Male or female age ≥ 18 years with histologically confirmed diagnosis of melanoma and unresected stage IIIB, IIIC, IVM1a, IVM1b, or IVM1c regardless of prior line of therapy. Subject is candidate for intralesional therapy administration into cutaneous, subcutaneous, or nodal disease and must also have measurable disease, serum lactate dehydrogenase ≤ 1.5 x upper limit of normal, and Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and adequate hematologic, hepatic, and renal organ function.