Risk factors for radiographic progression in psoriatic arthritis: subanalysis of the randomized controlled trial ADEPT.

Abstract

INTRODUCTION:

To identify independent predictors of radiographic progression in psoriatic arthritis (PsA) for patients treated with adalimumab or placebo in the Adalimumab Effectiveness in PsA Trial (ADEPT).

METHODS:

Univariate analyses and multivariate linear regression analyses assessed risk for radiographic progression (change in modified total Sharp score, DeltamTSS>0.5) from baseline to week 24 for C-reactive protein (CRP) and other baseline variables, and for 24-week time-averaged CRP (univariate analysis only). Subanalyses determined mean DeltamTSS for CRP subgroups. Analyses were post hoc, with observed data.

RESULTS:

One hundred and forty-four adalimumab-treated patients and 152 placebo-treated patients were assessed. Mean CRP was 64% lower by week 2 with adalimumab and essentially unchanged with placebo. Univariate analyses indicated that elevated CRP at baseline and time-averaged CRP were strongly associated with radiographic progression for placebo-treated patients but not for adalimumab-treated patients. Multivariate analysis confirmed that elevated baseline CRP was the only strong independent risk factor for radiographic progression (for CRP>or=1.0 mg/dl: odds ratio=3.28, 95% confidence interval=1.66 to 6.51, P<0.001). Adalimumab treatment reduced risk of progression approximately fivefold. The difference between mean DeltamTSS for adalimumab versus placebo was greatest for patients with baseline CRP>or=2.0 mg/dl (-0.5 vs. 2.6).

CONCLUSIONS:

Systemic inflammation in PsA, as indicated by elevated baseline CRP, was the only strong independent predictor of radiographic progression. This association was observed predominantly for placebo-treated patients. Adalimumab treatment substantially reduced the overall risk of radiographic progression, and provided greatest radiographic benefit for patients with the greatest CRP concentrations at baseline.

TRIAL REGISTRATION:

Trial registration: NCT00195689.

• Authors: Dafna D Gladman, Philip J Mease, Ernest H S Choy, Christopher T Ritchlin, Renee J Perdok, Eric H Sasso
• Journal: Arthritis research & therapy (Arthritis Res Ther) Vol. 12 Issue 3 Pg. R113 ( 2010) ISSN: 1478-6362 [Electronic] England
• PMID: 20537151 (Publication Type: Clinical Trial, Phase III, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Antibodies, Monoclonal, Humanized
• Antirheumatic Agents
• C-Reactive Protein
• Adalimumab

Topics

• Adalimumab
• Adult
• Antibodies, Monoclonal (therapeutic use)
• Antibodies, Monoclonal, Humanized
• Antirheumatic Agents (therapeutic use)
• Arthritis, Psoriatic (diagnostic imaging, drug therapy, metabolism)
• C-Reactive Protein (metabolism)
• Disease Progression
• Double-Blind Method
• Female
• Humans
• Linear Models
• Male
• Middle Aged
• Multivariate Analysis
• Radiography
• Risk Factors
• Treatment Outcome