What's anakinra?

According to this Reuters article, a new study suggests that anakinra may be effective against AS. The three-month study gave daily injections of the drug to nine AS sufferers for whom normal treatment didn't work. This is all very interesting, but it's also the first time I've heard of anakinra. Nor does the article mention what kind of drug it is -- biologic, cox-2 inhibitor, or NSAID. Must investigate further. It's still at the clinical stage, so it may simply be that we haven't been subjected to the onslaught of pharmaceutical marketing yet.