MK-145-002: This phase II trial is trying to determine whether adding an injection to immunotherapy is safe and effective for the treatment of advanced squamous cell carcinomas of the head and neckA Phase 2 Study in First Line Metastatic or Unresectable, Recurrent Head and Neck Squamous Cell Carcinoma to Evaluate Intratumoral MK-1454 in Combination With IV Pembrolizumab vs IV Pembrolizumab Monotherapy

Exclusion

• Has disease that is suitable for local therapy administered with curative intent
• Has progressive disease (PD) within 6 months of completion of curatively intended systemic treatment for locoregionally advanced HNSCC
• Has had chemotherapy or biological cancer therapy in the recurrent or metastatic setting for the treatment of HNSCC
• Has had radiation therapy (or other non-systemic therapy) within 2 weeks prior to randomization or participant has not fully recovered from adverse events (AEs) due to a previously administered treatment
• Is expected to require any other form of antineoplastic therapy while on study
• Has a history of a second malignancy, unless potentially curative treatment has been completed, with no evidence of malignancy for at least 2 years
• Has clinically active central nervous system (CNS) metastases and/or carcinomatous meningitis
• Has an active autoimmune disease that has required systemic treatment in the past 2 years
• Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of study treatment
• Has had an allogenic tissue/solid organ transplant
• Has a history of vasculitis
• Has a history of interstitial lung disease
• Has an active infection requiring systemic therapy
• Has a known history of active tuberculosis (TB; Bacillus tuberculosis)
• Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis
• Has had a severe hypersensitivity reaction to treatment a monoclonal antibody/components of the study treatment
• Has known Hepatitis B virus or Hepatitis C virus infections
• Has received prior therapy with an anti-programmed cell death 1 (anti-PD-1), anti-programmed cell death-ligand 1 (anti-PD-L1), or anti-programmed cell death-ligand 2 (anti-PD-L2) agent or if the participant has previously participated in Merck Sharp & Dohme (MSD) MK-3475 clinical trials
• HIV infected participant who has had an HIV-related opportunistic infection within 6 months
• HIV infected participants who have a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
• Is pregnant, breastfeeding, or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of study treatment
• Has not fully recovered from any effects of major surgery without significant detectable infection
• Has a history of re-irradiation for HNSCC at the projected injection site in the head and neck
• Has received a live-virus vaccine within 30 days of planned study treatment start
• Has been treated with a stimulator of interferon genes (STING) agonist (e.g. ulevostinag, ADU-S100)
• Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy, or used an investigational device, any of which occurred within 4 weeks of the first dose of study treatment