Clinical Trial Design in Juvenile Idiopathic Arthritis

Baricitinib in juvenile idiopathic arthritis: an international, phase 3, randomised, double-blind, placebo-controlled, withdrawal, efficacy, and safety trial

BACKGROUND

Juvenile idiopathic arthritis can be refractory to some or all treatment regimens, therefore new medications are needed to treat this population. This trial assessed the efficacy and safety of baricitinib, an oral Janus kinase 1/2-selective inhibitor, versus placebo in patients with juvenile idiopathic arthritis.

METHODS

This phase 3, randomised, double-blind, placebo-controlled, withdrawal, efficacy, and safety trial was conducted in 75 centres in 20 countries. We enrolled patients (aged 2 to <18 years) with polyarticular juvenile idiopathic arthritis (positive or negative for rheumatoid factor), extended oligoarticular juvenile idiopathic arthritis, enthesitis-related arthritis, or juvenile psoriatic arthritis, and an inadequate response (after ≥12 weeks of treatment) or intolerance to one or more conventional synthetic or biologic disease-modifying antirheumatic drugs (DMARDs). The trial consisted of a 2-week safety and pharmacokinetic period, a 12-week open-label lead-in period (10 weeks for the safety and pharmacokinetic subcohort), and an up to 32-week placebo-controlled double-blind withdrawal period. After age-based dosing was established in the safety and pharmacokinetic period, patients received a once-daily 4 mg adult-equivalent dose of baricitinib (tablets or suspension) in the open-label lead-in period. Patients meeting Juvenile Idiopathic Arthritis-American College of Rheumatology (JIA-ACR) 30 criteria (JIA-ACR30 responders) at the end of the open-label lead-in (week 12) were eligible for random assignment (1:1) to receive placebo or continue receiving baricitinib, and remained in the double-blind withdrawal period until disease flare or up to the end of the double-blind withdrawal period (week 44). Patients and any personnel interacting directly with patients or sites were masked to group assignment. The primary endpoint was time to disease flare during the double-blind withdrawal period and was assessed in the intention-to-treat population of all randomly assigned patients. Safety was assessed in all patients who received at least one dose of baricitinib throughout the three trial periods. For adverse events in the double-blind withdrawal period, exposure-adjusted incidence rates were calculated. The trial was registered on ClinicalTrials.gov, NCT03773978, and is completed.

FINDINGS

Between Dec 17, 2018 and March 3, 2021, 220 patients were enrolled and received at least one dose of baricitinib (152 [69%] girls and 68 [31%] boys; median age 14·0 years [IQR 12·0-16·0]). 219 patients received baricitinib in the open-label lead-in period, of whom 163 (74%) had at least a JIA-ACR30 response at week 12 and were randomly assigned to placebo (n=81) or baricitinib (n=82) in the double-blind withdrawal period. Time to disease flare was significantly shorter with placebo versus baricitinib (hazard ratio 0·241 [95% CI 0·128-0·453], p<0·0001). Median time to flare was 27·14 weeks (95% CI 15·29-not estimable) in the placebo group, and not evaluable for patients in the baricitinib group (<50% had a flare event). Six (3%) of 220 patients had serious adverse events during the safety and pharmacokinetic period or open-label lead-in period. In the double-blind withdrawal period, serious adverse events were reported in four (5%) of 82 patients (incidence rate [IR] 9·7 [95% CI 2·7-24·9] per 100 patient-years at risk) in the baricitinib group and three (4%) of 81 (IR 10·2 [2·1-29·7]) in the placebo group. Treatment-emergent infections were reported during the safety and pharmacokinetic or open-label lead-in period in 55 (25%) of 220 patients, and during the double-blind withdrawal period in 31 (38%) of 82 (IR 102·1 [95% CI 69·3-144·9]) in the baricitinib group and 15 (19%) of 81 (IR 59·0 [33·0-97·3]) in the placebo group. Pulmonary embolism was reported as a serious adverse event in one patient (1%; IR 2·4 [95% CI 0·1-13·3]) in the baricitinib group in the double-blind withdrawal period, which was judged to be related to study treatment.

