Study of PYX-201 in Combination With Pembrolizumab in Advanced Solid Tumors

Inclusion Criteria

• 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.
• Male or non-pregnant, non-lactating female participants age ≥18 years.
• Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 to 1.
• Participant must have at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumours (RECIST) v1.1 criteria.
• Life expectancy of >3 months, in the opinion of the Investigator.
• Adequate hematologic function.
• Adequate hepatic function.
• Adequate renal function.
• Adequate coagulation profile.
• Clinical sites must conduct fresh tumor biopsy or provide participant's archived tumor tissue sample.

Exclusion Criteria

• Known additional malignancy that is progressing or has required active treatment within the past 2 years.
• Known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
• Significant cardiovascular disease within 6 months prior to start of study drug.
• Evidence of an active systemic bacterial, fungal, or viral infection requiring treatment at the start of study drug.
• Known active hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS).
• Failure to recover to Baseline severity or National Cancer Institute - Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0 Grade ≤1 from acute non-hematologic toxicity due to previous therapy, prior to Screening.
• Participants with active neuropathy of any grade per CTCAE v5.0 at Screening.
• History of uncontrolled diabetes mellitus.
• Participants with immunodeficiency or active autoimmune disease that is contraindicated for pembrolizumab.
• Participants with a history of (noninfectious) pneumonitis/interstitial lung disease (ILD) that required steroids or has current pneumonitis/ILD.
• Prior solid organ or bone marrow progenitor cell transplantation.
• Prior high-dose chemotherapy requiring stem cell rescue.
• Previously received treatment with a programmed death-1 (PD-1)/L1 inhibitor any prior treatment with an agent directed to another stimulatory or co inhibitory T-cell receptor.
• Severe hypersensitivity (Grade ≥3) to pembrolizumab and/or any of its excipients and/or PYX-201 and/or any of its excipients.