R788 in TASKi3 Clinical Trial Does Not Meet Efficacy Endpoints in RA Patients Who Had Previously Failed Biologic Therapies - Results I...( SOUTH SAN FRANCISCO...),Health

SOUTH SAN FRANCISCO, Calif., July 23 /PRNewswire-FirstCall/ -- Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced that in the TASKi3 Phase 2b clinical trial in rheumatoid arthritis (RA) patients who had failed to respond to at least one biologic treatment, the group treated with R788 (fostamatinib disodium) did not report significantly higher ACR 20, ACR 50, ACR 70 and DAS28 response rates than the placebo group at three months, and therefore, the trial failed to meet its efficacy endpoints. The objective components (CRP and ESR)* of these ACR scores did show a statistically significant difference; however, the subjective reported response rate components did not as compared to placebo. Although the ACR scores for the R788 group were within the expected range in this patient population, the reported placebo response rates were considerably higher than seen in any other previous study of RA biologic failure patients and rose unaccountably between week 6 (at which point the reported response rates between R788 and placebo were significantly different) and month 3 (when such reported response rates were no longer significantly different).

TASKi3 was the first clinical trial evaluating R788 in which anatomical changes in the patients' wrist and hands were evaluated using Magnetic Resonance Imaging (MRI) and scored using the RAMRIS (Rheumatoid Arthritis Magnetic Resonance Imaging Scoring) system. Those results showed improvements in the treated group versus the placebo group in the Synovitis and Osteitis scores, while the Erosion scores, known to be the slowest to change, showed no significant effect at three months. The most frequent adverse events were as expected from the earlier TASKi trials and appear to be manageable.

Rigel will host a conference call today at 7PM EDT/ 4PM PDT
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