NCT03311503

Phase I/II Trial of Lentiviral Gene Transfer for SCID-X1 With Low Dose Targeted Busulfan Conditioning

Recruiting now Phase 1, PHASE2 Last updated 11 December 2025

What this trial tests

Phase 1, PHASE2 trial testing autologous CD34+ cell transduced with G2SCID vector in Severe Combined Immunodeficiency, X Linked in 12 participants. Currently enrolling.

Timeline

26 February 2018

Primary endpoint
1 January 2028

1 January 2028

Quick facts

Lead sponsor	David Williams
Phase	Phase 1, PHASE2
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	non randomized
Design	single group
Masking	none
Primary purpose	treatment
Enrollment	12
Start date	26 February 2018
Primary completion	1 January 2028
Estimated completion	1 January 2028
Sites	4 locations across United States

Drugs / interventions tested

• autologous CD34+ cell transduced with G2SCID vector — full drug profile →

Conditions studied

• Severe Combined Immunodeficiency, X Linked — all drugs for Severe Combined Immunodeficiency, X Linked →
• Gene Therapy — all drugs for Gene Therapy →

Sponsor

David Williams — full company profile →

Who can join

Adults 0 to 5, male only, with Severe Combined Immunodeficiency, X Linked or Gene Therapy. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This is a phase I/II open label multi-center study in which patients will receive low dose targeted busulfan followed by infusion of autologous CD34+ selected bone marrow or mobilized peripheral blood cells transduced with the G2SCID vector. Subjects will be enrolled over 3 years and be followed for 2 years post-infusion on this protocol, then followed long-term on a separate long-term follow-up protocol.

Enrollment of subjects will be agreed upon by representatives of both sites. Data will be collected uniformly from both sites through an electronic capture system and key laboratory studies will be centralized.

Harvest, cellular manufacturing and infusion will occur at each site using the same SOPs. Key aspects of cellular product characterization will be centralized

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. Update on Clinical Ex Vivo Hematopoietic Stem Cell Gene Therapy for Inherited Monogenic Diseases.
   Tucci F, Scaramuzza S, Aiuti A, Mortellaro A. · · 2021 · cited 72× · PMID 33221437 · DOI 10.1016/j.ymthe.2020.11.020
2. Designing Lentiviral Vectors for Gene Therapy of Genetic Diseases.
   Poletti V, Mavilio F. · · 2021 · cited 64× · PMID 34452394 · DOI 10.3390/v13081526
3. Autologous Stem-Cell-Based Gene Therapy for Inherited Disorders: State of the Art and Perspectives.
   Staal FJT, Aiuti A, Cavazzana M. · · 2019 · cited 61× · PMID 31737588 · DOI 10.3389/fped.2019.00443
4. Immunological barriers to haematopoietic stem cell gene therapy.
   Charlesworth CT, Hsu I, Wilkinson AC, Nakauchi H. · · 2022 · cited 47× · PMID 35301483 · DOI 10.1038/s41577-022-00698-0
5. Immune Reconstitution After Gene Therapy Approaches in Patients With X-Linked Severe Combined Immunodeficiency Disease.
   Blanco E, Izotova N, Booth C, Thrasher AJ. · · 2020 · cited 29× · PMID 33329605 · DOI 10.3389/fimmu.2020.608653
6. Retroviral gene therapy in Germany with a view on previous experience and future perspectives.
   Morgan MA, Galla M, Grez M, Fehse B, et al · · 2021 · cited 28× · PMID 33753908 · DOI 10.1038/s41434-021-00237-x
7. Treatment of primary immunodeficiency with allogeneic transplant and gene therapy.
   Pai SY. · · 2019 · cited 20× · PMID 31808905 · DOI 10.1182/hematology.2019000052
8. Advances in gene therapy for inborn errors of immunity.
   Ott de Bruin LM, Lankester AC, Staal FJT. · · 2023 · cited 17× · PMID 37846903 · DOI 10.1097/aci.0000000000000952