FDA questions Arcalyst for gout

FDA reviewers said Arcalyst rilonacept from Regeneron Pharmaceuticals Inc. (NASDAQ:REGN) had a "small" treatment effect to prevent gout flares in adults initiating uric acid-lowering therapy and that the drug appears to be associated with an increased risk of malignancy. In briefing documents released ahead of Tuesday's Arthritis Advisory Committee meeting to discuss an sBLA for Arcalyst, FDA said that while two Phase III trials showed the drug significantly reduced the mean number of gout flares, the primary endpoint, compared with placebo, the clinical meaning of the absolute treatment effect is "unclear." The agency noted the placebo group had about a mean of one flare in the 16-week period, which was reduced to a mean of about 0.3 flares in the Arcalyst group.

Reviewers also said there were six malignancies in patients receiving Arcalyst, including prostate, gastric, breast and oropharyngeal cancer. The reviewers said these types of cancers are expected in a typical gout population, but added that it is "notable" that there were no malignancies in placebo patients. The reviewers also pointed to the lack of long-term safety data for Arcalyst and questioned whether the 16-week safety studies submitted by Regeneron were adequate. ...