Nanatinostat Plus Valganciclovir in Advanced EBV+ Solid Tumors and in Combination With Pembrolizumab in EBV+ RM-NPC

Key Inclusion Criteria:

* Recurrent or metastatic EBV+ nasopharyngeal carcinoma (RM-NPC) for whom no potentially curative options are available, who have received at least 1 prior line of platinum-based chemotherapy and no more than 3 prior lines of therapy for RM-NPC.
* Phase 1b exploratory proof-of-concept cohort only: Advanced/metastatic EBV+ non-NPC solid tumors with no available curative therapies.
* Measurable disease per RECIST v1.1
* ECOG performance status 0 or 1
* Adequate bone marrow and liver function

Key Exclusion Criteria:

* Anti-tumor treatment with cytotoxic drugs, biologic therapy, immunotherapy, or other investigational drugs within 4 weeks or \>5 half-lives, whichever is shorter
* Active CNS disease
* Inability to take oral medication, malabsorption syndrome or any other gastrointestinal condition (nausea, diarrhea, vomiting) that may impact the absorption of nanatinostat and valganciclovir
* Active infection requiring systemic therapy
* Active autoimmune disease that has required systemic therapy with modifying agents, corticosteroids, or immunosuppressive agents
* Positive hepatitis B or hepatitis C