Clinical and serological predictors of remission in rheumatoid arthritis are dependent on treatment regimen.

Objective: Early intensive treatment is now the cornerstone for the management of rheumatoid arthritis (RA). In the era of personalized medicine, when treatment is becoming more individualized, it is unclear from the current literature whether all patients with RA benefit equally from such intensive therapies. We investigated the benefit of different treatment regimens on remission rates when stratified to clinical and serological factors.

Methods: The Combination Anti-rheumatic Drugs in Early Rheumatoid Arthritis (CARDERA) trial recruited patients with RA of less than 2 years' duration who had active disease. The trial compared 4 treatment regimens: methotrexate monotherapy, 2 different double therapy regimens (methotrexate and cyclosporine or methotrexate and prednisolone) and 3-drug therapy. Clinical predictors included age, male sex, and tender joint count (TJC) and serological biomarkers included rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA).

Results: Patients who were male, over 50 years, had ≥ 6 TJC, were RF-IgM-positive, or ACPA-positive were more likely to achieve remission at 24 months using 3-drug therapy compared to monotherapy (OR 2.99, 4.95, 2.71, 2.54, and 3.52, respectively). There were no differences in response to monotherapy and 3-drug therapy if patients were female, under 50 years, had < 6 TJC, or were seronegative.

Conclusion: Early intensive regimens have become the gold standard in the treatment of early RA. Our study suggests that this intensive approach is only superior to monotherapy in certain subsets of patients. Although these are unlikely to be the only predictors of treatment response, our study brings us a step closer to achieving personalized medicine in RA.