A Phase I/II Study of TheraT? Vector(s) Expressing Human Papillomavirus 16 Positive (HPV 16+) Specific Antigens in Patients with HPV 16+ Confirmed Cancers.

Inclusion Criteria

All Patients:

- Documentation of confirmed HPV 16+ cancer via genotype testing.

- ≥ 1 measurable lesion by imaging for tumor response following RECIST

- ECOG performance status of 0 to 1.

- Prior curative radiation therapy and prior focal palliative completed per

protocol-specified wash-out windows.

- Screening laboratory values must meet protocol-specified criteria.

- Able to provide tumor tissue following last treatment, unless otherwise agreed.

Treatment Group E or Group F:

- Documentation of confirmed head and neck squamous cell carcinoma.

- Eligible to receive pembrolizumab, per standard of care and product label.

- Group E: this group includes first line / 1L patients who have not yet received

treatment in the metastatic/recurrent setting.

- Group F: Tumor progression or recurrence on standard of care therapy, including ≥1

systemic therapy.

Imaging Sub-Study (for specific participants at Memorial Sloan Kettering Cancer Center

only):

- Meeting requirements of inclusion criteria for Treatment Group 1 or Group 3.

- At least 1 non-irradiated measurable lesion documented through imaging.

Exclusion Criteria

All patients:

- Metastatic central nervous system disease, and/or carcinomatous meningitis.

- Any serious or uncontrolled medical disorder that, in the opinion of the Investigator,

may increase the risk associated with study participation / treatment administration.

- Concurrent malignancy that is clinically significant or requires active intervention,

unless protocol-defined criteria are met.

- Active, known or suspected, autoimmune or inflammatory disorders requiring

immunosuppressive therapy.

- Has a life expectancy of less than 3 months.

- Any toxicities attributed to systemic prior anticancer therapy o that have not

resolved to Grade 1 or baseline prior to the first administration of study drug,

unless protocol-defined criteria is met.

- Not meeting the protocol-specified washout periods for prohibited medications.

- Prior anaphylactic reaction to or known allergy or hypersensitivity to investigational

product(s) or any of the excipients of the investigational product(s).

- Positive hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV) antibody,

indicating acute or chronic infection.

- Known history of acquired immunodeficiency syndrome.

For patients in Groups E or F and certain backfill cohorts:

- History of severe hypersensitivity reaction to or other contraindication to receiving

pembrolizumab.

- History of/Presently having non-infectious pneumonitis requiring treatment.

- Was discontinued due to a Grade 3 or higher immune-related AE (irAE) after receiving

prior therapy with check point inhibitors.

Imaging Sub-Study (for specific participants at Memorial Sloan Kettering Cancer Center

only):

- Having splenic disorders or prior splenectomy, and can compromise protocol objectives

per Investigator and/or Sponsor.

- Meeting requirements of exclusion criteria for Treatment Group 3