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Autologous Hematopoietic Stem Cell Transplantation for Allogeneic Organ Transplant Tolerance

Autologous Hematopoietic Stem Cell Transplantation for Allogeneic Organ Transplant Tolerance

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02549586
Acronym
ASCOTT
Enrollment
5
Registered
2015-09-15
Start date
2015-12-31
Completion date
2020-04-30
Last updated
2021-04-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Complication of Transplanted Organ, Nos

Keywords

solid organ transplant, immune tolerance, autologous stem cell transplant, blood and marrow transplant, autoimmune disease

Brief summary

This open-label, proof-of-principle two center cohort study will evaluate the ability of autologous hematopoietic stem cell transplantation to induce tolerance in recipients of deceased or live donor liver transplants (ASCOTT). A maximum of 10 participants will be entered at a minimum of 3 months post liver transplant. The participants will undergo autologous hematopoietic stem cell transplants (HSCT) to re-educate their immune systems to accept the graft without the need for long term immunosuppression (tolerance).

Detailed description

Although short-term results for liver transplantation are excellent, the need for immunosuppression limits quality of life and long-term survival. Investigators plan to examine the utility and safety of autologous hematopoietic stem cell transplantation (HSCT) to allow withdrawal of immunosuppression in 10 liver transplant recipients who are at a high risk of developing recurrent liver damage from repeated bouts of rejection, or recurrent disease or who have a high likelihood of developing serious medical complications from complications of immune suppression. Hematopoietic stem cells will be mobilized, purified and cryopreserved. Following a chemotherapy and Anti-thymocyte Globulin (ATG) based-regimen for immune ablation, the purified stem cells will be thawed and infused back into participants (autologous hematopoietic stem cell transplant - HSCT). Participants will be converted to everolimus, a mammalian target of rapamycin inhibitor (mTORi), which will be continued for 6 months and then withdrawn based on histologic evidence of graft acceptance. Participants will be followed closely for a total of 24 months for any biochemical and histologic evidence of tolerance or rejection. Re-vaccination to common viral and bacterial antigens will be undertaken as required using a standard protocol for recipients of a hematopoietic stem cell transplant (HSCT).

Interventions

Step 1: Participants will receive intravenous chemotherapy and cytokine-based treatment for mobilization of hematopoietic stem cells (HSC) into the circulation, followed by collection using peripheral vein leukopheresis. The HSC graft product will undergo ex vivo purification with CD34 selection using Miltenyil CliniMACS and cryopreserved. Step 2: Intravenous busulphan, cyclophosphamide and anti-thymocyte globulin will be administered to participants to achieve immune ablation prior to the infusion of the participants' own thawed HSC graft product (HSC transplant). Routine supportive measures will be employed during the recovery from the chemotherapy and HSCT. Participants' immune suppression will be stopped at the time of immunoablative therapy and will be switched to everolimus which will be discontinued at 6 months post HSCT.

Sponsors

Ottawa Hospital Research Institute
CollaboratorOTHER
Gary A Levy, O. Ont. MD. FRCP AGAF
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Pt are receiving everolimus in combination with autologous stem cell transplant to induce tolerance

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Participants must be 18 years of age or older. 2. Participants must be a minimum of 6 months post-transplant; 3. Participants are recipients of a hepatic allograft for alcohol induced liver disease; or a genetic form of liver disease such as hemochromatosis or Wilson's disease; or an autoimmune liver disease including sclerosing cholangitis, autoimmune hepatitis, and/or primary biliary cirrhosis. 4. Participants have a complication of transplantation that might be ameliorated by HSCT and/or withdrawal of immunosuppression such as: evidence of recurrent autoimmune disease in the graft; repeated episodes (minimum of 2) of acute cellular rejection; and/ or development of adverse events related to immune suppression which have not been well managed by conventional methods including drug dose reduction or substitution of other medications. Examples include progression of renal dysfunction, repeated infections, neurologic complications, cardiovascular complications, or post-transplant lymphoproliferative disease (PTLD) that has been in remission for at least 12 months. These complications must be deemed serious enough to warrant inclusion in the study by the investigator.

Exclusion criteria

1. Participants \< 18 yr. 2. Participants with cardiac, renal, pulmonary, hepatic, or other organ impairment that would limit their ability to receive dose intensive chemotherapy; 3. Participants with any active or chronic infection. Participants with previous reactivation of Epstein-Barr virus, cytomegalovirus , BK, human herpesvirus 6 or varicella-zoster virus would be considered eligible if the virus has returned to a latent state; 4. Participants who are seropositive for HIV1, HIV2, Hepatitis B Surface Antigen, and Hepatitis C; 5. Participants with a previous history of a malignancy other than squamous or basal cell carcinoma of the skin, or post-transplant lymphoproliferative disease (PTLD); 6. Participants whose life expectancy is severely limited by another co-morbid illness; 7. Participants with evidence of myelodysplasia, other non-autoimmune cytopenia, or an inherited immunodeficiency state; 8. Pregnancy or Participants who are unwilling to practice two active forms of contraception during the time of chemotherapy administration. Participants must be willing to commit to not becoming pregnant from enrollment in the study until 2 years following their HSCT. 9. Participants unable to comply with the medical treatment specified in the protocol; 10. Participants unable to give written informed consent in accordance with research ethics board guidelines.

Design outcomes

Primary

MeasureTime frameDescription
Number of patients who develop tolerance post autologous HSCT24 months post HSCTNumber of patients who develop tolerance at 24 months post HSCT as defined clinically and histologically in the absence of any immunosuppression in liver transplant recipients.

Secondary

MeasureTime frame
HSCT mortality2 years post HSCT
HSCT related morbidityat 2 years post HSCT
Rate of immune reconstitutionat 2 years post HSCT

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026