A Phase 1b/2 Study of Intravenous Brincidofovir in Patients With Relapsed or Refractory Lymphoma and Relapsed or Refractory Extranodal Natural Killer/T-cell Lymphoma

Inclusion Criteria:

• Patients who are histopathologically diagnosed with ENKL based on the World HealthOrganization (WHO) Classification of Malignant Lymphoma 5th Edition (WHO-HAEM5) (canbe enrolled in the Phase 1b part and the Phase 2 part) or patients diagnosed withEBV-positive nodal T- and NK-cell lymphoma (EBV + nTNKCL), nodal T-follicular helpercell lymphoma (nTFHcL) (including angioimmunoblastic T-cell lymphoma (AITL) asdefined in the WHO Classification, 4th Edition), peripheral T-cell lymphoma nototherwise specified (PTCL, NOS), anaplastic large cell lymphoma (ALCL), diffuselarge B-cell lymphoma (DLBCL) (e.g., DLBCL, NOS), or adult T-Cell Leukemia Lymphoma (ATLL) (can only be enrolled in the Phase 1b part)

• Patients with relapsed or refractory lymphoma and previously treated with systemicchemotherapy (history of multidrug chemotherapy including L-asparaginase such asSMILE therapy for ENKL is mandatory) who are ineligible for other systemic therapies

• Patients with the following Eastern Cooperative Oncology Group (ECOG) PerformanceStatus (PS):

• Phase 1b part: 0-1

• Phase 2 part: 0-2

Exclusion Criteria:

• Patients with another active malignant tumor requiring treatment

• Patients with NCI-CTCAE Grade 2 or higher diarrhea (increase of 4 or more bowelmovements per day compared to usual number of bowel movements) within 7 days priorto starting the first dose of BCV

• Graft-Versus-Host Disease (GVHD) patients requiring immunosuppressive agents

• Patients with a history of Cidofovir intolerance

• Patients with a history of being diagnosed with cirrhosis