Amgen tested T-Vec against subcutaneous GM-CSF, not against any of the current active agents.Well, GM-CSF is not exactly inactive; in fact, a phase-2 study presented at ASCO showed that Leukine + Yervoy worked better than Yervoy alone (http://www.healio.com/hematology-oncology/highlights-from-asco-2013/gm-csf-plus-ipilimumab-extended-os-in-metastatic-melanoma ).