AZ's phase III RA trial underway

AstraZeneca (AZ) has announced the beginning of phase III clinical trial development for rheumatoid arthritis (RA) treatment fostamatinib.

The trial will study the effects of fostamatinib – developed as an oral syk inhibitor – in patients with previously inadequate response to disease-modifying anti-rheumatic drugs (DMARDs).

Syk is a form of tyrosine kinase protein that can lead to the inflammatory conditions of RA when functioning abnormally. Fostamatinib is designed to block the function of syk, halting progression of the disease.

Phase III development of the drug will see three trials assessing its efficacy and safety, including two 12-month studies examining the effect of fostamatinib on patients responding inadequately to DMARDs.

As published in the New England Journal of Medicine, a previous phase II programme demonstrated positive results for the drug, then known as R788, in RA patients who failed to respond adequately to current treatments.

Commenting on the development of fostamatinib, Anders Ekblom, AZ's executive vice president of global medicines development, said: "Patients with rheumatoid arthritis currently have limited treatment options after they stop responding adequately to DMARDs or anti-TNF therapy, and we are hopeful that fostamatinib may represent a novel alternative for patients to help manage their condition beyond this stage."

Fostamatinib was initially developed by Rigel Pharmaceuticals, with AZ purchasing rights to further develop and commercialise the drug in February 2010.