Retroviral Insertion Site Methodology Study
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|ClinicalTrials.gov Identifier: NCT03311074|
Recruitment Status : Withdrawn (Replaced with new observational study design)
First Posted : October 16, 2017
Last Update Posted : July 15, 2020
|Condition or disease||Intervention/treatment||Phase|
|Immune System Diseases||Biological: Strimvelis||Phase 4|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||0 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||There will be no separate treatment groups in the study.|
|Masking:||None (Open Label)|
|Masking Description:||No masking will be performed in the study and all subjects who have received Strimvelis, either in previous clinical trials or as a registered product, will be included in the analysis.|
|Official Title:||Methodology Study to Investigate the Utility of Retroviral Insertion Site Analysis in Samples From Subjects Treated With Strimvelis™ Gene Therapy|
|Estimated Study Start Date :||June 25, 2020|
|Estimated Primary Completion Date :||July 30, 2024|
|Estimated Study Completion Date :||July 30, 2024|
Experimental: Strimvelis treatment receivers
Approximately 15 subjects with ADA-SCID who were previously received Strimvelis will be included in the analysis and a total of 5 blood samples will be collected from each subject at approximately annual interval.
Strimvelis is a gene therapy that aims to restore ADA function in hematopoietic cell lineages and prevent the immunological manifestations. Strimvelis is a cluster of differentiation (CD) 34+ cell enriched dispersion of human bone marrow derived hematopoietic stem cells for infusion which have been transduced with a retroviral vector containing the human ADA gene.
- Mean abundance measurement [ Time Frame: Up to 5 years ]The accuracy and precision of SLiM-PCR methodology will be assessed using whole blood samples, taken from subjects treated with Strimvelis, spiked with control insertion site deoxyribonucleic acid (DNA). The mean abundance will be calculated between subjects at every time point, within subjects over time points and between the same sample within a time point within a subject.
- Coefficient of variation measurement [ Time Frame: Up to 5 years ]The accuracy and precision of SLiM-PCR methodology will be assessed using whole blood samples, taken from subjects treated with Strimvelis, spiked with control insertion site DNA. The coefficient of variation will be calculated between subjects at every time point, within subjects over time points and between the same sample within a time point within a subject.
- Measurement of clone abundance of more than 5 percent [ Time Frame: Up to 5 years ]Abundance of clones in subject's samples will be measured by SLiM-PCR, where abundance estimates will be derived from the number of individual sheared DNA fragments and the number of DNA barcodes in the linker sequences.
- Shannon diversity index measurement [ Time Frame: Up to 5 years ]The Shannon diversity index is an index that is commonly used to characterize species diversity in a community. The diversity of the clones in subject's samples will be determined using Shannon diversity. Shannon diversity index will be summarized using mean and coefficient of variation.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03311074
|Study Director:||Orchard Clinical Trials||Orchard Therapeutics|