PR610E

PR610E is the active metabolite of the prodrug TH-4000 (also called PR610 or Hypoxin), a **hypoxia-activated prodrug** developed to release a targeted tyrosine kinase inhibitor under low-oxygen conditions typical of many solid tumors. In vivo, TH-4000 is converted to PR610E, which acts as a selective inhibitor of **epidermal growth factor receptor (EGFR)** and **human epidermal growth factor receptor 2 (HER2)** kinase activity, particularly in the hypoxic microenvironments of certain cancers. This design aims to minimize toxicity in normal tissues by activating the drug specifically in tumor tissue. The drug has been primarily developed for various solid cancers, especially **non-small cell lung cancer (NSCLC)**, but also includes esophageal, pancreatic, rectal, head and neck, skin, colon, cervical, bladder, breast, gastrointestinal stromal tumor (GIST), ovarian, gastric, endometrial, uterine, prostate, liver, melanoma, brain cancer, and mesothelioma[1][2].