Etanercept Concentration in Patients with Rheumatoid Arthritis and Its Potential Influence on Treatment Decisions: A Pilot Study
The Journal of Rheumatology, 07/05/2012
Daïen CI et al. – Etanercept (ETN) concentrations at 3 months predict response to ETN therapy at 6 months. Low ETN concentrations could explain the absence of response to ETN, suggesting that patients with low ETN levels could benefit from increased ETN dose or earlier interruption of treatment.Methods
- Between 2009 and 2010, the authors included 19 women with active rheumatoid arthritis (RA) who were candidates for ETN therapy.
- Response criteria were evaluated at 3 and 6 months.
- Serum concentrations of ETN and anti–ETN antibodies were measured by ELISA at baseline and at 3 and 6 months.
- Eighteen patients completed followup.
- Three–month ETN concentrations were lower for 6– month nonresponders than responders (p = 0.03).
- Three–month ETN levels correlated significantly with change in DAS28 between baseline and 6 months (r = –0.62, p = 0.006).
- The best predictor of response at 6 months was observed with an ETN threshold of 3.1 μg/ml at 3 months.
- No anti–ETN antibodies were found.