Monotherapy in rheumatoid arthritis

Therapeutic strategies for rheumatoid arthritis (RA) have evolved over time. Novel therapies have morphed in parallel to the ever-increasing understanding of RA pathogenesis, diagnosis and outcomes tools. For a century, the principal armamentarium was mainly composed by steroidal and non-steroidal anti-inflammatories. Over the last 25 years, however, the concept of disease-modifying anti-rheumatic drugs (DMARDs) has made possible the notion that the natural history of RA could actually be altered. Since then, synthetic DMARDs-particularly methotrexate (MTX) -have been used as monotherapy with significant success. This was followed by a revolutionary paradigm shift with the advent of anti-TNFα inhibitors and other "biologics" in the 1990s. Contemporary guidelines advocate for the use of a combina- tion therapy (i.e., MTX and a biologic) in aggressive RA cases given their proven additive effect. However, some patients are either intolerant to synthetic DMARDs or develop side effects that preclude their use. New data has recently emerged point- ing towards the potential for biologic monotherapy regimens in certain RA cases. This review will, therefore, describe the available evidence supporting the use of biologic DMARDs and the circumstances in which they are indicated.