Biologics in Pediatric Rheumatology: Quo Vadis?

Value of Literature Review to Inform Development and Use of Biologics in Juvenile Idiopathic Arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is one of the most common pediatric inflammatory rheumatic diseases (PiRDs). Uncontrolled disease activity is associated with decreased quality of life and chronic morbidity. Biologic disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitors (JAKi) have considerably improved clinical outcomes. For optimized patient care, understanding the efficacy-safety profile of biologics in subgroups of JIA is crucial. This systematic review based on published randomized controlled trials (RCTs) aims to assess efficacy and safety data for bDMARDs and JAKi with various JIA subgroups after 3 months of treatment.

METHODS

Data for American College of Rheumatology (ACR) pediatric (Pedi) 30, 50, and/or 70 responses after 3 months of treatment were selected from RCTs investigating bDMARDs or JAKi in JIA according to predefined inclusion/exclusion criteria. Treatment and control arms were compared by calculating risk ratios (RRs) with 95% confidence intervals (CIs), and proportions of overall, serious adverse events (AEs) and infections were analyzed. Forest plots were generated to summarize efficacy and safety endpoints across studies, JIA subgroups, and type of biologics.

RESULTS

Twenty-eight out of 41 PiRD RCTs investigated bDMARD or JAKi treatments in JIA. 9 parallel RCTs reported ACR Pedi 30, 50, and/or 70 responses 3 months after treatment initiation. All treatment arms showed improved ACR Pedi responses over controls. RRs ranged from 1.05 to 3.73 in ACR Pedi 30, from 1.20 to 7.90 in ACR Pedi 50, and from 1.19 to 8.73 in ACR Pedi 70. An enhanced effect for ACR Pedi 70 was observed with infliximab combined with methotrexate in PJIA vs. methotrexate monotherapy. A slightly higher risk of gastrointestinal AEs and infections was observed with treatment arms compared to placebo or methotrexate monotherapy.

CONCLUSION

Investigated bDMARDs and JAKi showed superior treatment responses compared to controls after 3 months of treatment, which were more pronounced in ACR Pedi 50 and 70 than in ACR Pedi 30. Higher susceptibility to infections associated with bDMARDs or JAKi vs. control arms must be weighed against efficacious treatment of the underlying disease and prevention of disease-related damage. Additional RCTs are warranted to further inform development and utilization of biologics in JIA.

Temporomandibular joint involvement in children with juvenile idiopathic arthritis-Symptoms, clinical signs and radiographic findings

BACKGROUND

Although many children with juvenile idiopathic arthritis (JIA) develop arthritis and deformity of the temporomandibular joint (TMJ), many go undetected.

OBJECTIVE

This study investigates whether findings from patient history and clinical examination using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) can be used to diagnose TMJ involvement.

METHODS

As a part of the screening program, 59 consecutive JIA patients age 7-14 years underwent a clinical examination according to RDC/TMD including self-reported orofacial pain and pain related to jaw function, and cone beam computer tomography (CBCT). Data were obtained from the patient's medical charts. Patients were divided into two groups based on the presence or absence of TMJ deformities on CBCT.

RESULTS

Self-reported TMJ symptoms before inclusion were reported by 52% of children with and 18% of children without TMJ deformities on CBCT (p = .020). On a group level, the maximum unassisted (mouth) opening (MUO) with and without pain was within the normal range, but children with TMJ deformities showed a significantly smaller MUO with pain (p = .035). A diagnosis of osteoarthritis and osteoarthrosis was more prevalent in children with TMJ deformities.

CONCLUSION

Although there were few differences between children with and without radiographic TMJ deformities, self-reported previous TMJ symptoms and reduced MUO with pain could indicate the presence of TMJ involvement. However, radiographic examinations are needed to confirm TMJ involvement. Thus, this study indicates that the RDC/TMD protocol is a blunt tool when targeting TMJ involvement in JIA.

Biologic medicine inclusion in 138 national essential medicines lists

BACKGROUND

Essential medicines lists (EMLs) are intended to reflect the priority health care needs of populations. We hypothesized that biologic disease-modifying antirheumatic drugs (DMARDs) are underrepresented relative to conventional DMARDs in existing national EMLs. We aimed to survey the extent to which biologic DMARDs are included in EMLs, to determine country characteristics contributing to their inclusion or absence, and to contrast this with conventional DMARD therapies.

METHODS

We searched 138 national EMLs for 10 conventional and 14 biologic DMARDs used in the treatment of childhood rheumatologic diseases. Via regression modelling, we determined country characteristics accounting for differences in medicine inclusion between national EMLs.

