SAT0126 Evaluation of two dosing regimens of certolizumab pegol for maintenance of clinical response in patients with active rheumatoid arthritis: Primary results from doseflex, a phase IIIB study
Authors: D.E. Furst, S.A. Shaikh, M. Greenwald, B. Bennett, F. Staelens, W. Koetse, P. Bertin
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Certolizumab pegol (CZP) + methotrexate (MTX) is approved in Europe as a maintenance dose of 200mg CZP every 2 weeks (Q2W) for patients (pts) with active rheumatoid arthritis (RA); 400mg CZP Q4W has been assessed as an alternative and is approved in the USA.<sup>1,2</sup> <h3>Objectives</h3> To compare the clinical efficacy of two maintenance dosing regimens of CZP (200mg Q2W + MTX or 400mg Q4W + MTX) in pts with active RA who achieved ACR20 after a 16 weeks (Wk) open-label run-in period of CZP 200mg Q2W + MTX. <h3>Methods</h3> DOSEFLEX was an open-label run-in and double-blind (DB) placebo (PBO)-controlled randomized study in pts with active RA (NCT00580840). During run-in all pts received 400mg CZP at Wks 0, 2, and 4, and 200mg CZP Q2W to Wk16. ACR20 responders at Wk16 were randomized 1:1:1 at Wk18 to receive 200mg CZP Q2W, 400mg CZP Q4W, or PBO (all + MTX). Primary efficacy end-point was ACR20 response at Wk34. ACR responses and DAS28/SDAI/CDAI remission were assessed using NRI and DAS28(ESR) using LOCF. <h3>Results</h3> 333 pts entered run-in; 53.5% had prior TNF inhibitor exposure. At Wk16, 61.3% pts achieved ACR20 response; 209 pts were randomized at Wk18 (CZP 200mg n=70; CZP 400mg n=70; PBO n=69). Mean baseline characteristics were similar among the 3 groups. At Wk34, ACR20/50/70 response rates were comparable between 200mg and 400mg groups (67.1/50.0/30.0% and 65.2/52.2/37.7%) and significantly higher than CZP→PBO (44.9/30.4/15.9%, p&lt;0.05 for CZP 200mg ACR20/50 and CZP 400mg ACR20/50/70). DAS28 change from baseline to Wk34 was significantly greater in the CZP 200mg and 400mg groups (LS Mean -2.8 vs. -3.0) vs. CZP→PBO (-1.65 p&lt;0.001 for both) (Fig). More pts in the CZP 200mg and 400mg groups compared to CZP→PBO had DAS28 (18.6% vs. 29.0% vs. 5.8%, p&lt;0.05 for both), SDAI (17.1% vs. 29.0% vs. 13.0%, p&lt;0.05 for CZP 400mg) and CDAI (21.4% vs. 27.5% vs. 15.9%) remission at Wk34. CZP was well tolerated (adverse event [AE] rates in DB phase: 62.9% vs. 60.9% vs. 62.3%; serious AE rates: 7.1% vs. 2.9% vs. 0% in CZP 200mg, 400mg and CZP→PBO groups). The most common serious AEs were infections and infestations (4.3% in CZP 200mg groups; 0 in the other groups). No cases of TB were reported. <h3>Conclusions</h3> In RA pts with active disease and incomplete response to MTX, 200mg CZP Q2W and 400mg CZP Q4W showed comparable efficacy in maintaining clinical response to Wk34 following a 16 Wk run-in, whereas withdrawal of CZP led to worse outcomes. <h3>References</h3> Fleischmann et al. Ann Rheum Dis 2009;68:805–811. CIMZIA® Prescribing Information <h3>Disclosure of Interest</h3> D. Furst Grant/Research support from: UCB Pharma, Consultant for: UCB Pharma, Speakers Bureau: UCB Pharma, S. Shaikh: None Declared, M. Greenwald: None Declared, B. Bennett Shareholder of: UCB Pharma, F. Staelens Employee of: UCB Pharma, W. Koetse Employee of: UCB Pharma, P. Bertin: None Declared