PF-07265028 + sasanlimab

**PF-07265028 + sasanlimab** is an investigational combination therapy studied for advanced and metastatic solid tumors. PF-07265028 is a highly-selective, orally administered small molecule inhibitor of Hematopoietic Progenitor Kinase 1 (HPK1), which enhances T cell receptor signaling and activation, thereby potentially improving anti-tumor immune responses and efficacy of PD-1 blockade[3][4][6]. Sasanlimab (PF-06801591) is a monoclonal antibody targeting the PD-1 receptor, functioning as an immune checkpoint inhibitor that blocks the programmed cell death-1 (PD-1) pathway to enable the immune system to attack cancer cells more effectively[1][7]. The combination is designed to synergize augmentation of T cell activation (by inhibiting HPK1) with immune checkpoint blockade (by inhibiting PD-1), aiming to overcome resistance to immunotherapy in various cancers. Both components are developed by Pfizer and have been investigated in phase 1 trials for safety, dose finding, and preliminary anti-tumor activity across multiple tumor types, including head and neck squamous cell carcinoma, urothelial cancer, gastric/gastroesophageal junction cancer, and non-small cell lung cancer[2][3][9].