2422 - A Bayesian Mixed Treatment Comparison Demonstrates Differences Between Anti-Tumour Necrosis Factor Agents in Rheumatoid Arthritis

Tuesday, November 8, 2011: 9:00 AM-6:00 PM
Hall F2 - Poster Hall (McCormick Place West)
Susanne Schmitz1, Roisin C. Adams2, Michael Barry2, Cathal Walsh3 and Oliver M. FitzGerald4, 1Department of Statistics,Trinity College Dublin, Dublin, Ireland, 2National Centre for Pharmacoeconomics, Dublin, Ireland, 3Trinity College Dublin and National Centre for Pharmacoeconomics, Dublin, Ireland, 4St. Vincent's University Hospital, Dublin, Ireland
Presentation Number: 2422

Background/Purpose: A number of tumour necrosis factor alpha antagonists (anti-TNF-α) are available to treat rheumatoid arthritis.  All of these have demonstrated considerable efficacy in placebo controlled trials, but few head-to-head comparisons exist to date.  This work's objective is to estimate the relative efficacy among licensed anti-TNFs in patients who have had an inadequate response to methotrexate.  Different outcome measures are used to highlight the advantages of continuous measures in such methodologies.

Method: A systematic review indentified randomized controlled trials comparing the efficacy of licensed anti-TNF-a agents to placebo at 24 weeks in patients who have had an inadequate response to methotrexate.  Relative efficacy was estimated using Bayesian mixed treatment comparison (MTC) models.  Three different outcome measures were used; Risk ratios of achieving an ACR20 and ACR50 response and the percentage improvement in HAQ score. 80% credible intervals are presented for risk ratios and HAQ improvement.

Result: 16 published trials were included in the analysis.  All anti-TNFs show considerably improved efficacy over placebo.  The MTC results also provide evidence of some differences in efficacy of the anti-TNF-α antagonists.  Etanercept appears superior to infliximab and golimumab; certolizumab to infliximab and adalimumab.  The ACR results find evidence of certolizumab being more effective than golimumab.  For HAQ improvement all anti-TNFs appear superior to infliximab and etanercept shows improved efficacy to adalimumab.

Figure 1: Graph for pair wise log risk ratios (LRRs) for ACR 20 and ACR 50 outcome and estimated HAQ improvement of anti-TNF against placebo and one another. Results are presented at 80% credible intervals.

Conclusion: There are differences in efficacy among the anti-TNF-α antagonists.  In a MTC a continuous outcome measure has more strength to detect such differences than a binomial outcome measure, due to its enhanced sensitivity to change.

Keywords: meta-analysis, monoclonal antibodies and rheumatoid arthritis (RA)

Disclosure: S. Schmitz, None; R. C. Adams, None; M. Barry, None; C. Walsh, None; O. M. FitzGerald, Pfizer, Abbott, UCB, Roche, MSD,BMS, 2, Pfizer, Abbott, UCB, Roche, MSD and BMS, 8 .