly adalimumab, exhibit clinical efficacy in patients with hidradenitis suppurativa. Careful patient selection and close monitoring during treatment are mandatory to provide safe and effective use of the TNF-α inhibitor. Familiarity with biologic agents is crucial because these agents could become a consolidated treatment option in the clinician's therapeutic approaches.

Serum miRNAs Are Pharmacodynamic Biomarkers Associated With Therapeutic Response in Pediatric Inflammatory Bowel Disease.

BACKGROUND: We sought to identify microRNAs (miRNAs) associated with response to anti-TNF-α or glucocorticoids in children with inflammatory bowel disease (IBD) to generate candidate pharmacodynamic and monitoring biomarkers. METHODS: Clinical response was assessed by Pediatric Crohn's Disease Activity Index and Pediatric Ulcerative Colitis Activity Index. Quantitative real-time polymerase chain reaction via Taqman Low-Density Array cards were used to identify miRNAs in a discovery cohort of responders (n = 11) and nonresponders (n = 8). Seven serum miRNAs associated with clinical response to treatment, along with 4 previously identified (miR-146a, miR-146b, miR-320a, miR-486), were selected for further study. Candidates were assessed in a validation cohort of serum samples from IBD patients pre- and post-treatment and from healthy controls. Expression of miRNA was also analyzed in inflamed mucosal biopsies from IBD patients and non-IBD controls. RESULTS: Discovery cohort analysis identified 7 miRNAs associated with therapeutic response: 5 that decreased (miR-126, miR-454, miR-26b, miR-26a, let-7c) and 2 that increased (miR-636, miR-193b). In the validation cohort, 7 of 11 candidate miRNAs changed in the same direction with response to anti-TNF-α therapies, glucocorticoids, or both. In mucosal biopsies, 7 out of 11 miRNAs were significantly increased in IBD vs healthy controls. CONCLUSIONS: Five candidate miRNAs associated with clinical response and mucosal inflammation in pediatric IBD patients were identified (miR-126, let-7c, miR-146a, miR-146b, and miR-320a). These miRNAs may be further developed as pharmacodynamic and response monitoring biomarkers for use in clinical care and trials.

Characterization of concurrent target suppression by JNJ-61178104, a bispecific antibody against human tumor necrosis factor and interleukin-17A.

Tumor necrosis factor (TNF) and interleukin (IL)-17A are pleiotropic cytokines implicated in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA) and psoriatic arthritis (PsA). JNJ-61178104 is a novel human anti-TNF and anti-IL-17A monovalent, bispecific antibody that binds to both human TNF and human IL-17A with high affinities and blocks the binding of TNF and IL-17A to their receptors in vitro. JNJ-61178104 also potently neutralizes TNF and IL-17A-mediated downstream effects in multiple cell-based assays. In vivo, treatment with JNJ-61178104 resulted in dose-dependent inhibition of cellular influx in a human IL-17A/TNF-induced murine lung neutrophilia model and the inhibitory effects of JNJ-61178104 were more potent than the treatment with bivalent parental anti-TNF or anti-IL-17A antibodies. JNJ-61178104 was shown to engage its targets, TNF and IL-17A, in systemic circulation measured as drug/target complex formation in normal cynomolgus monkeys (cyno). Surprisingly, quantitative target engagement assessment suggested lower apparent in vivo target-binding affinities for JNJ-61178104 compared to its bivalent parental antibodies, despite their similar in vitro target-binding affinities. The target engagement profiles of JNJ-61178104 in humans were in general agreement with the predicted profiles based on cyno data, suggesting similar differences in the apparent in vivo target-binding affinities. These findings show that in vivo target engagement of monovalent bispecific antibody does not necessarily recapitulate that of the molar-equivalent dose of its bivalent parental antibody. Our results also offer valuable insights into the understanding of the pharmacokinetics/pharmacodynamics and target engagement of other bispecific biologics against dimeric and/or trimeric soluble targets in vivo.

Immunogenicity of TNF-Inhibitors.

