Thanks Joe for posting the Reuters article on Anti-4-1BB immunotherapies-
In general, checkpoint inhibitors (like PD-1 inhibitors) can be thought of as "releasing the brake" on the immune system; CD137 inhibitors act on the other side of the equation - they "push the gas pedal").
There is currently a trial going on specifically for CRC patients. It is a combination study of Urelumab with cetuximab at about 10 trial locations:
https://clinicaltrials.gov/ct2/show/NCT ... mab&rank=6
It is based upon this published pre-clinical study showing synergy between cetuximab & Urelumab
Full Paper: http://www.jci.org/articles/view/73014
Scientific editorial: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4089450/
Interestingly, since it means to optimize the immunotherapy component of cetuximab's activity, in preclinical models they saw significant activity whether kRAS-wild type or KRAS-mutant.
I haven't seen any clinical data released yet, crossing fingers-
-DK