INTERPRETATION

Baricitinib was efficacious with an acceptable safety profile in the treatment of polyarticular juvenile idiopathic arthritis, extended oligoarticular juvenile idiopathic arthritis, enthesitis-related arthritis, and juvenile psoriatic arthritis, after inadequate response or intolerance to standard therapy.

FUNDING

Eli Lilly and Company under licence from Incyte.

Implications of Evolving Disease Classification for Drug Approval in Juvenile Idiopathic Arthritis

The classification of inflammatory arthritis incorporates a sharp divide between diseases of childhood onset, grouped together as juvenile idiopathic arthritis, and diseases such as rheumatoid arthritis that begin by definition in adulthood. An important consequence of this divide is that regulatory authorities and many rheumatologists regard pediatric and adult arthritides as truly different, with the implication that drugs should be evaluated separately for each category. However, it is now clear that most forms of arthritis transcend the pediatric/adult boundary and that agents generally exhibit comparable success irrespective of age of onset, offering new opportunities in drug development and regulation focused on pharmacology and safety rather than efficacy. This paradigm shift will enable advances in arthritis treatment, originating either with adults or children, to translate more rapidly across the age spectrum.

Precision Medicine: Towards Individualized Dosing in Pediatric Rheumatology

Despite an increase in the number of available therapeutics, many children with rheumatic disease continue to experience active inflammatory disease and treatment failure. One reason for treatment failure is the lack of dosing paradigms to account for the wide between-patient variability in drug pharmacokinetics because of developmental changes or genetic polymorphisms that effect drug absorption, distribution, metabolism, and elimination. This review highlights several strategies to optimize dosing for biologic and nonbiologic disease-modifying antirheumatic drugs, including therapeutic drug monitoring, pharmacogenomics, and the use of pharmacokinetic/pharmacodynamic modeling.

Trajectory of treatment response in the child and adolescent migraine prevention (CHAMP) study: A randomized clinical trial

OBJECTIVE

Identify preventive medication treatment response trajectories among youth participating in the Childhood and Adolescent Migraine Prevention study.

METHODS

Data were evaluated from 328 youth (ages 8-17). Childhood and Adolescent Migraine Prevention study participants completed headache diaries during a 28-day baseline period and a 168-day active treatment period during which youth took amitriptyline, topiramate, or placebo. Daily headache occurrence trajectories were established across baseline and active treatment periods using longitudinal hierarchical linear modeling. We tested potential treatment group differences. We also compared final models to trajectory findings from a clinical trial of cognitive behavioral therapy plus amitriptyline for youth with chronic migraine to test for reproducibility.

RESULTS

Daily headache occurrence showed stability across baseline. Active treatment models revealed decreases in headache frequency that were most notable early in the trial period. Baseline and active treatment models did not differ by treatment group and replicated trajectory cognitive behavioral therapy plus amitriptyline trial findings.

CONCLUSIONS

Replicating headache frequency trajectories across clinical trials provides strong evidence that youth can improve quickly. Given no effect for medication, we need to better understand what drives this clinically meaningful improvement. Results also suggest an expected trajectory of treatment response for use in designing and determining endpoints for future clinical trials.Trial Registration. ClinicalTrials.gov Identifier: NCT01581281.

Advancing the treatment of juvenile idiopathic arthritis

Treatment for juvenile idiopathic arthritis has undergone substantial changes in recent decades. These changes are partly due to the availability of new treatments, mainly biological agents, as well as developments in treatment strategies, including a focus on concepts such as treat-to-target. In addition, the creation of large paediatric research networks has improved patient access to, and design of, clinical trials for rare paediatric diseases. Although these advances have resulted in improvements in care for most patients with juvenile idiopathic arthritis, certain subgroups of patients continue to have a poor prognosis. Further research aims to identify patients in these subgroups early, to personalise their care, improve functional outcomes, and minimise long-term damage and harm. Optimising the duration of therapy for those individuals who require systemic immunosuppression is also of importance. Incorporation of novel biomarkers in combination with validated clinical measures in an effort to predict outcomes and target therapy accordingly is an exciting development.

