OH2 Administered by Intratumoral Injection

Male or female subjects aged ≥ 18 years old

Subject must have histologically- or cytologically-confirmed diagnosis of unresectable locally advanced or metastatic melanoma, pancreatic cancer, liver metastases from colorectal cancer, breast cancer, and other solid tumors. (Part 1 and Part 2 Cohort A will include patients who have solid tumors with cutaneous/subcutaneous tumor lesions, such as melanoma, cutaneous squamous cell carcinoma, and cutaneous/subcutaneous metastasis from pancreatic cancer, colorectal cancer, breast cancer etc. Part 2 Cohort B will include patients who have visceral tumors.)

Subject has measurable disease as determined by RECIST version 1.1. At least 1 lesion must be suitable for intratumoral (IT) injection. Lesions for injection must be ≥ 10 mm and ≤ 60 mm in longest diameter.

Subjects who have progressed on or are ineligible for available standard therapy are eligible for this trial after the last dose of the previous treatment which is ≥ 4 weeks or 5 half-lives (if required) before the first dose of study treatment. Note: patients who have previously been treated with IMLYGIC (Talimogene laherparepvec, T-Vec) are eligible after discontinuing the last dose of previous T-Vec treatment for ≥ 12 weeks before first dose of study treatment.