Safety, effectiveness, and pharmacokinetics of adalimumab in children with polyarticular juvenile idiopathic arthritis aged 2 to 4 years

Population Pharmacokinetics of Adalimumab in Juvenile Idiopathic Arthritis Patients: A Retrospective Cohort Study Using Clinical Care Data

BACKGROUND AND OBJECTIVE

Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disorder that primarily affects the joints in children. Notably, it is known to co-occur with uveitis. Adalimumab, a monoclonal anti-TNF antibody, is effective in treating both conditions. A deeper understanding of the pharmacokinetics (PK) of adalimumab in JIA is crucial to advance in more personalized treatment approaches. The objective of this study is to evaluate the population PK profile of adalimumab in JIA and to explain causes for its variability.

MATERIALS AND METHODS

Adalimumab and antidrug antibody concentrations were retrospectively retrieved from the charts of patients with JIA. Initially, five literature-based population PK models of adalimumab were evaluated to assess their ability to describe the observed concentration-time profiles in the JIA cohort. These models included one specifically for the pediatric Crohn's disease population and four derived from studies in adult populations in healthy subjects and rheumatoid arthritis patients. Subsequently, a novel population PK model tailored to the JIA population was developed using NONMEM software. Monte Carlo simulations were then conducted utilizing the final PK model to visualize the concentration-time profile of adalimumab in patients with JIA and the impact of covariates.

RESULTS

A cohort of 50 patients with JIA with 78 available adalimumab samples was assessed. The mean age was 11.8 ± 3.9 years, with a median body weight of 49 kg (interquartile range 29.4-59.8 kg). All literature models adequately described the concentration-time profiles in JIA. The best model, which was developed in patients with rheumatoid arthritis during the maintenance phase of treatment, served as a basis for estimating clearance in JIA, resulting in a value of 0.37 L per day per 70 kg. Patient body weight, antidrug antibodies, methotrexate use, CRP level, and comorbidity of uveitis were found to have a significant impact on adalimumab clearance, and these reduced the inter-patient variability from 58.6 to 28.0%. On steady state in the simulated patient population, the mean trough level was 7.4 ± 5.5 mg/L. The two dosing regimens of 20 and 40 mg every other week, based on patients' body weight, resulted in comparable simulated overall drug exposure.

CONCLUSIONS

Five literature models effectively described adalimumab PK in this pediatric cohort, highlighting the potential for extrapolating existing models to the pediatric population. The new JIA model confirmed the effect of several known covariates and found a novel association for drug clearance with methotrexate use (lower) and uveitis (higher), which might have clinical relevance for personalized dosing in JIA.

Adverse events of biological agents in pediatric rheumatologic diseases

OBJECTIVES

To evaluate adverse events (AEs) in pediatric patients with rheumatologic diseases being treated with approved or off-label biologic agents (BAs).

METHODS

This observational, retrospective, multicenter study was conducted from 2010 to 2022 in patients under 18 years of age with rheumatic diseases who were receiving interleukin-1 antibodies (Anti-IL1), interleukin-6 antibodies (Anti-IL6), and tumor necrosis factor alpha inhibitors (anti-TNF). Efficacy, AEs, and timing of AEs were collected from electronic medical records.

RESULTS

Three hundred and fifteen BAs were prescribed to 237 patients. Fifty AEs occurred in 44 patients (18.6%). Anti-TNF exposure was present in 8 (72.2%) of 11 patients with latent tuberculosis (TB) and in all 7 patients with herpes infections. Four of 6 patients (66.7%) with recurrent upper respiratory tract infections and 7 of 8 patients (87.5%) with local skin reactions were on Anti-IL1. The cutoff value for latent TB development was determined as 23.5 months by ROC analysis (AUC: 0.684 ± 0.072, p = 0.038, 95% CI: 0.54-0.82). In patients who used BA for 23.5 months or more, the risk of latent TB was 5.94-fold (p = 0.024, 95% CI: 1.26-27.97). Drug rash with eosinophilia and systemic symptoms (DRESS) occurred in 2 patients on anakinra, and anaphylaxis occurred in 1 patient on anti-IL6. There were no cases of malignancy or death in any patient.

CONCLUSION

The physician should be vigilant for latent TB in patients exposed to BA for more than 2 years. While local skin reactions are more prevalent in patients receiving anti-IL1, severe skin reactions such as DRESS may also occur.

Prospective study to characterize adalimumab exposure in pediatric patients with rheumatic diseases

BACKGROUND

In pediatric rheumatic diseases (PRD), adalimumab is dosed using fixed weight-based bands irrespective of methotrexate co-treatment, disease activity (DA) or other factors that might influence adalimumab pharmacokinetics (PK). In rheumatoid arthritis (RA) adalimumab exposure between 2-8 mg/L is associated with clinical response. PRD data on adalimumab is scarce. Therefore, this study aimed to analyze adalimumab PK and its variability in PRD treated with/without methotrexate.

METHODS

A two-center prospective study in PRD patients aged 2-18 years treated with adalimumab and methotrexate (GA-M) or adalimumab alone (GA) for ≥ 12 weeks was performed. Adalimumab concentrations were collected 1-9 (maximum concentration; Cmax), and 10-14 days (minimum concentration; Cmin) during ≥ 12 weeks following adalimumab start. Concentrations were analyzed with enzyme-linked immunosorbent assay (lower limit of quantification: 0.5 mg/L). Log-normalized Cmin were compared between GA-M and GA using a standard t-test.

RESULTS

Twenty-eight patients (14 per group), diagnosed with juvenile idiopathic arthritis (71.4%), non-infectious uveitis (25%) or chronic recurrent multifocal osteomyelitis (3.6%) completed the study. GA-M included more females (71.4%; GA 35.7%, p = 0.13). At first study visit, children in GA-M had a slightly longer exposure to adalimumab (17.8 months [IQR 9.6, 21.6]) compared to GA (15.8 months [IQR 8.5, 30.8], p = 0.8). Adalimumab dosing was similar between both groups (median dose 40 mg every 14 days) and observed DA was low. Children in GA-M had a 27% higher median overall exposure compared to GA, although median Cmin adalimumab values were statistically not different (p = 0.3). Cmin values ≥ 8 mg/L (upper limit RA) were more frequently observed in GA-M versus GA (79% versus 64%). Overall, a wide range of Cmin values was observed in PRD (0.5 to 26 mg/L).