Response Similarity Assessment Between Polyarticular Juvenile Idiopathic Arthritis and Adult Rheumatoid Arthritis for Biologics

Polyarticular juvenile idiopathic arthritis (pJIA) is a pediatric chronic inflammatory arthritis, much like rheumatoid arthritis (RA) in adults. Drug development for pJIA can potentially be expedited by using extrapolation of efficacy from adult RA; however, the lack of understanding of the response and exposure relationship between pJIA and RA to therapeutic interventions has been a major roadblock. To address this, the objective of our analysis was to conduct a systematic response and exposure comparison between pJIA and RA trials for biologic products. Data from registration RA and pJIA clinical trials (parallel or withdrawal design) for infliximab, tocilizumab, golimumab, and adalimumab were utilized. First, exposure was compared between the pJIA trials and RA pivotal trials. Subsequently, the pJIA vs. RA response similarity was assessed by comparing similar individual subcomponents of the American College of Rheumatology (ACR) scores between the two populations. The exposure comparison demonstrated that at the pJIA trial dose, exposure in pediatric patients was similar to or higher than adults for all biologics evaluated except infliximab, where lower exposure was observed in pJIA patients ≤ 35 kg. Response comparison for individual subcomponents indicated that in a majority of the cases, pJIA response was similar or higher as compared with response from RA trials. Overall, this analysis suggests response similarity between pJIA and RA across the biologic products when exposures are matched between the two populations. These analyses provide support for the use of pharmacokinetic exposure-matching for extrapolation of efficacy from adult RA to pediatric pJIA for the products with established mechanism(s) of action.

Different corticosteroid induction regimens in children and young people with juvenile idiopathic arthritis: the SIRJIA mixed-methods feasibility study

BACKGROUND

In the UK, juvenile idiopathic arthritis is the most common inflammatory disorder in childhood, affecting 10 : 100,000 children and young people aged < 16 years each year, with a population prevalence of around 1 : 1000. Corticosteroids are commonly used to treat juvenile idiopathic arthritis; however, there is currently a lack of consensus as to which corticosteroid induction regimen should be used with various disease subtypes and severities of juvenile idiopathic arthritis.

OBJECTIVE

The main study objective was to determine the feasibility of conducting a randomised controlled trial to compare the different corticosteroid induction regimens in children and young people with juvenile idiopathic arthritis.

DESIGN

This was a mixed-methods study. Work packages included a literature review; qualitative interviews with children and young people with juvenile idiopathic arthritis and their families; a questionnaire survey and screening log to establish current UK practice; a consensus meeting with health-care professionals, children and young people with juvenile idiopathic arthritis, and their families to establish the primary outcome; a feasibility study to pilot data capture and to collect data for future sample size calculations; and a final consensus meeting to establish the final protocol.

SETTING

The setting was rheumatology clinics across the UK.

PARTICIPANTS

Children, young people and their families who attended clinics and health-care professionals took part in this mixed-methods study.

INTERVENTIONS

This study observed methods of prescribing corticosteroids across the UK.

MAIN OUTCOME MEASURES

The main study outcomes were the acceptability of a future trial for children, young people, their families and health-care professionals, and the feasibility of delivering such a trial.

RESULTS

Qualitative interviews identified differences in the views of children, young people and their families on a randomised controlled trial and potential barriers to recruitment. A total of 297 participants were screened from 13 centres in just less than 6 months. In practice, all routes of corticosteroid administration were used, and in all subtypes of juvenile idiopathic arthritis. Intra-articular corticosteroid injection was the most common treatment. The questionnaire surveys showed the varying clinical practice across the UK, but established intra-articular corticosteroids as the treatment control for a future trial. The primary outcome of choice for children, young people, their families and health-care professionals was the Juvenile Arthritis Disease Activity Score, 71-joint count. However, results from the feasibility study showed that, owing to missing blood test data, the clinical Juvenile Arthritis Disease Activity Score should be used. The Juvenile Arthritis Disease Activity Score, 71-joint count, and the clinical Juvenile Arthritis Disease Activity Score are composite disease activity scoring systems for juvenile arthritis. Two final trial protocols were established for a future randomised controlled trial.

LIMITATIONS

Fewer clinics were included in this feasibility study than originally planned, limiting the ability to draw strong conclusions about these units to take part in future research.

