Study of Talimogene Laherparepvec With Atezolizumab for Triple Negative Breast Cancer and Colorectal Cancer With Liver Metastases

Inclusion Criteria:

* Criteria1, Participant provided informed consent prior to any study-specific activities/procedures.
* Criteria 2, Confirmation of triple negative breast cancer or colorectal cancer with liver metastases by laboratory testing.
* Criteria 3, Subjects with triple negative breast cancer with liver metastases, or subjects with colorectal cancer with liver metastases are eligible if they have had disease progression during or after one or more prior standard of care systemic anti-cancer therapy (eg,chemotherapy, targeted therapy) for metastatic disease or if they progress during or within 6 months of receiving adjuvant therapy. If subjects, in the opinion of the investigator, are deemed not appropriate candidates for systemic anti-cancer therapy for metastatic disease or if they refuse systemic anti-cancer therapy for metastatic disease, they may be eligible after investigator discussion with Sponsor medical monitor for approval.
* Criteria 4, Participants have measurable disease which is equal to one or more metastatic liver lesions that can be accurately and serially measured that are greater than or equal to 1 cm dimension and for which the longest diameter is greater or equal to 1 cm as measured by CT (Computed Tomography) scan or magnetic resonance imaging. The metastatic liver lesion(s) must not be in an area that received prior localized therapies.
* Criteria 5, Metastatic liver lesions for injection must be without necrosis (dead tissue )and must be be located where any tumor swelling will not lead to gall bladder tract obstruction or lead to bleeding risk.
* Criteria 6, Eastern Cooperative Oncology Group performance status (ECOG PS) 0 or 1.
* Criteria 7, Life expectancy greater than or equal to 5 months.
* Criteria 8, Adequate organ function within 4 weeks prior to enrollment. This includes hematology, renal, hepatic and blood-clotting functions as defined by protocol.
* Criteria 9, Female subjects of childbearing potential should have a negative serum pregnancy test within 1 week prior to enrollment.
* Criteria 10, Other Inclusion Criteria May Apply.

Exclusion criteria:

* Criteria 1, Participant is a candidate for hepatic surgery or local regional therapy of liver metastases with curative intent.
* Criteria 2, More than one third of the liver is estimated to be involved with metastases.
* Criteria 3, There is invasion by cancer into the main blood vessels such as the portal vein, hepatic vein or the vena cava.
* Criteria 4, Participant is currently receiving or has received liver metastatic-directed therapy ( eg: radiation, ablation, embolization) less than 4 wks prior to enrollment or hepatic surgery.
* Criteria 5, History of other malignancy within the past 5 years prior to enrollment with some exceptions, as outlined in the protocol.
* Criteria 6, Active or untreated central nervous system (CNS) metastases per CT or magnetic resonance imagine (MRI) evaluation during screening.
* Participants with a history of CNS metastases are eligible provided they are stable and meet the criteria details in the protocol.
* Criteria 7, Other Medical Conditions as noted in the protocol.
* Criteria 8, Other Exclusion Criteria May Apply.