Regeneron reports positive results from gout study

Arcalyst is already approved to treat one rare inflammatory disease. Regeneron is currently studying the injectable drug as a treatment for gout, which causes swelling and stiffness of the joints.

Regeneron said an 83-patient study showed gout patients taking Arcalyst had 81 percent fewer flare ups then those taking placebo.

No serious adverse reactions were reported during the study, which lasted 12 weeks.

Shares of Regeneron Pharmaceuticals Inc. rose $1.01, or 4.9 percent, to $21.59 in midday trading.