THU0142 Methotrexate Use at Infliximab Initiation and Impact on Treatment Outcomes: An Analysis from the Canadian Registry, Biotrac
Authors: D. Choquette, C. Thorne, J. Kelsall, M. Zummer, M. Starr, M. Sheriff, W. G. Bensen, A. Chow, P. Baer, E. Rampakakis, J. S. Sampalis, F. Nantel, A. J. Lehman, S. Otawa, M. Shawi
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Clinical trials of anti-TNF therapies have shown that concurrent methotrexate (MTX) therapy enhances the efficacy of infliximab (IFX)<sup>1</sup>. Data on the benefits of combination therapy with MTX and IFX in a real-life clinical setting are scarce. <h3>Objectives</h3> Describe changes in the use of MTX at IFX initiation in patients enrolled in routine clinical practice and assess the impact of the MTX dose on the real-life effectiveness of IFX. <h3>Methods</h3> BioTRAC is an ongoing, prospective registry of RA, AS or PSA patients initiating treatment with IFX or golimumab as first biologics or after having been treated with a biologic &lt;6 mos. Data from RA patients treated with IFX between Jan 2002 and Jun 2011 were analysed. Patients were stratified based on the use of MTX (0mg of MTX,≤10mg/week, 10.1-24.9mg/week, ≥25mg/week) or by the 3-yr period of enrolment (01/2002-06/2005,07/2005-06/2008,07/2008-06/2011). Cox regression was used to examine time-dependent association between the attainment of disease remission as per the DAS28, CDAI and SDAI criteria and MTX dose. <h3>Results</h3> 790 RA patients were included with a mean (SD) age of 55.75 (13.46) yrs, mean (SD) disease duration of 10.15 (10.08) yrs. The concomitant use of MTX at infliximab initiation increased across enrolment periods (66.5% vs. 73.3% vs. 77.6%; P=0.022) which was also associated with decreased disease activity at baseline. Concomitant use of azathioprine (5.2% vs. 0.2%; P&lt;0.001) and leflunomide (46.1% vs. 14.5%; P&lt;0.001) at baseline, and prior past use of MTX (77.8% vs. 65.7%; P=0.001) was more frequent in patients not treated with MTX at infliximab initiation than those treated with MTX. Among patients treated with MTX at baseline the most common MTX dose category was 10-25mg/week (66.3% of patients). A trend towards higher MTX doses was observed over time with more patients treated with &gt;25mg/week of MTX in recent yrs. Survival analysis shows that, upon adjusting for baseline disease activity, use of MTX over time was associated with an increased hazard ratio [HR (95%CI)] of attaining disease DAS28-CRP [1.35 (1.06-1.71)], CDAI [1.33 (1.02-1.72)], and SDAI [1.62 (1.14-2.32)] remission. This effect was observed across all MTX dose categories except for DAS28-CRP and CDAI in the &gt;25mg/week dose category. <h3>Conclusions</h3> Clinical practice has changed over time with physicians using concomitant MTX at IFX initiation more frequently in recent years despite lower disease activity in patients today. The data support improved outcomes among patients treated with IFX in routine clinical care when receiving concomitant MTX. This is consistent with the current label and recent recommendations of the Canadian Rheumatology Association. <h3>References</h3> Arthritis Rheum 1998;41:1552–63 <h3>Disclosure of Interest</h3> D. Choquette: None Declared, C. Thorne: None Declared, J. Kelsall: None Declared, M. Zummer: None Declared, M. Starr: None Declared, M. Sheriff: None Declared, W. Bensen: None Declared, A. Chow: None Declared, P. Baer: None Declared, E. Rampakakis Employee of: JSS Medical Research, J. Sampalis Employee of: JSS Medical Research, F. Nantel Employee of: Janssen, A. Lehman Employee of: Janssen, S. Otawa Employee of: Janssen, M. Shawi Employee of: Janssen