Abstract
Objectives: To investigate changes in disease activity based on Disease activity score (DAS) 28-CRP measured
at the initiation of etanercept (ETN) administration and on evaluation, clinical remission rate, retention rate, progression
of bone destruction, and reasons for discontinuation.
Methods: The subjects were 105 rheumatoid arthritis (RA) patients treated with ETN at a dose of 25 mg/week
for 24 weeks or longer at my clinic. DAS28-CRP was used to evaluate RA activity, the Kaplan-Meier method was
used to evaluate retention rate, and the van der Heijde modified total Sharp score (mTSS) was used to evaluate
radiographic progression of bone destruction.
For multivariate analysis of factors influencing the retention rate and clinical efficacy, the Cox proportional hazards
model and binary logistic regression analysis were used, respectively.
Results: DAS28-CRP in all 105 patients was 5.17 ± 1.20 at initiation and decreased significantly to 3.13 ± 1.44
on evaluation ( p < 0.01). Remission based on DAS28-CRP was achieved in 34% of the patients on evaluation.
The 2-, 5-, 7-, and 10- year retention rates were 71.2, 53.7, 43.9, and 37.7%, respectively. The adherence tended
to be shorter in females and patients who had undergone previous treatment with a biological agent. An MMP3
level < 100 ng/ml at initiation was extracted as a factor associated with achievement of low disease activity. An
RF level ≤ 100 ng/ml or higher at initiation was extracted as a factor associated with difficulty in achieving low
disease activity. On radiographic evaluation of the yearly progression of joint destruction (δmTSS/year), structural
remission was maintained in 27.5% of the patients. Administration of the drug was discontinued due to adverse
events in 9 patients, and the reason was interstitial pneumonia in 2 and acute appendicitis, aggravation of nontuberculous
mycobacteriosis, skin reaction, muscle pain, nausea, and diagnosis of breast cancer during treatment in
one each.
Conclusion: The long-term clinical improvement and inhibition of joint destruction by 25 mg/week ETN were
clarified, along with its safety.
