CSF2 and melanoma: Following positive results in early phase I (NCT03064763) and II (NCT00289016) clinical trials testing the efficacy and safety of T-VEC in melanoma, a phase III (OPTiM trial) randomized open-label trial (NCT00769704) was initiated, testing T-VEC against subcutaneous GM-CSF in unresectable stage IIIB–IVM1c melanoma.