SK,
Thanks for sharing the article.
If I read it correctly, the drug is Stelara (Ustekinumab)
which I believe was also just approved for PsA use in the US, as well as, the UK.
http://www.stelarainfo.com/psoriatic-arthritis/
And there is much discussion already in this other thread
http://discussion.livingwithpsoriaticarthritis.org/forum/topics/interesting-reading