Tumor necrosis factor inhibitors (TNFi) have significantly improved treatment outcome of rheumatic diseases since their incorporation into treatment protocols two decades ago. Nevertheless, a substantial fraction of patients experiences either primary or secondary failure to TNFi due to ineffectiveness of the drug or adverse reactions. Secondary failure and adverse events can be related to the development of anti-drug antibodies (ADA). The earliest studies that reported ADA toward TNFi mainly used drug-sensitive assays. Retrospectively, we recognize this has led to an underestimation of the amount of ADA produced due to drug interference. Drug-tolerant ADA assays also detect ADA in the presence of drug, which has contributed to the currently reported higher incidence of ADA development. Comprehension and awareness of the assay format used for ADA detection is thus essential to interpret ADA measurements correctly. In addition, a concurrent drug level measurement is informative as it may provide insight in the extent of underestimation of ADA levels and improves understanding the clinical consequences of ADA formation. The clinical effects are dependent on the ratio between the amount of drug that is neutralized by ADA and the amount of unbound drug. Pharmacokinetic modeling might be useful in this context. The ADA response generally gives rise to high affinity IgG antibodies, but this response will differ between patients. Some patients will not reach the phase of affinity maturation while others generate an enduring high titer high affinity IgG response. This response can be transient in some patients, indicating a mechanism of tolerance induction or B-cell anergy. In this review several different aspects of the ADA response toward TNFi will be discussed. It will highlight the ADA assays, characteristics and regulation of the ADA response, impact of immunogenicity on the pharmacokinetics of TNFi, clinical implications of ADA formation, and possible mitigation strategies.

An Open-Label, Randomized, Single-Dose, Crossover, Comparative Pharmacokinetics Study of YLB113 and the Etanercept Reference Product in Healthy Adult Male Subjects.

BACKGROUND AND OBJECTIVES: YLB113 is being developed as a biosimilar of the antitumor necrosis factor-alpha antagonist etanercept, which is approved for the treatment of moderate-to-severe rheumatoid arthritis (RA) and other chronic immune-mediated inflammatory diseases. An open-label, crossover, pharmacokinetic study was conducted to compare the relative bioavailability and safety of YLB113 and the etanercept reference product (RP) Enbrel®. METHODS: Healthy male subjects aged 18-50 years were randomized to receive a single subcutaneous dose of YLB113 in one period and the etanercept RP in another period. A washout period of 28 days separated the two treatment periods. Blood samples were collected for pharmacokinetic analysis predose and until 480 h postdose during both periods. RESULTS: Overall, 52 subjects were enrolled, including 51 subjects who completed the first period and 43 subjects who completed the second period. The 90% confidence intervals for the least squares means derived from an analysis of the log-transformed pharmacokinetic parameters maximum serum concentration (Cmax), area under the serum concentration-time curve (AUC) from 0 to the last measurable concentration (AUC(0-t)) and AUC from 0 to infinity (AUC(0-∞)) for etanercept were between the limits of 80 and 125%. Thus, YLB113 met the bioequivalence criterion. YLB113 and the etanercept RP were well tolerated, with 24 subjects reporting 53 adverse events, including 42 mild and 11 moderate events. Treatment-emergent adverse events were reported by 14 and 16 subjects following the administration of YLB113 and the etanercept RP, respectively. CONCLUSIONS: A single dose of YLB113 exhibited pharmacokinetic and safety profiles comparable with those of the etanercept RP in healthy adult male subjects. Therefore, YLB113 and the etanercept RP can be considered bioequivalent. These findings support the continued development of YLB113 for use in patients with RA. JORDAN FOOD & DRUG ADMINISTRATION UNIQUE TRIAL NUMBER: 31/Clinical/2018.

Assessment of Placental Disposition of Infliximab and Etanercept in Women With Autoimmune Diseases and in the Ex Vivo Perfused Placenta.

Tumor necrosis factor (TNF) inhibitors are increasingly applied during pregnancy without clear knowledge of the impact on placenta and fetus. We assessed placental transfer and exposure to infliximab (n = 3) and etanercept (n = 3) in women with autoimmune diseases. Furthermore, we perfused healthy term placentas for 6 hours with 100 µg/mL infliximab (n = 4) or etanercept (n = 5). In pregnant women, infliximab transferred into cord blood but also entered the placenta (cord-to-maternal ratio of 1.6 ± 0.4, placenta-to-maternal ratio of 0.3 ± 0.1, n = 3). For etanercept, a cord-to-maternal ratio of 0.04 and placenta-to-maternal ratio of 0.03 was observed in one patient only. In ex vivo placenta perfusions, the extent of placental transfer did not differ between the drugs. Final concentrations in the fetal compartment for infliximab and etanercept were 0.3 ± 0.3 and 0.2 ± 0.2 µg/mL, respectively. However, in placental tissue, infliximab levels exceeded those of etanercept (19 ± 6 vs. 1 ± 3 µg/g, P < 0.001). In conclusion, tissue exposure to infliximab is higher than that of etanercept both in vivo as well as in ex vivo perfused placentas. However, initial placental transfer, as observed ex vivo, does not differ between infliximab and etanercept when administered in equal amounts. The difference in placental tissue exposure to infliximab and etanercept may be of clinical relevance and warrants further investigation. More specifically, we suggest that future studies should look into the occurrence of placental TNF inhibition and possible consequences thereof.

Pharmacomicrobiomics in inflammatory arthritis: gut microbiome as modulator of therapeutic response.

