Background Certolizumab pegol (CZP) a Tumor Necrosis Factor inhibitor (TNFi) is one of five TNFi's presently approved and available in Sweden. It was approved for the treatment of Rheumatoid Arthritis (RA) in Oct 2009, for Ankylosing Spondylitis (AS) and non-radiographic axial Spondyloarthritis (AxSpa) in Oct 2013, and for Psoriatic Arthritis (PsA) in Nov 2013. CZP has to some extent been used for non-RA diagnoses since 2011, with recordings of treatment in the Swedish Rheumatology Quality Register (SRQ). In longitudinal observational studies, the 6 month adherence for TNFi-naïve patients with AS and PsA treated with other TNFi has ranged from about 82-85% and 78-92% respectively1-10.
The aim of this study was to evaluate cumulative survival probability of CZP in clinical practice over the first year of treatment for AS, PsA and undifferentiated Spondyloarthritis (uSpA).
Methods Data from all patients with AS/PsA/uSPA initiating CZP treatment before August 15th 2014 were retrieved from SRQ. SRQ includes the register of biologic treatments ARTIS (Anti Rheumatic Treatment In Sweden). Data on follow-up was available until October 30th. Survival analysis (Kaplan-Meier) was performed with right censoring and log-rank test of equality across strata for comparison of bio-naïve patients versus patients with previous treatment with biological Disease-Modifying Anti-Rheumatic Drugs (bDMARD).
Results There were 541 patients who initiated CZP. Of those 109 (20%) were registered as AS, 276 (51%) as PsA and 156 (29%) as uSpA, with a mean follow-up time of 9,6/ 6,9/6,6 months. The proportions of men in AS/PsA/SpA patient groups were 64/ 40/44% respectively; and their median ages at baseline were 42/51/45 years respectively. In patients with AS/PsA /uSpA the proportions receiving CZP as the first biological treatment were 43/37/38%; and the proportion receiving concurrent conventional DMARDs were 41/53/40%.
Cumulative survival probability of CZP treatment (Table 1), were significantly better (P<0,001) for bDMARD-naïve patients versus others in both AS, PsA and uSpA.
Conclusions Real life experience from this nationwide rheumatology register, demonstrated that drug survival in bio-naïve patients with SpA receiving CZP treatment was statistically higher in patients compared to patients previously treated with bDMARDs. Adherence rates after 6 and 12 month were well within the range of published results for other TNF inhibitors.
Carmona L et al; Arthritis Res Ther 2006;8(3):R72
Fagerlie K et al; Ann Rheum dis;2013;72(11):1840-4
Glintborg B et al; A&R 2011;63(2):382-90
Gulfe A et al; Scand J Rheum; 2014;43(6):493-7
Heiberg M et al: A&R; 2008;59(2):234-240
Kristensen LE et al; Ann Rheum Dis 2008;67:364-369
Pavelka K et al; 2009;27(6):958-63
Zuffrey P et al; Rheum inter. Epub 2014 juli
Kristensen LE et al; Arth Care & Res 2010;62(10):1362-1369
Glintborg et al; Ann Rheum Dis. 2013;72(7):1149-55
Disclosure of Interest C. Dackhammar Grant/research support from: Data extraction and analyses was supported by UCB pharma, H. Forsblad-d'Elia: None declared, L.-E. Kristensen: None declared, U. Lindström: None declared, S. Ernestam: None declared, L. Jacobsson Grant/research support from: Data extraction and analyses was suppported by UCB Pharma