Primary Immunodeficiency and Haematopoietic stem-cell transplantation (HSCT): what the trial registry contains
The ClinicalTrials.gov registry holds 70 records for HSCT in Primary Immunodeficiency: 10 recruiting now, 3 labelled Phase 3 or 4, across 15 countries. Snapshot 2026-08-29.
Why this is studied in Primary Immunodeficiency
Primary immunodeficiencies are inherited defects of immune development, and for several of them haematopoietic transplantation and gene-modified cell therapy are established curative treatments. This is the part of the field where 'stem cell therapy' genuinely means a licensed or standard-of-care procedure — which makes borrowed credibility elsewhere all the more misleading.
What HSCT means in this table
Haematopoietic transplantation is the oldest and most consequential cell therapy in medicine, with conditioning regimens that carry real mortality risk alongside genuine disease-modifying power. Registrations under this label therefore mix decades-old standard-of-care protocols with newer autoimmune-reset trials, and the risk profile is nothing like that of an outpatient infusion.
The numbers
Every figure below comes from one reproducible query (primary immunodeficiency x hematopoietic stem cell transplantation) run against ClinicalTrials.gov API v2 on 2026-08-29.
| Metric | Value |
|---|---|
| Registered studies (all statuses) | 70 |
| Interventional studies in the sample | 61 |
| Recruiting right now | 10 |
| Completed | 29 |
| Terminated, withdrawn or suspended | 12 |
| Phase 3 or Phase 4 records | 3 |
| Countries with at least one site | 15 |
| Median planned enrolment | 23 participants |
| Largest single planned enrolment | 690 participants |
| First / most recent start year | 1996 — 2026 |
How mature is this evidence?
The ladder is partly climbed: 3 confirmatory-phase records against 70 in total, with the remainder concentrated in dose-finding and safety territory.
Registrations do not all survive contact with recruitment — 29 completed here, 12 stopped early, giving a 17% attrition rate.
| Phase label | Records | Share |
|---|---|---|
| Phase 2 | 46 | 49% |
| Phase 1 | 29 | 31% |
| Not applicable | 15 | 16% |
| Phase 3 | 3 | 3% |
Median planned enrolment is 23 participants (largest single study: 690). Trials of this size can describe safety and generate hypotheses; detecting a modest clinical benefit reliably usually needs substantially larger numbers with a control group.
Where the studies are
Across 15 countries with registered sites, United States dominates at roughly 67% — a concentration driven by funding and regulation rather than by clinical outcome.
| Country | Studies with a site there |
|---|---|
| United States | 50 |
| France | 8 |
| United Kingdom | 4 |
| Italy | 3 |
| Canada | 3 |
| Germany | 2 |
| Russia | 2 |
| Belgium | 1 |
| Slovakia | 1 |
| Switzerland | 1 |
Legal pathway differs by country — see where cell therapy is legal, by country.
Who runs them
Funding profile: 13 academic or hospital sponsors against 12 commercial ones — academic overall, which is worth knowing before reading any single positive report.
- National Institute of Allergy and Infectious Diseases (NIAID) — 6 records
- Fred Hutchinson Cancer Center — 5 records
- National Cancer Institute (NCI) — 4 records
- Paul Szabolcs — 4 records
- Genethon — 3 records
- Masonic Cancer Center, University of Minnesota — 3 records
Representative registered studies
Recruiting studies first, then the most advanced phases. Each identifier links to the registry record, where eligibility criteria, outcome measures and contacts are published.