CONCLUSION

This study revealed a high heterogeneity in adalimumab exposure in PRD. Adalimumab exposure tended to be higher with methotrexate co-treatment compared to adalimumab monotherapy although differences were not statistically significant. Most children showed adalimumab exposure exceeding those reported for RA with clinical response, particularly with methotrexate co-treatment. This highlights the need of further investigations to establish model-based personalized treatment strategies in PRD to avoid under- and overexposure.

TRIAL REGISTRATION

NCT04042792 , registered 02.08.2019.

An Overview of Adalimumab Therapy for Ankylosing Spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease known for causing pain, stiffness, and reduced mobility in the axial skeleton. Adalimumab, a tumor necrosis factor (TNF) inhibitor, has emerged as a promising therapeutic option for AS.

METHODS

This systematic review involved a comprehensive search of randomized controlled trials related to AS treatment, conducted in major databases such as MEDLINE, Google Scholar, and PubMed. The search terms encompassed ankylosing spondylitis, adalimumab, methotrexate, other non-biologic DMARDs, glucocorticoids, NSAIDs, and analgesics. A total of 14 randomized controlled trials with 4,500 participants were included in the review.

RESULTS

The review's results revealed that adalimumab demonstrated notable superiority when compared to a placebo. It effectively reduced disease activity, improved physical function, and lowered inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate. Adalimumab demonstrated a favorable safety profile, with adverse events comparable to those observed with placebo.

CONCLUSION

Based on the results, adalimumab is deemed an effective treatment for AS, showcasing its potential as a first-line therapeutic option. Notably, no significant increase in adverse events was observed compared to placebo. However, the conclusion emphasizes the need for further studies with extended follow-up durations to ascertain the long-term efficacy and safety of adalimumab in AS management. This systematic review provides valuable insights supporting the use of adalimumab in the treatment of AS and underscores the importance of ongoing investigations into its long-term effects to optimize its clinical utilization in AS patients.

Defining a therapeutic range for adalimumab serum concentrations in the management of pediatric noninfectious uveitis, a step towards personalized treatment

BACKGROUND

Adalimumab is currently considered the most efficacious anti-TNFα agent for childhood noninfectious uveitis (NIU). The objective of this study was to define a therapeutic range for adalimumab trough levels in the treatment of childhood NIU.

METHODS

A retrospective, observational, pilot study of 36 children with NIU aged < 18 years, treated with adalimumab. Serum adalimumab through levels and adalimumab anti-drug antibodies (ADA) were analysed at least 24 weeks after start adalimumab.

RESULTS

Adalimumab trough levels were significantly higher in complete responders 11.8 μg/mL (range 6.9-33.0) compared to partial or non-responders 9,2 μg/mL (range 0-13.6) (p = 0,004). Receiver-operator characteristics analyses with an area under the curve of 0,749 (95% CI, 0,561-0,937) defined 9.6 µg/mL as the lower margin for the therapeutic range. This cut-off corresponds with a sensitivity of 88% and a specificity of 56% (positive predictive value, 85%; negative predictive value, 62.5%). A concentration effect curve defined 13 µg/mL as the upper margin. Approximately one-third (30.5%) of patients had an adalimumab trough concentration exceeding 13 µg/mL. Free ADA were observed in 2 patients (5.5%).

CONCLUSIONS

A therapeutic range of adalimumab trough levels of 9.6 to 13 µg/mL, which corresponds with an optimal clinical effect, was identified. Therapeutic drug monitoring may guide the optimisation of treatment efficacy in children with NIU in the treat-to-target era.

Rheumatoid Arthritis Has Won the Battle but Not the War: How Many Joints Will We Save Tomorrow?

Rheumatoid arthritis refers to joint diseases of unclear etiology whose final stages can lead to unbearable pain and complete immobility of the affected joints. As one of the most widely known diseases of the joints, it serves as a study target for a large number of research groups and pharmaceutical companies. Modern treatment with anti-inflammatory drugs, including janus kinase (JAK) inhibitors, monoclonal antibodies, and botanicals (polyphenols, glycosides, alkaloids, etc.) has achieved some success and hope for improving the course of the disease. However, existing drugs against RA have a number of side effects which push researchers to elaborate on more selective and effective drug candidates. The avant-garde of research, which aims to develop treatment of rheumatoid arthritis using antisense oligonucleotides along with nonsteroidal drugs and corticosteroids against inflammation, increases the chances of success and expands the arsenal of drugs. The primary goal in the treatment of this disease is to find therapies that allow patients with rheumatoid arthritis to move their joints without pain. The main purpose of this review is to show the victories and challenges for the treatment of rheumatoid arthritis and the tortuous but promising path of research that aims to help patients experience the joy of freely moving joints without pain.

Therapeutic Development in Polyarticular Course Juvenile Idiopathic Arthritis: Extrapolation, Dose Selection, and Clinical Trial Design

OBJECTIVE

Stakeholders met to address persistent challenges facing the development of therapeutics for polyarticular juvenile idiopathic arthritis (pJIA), which result in fewer approved therapies for children with pJIA than adults with rheumatoid arthritis (RA) and long lag times from adult RA approval to pediatric labeling. Ensuring that new medications are authorized in a timely manner to meet the needs of JIA patients worldwide is critically important to multiple stakeholders.

METHODS

The Food and Drug Administration in collaboration with the University of Maryland Center for Regulatory Science and Innovation held a public workshop entitled "Accelerating Drug Development for pJIA" on October 2, 2019, to address challenges surrounding access to new medications for children and adolescents with pJIA. Regulatory, academic, and industry stakeholders, as well as patient representatives, participated in the workshop, which consisted of 4 sessions, including panel discussions.

RESULTS

The workshop facilitated broad public discussion of challenges facing the development of pJIA therapeutics, highlighting areas of need and outlining opportunities to expedite development, while underscoring the necessity of close collaboration between all stakeholders, including patients and families.

CONCLUSION

This report summarizes key aspects of the workshop, including the appropriate application of innovative approaches to the development of pJIA therapeutics, including extrapolation, to address current challenges and provide timely access to newer safe and effective treatments. Long-term safety assessment is of pressing concern to stakeholders and cannot be fully extrapolated from adult studies but requires consistent postmarketing long-term follow-up.

Efficacy and safety of TNF inhibitors in the treatment of juvenile idiopathic arthritis: a systematic literature review

OBJECTIVE

A systematic literature review was conducted to summarize efficacy and safety data from studies that evaluated tumor necrosis factor inhibitors in patients with juvenile idiopathic arthritis (JIA).

