PF-07265028 As Single Agent And In Combination With Sasanlimab in Advanced or Metastatic Solid Tumors

Key Inclusion Criteria:

Across all cohorts:

1. Eastern Cooperative Oncology Group (ECOG) performance status ≤1

2. Adequate hematological, kidney and liver function

3. Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.

4. Resolved acute effects of any prior therapy

5. All participants must provide archival formalin-fixed paraffin-embedded (FFPE) tumortissue:

Part 1: If archival sample is older than 6 months, the participant must consent to undergo a fresh biopsy during the screening.

Part 2 Fresh tumor biopsy during screening is required unless there is archival tissues less than 3 months old and subsequent to the last systemic anti-cancer therapy.

Part 1A Monotherapy:

Histologically or cytologically confirmed advanced or metastatic solid tumors which have progressed following systemic anticancer therapies, or are resistant to standard therapy or for which no standard therapy is available, or for whom standard therapy is not tolerated.

Part 1B Combination Therapy:

Histologically or cytologically confirmed advanced or metastatic solid tumor which have progressed following systemic anticancer therapies, including at least 1 checkpoint inhibitor.

Part 2 Dose Expansion:

Histologically or cytologically confirmed advanced or metastatic malignancies, including gastric/Gastroesophageal junction cancer, Head and neck squamous cell carcinoma, or urothelial cancer (non-small cell lung cancer and other solid tumors may be included) who have progressed following systemic anticancer therapies, including at least 1 checkpoint inhibitor

Key Exclusion Criteria:

1. Participants with any other active malignancy within 3 years prior to enrollment

2. Participants with active autoimmune conditions or history of autoimmune diseasesthat may relapse

3. History of interstitial lung disease, pneumonitis (non-infectious) or uncontrolledlung diseases

4. History of prior immune-related adverse events (irAEs) Grade ≥3

5. Central nervous system metastases

6. Significant cardiac or pulmonary conditions or events within previous 6 months

7. Active, uncontrolled bacterial, fungal, or viral infection

8. Impairment of gastrointestinal (GI) function or GI disease that may significantlyalter the absorption of PF-07265028

9. Prior administration of HPK1 inhibitor