CONCLUSIONS

A definitive randomised controlled trial is likely to be feasible based on the findings from this study; however, important recommendations should be taken into account when planning such a trial.

FUTURE WORK

This mixed-methods study has laid down the foundations to develop the evidence base in this area and conducting a randomised control trial to compare different corticosteroid induction regimens in children and young people with juvenile idiopathic arthritis is likely to be feasible.

STUDY REGISTRATION

Current Controlled Trials ISRCTN16649996.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 36. See the NIHR Journals Library website for further project information.

The benefit–risk balance for biological agents in juvenile idiopathic arthritis: a meta-analysis of randomized clinical trials

Objective

To assess the net benefit of biological agents (BA) used in JIA.

Methods

We systematically searched databases up to March 2019 for randomized controlled trials (RCT) performed in JIA disease. Separate random-effects meta-analyses were conducted for efficacy (ACR paediatric score 30%, ACRpedi30) and serious adverse events for safety. In order to standardize the baseline risk, we performed a meta-analysis of baseline risk in the control group (for both efficacy and safety meta-analysis). The net benefit was determined as the risk difference of efficacy subtracted by the risk difference of safety.

Results

We included 19 trials: 11 parallel RCTs (754 patients) and 8 withdrawal RCTs (704 patients). The net benefit ranged from 2.4% (adalimumab) to 17.6% (etanercept), and from 2.4% (etanercept) to 36.7%, (abatacept) in parallel and withdrawal trials assessing non-systemic JIA, respectively. In the systemic JIA category, the net benefit ranged from 22.8% (rilonacept) to 70.3% (canakinumab), and from 32.3% (canakinumab) to 58.2% (tocilizumab) in parallel and withdrawal trials, respectively.

Conclusion

The results suggest that a greater number of patients experienced therapeutic success without serious adverse events in the systemic onset JIA category compared with the BAs for non-systemic JIA categories. Baseline risk, design of trial and JIA categories impact the measure of net benefit of BAs in JIA patients.

Toward Accelerated Authorization and Access to New Medicines for Juvenile Idiopathic Arthritis

A meeting was organized to bring together multiple stakeholders involved in the testing and authorization of new medications for juvenile idiopathic arthritis (JIA) to discuss current issues surrounding clinical trials and access to new medications for children and adolescents with JIA. The Childhood Arthritis and Rheumatology Research Alliance invited representatives of regulatory agencies (Food and Drug Administration and European Medicines Agency), and major pharmaceutical companies with JIA-approved products or products in development, patient and parent representatives, representatives of an advocacy organization (Arthritis Foundation), and pediatric rheumatology clinicians/investigators to a 1-day meeting in April 2018. The participants engaged in discussion regarding issues in clinical trials. As the pharmacologic options to treat inflammatory arthritis rapidly expand, registration trial designs to test medications in JIA patients must adapt. Many methodologies successfully used in the recent past are no longer feasible. The pool of patients meeting entry criteria who are willing to participate is shrinking while the number of medications to be tested is growing. Suggested solutions included proposing innovative clinical trial methods to regulatory agencies, as well as open discussions among stakeholders. Ensuring that new medications are authorized in a timely manner to meet the needs of JIA patients worldwide is critical. Approaches should include open dialog between regulatory agencies, pharmaceutical companies, and other stakeholders to develop and implement novel study designs, including patient and clinician perspectives to define meaningful trial outcomes, and changing existing study plans.

Developing comparative effectiveness studies for a rare, understudied pediatric disease: lessons learned from the CARRA juvenile localized scleroderma consensus treatment plan pilot study

BACKGROUND

We designed and initiated a pilot comparative effectiveness study for juvenile localized scleroderma (jLS), for which there is limited evidence on best therapy. We evaluated the process we used, in relation to the specific protocol and to the general task of identifying strategies for implementing studies in rare pediatric diseases.

METHODS

This was a prospective, multi-center, observational cohort study of 50 jLS patients initiating treatment, designed and conducted by the jLS group of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) from 2012 to 2015. A series of virtual and physical meetings were held to design the study, standardize clinical assessments, generate and refine disease activity and damage measures, and monitor the study. Patients were initiated on one of three standardized methotrexate-based treatment regimens (consensus treatment plans, CTPs) and monitored for 1 year. An optional bio-banking sub-study was included.

