ERAS-4001 + pembrolizumab

**ERAS-4001 + pembrolizumab** is an investigational combination therapy consisting of ERAS-4001, an engineered herpes simplex virus type 1 (HSV-1) derivative designed as an oncolytic virus, and pembrolizumab, a monoclonal antibody checkpoint inhibitor targeting programmed cell death-1 (PD-1) on T cells. *ERAS-4001* is intended to selectively replicate within tumor cells and induce local immune responses, while *pembrolizumab* blocks the PD-1 receptor, thus unleashing systemic antitumor T-cell-mediated immunity. The combination aims to synergistically enhance tumor immunogenicity and promote durable antitumor responses. Pembrolizumab is approved for various cancers; however, ERAS-4001 is still in clinical development, with ongoing trials primarily in solid tumors. The combination is being tested for its safety, tolerability, and initial antitumor activity, especially for patients with advanced/metastatic solid tumors.