METHODS

Relevant publications were identified via online searches (cutoff: March 16, 2021). After screening search results, outcome data were extracted if the treatment arm included ≥ 30 patients. Outcomes were described narratively, with efficacy assessed by JIA-American College of Rheumatology (ACR) response criteria and safety assessed by the incidence of serious adverse events (SAEs) per 100 patient-years (100PY).

RESULTS

Among 87 relevant publications included in the qualitative synthesis, 19 publications described 13 clinical trials. Across the 13 trials, the percentages of patients who achieved JIA-ACR30/50/70/90 responses at Week 12 with adalimumab ranged 71-94%, 68-90%, 55-61%, and 39-42%, respectively; with etanercept (Week 12), 73-94%, 53-78%, 36-59%, and 28%; with golimumab (Week 16), 89%, 79%, 66%, and 36%; and with infliximab (Week 14), 64%, 50%, and 22% (JIA-ACR90 not reported). SAE incidence across all time points ranged 0-13.7 SAE/100PY for adalimumab, 0-20.0 SAE/100PY for etanercept, and 10.4-24.3 SAE/100PY for golimumab (1 study). SAE incidence could not be estimated from the 2 infliximab publications.

CONCLUSION

Tumor necrosis factor inhibitors are effective and well tolerated in the treatment of JIA, but additional evidence from head-to-head studies and over longer periods of time, especially in the context of the transition from pediatric to adult care, would be useful.

Dosing Variation at Initiation of Adalimumab and Etanercept and Clinical Outcomes in Juvenile Idiopathic Arthritis: A Childhood Arthritis and Rheumatology Research Alliance Registry Study

OBJECTIVE

To determine the dose-response relationship of tumor necrosis factor (TNF) inhibition in the treatment of juvenile idiopathic arthritis (JIA).

METHODS

Participants of the Childhood Arthritis and Rheumatology Research Alliance Registry were eligible for inclusion in the analyses if they started TNF inhibition treatment for JIA. The primary treatment response was determined 3 to 7 months after the start of treatment, based on the JIA American College of Rheumatology Pediatric criteria for improvement, clinical Juvenile Arthritis Disease Activity Score, and persistence of treatment after 6 months. Subsequently, pooled logistic regression models were performed to include long-term follow-up data. The models were adjusted for risk factors associated with poor treatment response. Dosing was expressed by body weight, body surface area, ideal body weight, fat free mass, and lean body mass.

RESULTS

Participants treated with adalimumab (n = 328) and etanercept (n = 437) were included in the analyses (median dose 0.82 mg/kg body weight [interquartile range (IQR) 0.66-1.04] and 0.83 mg/kg body weight [IQR 0.75-0.95], respectively). The majority of analyses did not show a relationship between dose and outcome. Where associations were found, results were conflicting. Alternative dosing characteristics based on ideal body weight, fat free mass, and lean body mass did not result in stronger or more consistent associations.

CONCLUSION

This study was not able to confirm our hypothesis that increased dosing of TNF inhibitors results in improved treatment outcomes. Although adjustment was performed for risk factors of impaired treatment response, residual confounding by indication likely explains the negative associations found in this study.

OBSIDIAn - real world evidence of Originator to BioSImilar Drug switch in juvenile idiopathic arthritis

OBJECTIVES

Limited data about use of biosimilars are available in children with Juvenile Idiopathic Arthritis (JIA). This study therefore aimed to evaluate long-term efficacy and safety of switching from etanercept (ETA) and adalimumab (ADA) originators to their biosimilars, in children with JIA, in a real-world setting.

METHODS

This is a retro-prospective non-interventional multicentre Italian comparative cohort study. Medical charts of JIA children treated with biosimilars of ETA or ADA were included. Efficacy and safety of TNF-inhibitors therapy was evaluated at last follow-up during originator and at 3, 6 and 12 months following the switch to biosimilar.

RESULTS

59 children (42 female, median age at onset 88 months) were treated with biosimilar of ETA (21) and ADA (38). Forty-five switched from the originator to the BIO (17 ETA, 28 ADA). At time of switch, 12/17 patients on ETA and 18/28 on ADA were in remission. No significant difference has been found at 3, 6 and 12 months after the switch. Ten patients discontinued biosimilars due to disease remission (4 ETA, 3 ADA), family willing (1 ETA), occurrence of burning at injection site (1 ETA), and persistent activity (1 ADA). No statistically significant difference was observed between originator and BIOs, nor between originator and BIOs, and between ADA and ETA in time to disease remission achievement, time to relapse and number of patients who experienced AE.

CONCLUSION

Our real-life results seem to confirm the efficacy and safety profile of switching from originator of ADA and ETA to their respective BIOs also in paediatric patients with JIA.

Long-term outcomes in patients with polyarticular juvenile idiopathic arthritis receiving adalimumab with or without methotrexate

Objectives

Long-term safety and efficacy of adalimumab among patients with juvenile idiopathic arthritis (JIA) was evaluated through 6 years of treatment.

Methods

Children aged 4–17 years with polyarticular JIA were enrolled in a phase III, randomised-withdrawal, double-blind, placebo-controlled trial consisting of a 16-week open-label lead-in period, 32-week randomised double-blind period and 360-week long-term extension. Patients were stratified by baseline methotrexate use. Adverse events (AEs) were monitored, and efficacy assessments included JIA American College of Rheumatology (JIA ACR) 30%, 50%, 70% or 90% responses and the proportions of patients achieving 27-joint Juvenile Arthritis Disease Activity Score (JADAS27) low disease activity (LDA, ≤3.8) and inactive disease (ID, ≤1).

Results

Of 171 patients enrolled, 62 (36%) completed the long-term extension. Twelve serious infections in 11 patients were reported through 592.8 patient-years of exposure. No cases of congestive heart failure-related AEs, demyelinating disease, lupus-like syndrome, malignancies, tuberculosis or deaths were reported. JIA ACR 30/50/70/90 responses and JADAS27 LDA were achieved in 66% to 96% of patients at week 104, and 63 (37%) patients achieved clinical remission (JADAS27 ID sustained for ≥6 continuous months) during the study. Attainment of JIA ACR 50 or higher and JADAS27 LDA or ID in the initial weeks were the best predictors of clinical remission. Mean JADAS27 decreased from baseline, 22.5 (n=170), to 2.5 (n=30) at week 312 (observed analysis).

Conclusions

Through 6 years of exposure, adalimumab was well tolerated with significant clinical response (up to clinical remission) and a relatively low retention rate.

