Study of EN-374 Gene Therapy in Participants With X-Linked Chronic Granulomatous Disease

The goal of this clinical trial is to evaluate the safety and potential efficacy of the EN-374 treatment regimen and identify a dose level for further evaluation in participants with x-linked chronic granulomatous disease. The main questions it aims to answer are: * safety of the EN-374 treatment regimen * effect of the EN-374 treatment regimen on the production of functional neutrophils with NADPH oxidase activity

Inclusion Criteria: * Male * ≥ 18 years of age during dose escalation, then ≥ 3 months of age during dose expansion * Diagnosis of X-CGD with a pathogenic mutation in the CYBB gene * History of at least 1 severe infection requiring medical intervention or chronic inflammatory disorder * Does not have a suitable, available, and willing human leukocyte antigens (HLA)-matched (10/10) related donor * Non-sterile male participants who are or may become sexually active with female partners of childbearing potential are required to use highly effective contraception * Informed consent, with informed assent from capable participants * Adequate organ function Exclusion Criteria: * Active bacteremia or fungemia * History of human immunodeficiency virus (HIV), hepatitis B, or hepatitis C * History or clinical evidence of any medical or social issues likely to put the participant at additional risk or to interfere with study conduct * History of HSCT or granulocyte transfusions * Known hypersensitivity to elements in the treatment regimen * Undergone investigational gene therapy * Treated with another investigational drug product within 30 days before screening * Unable to comply with the visits and requirements of the protocol as determined by the Investigator