Objectives To analyze the survival of treatment lines with different biologics in a cohort of patients diagnosed with rheumatoid arthritis (RA), psoriatic arthritis (AP), ankylosing spondylitis (AS) and other spondyloarthropathies (O).
Methods Retrospective observational study.All patients who had been treated with a biological drug for at least six months during the period between 01/01/2009 and 31/08/2014, for any of the previously specified indications were included.In addition to demographic data, all lines of treatment received from the diagnosis and the duration of them were collected.It has been analyzed whether there were differences in the duration of treatment depending upon the drug and the disease.
A survival analysis of all lines of treatment was performed using the Kaplan-Meier curves for each drug, including those who had not finished.It was represented on the vertical axis the percentage of patients who had each treatment and in the other axis, duration in days.It was analyzed whether there were differences between these curves using the log-rank test.
Results We studied 484 patients with a mean age of 56 years (SD 14.4), 54.3% women. 742 lines of treatment were analyzed. Drug distribution: Adalimumab 344, etanercept 219, infliximab 96, golimumab 20, certolizumab 6, abatacept 20 and tocilizumab 26. In the cutoff point of the study (31.AUG.2014) had completed 342 of these lines.
The average duration of treatment in days (± SD) was calculated with the following results: Adalimumab: 1034 (±864)days; Etanercept: 735 (±768)days; Infliximab: 959 (±845) days; Golimumab: 302 (±225)days; Certolizumab: 90±0 days; Abatacept: 429 (±360)days; Tocilizumab: 328 (±337)days. The average length of treatment depending on the pathology (± SD) was also calculated. AR: 989 (±853)days; AP: 975 (±843)days; EA: 766 (± 677)days and O: 912 (±920)days.Given the standard deviations found, a survival analysis was performed using the Kaplan-Meier curves.Significant difference were observed when comparing the drugs 2–2 for the following pairs:adalimumab and infliximab have longer lines comparing to golimumab, certolizumab, abatacept and tocilizumab (p<0.05) and etanercept longer than golimumab, certolizumab and tocilizumab (p<0.01).
Conclusions The duration of treatment lines is variable in all drugs and for all conditions tested. No differences were found with regard to the length of the lines between the three drugs analyzed with a longer time since its commercialization: adalimumab, etanercept and infliximab.
Supported by an unrestricted grant from Pfizer.
Disclosure of Interest None declared