Association of adalimumab trough concentrations and treatment response in patients with Juvenile Idiopathic Arthritis

OBJECTIVE

To assess the relationship of adalimumab trough concentrations and treatment response in paediatric patients with juvenile idiopathic arthritis (JIA).

METHODS

Monocentric cohort study of JIA patients treated with adalimumab. Clinical data and samples were collected during routine follow-up. Adalimumab trough concentrations were quantified by a novel liquid chromatography-tandem mass spectrometry assay. Anti-adalimumab antibodies were measured in samples with trough concentrations ≤5mg/l. Disease activity was evaluated using the clinical Juvenile Arthritis Disease Activity Score with 71 joint-count (cJADAS71). Response to adalimumab was defined according to recent international treat-to-target guidelines.

RESULTS

35 adalimumab trough samples were available from 34 paediatric patients with JIA. Although there was no significant difference in adalimumab dose, trough concentrations were significantly lower in patients with secondary failure (median 1.0 mg/l; IQR 1.0-5.3) compared with patients with primary failure (median 13.97 mg/l; IQR 11.81-16.67) or an adequate response (median 14.94 mg/l; IQR 10.31-16.19) to adalimumab.

CONCLUSION

Adalimumab trough concentrations were significantly lower in JIA patients with secondary failure compared with patients with primary failure or an adequate response to adalimumab. Results suggest that trough concentration measurements could identify JIA patients who require increased adalimumab doses to achieve or maintain therapeutic drug concentrations.

Nanotechnological approach and bio-inspired materials to face degenerative diseases in aging

The aging of the world population is increasingly claimed as an alarming situation, since an ever-raising number of persons in advanced age but still physically active is expected to suffer from invalidating and degenerative diseases. The impairment of the endogenous healing potential provoked by the aging requires the development of more effective and personalized therapies, based on new biomaterials and devices able to direct the cell fate to stimulate and sustain the regrowth of damaged or diseased tissues. To obtain satisfactory results, also in cases where the cell senescence, typical of the elderly, makes the regeneration process harder and longer, the new solutions have to possess excellent ability to mimic the physiological extracellular environment and thus exert biomimetic stimuli on stem cells. To this purpose, the "biomimetic concept" is today recognized as elective to fabricate bioactive and bioresorbable devices such as hybrid osteochondral scaffolds and bioactive bone cements closely resembling the natural hard tissues and with enhanced regenerative ability. The review will illustrate some recent results related to these new biomimetic materials developed for application in different districts of the musculoskeletal system, namely bony, osteochondral and periodontal regions, and the spine. Further, it will be shown how new bioactive and superparamagnetic calcium phosphate nanoparticles can give enhanced results in cardiac regeneration and cancer therapy. Since tissue regeneration will be a major demand in the incoming decades, the high potential of biomimetic materials and devices is promising to significantly increase the healing rate and improve the clinical outcomes even in aged patients.

Open-Label Phase 3 Study of Intravenous Golimumab in Patients With Polyarticular Juvenile Idiopathic Arthritis

Objectives

To assess efficacy, pharmacokinetics (PK) and safety of intravenous (i.v.) golimumab in patients with polyarticular-course JIA (pc-JIA).

Methods

Children aged 2 to <18 years with active pc-JIA despite MTX therapy for ≥2 months received 80 mg/m² golimumab at weeks 0, 4, then every 8 weeks through week 52 plus MTX weekly through week 28. The primary and major secondary endpoints were PK exposure and model-predicted steady-state area under the curve (AUC_ss) over an 8-week dosing interval at weeks 28 and 52, respectively. JIA ACR response and safety were also assessed.

Results

In total, 127 children were treated with i.v. golimumab. JIA ACR 30, 50, 70, and 90 response rates were 84%, 80%, 70% and 47%, respectively, at week 28 and were maintained through week 52. Golimumab serum concentrations and AUC_ss were 0.40 µg/ml and 399 µg ⋅ day/ml at week 28. PK exposure was maintained at week 52. Steady-state trough golimumab concentrations and AUC_ss were consistent across age categories and comparable to i.v. golimumab dosed 2 mg/kg in adults with rheumatoid arthritis. Golimumab antibodies and neutralizing antibodies were detected via a highly sensitive drug-tolerant assay in 31% (39/125) and 19% (24/125) of patients, respectively. Median trough golimumab concentration was lower in antibody-positive vs antibody-negative patients. Serious infections were reported in 6% of patients, including one death due to septic shock.

Conclusion

Body surface area-based dosing of i.v. golimumab was well tolerated and provided adequate PK exposure for clinical efficacy in paediatric patients with active pc-JIA.

ClinicalTrials.gov number NCT02277444

Safety and Effectiveness of Adalimumab in Patients With Polyarticular Course of Juvenile Idiopathic Arthritis: STRIVE Registry Seven-Year Interim Results

OBJECTIVE

To evaluate safety and effectiveness of adalimumab (ADA) in polyarticular-course juvenile idiopathic arthritis (JIA) in the STRIVE registry.

METHODS

STRIVE enrolled patients with polyarticular-course JIA into 2 arms based on treatment with methotrexate (MTX) alone or ADA with/without MTX (ADA ± MTX). Adverse events (AEs) per 100 patient-years of observation time were analyzed by registry arm. Patients who entered the registry within 4 weeks of starting MTX or ADA ± MTX, defined as new users, were evaluated for change in disease activity assessed by the 27-joint Juvenile Arthritis Disease Activity Score with the C-reactive protein level (JADAS-27_CRP ).

RESULTS

At the 7-year cutoff date (June 1, 2016), data from 838 patients were available (MTX arm n = 301, ADA ± MTX arm n = 537). The most common AEs were nausea (10.3%), sinusitis (4.7%), and vomiting (4.3%) in the MTX arm and arthritis (3.9%), upper respiratory tract infection (3.5%), sinusitis, tonsillitis, and injection site pain (3.0% each) in the ADA ± MTX arm. Rates of serious infection were 1.5 events/100 patient-years in the MTX arm and 2.0 events/100 patient-years in the ADA ± MTX arm. AE and serious AE rates were similar in patients receiving ADA with versus without MTX. No deaths or malignancies were reported. New users in the ADA ± MTX arm showed a trend toward lower mean JADAS-27_CRP compared with new users in the MTX arm in the first year of STRIVE.

