Predicted versus observed radiographic progression in early rheumatoid arthritis (POPeRA) was applied to demonstrate how various treatment modalities affect and potentially minimise radiographic progression over time.
The POPeRA method utilises the baseline radiographic score and patient-reported symptom duration to predict radiographic outcomes. It was applied at baseline, 2, and 5 years to patients with eRA from the randomised Finnish RA Combination trial (FIN-RACo) (n=144) and New Finnish RA Combination Therapy (NEO-RACo) (n=90) trials. For FIN-RACo, patients were randomised either to a single DMARD (sulfasalazine, with or without prednisolone) or to combination therapy (methotrexate+sulfasalazine+hydroxychloroquine, i.e. triple therapy, with prednisolone). In NEO-RACo, all patients were assigned intensified combination therapy (including 7.5 mg prednisolone/day) plus a randomised 6-month induction of either placebo or anti-TNF treatment (infliximab).
In FIN-RACo, combination versus monotherapy resulted in superior outcomes in the change from predicted progression over 2 and 5 years (mean 35.7% reduction vs. -32.9%, a worsening from predicted, p=0.001; 34.2% vs. -17.8%, p=0.003, respectively). In NEO-RACo, combination+anti-TNF induction led to significantly greater reductions from predicted progression than combination+placebo, both at 2 and 5 years of follow-up (98.5% vs. 83.4%, p=0.005; 92.4% vs. 82.5%, p=0.027, respectively). Importantly, anti-TNF add-on led to superior reductions from predicted among RF-positive patients (2 years: 97.4% vs. 80.4%, p=0.009; 5 years: 90.2% vs. 80.1%, p=0.030), but not among RF-negative patients.
These results confirm that conventional combination therapy in eRA has a long-term radiographic benefit versus monotherapy. Through POPeRA, it was made evident that anti-TNF induction therapy for 6 months further increases the long-term radiographic benefit of combination therapy in RF-positive patients.