Key Inclusion Criteria:

          -  Have a histologically or pathologically documented, locally-advanced or metastatic
             solid tumor for which standard curative measures do not exist or are no longer
             effective

          -  Measurable disease as per RECIST 1.1 criteria

          -  At least one tumor amenable to safe ITu injections and biopsies

          -  ECOG performance status 0 or 1

          -  Demonstrate adequate organ function

          -  Must be willing to comply with all protocol procedures and adhere to post-treatment
             care instructions

          -  Additional Inclusion criteria exist

        For patients in phase 2 only: Have a histologically or cytologically confirmed advanced
        (metastatic and/or unresectable) solid tumor listed below, that is incurable and for which
        prior standard treatment has failed:

          1. MSS-CRC patients that have progressed to at least 2 prior lines of systemic therapy
             which should include irinotecan and oxaliplatin with or without bevacizumab, or,

          2. TNBC patients who have failed anthracycline- and taxane-based chemotherapy. TNBC
             patients with PD-L1 positive tumors must also have failed treatment with PD-1 or PD-L1
             targeted therapy.

        Key Exclusion Criteria:

          -  Prior systemic therapy, including experimental, surgery or radiation therapy within 4
             weeks and must have recovered from acute toxicity.

          -  Prior treatment with any oncolytic virus.

          -  Requires use of anti-platelet or anti-coagulant therapy that cannot be safely
             suspended for per protocol biopsies or intra-tumoral injections.

          -  CNS metastases and/or carcinomatous meningitis that have not been completely resected
             or completely irradiated.

          -  Prior history of myocarditis

          -  Symptomatic or asymptomatic cardiovascular disease

          -  Known HIV/AIDS, active HBV or HCV infection.

          -  Received immunosuppressive medication within 4 weeks. (>10mg/day prednisone)

          -  Known intolerance to anti-PD-1 or anti-PD-L1 antibody therapy

          -  Additional Exclusion criteria exist