Ph1 Administration of VSV-IFNβ-NIS Monotherapy and in Combination With Avelumab in Pts With Refractory Solid Tumors

Inclusion Criteria:

* Be \> 18 years of age on day of signing informed consent.
* Have a histologically confirmed diagnosis of an advanced and/or metastatic solid tumor that is relapsed and/or refractory to standard therapy, as defined as progression on at least one prior line of therapy in the relapsed/metastatic setting and no existing options are felt to provide clinical benefit.
* Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1.
* Adequate hematological, liver and kidney function.
* Must be willing to implement contraception throughout study and for 120 days after receiving the study drug.

Exclusion Criteria:

* Has been receiving: radiotherapy, chemotherapy, or molecularly-targeted agents or tyrosine kinase inhibitors within 2 weeks or 5 half-lives (whichever is longer) of the start of study treatment; immunotherapy/monoclonal antibodies within 3 weeks of the start of study treatment; nitrosoureas, antibody-drug conjugates, or radioactive isotopes within 6 weeks of the start of study treatment.
* Has a history of a bone marrow or solid organ transplant.
* Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment.