Future therapies for rheumatoid arthritis: remedies from the horns of a dilemma?

Drugs used to treat arthritis can be broadly classified into either anti-inflammatory or immunosuppressive/immunomodulatory agents. Non-steroidal anti-inflammatory drugs (NSAIDs) are used for both osteoarthritis (OA) and rheumatoid arthritis (RA), while drugs with an immunological mechanism of action are only applicable to RA. The total market value for anti-arthritic drugs is estimated to be 8.4 bn dollars, with the OA segment worth 6.9 bn dollars. In contrast, the major RA markets are valued at approximately 1.5 bn dollars. Drugs currently in late phase development reflect the accepted approaches towards treating the symptoms of arthritis, or suppressing immunological mechanisms considered to be the driving force for the underlying disease process in RA. The size of both the RA and OA markets, however, creates an incentive to develop new therapeutics which do not conform to these two approaches, but target new molecular mechanisms. Compounds currently in preclinical development demonstrate that it may be possible to combine anti-inflammatory and slow-acting antirheumatic activity into a single therapeutic. This new generation of anti-arthritic compounds has the potential to redefine the way in which common forms of arthritis, mixed connective tissue diseases and musculoskeletal diseases are treated in the future.