Inclusion Criteria:

- 18 years of age or more and able to understand and sign a written informed consent
form

- Histologically confirmed diagnosis of cancer with liver metastases, or histologically
confirmed primary liver cancer (e.g. hepatocellular carcinoma, cholangiocarcinoma, or
gallbladder carcinoma). Subjects may have extrahepatic spread of malignancy, except
they may not have brain metastases. Subjects with a history of more than one
invasive malignancy remain eligible for this study, but in these instances, a liver
biopsy is required to document the histology of the liver tumor. An exception to
this criterion is made for basal cell carcinoma.

- Subjects must have primary or metastatic liver malignancies which are surgically
unresectable, and exhausted all standard therapeutic options

- Patients with hepatocellular carcinoma must have received sorafenib as one of the
standard treatment options prior to being enrolled into the study

- No liver surgery (including radiofrequency ablation), chemotherapy (including
bevacizumab), immunotherapy, or liver radiotherapy within 4 weeks of enrollment.

- ECOG performance status 0, 1 or 2 and life expectancy of greater than 12 weeks based
on the investigator's clinical judgment.

- Serum hematology and chemistry test results as outlined in the protocol.

- Tumor volume occupies less than 50% of liver by volume as assessed by CT scan or MRI
scan within 4 weeks of treatment

- Negative pregnancy test (serum or urine) in premenopausal women

- Prior exposure to HSV-1 as determined by blood test

Exclusion Criteria:

- Clinical or pathological diagnosis of cirrhosis, hemachromatosis, or heptic fibrosis

- Ascites or complete occlusion of main portal vein

- Hepatitis C infection, chronic infection with hepatitis B, infection with HIV, or
evidence of hepatic insufficiency

- Inability to practice contraception with condoms as prescribed by the protocol

- Active infection requiring treatment with systemic antibiotics or systemic
anti-fungal agents

- Being treated with immunosuppressive agents such as systemic corticosteroids or
cyclosporine

- Unstable angina, symptomatic congestive heart failure, serious uncontrolled cardiac
arrhythmia, or need for antiarrythmic medication for which inability to take an oral
preparation of regular medication for 48 hours would represent an unacceptable risk.

- Known existing uncontrolled coagulopathy, hemorrhagic disorder, or inability to
discontinue coumadin or plavix for 5 days prior to each treatment (except for
prophylaxis against portacath-associated thrombosis, which does not require cessation
of therapy).

- History of seizures

- Allergy to acyclovir or inability to receive contract for CT and MRI scans

- Prior liver resection of greater than 2 anatomic segments as defined by Couinaud
(subjects that have undergone prior liver wedge excisions or segmental resections are
not excluded on this basis alone).