Study of HB-200 alone and with pembrolizumab for patients with Recurrent/ Metastatic HPV 16+ Head and Neck and other Cancers

Inclusion Criteria:

• Must be ≥18 years old
• Documentation of confirmed HPV 16+ head and neck squamous cell carcinoma via genotype testing (HPV16 testing can be initiated at the study center)
• ECOG performance status of 0 to 1.
• Screening laboratory values and medication/radiation wash-out windows must meet protocol specified-criteria (the study center will confirm this)
• For patients who HAVE previously received treatment for metastatic/recurrent cancer (second line +, 2L+): must have had tumor progression or recurrence on standard of care therapy including ≥ 1 prior therapy
• Have ≥ 1 measurable tumor by tumor imaging assessment
• For patients who previously have NOT received treatment for metastatic/recurrent cancer (first line, 1L): must have head and neck squamous cell carcinoma and be eligible to receive pembrolizumab per standard of care / product label

Exclusion Criteria:

• Any serious or uncontrolled medical disorder that, in the opinion of the study doctor, may increase the risk associated with study participation / treatment administration.
• Another ongoing cancer that requires treatment, unless protocol defined criteria is met
• Any side effects to prior anticancer therapy that have not improved to normal unless protocol-defined criteria is met.
• Known history of acquired immunodeficiency syndrome (AIDS). HIV positive patients with CD4 T cells > 200/mm3 who do not have AIDS are eligible. Testing for HIV is not mandatory.
• For patients receiving pembrolizumab on trial: any contraindication to receiving pembrolizumab (including history of severe allergic reaction to pembrolizumab or like drugs and history of non-infectious pneumonitis requiring treatment)
• Untreated and/or symptomatic metastatic central nervous system disease, unless protocol-defined criteria is met.
• Active, known or suspected, autoimmune or inflammatory disorders requiring immunosuppressive therapy.
• Positive hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV) antibody, indicating acute or chronic infection.
• Allogenic tissue/solid organ transplant.