Biologic monotherapy as initial treatment in patients with early rheumatoid arthritis.

Although biologic agents are most well established as part of combination regimens in patients with RA, biologic monotherapy is common in clinical practice. To date, few double-blind, randomized clinical trials have compared biologic monotherapy with MTX monotherapy. Five randomized double-blind trials evaluating the TNF antagonists etanercept (ERA and TEMPO), adalimumab (PREMIER) and golimumab (GO-BEFORE) and the IL-6 receptor antagonist tocilizumab (AMBITION) were identified. We noted considerable variation in patient characteristics (i.e. disease duration and disease severity) in the five trials. Studies involving monotherapy with TNF inhibitors found no clear clinical efficacy advantage over MTX monotherapy. In the two trials that included a TNF inhibitor/MTX combination arm, combination therapy was superior to monotherapy with either agent alone. In contrast, the AMBITION trial demonstrated that tocilizumab monotherapy was superior to MTX in terms of clinical response, disease activity, remission and functionality. Although results cannot be compared across clinical trials, tocilizumab was the only biologic agent to demonstrate superiority to MTX as monotherapy in patients with RA with limited/no exposure to MTX.