| Study | Phase | Status | Planned n | Lead sponsor | Start |
|---|---|---|---|---|---|
| NCT07284641 — Hematopoietic Stem Cell Transplantation (HSCT) for Common Variable Immunodeficiency (CVID) and Other Autoimmune Manifestations of Primary Immune Regul | Phase 2 | Recruiting | 25 | Paul Szabolcs | 2026-05-04 |
| NCT06839456 — Phase 1/2: CD45RA Depleted Stem Cell Addback to Prevent Viral or Fungal Infections Post TCRab/CD19 Depleted HSCT | Phase 1, Phase 2 | Recruiting | 100 | Children's Hospital of Philadelphia | 2025-03-21 |
| NCT05071222 — Safety and Efficacy Study of Transplantation of Autologous CD34+ Cells Transduced With the G2ARTE Lentiviral Vector Expressing the DCLRE1C cDNA in Art | Phase 1, Phase 2 | Recruiting | 7 | Assistance Publique - Hôpitaux de Paris | 2023-07-19 |
| NCT04414046 — TCR Alpha Beta T-cell Depleted Haploidentical HCT in the Treatment of Primary Immunodeficiency and Inherited Metabolic Disorders in Children | Phase 2 | Recruiting | 17 | Johns Hopkins All Children's Hospital | 2020-07-22 |
| NCT04339777 — Allogeneic Hematopoietic Stem Cell Transplant for Patients With Inborn Errors of Immunity | Phase 2 | Recruiting | 66 | National Cancer Institute (NCI) | 2020-09-22 |
| NCT03538899 — Autologous Gene Therapy for Artemis-Deficient SCID | Phase 1, Phase 2 | Recruiting | 24 | University of California, San Francisco | 2018-05-31 |
| NCT01962415 — Reduced Intensity Conditioning for Non-Malignant Disorders Undergoing UCBT, BMT or PBSCT | Phase 2 | Recruiting | 100 | Paul Szabolcs | 2014-02-04 |
| NCT04691622 — Adoptive T Lymphocyte Administration for Chronic Norovirus Treatment in Immunocompromised Hosts | Phase 1 | Recruiting | 48 | Children's National Research Institute | 2022-03-17 |
| NCT06659588 — Study of Populations at Risk of Developing Chronic Hepatitis Linked to Chronic Enteric Virus Infection in Patients With Primary Immunodeficiency and S | n/a | Recruiting | 120 | Assistance Publique - Hôpitaux de Paris | 2024-10-10 |
| NCT04528355 — Data Collection Study of Patients With Non-Malignant Disorders Undergoing UCBT, BMT or PBSCT With RIC | n/a | Recruiting | 50 | Paul Szabolcs | 2020-08-20 |
What this page does and does not tell you
A registry is a plan repository. Counting entries tells you what people intended to study, which is a weaker thing than what they found.
If a clinic offers you this today, the useful question is not "is there research?" but "which of these registered studies is mine part of, and if none, what evidence applies to the exact product I am being sold?" The Provider Question Builder turns that into a scored checklist.
Frequently asked
How many HSCT studies for Primary Immunodeficiency are recruiting right now?
10 of 70 registered records were listed as recruiting in the 2026-08-29 snapshot. Recruitment status changes frequently; the registry record is authoritative.
Is HSCT an approved treatment for Primary Immunodeficiency?
Registration on ClinicalTrials.gov is not approval. Approval is granted by a regulator for a specific product and indication after review of submitted evidence. 70 registered studies tell you research exists, not that a product cleared review.
How advanced is the research on HSCT for Primary Immunodeficiency?
3 of 70 records carry a Phase 3 or Phase 4 label and 29 are marked completed. Registrations run from 1996 to 2026.
Registry and literature counts retrieved 2026-08-29 (ClinicalTrials.gov API v2; PubMed E-utilities). Registration or publication volume measures research activity, not effectiveness or approval. Educational information — not medical advice; verify product, indication, legal pathway and evidence with an independent qualified physician. Page generated 2026-08-29. See our editorial standards.
More on this condition
Download the query data
Query totals are full API matches; status, phase and country counts describe the first up to 400 returned records per query. Query classes overlap and must not be summed as unique trials. Counts are not treatment outcomes. Snapshot: 2026-08-29. Methods and field definitions.