In the past three decades, extraordinary advances have been made in the understanding of the pathogenesis of, and treatment options for, inflammatory arthritides, including rheumatoid arthritis and spondyloarthritis. The use of methotrexate and subsequently biologic therapies (such as TNF inhibitors, among others) and oral small molecules have substantially improved clinical outcomes for many patients with inflammatory arthritis; for others, however, these agents do not substantially improve their symptoms. The emerging field of pharmacomicrobiomics, which investigates the effect of variations within the human gut microbiome on drugs, has already provided important insights into these therapeutics. Pharmacomicrobiomic studies have demonstrated that human gut microorganisms and their enzymatic products can affect the bioavailability, clinical efficacy and toxicity of a wide array of drugs through direct and indirect mechanisms. This discipline promises to facilitate the advent of microbiome-based precision medicine approaches in inflammatory arthritis, including strategies for predicting response to treatment and for modulating the microbiome to improve response to therapy or reduce drug toxicity.

Safety and Effectiveness of Anti-Tumor Necrosis Factor-Alpha Biosimilar Agents in the Treatment of Psoriasis.

Biologic drugs have revolutionized the treatment of psoriasis and other chronic inflammatory diseases. In recent years, many tumor necrosis factor-alpha 'biosimilar' agents have been developed. These biosimilars are similar in structure and function to their originator molecules, although they are not identical. Given that the safety and efficacy of the original biologic have already been proven, biosimilars are only required to show bioequivalence, or non-inferiority, to the reference biologic to be approved. Based on extrapolation of these non-inferiority data, biosimilars may be subsequently approved for all indications of the originator biologic, even without being directly studied in these various conditions. These biosimilar agents have been purported as a method to reduce the costs of biologic therapies, thereby increasing the accessibility of these medications and subsequently improving the treatment of psoriasis worldwide. The US Food and Drug Administration and/or the European Medicines Agency have approved biosimilars of adalimumab (Amjevita/Amgevita/Solymbic, Cyltezo, Imraldi/Hadlima, Hyrimoz/Hefiya/Halimatoz, Idacio, Hulio, Abrilada), etanercept (Erelzi, Benepali/Eticovo), and infliximab (Inflectra/Remsima, Renflexis/Flixabi, Ixifi/Zessly) for the treatment of psoriasis, and others are under review. There are many phase III data supporting the bioequivalence of these anti-tumor necrosis factor-alpha biosimilar agents in treating psoriasis and rheumatologic disease, which are discussed here. In general, these biosimilar agents have been shown to have equivalent efficacy, tolerability, and immunogenicity profiles compared to their originators in patients with rheumatologic disease, although studies in patients with psoriasis are fairly limited. Additional switching studies and post-marketing safety analyses are needed to assess the interchangeability of biosimilar agents with their reference products.

A Population Pharmacokinetic and Exposure-Response Model of Golimumab for Targeting Endoscopic Remission in Patients With Ulcerative Colitis.

BACKGROUND: Unlike other anti-tumor necrosis factor alpha antibodies, golimumab does not deliver on its promise of effectiveness for treating patients with ulcerative colitis. We investigated the value of therapeutic drug monitoring for optimizing golimumab therapy. METHODS: We analyzed the golimumab pharmacokinetics data of 56 patients with moderate to severe ulcerative colitis. Induction and maintenance golimumab concentrations (296 venipuncture, 414 serum) were used to develop a population pharmacokinetic model. Exposure-response relationships were analyzed using the data of 40/56 patients with available endoscopy data. Receiver operating characteristic curve analysis was performed, and an exposure-response Markov model was developed, linking golimumab exposure to probabilities of transitioning between Mayo endoscopic subscore (MES) states from baseline to week (w)14. RESULTS: Golimumab pharmacokinetics was best described by a 2-compartment model with linear absorption and elimination. Antibodies to golimumab and previous biological therapy reduced golimumab exposure. Still, interindividual pharmacokinetic variability (IIVPK) remained largely unexplained. Endoscopic remission (ER; MESw14 ≤ 1) was achieved in 14/40 (35%) patients. Golimumab serum trough concentration thresholds of 7.4 mg/L (w6) and 3.2 mg/L (w14) predicted ER at w14 (positive predictive values [pv+] 83% and 91%, pv- 82% and 67%, respectively). The 3.2-mg/L target predicted 38% and 44% chances of achieving ER in patients with MESbaseline of 3 and 2, respectively. CONCLUSIONS: Personalized, model-based induction dosing aiming at here-established target concentrations may account for IIVPK and thus provide patients with more equal chances of achieving ER. As <50% of patients attained the exposure targets, higher golimumab induction dosing requires investigation to secure its future in clinical practice.