RESULTS

The target enrollment of 50 patients was achieved over 26 months at 10 sites, with patients enrolled into all CTPs. Enrolled patients were typical for jLS. Study eligibility criteria were found to perform well, capturing patients thought appropriate for treatment studies. Minor modifications to the eligibility criteria, primarily to facilitate recruitment for future studies, were discussed with consensus agreement reached on them by the jLS group. There were marked differences in site preferences for specific CTPs, with half the sites treating all their patients with the same CTP. Most patients (88%) completed the study, and 68% participated in the bio-banking substudy.

CONCLUSIONS

We demonstrate the feasibility of our approach for conducting comparative effectiveness research in a rare pediatric disease. Multi-center collaboration by dedicated investigators who met regularly was a key factor in the success of this project. Other factors that facilitate these studies include having a sufficient number of investigators to enroll in each regimen, and streamlining study approval and management.

Protective parents and permissive children: what qualitative interviews with parents and children can tell us about the feasibility of juvenile idiopathic arthritis trials

BACKGROUND

Patient recruitment can be very challenging in paediatric studies, especially in relatively uncommon conditions, such as juvenile idiopathic arthritis (JIA). However, involving children and young people (CYP) in the design of such trials could promise a more rapid trajectory towards making evidence-based treatments available. Studies involving CYP are advocated in the literature but we are not aware of any early stage feasibility studies that have qualitatively accessed the perspectives of parents and CYP with a long term condition to inform design and conduct of a trial. In the context of a feasibility study to inform the design of a proposed randomised controlled trial of corticosteroid induction regimen in JIA, we explored families' perspectives on the proposed trial and on JIA trials generally.

METHODS

We analysed interviews with 27 participants (8 CYP aged 8-16 years and 19 parents) from four UK paediatric rheumatology centres. CYP had recently received corticosteroids to treat JIA. Audio-recorded interviews were transcribed and analysed thematically, drawing on the Framework Method.

RESULTS

Both parents and CYP were capable of engaging with the logic of the proposed trial but pointed to challenges with its design. Treatment preferences influenced willingness to participate in the proposed trial. The preferences of older children and their parents often differed, with CYP being more willing to participate in the proposed trial than parents. Families' current treatment preferences were largely informed by past positive and negative treatment experiences. Some participants also indicated that their treatment preferences were influenced by those of their clinicians.

CONCLUSION

Previous research has typically focused on deficits in patients' understandings of trials. We found that both parents and CYP understood trial concepts and were able to identify potential flaws in the proposed trial. We propose recommendations to optimise the design of a planned corticosteroid induction regimen trial in JIA. Accessing both parents' and CYP's perspectives helps to identify and address recruitment challenges, which will ultimately optimise informed consent and future recruitment.

Innovative Study Designs Optimizing Clinical Pharmacology Research in Infants and Children

Almost half of recent pediatric trials failed to achieve labeling indications, in large part because of inadequate study design. Therefore, innovative study methods are crucial to optimizing trial design while also reducing the potential harms inherent with drug investigation. Several methods exist to optimize the amount of pharmacokinetic data collected from the smallest possible volume and with the fewest number of procedures, including the use of opportunistic and sparse sampling, alternative and noninvasive matrices, and microvolume assays. In addition, large research networks using master protocols promote collaboration, reduce regulatory burden, and increase trial efficiency for both early- and late-phase trials. Large pragmatic trials that leverage electronic health records can capitalize on central management strategies to reduce costs, enroll patients with rare diseases on a large scale, and augment study generalizability. Further, trial efficiency and safety can be optimized through Bayesian adaptive techniques that permit planned protocol changes based on analyses of prior and accumulated data. In addition to these trial design features, advances in modeling and simulation have paved the way for systems-based and physiologically based models that individualize pediatric dosing recommendations and support drug approval. Last, given the low prevalence of many pediatric diseases, collecting deidentified genetic and clinical data on a large scale is a potentially transformative way to augment clinical pharmacology research in children.