CONCLUSION

The STRIVE registry 7-year interim results support the idea that ADA ± MTX is well tolerated by most children. Registry median ADA exposure was 2.47 (interquartile range 1.0-3.6) years, with 42% of patients continuing ADA at the 7-year cutoff date.

Biologics in juvenile idiopathic arthritis-main advantages and major challenges: A narrative review

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. The disease is divided in different subtypes based on main clinical features and disease course. Emergence of biological agents targeting specific pro-inflammatory cytokines responsible for the disease pathogenesis represents the revolution in the JIA treatment. Discovery and widespread usage of biological agents have led to significant improvement in JIA patients’ treatment, with evidently increased functionality and decreased disease sequel. Increased risk of infections remains the main discussion topic for years. Despite the slightly increased frequency of upper respiratory tract infections reported in some studies, the general safety of drugs is acceptable with rare reports of severe adverse effects (SAEs). Tuberculosis (TBC) represents the important threat in regions with increased TBC prevalence. Therefore, routine screening for TBC should not be neglected when prescribing and during the follow-up of biological treatment. Malignancy represents a hypothetical complication that sometimes causes hesitations for physicians and patients in its prescription and usage. On the other hand, current reports from the literature do not support the increased risk for malignancy among JIA patients treated with biological agents. A multidisciplinary approach including a pediatric rheumatologist and an infectious disease specialist is mandatory in the follow- up of JIA patients. Although the efficacy and safety of biological agents have been proven in different studies, there is still a need for long-term, multicentric evaluation providing relevant data.

Towards therapeutic drug monitoring of TNF inhibitors for children with juvenile idiopathic arthritis: a scoping review

OBJECTIVES

Before a clinician decides whether treatment with TNF inhibition in children with JIA has failed, one should ensure adequate systemic exposure has been achieved. Therapeutic drug monitoring might allow for improved treatment outcome with lower treatment-associated costs. However, this requires understanding of the pharmacokinetic (PK) characteristics, and the pharmacokinetic/pharmacodynamic (PK/PD) relationship for children with JIA. We performed a scoping review to summarize the available literature and identify areas for future research.

METHODS

A systematic search was conducted of the Medline, EMBASE, Web of Science and Cochrane databases as well as the clinicaltrials.gov registry. In total, 3959 records were screened and 130 publications were selected for full text assessment.

RESULTS

Twenty publications were included and divided into three categories: PK (n = 9), PK/PD (n = 3) and anti-drug antibodies (n = 13). Industry involvement was significant in 14 publications. Although data are limited, systemic exposure to TNF inhibitors is generally lower in younger children but meta-analysis is not possible. The PK/PD relationship has had limited study but there is partial evidence for infliximab. Anti-drug antibodies are common, and are related to impaired clinical outcome with adalimumab and infliximab therapy.

CONCLUSION

The current knowledge about the PK and PK/PD of TNF inhibitors in the treatment of children with JIA is limited, which prevents the introduction of TDM. Re-analysis of available data from previous trials, incorporation of pharmacologic assessments into existing biorepository studies as well as new prospective PK and PK/PD trials are required to obtain this knowledge.

Immunogenicity of biologic agents in juvenile idiopathic arthritis: a systematic review and meta-analysis

OBJECTIVE

The clinical impact of anti-drug antibodies (ADAbs) in paediatric patients with JIA remains unknown. This systematic review and meta-analysis aimed to summarize the prevalence of ADAbs in JIA studies; investigate the effect of ADAbs on treatment efficacy and adverse events; and explore the effect of immunosuppressive therapy on antibody formation.

METHODS

PubMed, Embase and the Cochrane Library were systematically searched to identify relevant clinical trials and observational studies that reported prevalence of ADAbs. Studies were systematically reviewed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses and appropriate proportional and pairwise meta-analyses were performed.

RESULTS

A total of 5183 references were screened; 28 articles, involving 26 studies and 2354 JIA patients, met eligibility criteria. Prevalence of ADAbs ranged from 0% to 82% across nine biologic agents. Overall pooled prevalence of ADAbs was 16.9% (95% CI, 9.5, 25.9). Qualitative analysis of included studies indicated that antibodies to infliximab, adalimumab, anakinra and tocilizumab were associated with treatment failure and/or hypersensitivity reactions. Concomitant MTX uniformly reduced the risk of antibody formation during adalimumab treatment (risk ratio 0.33; 95% CI 0.21, 0.52).

CONCLUSION

The association of ADAbs with treatment failure and hypersensitivity reactions indicates their clinical relevance in paediatric patients with JIA. Based on our findings, we recommend a preliminary course of action regarding immunogenicity of biologic agents in patients with JIA. Further strategies to predict, prevent, detect and manage immunogenicity could optimize treatment outcomes and personalize treatment with biologic therapies.

Comparison of adverse events of biologicals for treatment of juvenile idiopathic arthritis: a systematic review

Objectives: Treatment of juvenile idiopathic arthritis has changed rapidly since the introduction of various biologics almost twenty years ago. Many clinical trials have been performed to monitor efficacy and safety of new agents. The aim of this review is to summarize safety concerns, which were observed during prospective clinical trials. Methods: Since etanercept was the first biologic approved and remains the most frequently used, as first biologic in polyarticular JIA patients, the authors calculated the relative risk of the adverse events for all examined biologicals and compared the values with the value of etanercept. Results: Relative rates for all adverse events showed similar rates for etanercept, infliximab, golimumab, and tocilizumab, whereas adalimumab showed higher rates and abatacept lower rates. Comparison of rates for serious adverse events demonstrated, that rates seemed comparable for etanercept, adalimumab, infliximab, and tocilizumab. Again, abatacept showed a lower rate, whereas golimumab seems to have a higher relative risk for serious adverse events. Rate of infection was lowest in patients treated with abatacept or tocilizumab, patients treated with etanercept, adalimumab and Infliximab again had similar rates. Conclusion: The safety profiles of actually approved biologics are highly acceptable. However, further observation, especially long-term observation through registry studies, is required.

Comparative Efficacy of Adalimumab and Etanercept in Children with Juvenile Idiopathic Arthritis Under 4 Years of Age Depending on Active Uveitis

Introduction:

In 2011, Etanercept (ETA) was approved for clinical application in patients with Juvenile Idiopathic Arthritis (JIA) older than 2 years of age; Adalimumab (ADA) was approved in 2013. However, the available data for these patients are not sufficient even in large-scale registers. In older children, uveitis is a factor taken into consideration when choosing anti-TNF therapy, so we believe that its onset at an early age may affect the efficacy of treatment with different anti-TNF drugs.

