Nobody guides this AFAIK.
It is occasionally guided, but I don't know if any of the clients have actually made the summit. Field Touring, for example has gone there every year for the last 5, but it appears that they haven't made it yet. To quote from their website:
In 2006 we had a number of members reach to near the 8000m mark on K2 and in 2009, 2010 & 2011 members reached the shoulder by way of the Cessen. In the course of these expeditions we have gained a significant knowledge of the mountain. We look forward to applying all that we learned to our fifth effort in 2012.
I know they send me an email every once in a while about their trips (not sure where they got my address though).