A Phase 1/2, Open-label, Global, Multicenter, Dose-Escalation and Dose-Expansion Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of PYX-201 in Combination With Pembrolizumab in Participants With Advanced Solid Tumors

Inclusion Criteria 1. Histologically or cytologically confirmed advanced solid tumors, including first-line (1L) head and neck squamous cell carcinoma (HNSCC), advanced or metastatic triple negative breast cancer (TNBC), hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative breast cancer (HER2- BC), gastric cancer (GC), cervical cancer, and second-line and higher (2L+) HNSCC. 2. Male or non-pregnant, non-lactating female participants age ≥18 years. 3. Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 to 1. 4. Participant must have at least 1…