Clinical Trial

Disease: Chronic Granulomatous Disease, CGD, (NCT06325709)

Disease info:

Chronic granulomatous disease (CGD) results in immune system dysfunction, leading to immunodeficiency. This may cause recurring bacterial and fungal infections and inflammation in various parts of the body. Symptoms usually start in childhood, though some may not appear until later in life.

Individuals with CGD often experience serious bacterial or fungal infections every few years, with the lungs being the most common site of infection, often leading to pneumonia. Exposure to certain organic materials can trigger fungal pneumonia. Other areas commonly affected include the skin, liver, and lymph nodes. In some cases, CGD can lead to autoimmune disorders, where the immune system mistakenly attacks the body's own tissues. Repeated infections and inflammation can shorten life expectancy, but with treatment, most people with CGD can live into their mid- to late adulthood.

Most cases of CGD are caused by mutations in five genes, CYBA, CYBB, NCF1, NCF2, CYBC1, or NCF4, which each encode a subunit of the NADPH oxidase enzyme complex that plays a crucial role in immune function. CGD is categorised into five types, distinguished by the associated genetic variant. A mutation in the CYBB gene (Xp21.1) is found in approximately 65% of cases in North America and Western Europe. The resulting deficiency in the NADPH oxidase enzyme complex leads to decreased production of reactive oxygen species (used by phagocytes to kill bacteria and fungi). Consequently, individuals with CGD are prone to infections and excessive inflammation. Some cases of CGD have unknown genetic causes. 

CGD presents with a range of symptoms affecting various organ systems. Common manifestations include severe and recurrent infections, often caused by specific pathogens such as Staphylococcus aureus and Aspergillus spp. Additionally, patients may develop granulomatous lesions, primarily affecting the lungs, lymph nodes, gastrointestinal tract, and liver. Up to half of patients may experience symptoms such as diarrhoea, abdominal pain, and failure to thrive. Common complications can include pneumonia, abscesses, cellulitis, adenitis, and osteomyelitis. Mycobacterial diseases are typically limited to tuberculosis or disseminated Bacillus Calmette-GuĂ©rin (BCG) infections, while invasive fungal infections are frequent. Dysregulated inflammation and granuloma formation can lead to various complications, including chorioretinal lesions, gastric outlet obstruction, inflammatory bowel disease (IBD), and wound complications. Most female carriers of CGD show no symptoms unless a significant portion of their neutrophils are dysfunctional. Some individuals with CGD may develop autoimmune disorders such as discoid lupus erythematosus and antiphospholipid syndrome.

CGD is estimated to occur in 1 in 200,000 to 250,000 people worldwide.
Official title:
Phase 1/2 Trial of Base Editing for Mutation Repair in Hematopoietic Stem & Progenitor Cells for X-linked Chronic Granulomatous Disease

National Institute of Allergy and Infectious Diseases (NIAID)


United States, Maryland
National Institutes of Health Clinical Center, Bethesda, Maryland, United States, 20892

Study start:
Apr. 10, 2024
10 participants
Gene editing method:
Type of edit:
Base edit
Cytochrome B Beta (CYBB)
Delivery method:
Lentivirus (LV) vector - Ex-vivo
IND Enabling Pre-clinical
Phase I Safety
Phase II Safety and Dosing
Phase III Safety and Efficacy

Status: Enrolling by invitation


Open-label, phase 1/2 trial to determine the safety, and efficacy of a single infusion of base-edited (BE) autologous hematopoietic stem and progenitor cells (HSPCs) for treatment of X-linked chronic granulomatous disease (X-CGD). Base editing is performed to repair CYBB missense gene mutations (eg, CYBB c.676C>T). The study hypotheses are that 1) base editing can efficiently repair gene mutations in HSPCs; and 2) BE HSPCs can engraft and differentiate into functional phagocytes with restored nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity.

During the initial development phase each study participant will undergo apheresis for CD34+ HSPC collection for the development and validation of a mutation-specific BE system.

During the treatment phase, participants will receive a one-time infusion of the BE autologous HSPC Investigational Medicinal Product (IMP) after busulfan (total 12 mg/kg) conditioning.

Participants will have follow-up evaluations at months 3, 6, 12, 18, and 24, and yearly thereafter until 5 years after treatment. Key study assessments include adverse event (AE) assessment, blood laboratory evaluations of functional protein made from the target gene (CYBB, encodes for gp91^phox), and deoxyribonucleic acid (DNA) sequencing to identify rates of gene repair and off-target mutation.

The final study follow-up under this protocol will be at 5 years, but long-term follow-up under a separate NIH protocol will continue annually to 15 years after treatment.

Last updated: Apr. 17, 2024
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