Objectives:

This study aimed to evaluate the comparative efficacy of ADA and ETA in children of young age depending on their uveitis status.

Methods:

Comparative analysis involved patients who had initiated ETA (n=49, no active uveitis) or ADA (n=25; 13 patients with active uveitis and 12 patients without uveitis) therapy at an age of ≤4 years. Treatment efficacy was evaluated according to the dynamics of clinical signs and laboratory values, the ACRPedi and Wallace criteria.

Results:

ETA and ADA proved very efficacious in children under 4 years of age already after the first month of therapy according to the disease activity scores, laboratory values, and morning stiffness duration. After 3 months of therapy, the number of affected joints was substantially reduced in all three groups (p<0.01). The percentage of patients who had achieved ACR50/70/90 by the end of the follow-up period was 42/41/38 (85.7/83.7/77.6%) in ETA group, 10/10/9 (76.9/76.9/69.2%) in ADA group with uveitis, and 9/7/5 (75/58.3/41.7) in ADA group without uveitis, respectively. A comparable proportion of ETA patients and ADA patients with uveitis achieved remission (26 (53.1%) and 7 (53.8%), respectively), while only 3 (25%) of ADA patients without uveitis achieved long-term clinical remission (p-values are insignificant).

Conclusion:

In children younger than 4 years, ADA shows higher efficacy in patients with uveitis as compared to those without uveitis. Children without uveitis show a better response to ETA, although there is a risk of de novo uveitis. Therefore, ADA is the drug of choice for children with uveitis under 4 years of age, while ETA is preferred in children without uveitis.

Safety evaluation of adalimumab in immune-mediated inflammatory disorders: a rheumatological point of view

INTRODUCTION

Immune-mediated inflammatory disorders (IMIDs) are systemic conditions which arise secondary to complex immune mechanism defects and can affect many organs. While previous therapies based on steroids and immunosuppressive agents had a poor risk/benefit balance, TNFα-specific inhibitors such as adalimumab have revolutionized the course of many diseases and patient outcomes. However, concerns were raised regarding the increased risk of infectious diseases and neoplasia due to potential prospective loss of immune control. This is especially true when considering that IMIDs concerns elderly/frail populations, with multiple co-morbidities, organ damage and often long-term steroid therapy. Areas covered: Now prescribed for more than 15 years for a diverse range of indications, long-term data highlighting the efficacy and safety are available and led to recommendations for the daily practice that will be discussed. Expert opinion: The efficacy of adalimumab changed the therapeutic paradigm of many diseases. Its tolerance is good and it is the most widely prescribed therapy in IMIDs. It is now the standard of care arm in head to head trials. In the long term, adalimumab dominant role might be weakened by more targeted therapies but its varied indications among IMIDs should secure its position as an important tool in our future practice.

Safety of Adalimumab in Pediatric Patients with Polyarticular Juvenile Idiopathic Arthritis, Enthesitis-Related Arthritis, Psoriasis, and Crohn's Disease

OBJECTIVE

To evaluate the safety of adalimumab in pediatric patients who participated in clinical trials of juvenile idiopathic arthritis (polyarticular juvenile idiopathic arthritis and pediatric enthesitis-related arthritis), psoriasis, and Crohn's disease.

STUDY DESIGN

This analysis included data from 7 global, randomized, and open-label AbbVie-sponsored clinical trials of adalimumab and their open-label extensions conducted between September 2002 and December 31, 2015 (cutoff date for ongoing studies). Patients who received ≥1 dose of adalimumab subcutaneously were included. Adverse events that occurred after the first dose of adalimumab and up to 70 days (5 half-lives) after the last dose were reported and events per 100 patient-years were calculated.

RESULTS

The analysis included 577 pediatric patients, representing 1440.7 patient-years of adalimumab exposure. Across indications, the most commonly reported adverse events (events/100 patient-years) were upper respiratory tract infections (24.3), nasopharyngitis (17.3), and headache (19.9). Serious infections (4.0 events/100 patient-years) were the most frequent serious adverse events across indications; the most commonly reported was pneumonia (0.6 events/100 patient-years). Serious infection rates were 2.7, 0.8, and 6.6 events/100 patient-years in patients with juvenile idiopathic arthritis, psoriasis, and Crohn's disease, respectively. No events of malignancies were reported. One death (accidental fall) occurred in a patient with psoriasis.

CONCLUSIONS

The safety profile of adalimumab in pediatric patients with polyarticular juvenile idiopathic arthritis, enthesitis-related arthritis, psoriasis, and Crohn's disease was generally similar across indications; no new safety signals were identified in the treatment of pediatric patients with adalimumab.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00048542, NCT00775437, NCT00690573, NCT01166282, NCT01251614, NCT00409682, and NCT00686374.

Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Current Practices for Therapeutic Drug Monitoring of Biopharmaceuticals in Pediatrics

Biopharmaceuticals have recently emerged as effective treatments for refractory pediatric autoimmune conditions. Several reports have shown a relationship between drug concentration, antidrug antibodies, and clinical response in these patients, strongly suggesting the potential interest, usefulness, and reliability of therapeutic drug monitoring (TDM) in children. This article reviews the current state of research in juvenile idiopathic arthritis, pediatric inflammatory bowel disease, and pediatric psoriasis from a TDM point of view. There is a remarkable lack of evidence-based data in pediatric patients, which is reflected throughout the article. Most investigations of TDM are focused on research of tumor necrosis factor alpha antagonists in inflammatory bowel disease, albeit preliminary publications are emerging from pediatric rheumatologists and dermatologists. To date, immunogenicity has been a primary concern, particularly regarding infliximab and adalimumab therapy in children, as it may lead to a loss of therapeutic response. Preliminary investigations show that adjusting the dose according to blood drug concentrations improves disease outcomes by overcoming antidrug antibodies, suggesting a crucial role for TDM. Patients who receive other drugs, such as etanercept, abatacept, or tocilizumab, could benefit from TDM because dosage can be optimized by adjusting it to the minimum effective dose.

