AstraZeneca halts fostamatinib development after Phase III trial results
AstraZeneca will not proceed with regulatory filings for fostamatinib, an oral treatment for rheumatoid arthritis. Top-line results from the pivotal Phase III OSKIRA trials did not meet expectations.
AstraZeneca announced on June 4, 2013, that it will not seek regulatory approval for fostamatinib, an oral spleen tyrosine kinase (SYK) inhibitor developed for rheumatoid arthritis (RA). The decision follows the completion of the pivotal Phase III OSKIRA clinical trial program.
The OSKIRA-2 study, testing fostamatinib in patients inadequately responding to disease-modifying anti-rheumatic drugs (DMARDs), showed statistically significant improvements in ACR20 response rates compared to placebo when used in combination with DMARDs. However, the OSKIRA-3 study, involving patients with inadequate response to methotrexate and a TNF-alpha antagonist, showed statistically significant improvements for only one of the two fostamatinib dosing regimens tested.
Based on the overall data from the OSKIRA trials, the company has decided not to proceed with regulatory submissions. The safety and tolerability findings for fostamatinib were consistent with earlier studies, with common adverse events including hypertension, diarrhea, and nausea.
AstraZeneca will incur an impairment charge of approximately $140 million related to the intangible assets for fostamatinib. Rights to the compound will revert to Rigel Pharmaceuticals, which will determine any future course for the drug. AstraZeneca stated its commitment to developing new treatments for rheumatic and inflammatory diseases remains.