Persistence, Effectiveness of TNF vs Non-TNF Inhibitors in JIA

In patients with juvenile idiopathic arthritis (JIA), persistence is significantly longer among those initiating a tumor necrosis factor inhibitor (TNFi) as their first biologic agent compared with those initiating a non-TNFi, according to study results published in Rheumatology (Oxford).

Researchers sought to assess the effectiveness and persistence of TNFi vs non-TNFi among patients with newly diagnosed JIA after the initiation of a biologic disease-modifying antirheumatic drug (bDMARD).

A cohort study was conducted between January 1, 2009, and December 31, 2018, using longitudinal patient-level data from a large Midwestern US pediatric rheumatology hospital. Data were obtained from patients’ electronic medical records (EMRs), including demographics, medical history, laboratory results, prescription drugs, and disease outcomes.  

Over the 10-year period, the EMRs included a total of 2082 patients diagnosed with JIA. All eligible study participants were aged less than 19 years, had a diagnosis of nonsystemic JIA, received at least 1 dose of a bDMARD, and had 1 or more follow-up visits. Overall, the researchers identified 6 disease subcategories of nonsystemic JIA, including oligoarthritis, polyarthritis rheumatoid factor (RF)-positive, polyarthritis RF-negative, enthesitis-related arthritis, psoriatic arthritis, and undifferentiated JIA.

In the current study, persistence was defined by the duration from initiation to discontinuation of treatment. Treatment initiation — also known as the index date — was defined as the date on which a patient first was prescribed (ie, their first-ever or second-ever) a biologic agent. Treatment response was assessed using the clinical Juvenile Disease Activity Score with active joint counts truncated at 10 (cJADAS-10).

Of 667 patients with nonsystemic JIA, 614 (92.0%) received a TNFi as their first biologic treatment. Of the bDMARDs, etanercept was the most frequently prescribed (n=412; 67.1%), followed by adalimumab (n=169; 27.5%). Approximately 5% of participants received off-label bDMARDs as their first-course therapy and more than 20% received off-label bDMARDs as their second-course therapy. Overall, 7.3% of participants received at least 4 bDMARDs.

Study results showed that the median persistence of the first-course bDMARD was

320 days, with the persistence of the TNFi being significantly longer than that of the non-TNFi (395 vs 320 days, respectively; P =.010). At the 6-month follow-up visit, the cJADAS reduction was significantly greater among TNFi users compared with non-TNFi users (6.6 reduction; 95% CI, 5.7-7.5 reduction vs 3.0 reduction; 95% CI, 1.5-4.6 reduction, respectively; P <.0001). Further, at the 12-month follow-up, no significant differences were observed between treatment with a TNFi vs non-TNFi.

Study limitations included the existence of unmeasured confounding factors, such as comorbidities, that could have affected treatment and disease outcomes; the limited number of patients receiving non-TNFi as a first-line biologic; and the inability to determine medication adherence.

Researchers concluded, “Further studies should focus on real-world effectiveness and safety to more precisely evaluate the various benefits and detriments of newly approved biologic therapy, especially in a large population, so that first-line therapy can be more appropriately prescribed and switching between medications can be reduced.”

Reference

Yue X, Huang B, Hincapie AL, et al. Comparative effectiveness and persistence of TNFi and non-TNFi in juvenile idiopathic arthritis: a large pediatric rheumatology center in US. Rheumatology (Oxford). Published online December 28, 2020. doi:10.1093/rheumatology/keaa877