The status of fostamatinib in the treatment of rheumatoid arthritis

Abstract

Fostamatinib (R788) is a prodrug rapidly converted to its active metabolite on oral administration. This (known as R406) is a potent inhibitor of spleen tyrosine kinase, required for the expression of a number of proinflammatory cytokines. Fostamatinib has shown significantly superior efficacy (when compared with placebo) in the control of patients with rheumatoid arthritis not responding to methotrexate in Phase II clinical trials. Treatment emergent adverse events with a higher frequency than in those on placebo included diarrhea, hypertension, urinary tract infections, neutropenia and elevated transaminases. The studied doses have shown a linear pharmacokinetic pattern and the administration of methotrexate does not affect it. Fostamatinib may have a role in the therapy of patients with rheumatoid arthritis with poor response to conventional therapy. If these results are confirmed once Phase III studies are completed, it may find a place in the evolving treatment algorithm for rheumatoid arthritis.

Keywords::

• fostamatinib
• kinase inhibitors
• rheumatoid arthritis
• SYK kinase

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.