Subcutaneous Tocilizumab in Juvenile Idiopathic Arthritis Associated Uveitis

How should we approach management of childhood onset chronic anterior uveitis refractory to adalimumab?

INTRODUCTION

The management of refractory juvenile idiopathic associated uveitis (JIAU) or childhood-onset chronic anterior uveitis (CAU) is a challenge. There is no clear consensus or evidence base for to suggest the most appropriate therapy after primary or secondary failure of biweekly adalimumab. In this scenario, most clinicians advocate switching to another anti-tumor necrosis factor alpha inhibitor; however, there are a variety of other disease modifying agents to choose from albeit with a differing levels of evidence.

AREAS COVERED

We discuss how to define nonresponse and potential treatment options for patients with JIAU and CAU refractory to biweekly adalimumab.

EXPERT OPINION

Uncontrolled CAU and JIAU remain one of the most challenging diseases to manage and can lead to irreversible loss of vision in a third of those affected. Amongst the possible choices, weekly adalimumab, infliximab, tocilizumab and abatacept have more evidence to support their use. JAK inhibitors seem to be a promising option. Golimumab and Rituximab has also been thought to be partially effective in some refractory cases, whereas IL-17, IL-23, and IL-12 inhibition along with apremilast seem not to be a therapeutic option currently. The route of administration should also be considered as there can be significant pros and cons for different children.

Subcutaneous tocilizumab in the management of non-infectious uveitis in children: a brief report

BACKGROUND

Tocilizumab is a humanized monoclonal antibody that acts as an IL-6 receptor antagonist. Intravenous tocilizumab is considered an option for children with anti-TNF refractory juvenile idiopathic arthritis-associated uveitis. In contrast, the potential of subcutaneous drug use with this indication is more controversial. Due to the decreased availability of intravenous tocilizumab during the COVID-19 pandemic, we started using the subcutaneous formulation of the drug in children with anti-TNF refractory uveitis. The study analyzes the serum concentration of tocilizumab and its clinical response in patients with anti-TNF refractory uveitis who started or switched to subcutaneous administration from intravenous use.

METHODS

Five patients with non-infectious uveitis were treated with subcutaneous tocilizumab. Ocular inflammation was evaluated on slit lamp examination during clinical control. Serum tocilizumab concentrations were determined by ELISA.

RESULTS

The mean blood concentration of tocilizumab was 61.4 µg/mL (range 2.7-137.0.), with higher values than levels recorded in adult patients with rheumatoid arthritis treated with intravenous tocilizumab. Three patients entered clinical remission. One patient developed a mild relapse and was treated with topical steroids. Only one patient did not respond to therapy. The medication was well tolerated without severe infection or other adverse events.

CONCLUSION

Our results support a possible role of subcutaneous tocilizumab in anti-TNF refractory uveitis.

Tocilizumab in Juvenile Idiopathic Arthritis Associated Uveitis, a Narrative Review

Juvenile idiopathic arthritis (JIA) associated uveitis (JIA-U) is the most common extra-articular manifestation of JIA, affecting 10–15% of patients, especially in oligoarticular JIA where its course may be faint. Therefore, JIA-U is one of the most challenging pediatric uveitis, associated with major ocular morbidity and possibly leading to irreversible structural ocular damage and to vision-threatening complications. Adequate management is crucial for avoiding visual impairment complications. Since the introduction of biologic disease modifying anti-rheumatic drugs (bDMARDS), the visual prognosis of JIA-U has dramatically improved over the decades. Tumor necrosis factor-α (TNF-α) blockers are the most used bDMARDs in treating JIA-U with large evidence of efficacy. However, inadequate response to these agents, either due to intolerance or inefficacy, may be observed, requiring a swap to other classes of immunosuppressive agents, including anti-IL-6, anti-CD20, and, more recently, JAK inhibitors. Tocilizumab is a humanized monoclonal antibody to the interelukin-6 receptor preventing IL-6 from binding to its soluble and membrane-bound receptors. A growing body of literature provides promising results about the efficacy of intravenous and subcutaneous tocilizumab in the treatment of JIA-U. A narrative review of the literature on this topic will improve our knowledge on the potential use of tocilizumab in JIA-U.