A Phase 1/2 Study in Patients with HPV16+ Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma and Other Cancers

Inclusion Criteria

• 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