The clinical effectiveness and cost-effectiveness of abatacept, adalimumab, etanercept and tocilizumab for treating juvenile idiopathic arthritis: a systematic review and economic evaluation

BACKGROUND

Juvenile idiopathic arthritis (JIA) is characterised by joint pain, swelling and a limitation of movement caused by inflammation. Subsequent joint damage can lead to disability and growth restriction. Treatment commonly includes disease-modifying antirheumatic drugs (DMARDs), such as methotrexate. Clinical practice now favours newer drugs termed biologic DMARDs where indicated.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of four biologic DMARDs [etanercept (Enbrel(®), Pfizer), abatacept (Orencia(®), Bristol-Myers Squibb), adalimumab (Humira(®), AbbVie) and tocilizumab (RoActemra(®), Roche) - with or without methotrexate where indicated] for the treatment of JIA (systemic or oligoarticular JIA are excluded).

DATA SOURCES

Electronic bibliographic databases including MEDLINE, EMBASE, The Cochrane Library and the Database of Abstracts of Reviews of Effects were searched for published studies from inception to May 2015 for English-language articles. Bibliographies of related papers, systematic reviews and company submissions were screened and experts were contacted to identify additional evidence.

REVIEW METHODS

Systematic reviews of clinical effectiveness, health-related quality of life and cost-effectiveness were undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A cost-utility decision-analytic model was developed to compare the estimated cost-effectiveness of biologic DMARDs versus methotrexate. The base-case time horizon was 30 years and the model took a NHS perspective, with costs and benefits discounted at 3.5%.

RESULTS

Four placebo-controlled randomised controlled trials (RCTs) met the inclusion criteria for the clinical effectiveness review (one RCT evaluating each biologic DMARD). Only one RCT included UK participants. Participants had to achieve an American College of Rheumatology Pediatric (ACR Pedi)-30 response to open-label lead-in treatment in order to be randomised. An exploratory adjusted indirect comparison suggests that the four biologic DMARDs are similar, with fewer disease flares and greater proportions of ACR Pedi-50 and -70 responses among participants randomised to continued biologic DMARDs. However, confidence intervals were wide, the number of trials was low and there was clinical heterogeneity between trials. Open-label extensions of the trials showed that, generally, ACR responses remained constant or even increased after the double-blind phase. The proportions of adverse events and serious adverse events were generally similar between the treatment and placebo groups. Four economic evaluations of biologic DMARDs for patients with JIA were identified but all had limitations. Two quality-of-life studies were included, one of which informed the cost-utility model. The incremental cost-effectiveness ratios (ICERs) for adalimumab, etanercept and tocilizumab versus methotrexate were £38,127, £32,526 and £38,656 per quality-adjusted life year (QALY), respectively. The ICER for abatacept versus methotrexate as a second-line biologic was £39,536 per QALY.

LIMITATIONS

The model does not incorporate the natural history of JIA in terms of long-term disease progression, as the current evidence is limited. There are no head-to-head trials of biologic DMARDs, and clinical evidence for specific JIA subtypes is limited.

CONCLUSIONS

Biologic DMARDs are superior to placebo (with methotrexate where permitted) in children with (predominantly) polyarticular course JIA who have had an insufficient response to previous treatment. Randomised comparisons of biologic DMARDs with long-term efficacy and safety follow-up are needed to establish comparative effectiveness. RCTs for JIA subtypes for which evidence is lacking are also required.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015016459.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Safety and efficacy of etanercept and adalimumab in children aged 2 to 4 years with juvenile idiopathic arthritis

The TNF inhibitors etanercept (ETA) and adalimumab (ADA) are approved for treating patients older than 2 years with polyarticular juvenile idiopathic arthritis (JIA). Because long-term experience of treating children younger than 4 years is limited, we evaluated the efficacy and safety of ETA or ADA in patients aged 2-4 years. This prospective, long-term, observational registry study documented baseline demographics, clinical characteristics, disease activity parameters, and safety of patients treated with ETA or ADA. Efficacy was determined using the JADAS-10, the JADAS criteria for minimal disease activity (MDA) and remission, and the PedACR response criteria after 3, 6, 12, 18, and 24 months. Between January 2001 and March 2015, 85 patients with polyarticular JIA aged 2-4 years started anti-TNF-α treatment. Seventy-four (54 girls) patients were treated with ETA and 11 (7 girls) with ADA. After 6/12/24 months of treatment, JADAS-MDA was reached by 55/58/58 % of ETA patients and 50/71/66 % of ADA patients. Furthermore, JADAS-Remission was achieved by 35/44/50 % of ETA patients and 16/28/66 % of ADA patients. PedACR 50/70/90 response was achieved by 64/54/41 % of ETA patients and 56/33/22 % of ADA patients at the last treatment observation. Discontinuation because of remission or inefficacy was recorded in 24 (29 %) and 28 (33 %) patients, respectively. Seventy-nine adverse events and four serious adverse events were reported. Administration of ETA and ADA in JIA patients younger than 4 years was efficacious, well tolerated, and safe. Patients younger than 4 years may show marked improvement following anti-TNF-alpha therapy.

Advances in Pediatric Pharmacology, Therapeutics, and Toxicology

In the United States, the Best Pharmaceuticals for Children Act and the Pediatric Research Equity Act continue to promote clinical trials in pediatric populations across all age ranges. In 2014 and 2015, over 70 changes were made to drug labels with updates on information regarding pediatric populations. Additionally, multiple new therapies have received first-approvals for the treatment of pediatric indications ranging form rare genetic metabolic diseases to oncology. In the European Union, there have been more than 30 new authorizations for medicines used in children and 130 approved pediatric investigation plans. Despite the progress that has been made over the last two years, much work remains to further the development of safe and effective therapies for pediatric patients.

Psoriasis in adults and children: Kids are not just little people

Pediatric psoriasis is a common skin disorder. Although pediatric psoriasis has many similarities to adult psoriasis, there are differences in presentation, particularly in infants. In addition, a more limited therapeutic armamentarium exists for children due to different inherent risks. Nearly all therapies are unapproved in the pediatric population, with far fewer pre- and postmarketing studies having been conducted. Despite these challenges, appropriate treatment should never be denied to a young patient, as physical and psychosocial ramifications of psoriasis in the school age child and adolescent are significant. A partnership with the patient, caregivers, and primary care providers is necessary and rewarding in meeting the challenges of this chronic, incurable disease. We address the presentation, treatment options, and counseling necessary when treating psoriasis in the pediatric population.

