SAN DIEGO, CA—Adalimumab (ADA) appears to be as effective as tocilizumab (TCZ) in treating polyarticular-course juvenile idiopathic arthritis (pcJIA). However, TCZ may be better than ADA as monotherapy, according to study results presented at the 2013 ACR/ARHP Annual Meeting.
Laura Sawyer, from Symmetron Limited, London, United Kingdom, and colleagues conducted a literature review of randomized controlled trials (RCTs) comparing the relative efficacy of biologic treatments for pcJIA, both alone and in combination with methotrexate. Researchers identified RCTs of abatacept, adalimumab, etanercept, infliximab, and tocilizumab in pcJIA.
Comparative effectiveness was estimated on the reported American College of Rheumatology response rates measured at the end of the randomized, double-blind phase by means of a Bayesian indirect comparison using a fixed-effects ordered probit model. Probabilities of reaching different levels of JIA ACR response were calculated for biologic treatments and placebo using all observed comparisons.
Researchers were only able to compare ADA and TCZ because differences were identified in how the RCTs reported JIA ACR responses with regard to methods of non-responder imputation during the blinded, controlled phase.
After correcting for previous biologic use, for a JIA ACR30 placebo response of 31%, TCZ monotherapy had a higher predicted probability of achieving JIA ACR30 (68%), JIA ACR50 (65%), JIA ACR70 (61%), and JIA ACR90 (41%) vs. ADA monotherapy, with 52%, 49%, 44%, and 26%, respectively.
On methotrexate background therapy and a JIA ACR30 placebo response of 52%, TCZ had a higher expected probability of response at JIA ACR30 (77%), JIA ACR50 (76%), JIA ACR70 (67%), and JIA ACR90 (51%) vs. ADA, with 76%, 75%, 66%, and 49%, respectively. Differences between TCZ and ADA did not reach statistical significance in monotherapy or combination therapy.
Sawyer and her team concluded that JIA ACR response after correction for a previous TNF inhibitor use is likely to be higher with TCZ than with ADA in both monotherapy and in combination treatment.