A Phase 1/2 Study Evaluating Gene Therapy by Transplantation of Autologous CD34+ Stem Cells Modified Ex Vivo Using Prime Editing (PM359) in Participants with Autosomal Recessive Chronic Granulomatous Disease due to Mutations in the NCF1 Gene

Chronic Granulomatous Disease (CGD) is a rare inherited autosomal recessive (inherited from both parents) or X-linked (male inherits from mother) hematologic disease that results in a failure of innate immunity against a variety of human pathogens and is also associated with autoimmune and inflammatory conditions. Given the limitations associated with current treatments for CGD and the poor quality of life and mortality associated with allogeneic haematopoietic stem cell transplantation, a one-time, transformative therapy is urgently needed for CGD. The purpose of this trial is to find out the safety and effectiveness of PM359, a medicine containing a participant's blood cells known as stem cells that have been corrected using a process called gene editing to fix a mutation (error) in the patient’s DNA that causes Chronic Granulomatous Disease (CGD). This study is being carried out in the United States, Canada and the United Kingdom. The study population will be males or females, who are at least 6 years of age, with adults being treated first before adolescents and children. Approximately 6 to 12 participants will be treated with PM359. They will be in this study. for about 40 months. The study will consist of a screening period of up to 8 weeks, a treatment period and 3 year follow-up period. There will be an optional 15-year follow-up study to further monitor the safety and effectiveness of PM359. Prime Medicine is the Sponsor that will be responsible for funding this clinical study.