RESULTS

Eleven countries (7.97%) included all 10 conventional DMARDs, 115 (83.33%) ≥5, and all countries listed at least one. Gross domestic product (GDP) per capita was associated with the total number of conventional DMARDs included (β₁1.02 [95% CI 0.39, 1.66]; P = 0.00279). Among biologic DMARDs, 3 countries (2.2%) listed ≥10, 15 (10.9%) listed ≥5, and 47 (34.1%) listed at least one. Ninety-one (65.9%) of countries listed no biologic DMARDs. European region (β₁ 1.30 [95% CI 0.08, 2.52]; P = 0.0367), life expectancy (β₁-0.70 [95% CI -1.22, - 0.18]; P = 0.0085), health expenditure per capita (β₁ 1.83 [95% CI 1.24, 2.42]; P < 0.001), and conventional DMARDs listed (β₁ 0.70 [95% CI 0.33, 1.07]; P < 0.001) were associated with the total number of biologic DMARDs included.

CONCLUSION

Biologic DMARDs are excluded from most national EMLs. By comparison, conventional DMARDs are widely included. Countries with higher health spending and longer life expectancy are more likely to list biologics.

The cytokine storms of COVID-19, H1N1 influenza, CRS and MAS compared. Can one sized treatment fit all?

An analysis of published data appertaining to the cytokine storms of COVID-19, H1N1 influenza, cytokine release syndrome (CRS), and macrophage activation syndrome (MAS) reveals many common immunological and biochemical abnormalities. These include evidence of a hyperactive coagulation system with elevated D-dimer and ferritin levels, disseminated intravascular coagulopathy (DIC) and microthrombi coupled with an activated and highly permeable vascular endothelium. Common immune abnormalities include progressive hypercytokinemia with elevated levels of TNF-α, interleukin (IL)-6, and IL-1β, proinflammatory chemokines, activated macrophages and increased levels of nuclear factor kappa beta (NFκB). Inflammasome activation and release of damage associated molecular patterns (DAMPs) is common to COVID-19, H1N1, and MAS but does not appear to be a feature of CRS. Elevated levels of IL-18 are detected in patients with COVID-19 and MAS but have not been reported in patients with H1N1 influenza and CRS. Elevated interferon-γ is common to H1N1, MAS, and CRS but levels of this molecule appear to be depressed in patients with COVID-19. CD4+ T, CD8+ and NK lymphocytes are involved in the pathophysiology of CRS, MAS, and possibly H1N1 but are reduced in number and dysfunctional in COVID-19. Additional elements underpinning the pathophysiology of cytokine storms include Inflammasome activity and DAMPs. Treatment with anakinra may theoretically offer an avenue to positively manipulate the range of biochemical and immune abnormalities reported in COVID-19 and thought to underpin the pathophysiology of cytokine storms beyond those manipulated via the use of, canakinumab, Jak inhibitors or tocilizumab. Thus, despite the relative success of tocilizumab in reducing mortality in COVID-19 patients already on dexamethasone and promising results with Baricitinib, the combination of anakinra in combination with dexamethasone offers the theoretical prospect of further improvements in patient survival. However, there is currently an absence of trial of evidence in favour or contravening this proposition. Accordingly, a large well powered blinded prospective randomised controlled trial (RCT) to test this hypothesis is recommended.

Biologic disease modifying antirheumatic drugs and Janus kinase inhibitors in paediatric rheumatology - what we know and what we do not know from randomized controlled trials

BACKGROUND

Biologic disease modifying antirheumatic drugs (bDMARDs) and Janus Kinase (JAK) inhibitors are prescribed in adult and paediatric rheumatology. Due to age-dependent changes, disease course, and pharmacokinetic processes paediatric patients with inflammatory rheumatic diseases (PiRD) differ from adult rheumatology patients.

METHODS

A systematic literature search for randomized clinical trials (RCTs) in PiRD treated with bDMARDs/JAK inhibitors was conducted on Medline, clinicaltrials.gov , clinicaltrialsregister.eu and conference abstracts as of July 2020. RCTs were included if (i) patients were aged ≤20 years, (ii) patients had a predefined rheumatic diagnosis and (iii) RCT reported predefined outcomes. Selected studies were excluded in case of (i) observational or single arm study or (ii) sample size ≤5 patients. Study characteristics were extracted.

