A Study to Determine the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of ABBV-368 Plus Tilsotolimod and Other Therapy Combinations in Participants With Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

Inclusion Criteria

• •Participants should weigh at least 35 kg.
• •Eastern Cooperative Oncology Group performance status of 0 or 1 and a life expectancy of \>= 3 months.
• •Participant have \>= 1 lesion accessible for intratumoral injection.
• •Histologically or cytologically confirmed R/M HNSCC (of the following 4 subsites: oral cavity, oropharynx, larynx, and hypopharynx) who previously progressed either during or after \<= 3 prior treatment regimens administered in the recurrent or metastatic setting.
• •* Must have received 1 immunotherapy regimen which included a PD-(L)1 inhibitor.
• •* Must have received platinum-based therapy, or be considered ineligible for platinum-based therapy by the investigator.