Fostamatinib Is Safe but Ineffective in Treating in Rheumatoid Arthritis

An oral spleen tyrosine kinase inhibitor known as Fostamatinib disodium has been discovered to be a safe but ineffective treatment of patients suffering from rheumatoid arthritis (RA) who failed biologic therapies.

According to a study published in the February issue of Arthritis & Rheumatism, Mark C. Genovese, M.D., of Stanford University in Palo Alto, Calif., and his colleagues created a double-blind, placebo controlled study with the intention of analyzing the effectiveness and safety of fostamatinib disodium (R788).

“Safety results appeared to suggest that 100 mg twice a day of R788 was a tolerable dose for chronic administration in RA,” said researchers of the study done, who said that while the dosage is not dangerous for patients, their research proves it to not be as effective as they had hoped.

The study consisted of 229 patients, all living with active RA, who had no response to biologic therapies. The participants of the study were randomly selected to be given 100 milligrams of fostamatinib or a placebo.

The chief goal and what was considered to be the finish line for these patients was the American College of Rheumatology 20 percent improvement (ACR20) response following three months of the treatment.

Secondary aims consisted of changes in inflammation and damage to the joints, which was evaluated by magnetic resonance imaging (MRI) and changes in the disease activity score.

As far as the primary goals were considered, the researchers of the study discovered that the ACR20 responses did not vary drastically between the group selected to receive fostamatinib and the group receiving the placebo. There was, however, a significant variation in the ACR20 among participants who entered the study with elevated C-reactive protein.

Secondary outcomes, on the other hand, proved to show distinction between the two groups: The group receiving fostamatinib showed improved synovitis scores on MRI and in C-reactive protein. The results may have been affected by “baseline differences in steroid use, prior biologic use, and MRI synovitis scores”, according to DoctorsLounge.

The researchers are not through with the treatment for RA patients just yet, however. “There appears to be sufficient grounds to study R788 in this refractory population again, with some important lessons learned from this phase II study,” the researchers of the study wrote.