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

Tofacitinib pharmacokinetics in children and adolescents with juvenile idiopathic arthritis

These analyses characterized tofacitinib pharmacokinetics (PKs) in children and adolescents with juvenile idiopathic arthritis (JIA). Data were pooled from phase I (NCT01513902), phase III (NCT02592434), and open-label, long-term extension (NCT01500551) studies of tofacitinib tablet/solution (weight-based doses administered twice daily [b.i.d.]) in patients with JIA aged 2 to less than 18 years. Population PK modeling used a nonlinear mixed-effects approach, with covariates identified using stepwise forward-inclusion backward-deletion procedures. Simulations were performed to derive dosing recommendations for children and adolescents with JIA. Two hundred forty-six pediatric patients were included in the population PK model. A one-compartment model with first-order elimination and absorption with body weight as a covariate for oral clearance and apparent volume of distribution sufficiently described the data. Oral solution was associated with comparable average concentration (Cavg) and slightly higher (113.9%) maximum concentration (Cmax) versus tablet, which was confirmed by a subsequent randomized, open-label, bioavailability study conducted in healthy adult participants (n = 12) by demonstrating adjusted geometric mean ratios (90% confidence interval) between oral solution and tablet of 1.04 (1.00-1.09) and 1.10 (1.00-1.21) for area under the curve extrapolated to infinity and Cmax, respectively (NCT04111614). A dosing regimen of 3.2 mg b.i.d. solution in patients 10 to less than 20 kg, 4 mg b.i.d. solution in patients 20 to less than 40 kg, and 5 mg b.i.d. tablet/solution in patients greater than or equal to 40 kg, irrespective of age, was proposed to achieve constant Cavg across weight groups. In summary, population PK characterization informed a simplified tofacitinib dosing regimen that has been implemented in pediatric patients with JIA.

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.

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.

Intravenous Golimumab in Patients with Polyarticular Juvenile Idiopathic Arthritis and Juvenile Psoriatic Arthritis and Subcutaneous Ustekinumab in Patients with Juvenile Psoriatic Arthritis: Extrapolation of Data from Studies in Adults and Adjacent Pediatric Populations

OBJECTIVES

To describe the extrapolation approaches used to support intravenous (IV) golimumab for polyarticular juvenile idiopathic arthritis (pJIA) and juvenile psoriatic arthritis (jPsA) and subcutaneous (SC) ustekinumab for jPsA.

METHODS

Pharmacokinetic, clinical response, and safety data from trials of IV golimumab and SC ustekinumab in polyarticular-course JIA (pc-JIA) (GO-VIVA) or pediatric psoriasis (PsO) (CADMUS and CADMUS Jr) and data from pivotal, phase 3 trials of these agents in adults with similar diseases were used to support extrapolation in pJIA and jPsA. In the phase 3 GO-VIVA trial, patients with pc-JIA aged 2 to < 18 years received IV golimumab 80 mg/m² at weeks 0, 4, then every 8 weeks (Q8W). In the phase 3, randomized, placebo-controlled CADMUS trial, patients with PsO aged ≥ 12 to < 18 years received ustekinumab at weeks 0, 4, then Q12W. In the phase 3 CADMUS Jr trial, patients with PsO aged ≥ 6 to < 12 years received ustekinumab at weeks 0, 4, then Q12W. The ustekinumab analyses used data only from patients who received the standard ustekinumab dosing regimen (≤ 60 kg: 0.75 mg/kg; > 60 to ≤ 100 kg: 45 mg; > 100 kg: 90 mg).

RESULTS

In the 127 patients with pc-JIA treated with IV golimumab (GO-VIVA), pharmacokinetic and exposure-response results were similar to those in adults with rheumatoid arthritis treated with IV golimumab. Additionally, pharmacokinetic and clinical response data from five patients with jPsA in GO-VIVA were comparable to those in adults with PsA treated with IV golimumab. No new safety signals were observed in GO-VIVA. Pharmacokinetic and clinical response data observed in the four pediatric patients with PsO and jPsA treated with ustekinumab in CADMUS and CADMUS Jr were similar to those in the 91 pediatric patients with PsO without jPsA in these trials and to those in adults with PsA treated with ustekinumab. Safety was extrapolated from CADMUS or CADMUS Jr; no new signals were observed.

CONCLUSIONS

These three sets of analyses corroborate similar exposure and efficacy of IV golimumab in pediatric patients with pc-JIA or jPsA and SC ustekinumab in patients with jPsA to support extrapolation of established adult efficacy. The overall safety profiles of IV golimumab in pediatric patients with pc-JIA or jPsA and SC ustekinumab in pediatric patients with PsO with or without jPsA were consistent with the safety profiles of these agents in the context of their clinical programs and cumulative use. Based on these analyses, the US Food and Drug Administration approved IV golimumab for polyarticular JIA and active PsA in patients 2 years and older and SC ustekinumab for pediatric PsA in patients 6 years and older, highlighting how use of an extrapolation approach can help streamline drug development for pediatric patient populations in whom larger clinical trials are not feasible.

CLINICAL TRIAL REGISTRATION

GO-VIVA (NCT02277444) was registered at clinicaltrials.gov on 29 October 2014; CADMUS (NCT01090427) was registered on 22 March 2010; and CADMUS Jr (NCT02698475) was registered on 3 March 2016.

Spectrum of Clinical Research in Juvenile Idiopathic Arthritis: A Cross-Sectional Analysis of Registered Studies in Clinicaltrials.gov and Clinicaltrialsregister.eu

The management of juvenile idiopathic arthritis (JIA) has improved tremendously in recent years due to the introduction of new drug therapies but remains complex in terms of non-pharmaceutical issues. In order to determine the direction of scientific progress by characterizing the current spectrum of ongoing clinical research in JIA, we analyzed all ongoing studies in the field of JIA—registered in clinicaltrials.gov and clinicaltrialsregister.eu—concerning sponsoring, enrollment, duration, localization, and particularly objectives. The close of the database was 7 January 2021. After identifying double-registered studies, n = 72 went into further analysis. Of these, 61.1% were academia-sponsored and 37.5% were sponsored by the pharma industry. The majority of the studies was of the interventional type (77.8%), while others (22.2%) were observational. The median planned enrollments were 100 participants (interventional studies) and 175 participants (observational studies), respectively. The duration differed remarkably from one month to more than 15 years, with a median of 42.5 months. A total of 61.1% of studies were located in a single country, and 38.9% were in several. Europe and North America clearly dominated the study localizations. The study objectives were DMARDs (56.9%), followed by diagnostics and disease activity measurement (18.1%), and medication other than DMARD (12.5%), besides others. Studies on DMARDs were mainly sponsored by industry, predominantly interventional studies on established and novel biologics, with several on specific issues such as systemic JIA and others. The spectrum of registered studies is currently centered on drug therapy and diagnostics, while other issues in JIA play a subordinated role in current research. Drug development was transferred from adult rheumatology into the JIA population with little innovation for children. Future research should take specific pediatric needs better into account.

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.