RESULTS

Out of 608 screened references, 65 references were selected, reporting 35 unique RCTs. All 35 RCTs reported efficacy while 34/3 provided safety outcomes and 16/35 provided pharmacokinetic data. The most common investigated treatments were TNF inhibitors (60%), IL-1 inhibitors (17%) and IL-6 inhibitors (9%). No RCTs with published results were identified for baricitinib, brodalumab, certolizumab pegol, guselkumab, risankizumab, rituximab, sarilumab, secukinumab, tildrakizumab, or upadacitinib. In patients with juvenile idiopathic arthritis (JIA) 25/35 RCTs were conducted. The remaining 10 RCTs were performed in non-JIA patients including plaque psoriasis, Kawasaki Disease, systemic lupus erythematosus and non-infectious uveitis. In JIA-RCTs, the control arm was mainly placebo and the concomitant treatments were either methotrexate, non-steroidal anti-inflammatory drugs (NSAID) or corticosteroids. Non-JIA patients mostly received NSAID. There are ongoing trials investigating abatacept, adalimumab, baricitinib, brodalumab, certolizumab pegol, etanercept, guselkumab, infliximab, risankizumab, secukinumab, tofacitinib and tildrakizumab.

CONCLUSION

Despite the FDA Modernization Act and support of major paediatric rheumatology networks, such as the Pediatric Rheumatology Collaborative Study Group (PRCSG) and the Paediatric Rheumatology International Trials Organization (PRINTO), which resulted in drug approval for PiRD indications, there are limited RCTs in PiRD patients. As therapy response is influenced by age-dependent changes, pharmacokinetic processes and disease course it is important to consider developmental changes in bDMARDs/JAK inhibitor use in PiRD patients. As such it is critical to collaborate and conduct international RCTs to appropriately investigate and characterize efficacy, safety and pharmacokinetics of bDMARDs/JAK inhibitors in paediatric rheumatology.

Pediatric macrophage activation syndrome, recognizing the tip of the Iceberg

Macrophage activation syndrome (MAS) is the name given to secondary hemophagocytic lymphohistiocytosis (sHLH) associated with rheumatic diseases. Previously, MAS has been best studied in children with systemic juvenile idiopathic arthritis (sJIA), who are at high risk of developing MAS. MAS/sHLH is a cytokine storm that results in multi-organ system failure and is frequently fatal. Early diagnosis and treatment is critical for improving survival. Various diagnostic tools have been developed for identifying MAS in the setting of sJIA, as well as for all forms of MAS/sHLH. These are largely based on clinical (e.g., fever) and laboratory features (e.g., cytopenias). None are perfectly sensitive and specific, however, increasing awareness of this condition is also paramount in making the diagnosis. Rare familial forms of HLH can also be diagnosed based on homozygous mutation in genes largely involved in perforin-mediated cytolytic function of lymphocytes (natural killer cells and CD8 T cells). Intriguingly, heterozygous defects in these same genes are frequently identified in patients with sHLH and MAS. Decreased cytolytic function results in prolonged interaction of the lytic lymphocytes and their target antigen presenting cells, thus resulting in the pro-inflammatory cytokine storm believed responsible for the multi-organ failure. Novel cytokine-targeted therapies are currently being explored for a less toxic yet effective alternative to chemotherapeutic approaches to treating children with sHLH/MAS. As increased recognition and diagnosis of MAS is on the rise, an earlier and cytokine-targeted approach to therapy will likely save many lives of children with this disorder.

Computational Evolution of Threonine-Rich β-Hairpin Peptides Mimicking Specificity and Affinity of Antibodies

The development of recognition molecules with antibody-like properties is of great value to the biotechnological and bioanalytical communities. The recognition molecules presented here are peptides with a strong tendency to form β-hairpin structures, stabilized by alternate threonines, which are located at one face of the peptide. Amino acids at the other face of the peptide are available for interaction with the target molecule. Using this scaffold, we demonstrate that recognition molecules can efficiently be designed in silico toward four structurally unrelated proteins, GFP, IL-1β, IL-2, and IL-6. On solid support, 10 different antibody-mimetic recognition molecules were synthesized. They displayed high affinity and no cross-reactivity, as observed by fluorescence microscopy. Stabilized variants were readily obtained by incorporation of azido acids and propargylglycine followed by cyclization via the Cu(I)-catalyzed alkyne-azide cycloaddition reaction. As this new class of antibody mimics can be designed toward essentially any protein, the concept is believed to be useful to a wide range of technologies. Here, their use in protein separation and in the detection of proteins in a sandwich-type assay is demonstrated.

