Key Inclusion Criteria:

          1. Voluntary agreement to provide written informed consent prior to any study procedures
             and the willingness and ability to comply with all aspects of the protocol and
             understand the risk to their organ allograft.

          2. Patients with histologically or cytologically confirmed recurrent, locally advanced or
             metastatic (to skin, soft tissue or lymph nodes) cutaneous squamous cell carcinoma,
             who have progressed following local resection or one local (i.e., topical) medical
             therapy.

          3. Patients who are renal or hepatic organ allograft recipients on a stable
             immunosuppressive regimen for at least 12 months prior to study participation with
             stable renal and/or hepatic function. NOTE: Patients who require CTLA-4-Ig medications
             are excluded.

          4. Patients for whom surgical or radiation treatment of lesions is contraindicated.

          5. At least 1 lesion that is measurable and injectable by study criteria (tumor of ≥1cm
             in longest diameter or ≥1.5 cm in shortest diameter for lymph nodes).

          6. Eastern Cooperative Oncology Group (ECOG) performance status ≤1.

          7. Anticipated life expectancy > 6 months

          8. Baseline ECG without evidence of acute ischemia.

          9. All patients must consent to provide archived or newly obtained tumor material (either
             formalin-fixed, paraffin-embedded [FFPE] block or 20 unstained slides).

        Key Exclusion Criteria:

          1. Prior treatment with an oncolytic therapy or more than one prior CSCC-directed
             local/topical therapy.

          2. Prior systemic anti-cancer treatment for CSCC.

          3. Patients with visceral metastases.

          4. Patients with active herpetic infections or prior complications of HSV-1 infection
             (e.g. herpetic keratitis or encephalitis).

          5. Patients with a history of organ graft rejection within 12 months.

          6. Patients with an ANC < 1.0 x 109/L at any point within 3 months of starting therapy.

          7. Had systemic infection requiring intravenous (IV) antibiotics or anti-virals, or other
             serious infection within 60 days prior to dosing.

          8. Patients who require intermittent or chronic use of systemic (oral or intravenous)
             anti-virals with known anti-herpetic activity (e.g. acyclovir) unless for organ
             allograft preservation.

          9. Patients requiring CTLA-4-Ig medications.

         10. Ongoing or recent (within 5 years) evidence of significant autoimmune disease that
             required treatment with systemic immunosuppressive treatments beyond that required for
             maintenance allograft rejection prevention. The following are not exclusionary:
             vitiligo, childhood asthma that has resolved, type 1 diabetes, residual hypothyroidism
             that requires only hormone replacement, or psoriasis that does not require systemic
             treatment.

         11. Active infection with hepatitis B virus (HBV), hepatitis C virus (HCV) or human
             immunodeficiency virus (HIV).

         12. Any history of transplant-related viral infections, such as BK, EBV or CMV, within 3
             months of study entry. Patients with a history of hepatitis B or C virus must have
             undetectable viral load within 3 months of study entry.

         13. Patients with a condition requiring an increase in the patient's usual
             immunosuppressive medications within 60 days of study treatment.

         14. Known active CNS metastases and/or carcinomatous meningitis.