• Histologically confirmed cutaneous squamous cell carcinoma (cSCC), melanoma, or Merkel cell carcinoma, meeting one of the following criteria:

‣ cSCC, resectable local tumors: must be Stage II or lower, amenable to curative resection and in a location where acceptable surgical margins are anticipated

⁃ cSCC, unresectable local tumors: must be Stage II or lower, tumor has been unresponsive to prior radiation therapy or is not a candidate for curative radiation therapy

⁃ cSCC, metastatic disease: disease has progressed during or following prior checkpoint inhibitor therapy (anti-PD-1 or anti-PD-L1 antibody)

⁃ Melanoma, metastatic disease: Stage IV disease with a cutaneous lesion that has progressed during or following checkpoint inhibitor therapy (anti-PD-1/-PD-L1), and if BRAF-mutation is present, has progressed during or following prior treatment with anti-BRAF + MEK therapy

⁃ Merkel cell carcinoma, metastatic disease: Stage IV disease with a cutaneous lesion that has progressed during or following checkpoint inhibitor therapy (anti-PD-1/PD-L1)

• A minimum of one tumor of ≥ 1.0 cm and \< 3.0 cm in longest dimension that is accessible (with or without imaging guidance) for intratumoral injection and for biopsy and surgical excision must be present. The tumor is not necrotic, hemorrhagic, or friable, and is not within 2 cm of the eye or within 0.5 cm of or on the lip (including the vermilion border) and is not in a mucosal or visceral location.