Mixed top-line results for AstraZeneca's RA drug candidate fostamatinib

Anglo-Swedish drug major AstraZeneca (LSE: AZN) this morning reported top-line results from the Phase III OSKIRA-1 study (n=923) showing that fostamatinib achieved a statistically significant improvement in ACR20 response rate at 24 weeks in both the 100mg twice daily group and the group that received 100 mg twice daily for four weeks followed by 150mg once daily (49%, p<0.001 and 44%, p=0.006 respectively) compared to placebo (34%).

However, fostamatinib did not demonstrate a statistically significant difference in mTSS compared to placebo at 24 weeks for either dose (p=0.252 and p=0.170, respectively). The most commonly reported adverse events were hypertension, diarrhea, nausea, headache and nasopharyngitis. The OSKIRA-2 and OSKIRA-3 study results are expected in 2Q 2013.

Briggs Morrison, executive vice president of Global Medicines Development and chief medical officer, said: "These top-line results provide important information on the efficacy and safety of fostamatinib and demonstrate that the compound has an effect on the signs and symptoms of rheumatoid arthritis. We will await the results of the remaining Phase III studies, OSKIRA-2 and OSKIRA-3, to further evaluate and characterize the profile of fostamatinib as a potential treatment for rheumatoid arthritis."