I would suggest that you look at the various websites for these medications to read the full prescribing info for each one. Ilaris and Arcalyst are FDA approved for patients with the FCAS and MWS forms of CAPS, and anakinra is approved in the US for the NOMID form of CAPS.
Anakinra was first approved for Rheumatoid Arthritis around 2001. Arcalyst was FDA approved for MWS and FCAS by 2008, and Ilaris was first approved in late 2009.
All drugs have to have many years of follow up and FDA reporting for any adverse events or significant issues with any medication. Also, I know that there are some ongoing registry follow up studies for Ilaris and there was one for arcalyst (it may still be going on.) Anakinra has been approved longer for RA, but was more recently approved for the NOMID form of CAPS in late December 2012.
If you want to have the websites and more info, please take a look at our website where we have links to the various drug websites and prescribing info. http://www.nomidalliance.com/capstreat.php
I think that you may have also posted on the CAPS community at rareconnect,org so I will also share this there for you too.
Let me know what we can do to help.