Long-term Etanercept Boasts Better Retention Rates than Adalimumab in RA

SAN FRANCISCO, CA—Long-term etanercept is associated with modestly better treatment retention rates than adalimumab among patients with rheumatoid arthritis (RA), according to an analysis of data from the RHUMADATA® clinical registry and database presented at the 2015 ACR/ARHP Annual Meeting.

“After 10 years of continuous exposure to a first biologic agent, etanercept offers a clinically small but statistically significant advantage over adalimumab in a population of RA patients,” reported lead study author Denis Choquette, MD, FRCP(C), FMSQ, Director of the Rheumatology Department, Institut de recherche en rhumatologie de Montréal (IRRM), in Montréal, Quebec, Canada, and coauthors.

Few previously-reported studies have provided data on RA treatment outcomes “over the very long term, up to 10 years,” Dr. Choquette and coauthors noted: “The vast majority of them have a duration of less than 3 to 4 years, are open-label, have selection entry criteria, and compare outcome measures such as DAS [disease activity score] score, DAS improvement, HAQ [health assessment questionnaire] improvement and so on.”

The RHUMADATA® database and registry enrolls “all patients in a given center for whom a specific diagnosis such as RA has been made,” offering an opportunity to compare retention rates for adalimumab and etanercept after DMARDs [disease-modifying antirheumatic drugs] failure in a large population of RA patients.

Data were analyzed for 548 RA patients who underwent biologic-based therapy after Jan. 1, 2002, including 184 patients who had been prescribed adalimumab (ADA) as a first biologic agent, and 364 patients prescribed etanercept (ETA). Variables included in the analyses included “patient age and gender, disease characteristics, clinical variables, patient- and physician-specific assessments, lab measures and composite assessment of disease activity (DAS28-ESR, SDAI and CDAI).”

“All patients were followed until they discontinued their treatment or June 2, 2015, the date at which the data was extracted from Rhumadata®,” said Dr. Choquette. “Secondary diagnoses and comorbidities established at or before the administration of the biologic agents were coded using the ICD-9-CM codes. Infections occurring during treatment, biologic status (ongoing or stopped) and the reasons for biologic cessation were also extracted. The 10-year drug retention rates were estimated and compared using Kaplan-Meier survival estimates and potential predictors were identified using univariate proportional hazard regression models.” 

“The patients were mostly women (74.5%) and had an average age of 53.3 (SD=12.8),” reported Dr. Choquette. “The patients had an average disease duration of 7.1 years (SD=8.0) and provided 2327.3 person-years of observation.”

The 10-year retention rates of ADA and ETA were 27.2% (SD=3.9%) and 35.0% (SD=3.1%; P=0.0031).

Which biologic was used, and fatigue Visual Analogue Scale (VAS)—but not concurrent use of non-biologic DMARDs—were identified as significant predictors of retention.