Biologics and Pediatric Generalized Pustular Psoriasis: An Emerging Therapeutic Trend

Generalized pustular psoriasis (GPP) is a rare form of childhood psoriasis, often requiring systemic therapy, which is challenging as there is a paucity of randomized controlled trials and standardized guidelines. Biologic agents have been used in adults and in pediatric plaque psoriasis, but evidence regarding their efficacy in pediatric GPP has slowly become available. The objective of this study is to summarize and compare the efficacy and safety of biologic agents, such as etanercept, infliximab, and adalimumab, in the treatment of pediatric GPP. A PubMed literature review was conducted and 12 studies met the inclusion criteria for analysis. After reviewing the efficacy of these drugs in pediatric GPP patients and their safety in the use of other pediatric conditions, etanercept was identified as a possible first-line biologic agent for pediatric psoriasis, including GPP, followed by infliximab and adalimumab. In conclusion, several case reports have documented the successful use of biologic agents in refractory cases of pediatric GPP, but clinical trials are needed to gain a better understanding of the efficacy and side effect profile in this population.

Safety of biologic therapies for the treatment of juvenile idiopathic arthritis

INTRODUCTION

The introduction of biological therapies opened a new era of treatment of juvenile idiopathic arthritis. After 15 years of experience with the first biologics for treatment of pediatric rheumatic disease, long-term safety effects are of great interest.

AREAS COVERED

This review summarizes published knowledge about safety aspects from clinical trials as well as from biologic registries in juvenile idiopathic arthritis patients. Beside infusion and injection reactions, the occurrence and aggravation of infections, the occurrence of a second autoimmune diseases, including uveitis, psoriasis, chronic inflammatory bowel disease, multiple sclerosis, diabetes mellitus, as well as cytopenias and the development of malignancies are major concerns regarding treatment with biologics.

EXPERT OPINION

The safety profiles of approved biologics, the TNF-α inhibitors etanercept and adalimumab, and the IL-6-inhibitor tocilizumab are highly acceptable. This conclusion is not easily expandable to the IL-1 inhibitor canakinumab as well as the T-cell-activation-inhibitor abatacept due to lack of experience; however, both have showed an excellent safety profile so far. An increase in knowledge about risk profiles in national and international collaborations, with national as well as international registries, is necessary.

A Randomized, Double-Blind, Placebo-Controlled Multicenter Study of Adalimumab in Pediatric Patients With Enthesitis-Related Arthritis

Objective

Enthesitis‐related arthritis (ERA) is a juvenile idiopathic arthritis (JIA) category, primarily affecting entheses and peripheral joints. This study evaluated efficacy, safety, and pharmacokinetics of adalimumab versus placebo in patients with ERA.

Methods

This is a phase III, multicenter, randomized double‐blind study in patients ages ≥6 to <18 years with ERA treated with adalimumab (24 mg/m², maximum dose 40 mg every other week) or placebo for 12 weeks, followed by up to 192 weeks of open‐label adalimumab. The primary end point was percent change from baseline in number of active joints with arthritis (AJC) at week 12. Samples were collected to determine adalimumab serum concentrations. Adverse events (AEs) were assessed throughout the study.

Results

Forty‐six patients were randomized (31 adalimumab/15 placebo). At baseline, mean age was 12.9 years, mean duration of ERA symptoms was 2.6 years, mean AJC was 7.8, and mean enthesitis count was 8.1. Mean percent change from baseline in AJC at week 12 was greater in the adalimumab group versus placebo (−62.6% versus −11.6%; P = 0.039). Most secondary variables favored adalimumab versus placebo at week 12. Treatment response further increased with continued adalimumab therapy through week 52. Mean steady‐state adalimumab serum concentrations were 7.5–11.8 μg/ml, similar to patients age ≥2 years with polyarticular JIA. AE rates were similar between placebo and adalimumab: any AE (53.3% versus 67.7%), serious AEs (0% versus 3.2%), and infectious AEs (20.0% versus 29.0%).

Conclusion

Adalimumab reduced signs and symptoms of ERA at week 12, with improvement sustained through week 52. The safety profile was consistent with previous adalimumab studies.

Efficacy of Adalimumab in a Girl with Refractory Intestinal Behcet's Disease

We describe our experience with a juvenile patient who had refractory intestinal Behcet's disease that responded to adalimumab, a fully humanized antibody against soluble TNF-α and its receptor. The patient, a 13-year-old girl, presented with oral aphthous ulcers, vulvar pain, and rashes on the lower extremities. She gradually developed a low-grade fever, abdominal pain, diarrhea, and hematochezia. Lower gastrointestinal endoscopy revealed ulcers in the terminal ileum, consistent with intestinal Behcet's disease. Methylprednisolone pulse therapy was initiated, after which the symptoms transiently improved, but, during the corticosteroid taper, the abdominal pain recurred. The symptoms resolved soon after the administration of adalimumab. Of importance, the dose of corticosteroids was successfully reduced without exacerbation during 8 months of observation. This is the first reported case in which adalimumab was used for pediatric gastrointestinal Behcet's disease. Adalimumab is a good choice for intestinal Behcet's disease refractory to conventional treatment.

Pharmacokinetics and pharmacokinetic-pharmacodynamic relationships of monoclonal antibodies in children

Monoclonal antibodies (mAbs) constitute a therapeutically and economically important drug class with increasing use in both adult and paediatric patients. The rather complex pharmacokinetic and pharmacodynamic properties of mAbs have been extensively reviewed in adults. In children, however, limited information is currently available. This paper aims to comprehensively review published pharmacokinetic and pharmacokinetic-pharmacodynamic studies of mAbs in children. The current status of mAbs in the USA and in Europe is outlined, including a critical discussion of the dosing strategies of approved mAbs. The pharmacokinetic properties of mAbs in children are exhaustively summarised along with comparisons to reports in adults: for each pharmacokinetic process, we discuss the general principles and mechanisms of the pharmacokinetic/pharmacodynamic characteristics of mAbs, as well as key growth and maturational processes in children that might impact these characteristics. Throughout this review, considerable knowledge gaps are identified, especially regarding children-specific properties that influence pharmacokinetics, pharmacodynamics and immunogenicity. Furthermore, the large heterogeneity in the presentation of pharmacokinetic/pharmacodynamic data limited clinical inferences in many aspects of paediatric mAb therapy. Overall, further studies are needed to fully understand the impact of body size and maturational changes on drug exposure and response. To maximise future knowledge gain, we propose a 'Guideline for Best Practice' on how to report pharmacokinetic and pharmacokinetic-pharmacodynamic results from mAb studies in children which also facilitates comparisons. Finally, we advocate the use of more sophisticated modelling strategies (population analysis, physiology-based approaches) to appropriately characterise pharmacokinetic-pharmacodynamic relationships of mAbs and, thus, allow for a more rational use of mAb in the paediatric population.