Background Although the use of infliximab (INF), adalimumab (ADA) and etanercept (ETA) for the treatment of spondyloarthropathy (SA) is widespread in clinical practice, there are no studies on its persistence over time.

Purpose To estimate the persistence of treatment with infliximab, adalimumab and etanercept in patients diagnosed with SA receiving their first biological treatment (FBT).

Material and methods Retrospective, observational study of all patients diagnosed with SA initiating FBT with INF, ADA and ETA since its commercialisation in 1999, 2003 and 2006, respectively, to June 2010 (at least 5 years of follow-up). Variables: age, sex, treatment start and suspension date and their reason (failure, intolerance, clinical improvement/remission, patient preference, neoplasms/infections and others). Persistence was defined as time (months) from the start of treatment until their suspension for dispensation periods higher than 3 months to include optimisation. Outcome variables were overall and specific persistence for each treatment. Persistence was calculated with Kaplan-Meier survival curves.

Results 100 patients (57% males) were included. 29, 33 and 38 received FBT with INF, ADA and ETA, respectively. Mean age was 52.67 years (95% CI 50.06 to 55.29). The median overall persistence was 40.04 months (95% CI 23.35 to 56.74). Regarding the specific persistence, INF median duration was 25.99 months (95% CI 4.98 to 47.00); ADA 55.49 (95% CI 40.75 to 70.23) and ETA 36.33 (95% CI 4.22 to 68.44). Survival curves were compared using the log rank function with no significant differences (p = 0.592). The reasons for suspension of INF, ADA and ETA, respectively, were: failure 44.82%, 18.18% and 23.68%; intolerance 13.79%, 6.06% and 10.52%; clinical improvement/remission 6.89%, 12.12% and 23.68%; patient preference 6.89%, 0% and 2.63%; and neoplasms/infections 3.44%, 9.09% and 2.63%. Other reasons were chest pain in 1 patient with ADA and alcoholism, heart failure and inflammatory bowel disease in 3 patients with ETA. Currently, there are 16 patients with ADA, 9 with ETA and 5 with INF.

Conclusion The high overall persistence of these drugs, more than a median of 3 years, makes us believe they are well tolerated and effective. A marked specific persistence with ADA (approximately 4.5 years) was observed. However, no significant differences were found between the drugs. The main reason for suspension was failure. Regarding clinical improvement/remission, ETA had better results.

No conflict of interest.