The Immunology of Macrophage Activation Syndrome

Synonymous with secondary hemophagocytic lymphohistiocytosis, macrophage activation syndrome (MAS) is a term used by rheumatologists to describe a potentially life-threatening complication of systemic inflammatory disorders, most commonly systemic juvenile idiopathic arthritis (sJIA) and systemic lupus erythematosus (SLE). Clinical and laboratory features of MAS include sustained fever, hyperferritinemia, pancytopenia, fibrinolytic coagulopathy, and liver dysfunction. Soluble interleukin-2 receptor alpha chain (sCD25) and sCD163 may be elevated, and histopathology often reveals characteristic increased hemophagocytic activity in the bone marrow (and other tissues), with positive CD163 (histiocyte) staining. A common hypothesis as to the pathophysiology of many cases of MAS proposes a defect in lymphocyte cytolytic activity. Specific heterozygous gene mutations in familial HLH-associated cytolytic pathway genes (e.g., PRF1, UNC13D) have been linked to a substantial subset of MAS patients. In addition, the pro-inflammatory cytokine environment, particularly IL-6, has been shown to decrease NK cell cytolytic function. The inability of NK cells and cytolytic CD8 T cells to lyse infected and otherwise activated antigen presenting cells results in prolonged cell-to-cell (innate and adaptive immune cells) interactions and amplification of a pro-inflammatory cytokine cascade. The cytokine storm results in activation of macrophages, causing hemophagocytosis, as well as contributing to multi-organ dysfunction. In addition to macrophages, dendritic cells likely play a critical role in antigen presentation to cytolytic lymphocytes, as well as contributing to cytokine expression. Several cytokines, including tumor necrosis factor, interferon-gamma, and numerous interleukins (i.e., IL-1, IL-6, IL-18, IL-33), have been implicated in the cytokine cascade. In addition to broadly immunosuppressive therapies, novel cytokine targeted treatments are being explored to dampen the overly active immune response that is responsible for much of the pathology seen in MAS.

The effects of TNF-alpha inhibitor therapy on the incidence of infection in JIA children: a meta-analysis

BACKGROUND

Juvenile Idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood. The diagnosis is based on the underlying symptoms of arthritis with an exclusion of other diseases Biologic agents are increasingly used on the side of disease-modifying anti-rheumatic drugs (DMARD) in JIA treatment.

MAIN BODY

The aim of this meta-analysis was to investigate the observed infections in JIA children during tumor necrosis factor (TNF)-alpha inhibitor therapy. A systematic search of three databases (Medline via PubMed, Embase, Cochrane Library) was carried out up to May 2018. Published trials that evaluated the infectious adverse events in patients receiving TNF-alpha inhibitor vs. a control group were included in the analysis. Full-text data extraction was carried out independently by the investigators from ten relevant publications. 1434 patients received TNF-alpha inhibitor therapy; the control group consisted of 696 subjects. The analysis presented the risk of infection in the active treatment group (OR = 1.13; 95% CI: 0.76-1.69; p = 0.543). The majority of infections were upper respiratory tract infections (URTIs). Furthermore, the subgroup analysis demonstrated a higher infection rate in the observed localization.

CONCLUSION

Anti-TNF therapy slightly but not significantly increases the incidence of infection in JIA children compared to other therapies (GRADE: moderate evidence). The most common infections reported were mild URTIs. Further studies with larger patients number with a strong evidence level are crucially needed to finalize the answer whether anti-TNF therapy elevates and if yes on what extent the incidence of infection in JIA children.

TRIAL REGISTRATION

Prospero: CRD42017067873 .

High rate of serious infection in juvenile idiopathic arthritis patients under biologic therapy in a real-life setting

OBJECTIVES

To assess the rate of serious and/or opportunistic infections in juvenile idiopathic arthritis (JIA) patients from a single tertiary center under biologic therapy and to identify possible risk factors associated to these complications.

METHODS

A total of 107 JIA patients followed at the biologic therapy center of our tertiary university hospital using a standardized electronic database protocol including demographic data, clinical and laboratorial findings and treatment at baseline and at the moment of infection. Opportunistic infections included tuberculosis, herpes zoster and systemic mycosis.

RESULTS

A total of 398 patient-yrs(py) were included. The median time of biologic exposure was 3.0 years (0.15-11.5). We observed 35 serious/opportunistic infectious events in 27 (25%) patients: 31(88.6%) were serious infections and four (11.4%) opportunistic infections. Serious/opportunistic infections rates were 10.6/100py for ETN, 10.9/100py for ADA, 2.6/100py for ABA and 14.8/100py for TCZ. Comparison of 27 patients with and 80 without infection showed a higher frequency of systemic-onset JIA, lower age at biologic therapy initiation and a history of previous serious infection (p < .05) in the former group.

CONCLUSIONS

This study demonstrated a high rate of serious infections in JIA patients under biologic therapy in a real-life setting. Systemic-onset JIA, lower age at biologic therapy start and history of previous serious infections were important risk factors for these complications. Also, higher rates of severe infections comparing to the former studies was possibly due to elevated MTX doses in our patients.