Background/Purpose:   The Tight Control of PsA (TICOPA) study was the first to address treat to target in PsA using the minimal disease activity (MDA) criteria, confirming a benefit in terms of disease activity, function and quality of life.  Median changes in modified Sharp-van der Heijde radiographic scores were 0 in both groups.  Our aim was to investigate further whether treating to target or achieving low disease activity states predicts radiographic change in the TICOPA study.

Methods: 206 patients with early PsA (<2 years disease duration) were randomised 1:1 to tight control (4 weekly review, treatment escalated to MDA) or standard care (12 weekly review, no set treatment).  Radiographs of the hands and feet were taken at week 0 and 48 and scored by consensus using the modified Sharp-van der Heijde (mSvdH) score.  Disease states examined included the MDA criteria, Disease Activity in Psoriatic Arthritis (DAPSA) remission and Very Low Disease Activity (VLDA) defined as meeting all 7 of the MDA cutpoints at any timepoint.  Bootstrapped quantile regression, adjusting for baseline values and minimisation factors, was used to compare radiographic scores defined according to treatment or disease states at the 50^th, 75^th and 90^th quantiles.

Results: For tight control vs standard therapy, there was no difference in radiographic progression at the median.  There was a trend towards reduced progression in total mSvdH score at the 75^th & 90^th quantiles but this was not significant (see figure and table). For some of the low disease activity states, change in total SvdH score was significantly different at the median for most and at the 75^th and 90^th quantile (see figure and table).  In all cases the trend was towards less progression in the low disease states.  Changes in erosion scores were non-significant.

Conclusion: There was no significant difference in radiographic outcome seen with tight control although progression was numerically lower.  Achieving MDA, DAPSA remission or VLDA was significantly predictive of total SvdH score for median and some 75/90^th quantile scores.  Radiographic progression was consistently numerically lower in those achieving the disease states.   The lack of effect on erosion scores is likely to reflect the TICOPA study design including a population with early milder disease (30% oligoarthritis), no placebo comparison and a step up treatment protocol.  These data suggest a potential impact of tight control and achieving low disease activity states on radiographic outcome but should be interpreted with caution.