Trial Outcomes & Findings for Gene Transfer for Severe Combined Immunodeficiency, X-linked (SCID-X1) Using a Self-inactivating (SIN) Gammaretroviral Vector (NCT NCT01129544)
NCT ID: NCT01129544
Last Updated: 2026-04-21
Results Overview
Immunological reconstitution defined as absolute CD3 cells of \>300/μl and PHA stimulation index \>15 at 6 months post infusion
Recruitment status
COMPLETED
Study phase
PHASE1/PHASE2
Target enrollment
8 participants
Primary outcome timeframe
6 Months Post Gene Transfer
Results posted on
2026-04-21
Participant Flow
Participant milestones
| Measure |
Gene Transfer
open label single arm study
Gene transfer: Three procedures: 1) Bone marrow harvest from the patient's posterior iliac crests. 2) Chemotherapy conditioning with Busulfan (\*\*patient 08 only) 3) One time infusion of patient's transduced bone marrow cells.
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|---|---|
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Overall Study
STARTED
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8
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Overall Study
COMPLETED
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6
|
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Overall Study
NOT COMPLETED
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2
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Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Gene Transfer for Severe Combined Immunodeficiency, X-linked (SCID-X1) Using a Self-inactivating (SIN) Gammaretroviral Vector
Baseline characteristics by cohort
| Measure |
Gene Transfer
n=8 Participants
open label single arm study
Gene transfer: Three procedures: 1) Bone marrow harvest from the patient's posterior iliac crests. 2.) Chemotherapy conditioning with Busulfan (\*\*only patient 08) 3)One time infusion of patient's transduced bone marrow cells.
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|---|---|
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Age, Categorical
<=18 years
|
8 Participants
n=13 Participants
|
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Age, Categorical
Between 18 and 65 years
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0 Participants
n=13 Participants
|
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Age, Categorical
>=65 years
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0 Participants
n=13 Participants
|
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Sex: Female, Male
Female
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0 Participants
n=13 Participants
|
|
Sex: Female, Male
Male
|
8 Participants
n=13 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
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2 Participants
n=13 Participants
|
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Ethnicity (NIH/OMB)
Not Hispanic or Latino
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4 Participants
n=13 Participants
|
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Ethnicity (NIH/OMB)
Unknown or Not Reported
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2 Participants
n=13 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
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0 Participants
n=13 Participants
|
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Race (NIH/OMB)
Asian
|
0 Participants
n=13 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
1 Participants
n=13 Participants
|
|
Race (NIH/OMB)
Black or African American
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0 Participants
n=13 Participants
|
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Race (NIH/OMB)
White
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6 Participants
n=13 Participants
|
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Race (NIH/OMB)
More than one race
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1 Participants
n=13 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=13 Participants
|
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Region of Enrollment
United States
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8 participants
n=13 Participants
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PRIMARY outcome
Timeframe: 6 Months Post Gene TransferPopulation: 8 subjects were treated with an infusion of gene modified cells. 5 of 8 had absolute CD3 counts (cells/uL) greater than 300 and a PHA stimulation index greater than 15 at 6 months post infusion and met the primary endpoint. 1 subject who did not reconstitute T cells was taken off study. 2 subjects received a second infusion of gene modified cells; of these 1 had improved CD3 counts and the other did not and came off study.
Immunological reconstitution defined as absolute CD3 cells of \>300/μl and PHA stimulation index \>15 at 6 months post infusion
Outcome measures
| Measure |
Gene Transfer
n=8 Participants
open label single arm study
Gene transfer: Three procedures: 1) Bone marrow harvest from the patient's posterior iliac crests. 2) Chemotherapy conditioning with Busulfan (\*\*patient 08 only) 3) One time infusion of patient's transduced bone marrow cells.
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|---|---|
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CD3 Cell Count Post Infusion
Primary Outcome Met
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5 Participants
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CD3 Cell Count Post Infusion
Primary Outcome Not Met
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3 Participants
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PRIMARY outcome
Timeframe: 4.5-12 years post infusion of the gene therapy productPopulation: Patient #3 \& #5 failed primary endpoint and had allo transplant and withdrawn from study
Follow up time for each of the 8 enrolled patients is as follows: Patient #1 -12 yrs, Patient#2 -11 yrs, Patient #6- 9 yrs, Patient #7- 8 yrs, Patient #8 - 4.5 yrs. Patient #3 \& #5 failed primary endpoint and had allo transplant, Patient #4 retreated with Gene therapy and is 6 years post 2nd infusion.
Outcome measures
| Measure |
Gene Transfer
n=6 Participants
open label single arm study
Gene transfer: Three procedures: 1) Bone marrow harvest from the patient's posterior iliac crests. 2) Chemotherapy conditioning with Busulfan (\*\*patient 08 only) 3) One time infusion of patient's transduced bone marrow cells.
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|---|---|
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Incidence of Life Threatening Adverse Reactions Related to the Gene Therapy Procedure
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6 Participants
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Adverse Events
Gene Transfer
Serious events: 3 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Gene Transfer
n=8 participants at risk
open label single arm study
Gene transfer: Three procedures: 1) Bone marrow harvest from the patient's posterior iliac crests. 2.) Chemotherapy conditioning with Busulfan (\*\*only patient 08) 3)One time infusion of patient's transduced bone marrow cells.
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Infections and infestations
Varicella infection
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12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Infections and infestations
Upper respiratory infection
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12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Infections and infestations
E. Coli and Klebsiella Infection
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12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Immune system disorders
Rhinovirus
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12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Infections and infestations
Pseudomonas/Stenotrophomonas Infection
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12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Infections and infestations
BCGosis
|
12.5%
1/8 • Number of events 1 • Adverse event data were collected from the time an enrolled participant underwent the bone marrow harvest through five years post gene therapy infusion.
Common adverse event and serious adverse event definitions were used for this study. SAEs that were considered life threatening or required hospitalization or prolongation of a hospitalization are listed below. No SAEs that resulted in death, resulted in a persistent or significant disability/incapacity, was a new malignancy, or led to a congenital anomaly or birth defect occurred. No AEs or SAEs were deemed related to the gene therapy product.
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Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place