Delayed Response to Ipilimumab

This case of delayed Melanoma response to Ipilimumab is clearly puzzling and raises the question of the appropriateness of our measurement of disease response to treatment in solid cancers being treated with Immune approach.  The need for "Immune Response Criteria" or Biomarker is clearly here!
We block CTLA4, a lymphocyte related molecule but we stick to the mass volume criteria to assess response when indeed activation of lymphocytes should be the criteria.  One would think that Adenyl Cyclase activation would be the first proof of Medication activity since most pathways will pass by this?
gene activation would be best bio-markers and attraction to the tumor would be best quantified here (by certain gene activation)
Dampening of B7, particularly with closure of  related downstream genes would make a stronger indication of disease response...And we know suppression of receptors is marked when this happens.
The awakening of the Lymphocyte theoritically should raise the possibility of inducing Inflammatory  process in some patients based on genetic heterogeneity (which is the question behind this possibility), in the case presented, an inflammatory bowel disease was reactivated...did the patient present such an genetic atopy or background?  does use of steroids contribute to the delayed response or is-it the other way? that is genetic back ground actually drives the delay in response?  which background? IBD? (the fact is that in the case presented, one of the metastatic Melanoma mass involved the Colon provide further clue as to further link of this Melanoma with the GI tract could be surmised!)   The resection of this mass is an heroic activity that struck me !  most clinical settings would not have tried this exercise deemed futile in most American institutions...a paper should be provided just on what prompted this resection...please tell us what prompted the resection of a metastatic Melanoma lesion?it is puzzling but at the end a good thing for this patient!