EGFR Positive Solid Tumors

This Phase 1, first-in-human (FIH), dose-escalation and dose-expansion study is designed to evaluate the safety, PK, and preliminary anti-tumor activity of VIR-5525 as a monotherapy and in combination with pembrolizumab in participants with solid tumors that are known to express EGFR. The study will be conducted in the following 4 parts: * Part 1: VIR-5525 monotherapy dose escalation * Part 2: VIR-5525 monotherapy dose expansion * Part 3: VIR-5525 plus pembrolizumab dose escalation * Part 4: VIR-5525 plus pembrolizumab dose expansion