NCT03077542

Nonmyeloablative Haploidentical Peripheral Blood Mobilized Hematopoietic Precursor Cell Transplantation for Sickle Cell Disease

• Status: Active Not Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 57 (actual)
• Sponsor: National Heart, Lung, and Blood Institute (NHLBI) · NIH
• Sex: All
• Age: 2 Years – 100 Years
• Healthy volunteers: Not accepted

Summary

Background: Peripheral blood stem cell transplantation procedures are used for people with sickle cell disease. Researchers want to improve the success and reduce the complications for these procedures. This might allow more people to have a transplant. Objective: To see if a new transplant regime is effective, safe and well tolerated in people with sickle cell disease. Eligibility: Adults at least 18 years old with sickle cell disease and certain complications. A relative who is a half tissue match. Design: Participants will be screened with medical history, physical exam, and blood tests. Recipients will also have: * Heart, lung, and mental health tests * Chest x-rays * Bone marrow taken from the pelvic bone * Eyes and teeth checked Recipients will have a large central line inserted into a vein for up to 6 months. Donors will have their veins tested and have an IV inserted for 1 day or on rare occasions 2 days. Donors will get a drug to activate bone marrow. It will be injected for about 6 days. Donors will have at least 1 five-hour procedure where bone marrow stem cells will be collected. Blood will be taken from a vein in one arm or in rare cases from a groin vein and put through a machine. Some blood will be saved and the rest will be returned. Stem cells will be taken from the saved blood in a lab and frozen until ready to give to the recipient. Recipients will have: * Stems cells collected and frozen * Hygiene lessons * Bone density scans * Low-dose radiation * Drugs for their immune system * Donor cells infused through their central line * Transfusions After about 30 days, recipients will leave the hospital. They must stay near NIH for 3 months after the transplant and have frequent visits. After returning home, they will have 8 visits over 5 years, then be contacted yearly.

Detailed description

Nonmyeloablative allogeneic peripheral blood stem cell (PBSC) transplants are currently being investigated in phase I/II trials assessing engraftment, efficacy, and toxicity at a number of transplant centers. Our ongoing protocol for patients with severe congenital anemias, particularly sickle cell disease (SCD), and an HLA-matched sibling donor has had excellent preliminary results. None of the patients who engrafted had sickle-related events or any evidence of graft versus host disease (GVHD). There was no significant toxicity associated with the conditioning regimen. An additional protocol is ongoing for patients with high risk of graft rejection which employs pentostatin and oral cyclophosphamide (PC) pre-transplant to further deplete recipient lymphocytes in an attempt to decrease the rate of graft rejection. Four of 4 patients transplanted remain free of SCD. Our main limitation has been a lack of HLA-matched sibling donors in the majority of patients. We performed a study in which patients with severe SCD who lacked a suitable donor underwent a search for a matched unrelated donor or umbilical cord donor. The vast majority of patients were not found to have an appropriate alternative donor. We therefore seek to develop a safe nonmyeloablative regimen to be applied to the haploidentical setting so that family members can serve as donors and greatly expand the donor pool. We developed a nonmyeloablative haploidentical PBSC transplant protocol which included 3 cohorts, with stopping rules built in for regimen failure, defined as graft rejection or severe GVHD. All included 400 cGy total body irradiation (TBI) in divided doses 1 and 2 days prior to transplant, alemtuzumab, and sirolimus. The first cohort included no cyclophosphamide. The 2nd included one dose of cyclophosphamide given at 50mg/kg on day 3 post-transplant, and the 3rd included 100mg/kg cyclophosphamide given in divided doses on days 3 and 4 post-transplant. The engraftment rate and percentage of patients who remained free of SCD improved with each successive cohort. However, the graft rejection rate in the 3rd cohort remained high at 50%. To attempt to reduce the rate of graft rejection in the haploidentical setting, this protocol will add PC to the conditioning regimen. In this protocol, we propose PBSC transplantation in patients with SCD considered at high risk for complications from or ineligible for standard bone marrow transplantation, with allogeneic peripheral blood stem cells from a haploidentical donor using a novel immunosuppressive regimen without myeloablation in an attempt to further decrease the transplant-related morbidity/mortality. The low intensity nonmyeloablative conditioning regimen will consist of a relatively low radiation dose for therapeutic radiation, Alemtuzumab (Campath ), Sirolimus (Rapamune ), Cyclophosphamide (Cytoxan ), and pentostatin (Nipent ) as a strategy to provide adequate immunosuppression to allow sufficient engraftment for clinical remission with a lower risk of GVHD development. T-cell replete, donor-derived, granulocyte colony-stimulating factor (G-CSF)- mobilized PBSC will be used to establish hematopoietic and lymphoid reconstitution. The primary endpoint of this study is the percentage of patients at 100 days post-transplant who have not rejected their grafts, and who are without severe GVHD (defined as grade 3 and higher acute GVHD and moderate to severe chronic GVHD). Other endpoints include degree of donor-host chimerism necessary for long-term graft survival and disease amelioration, incidence of acute and chronic GVHD, incidence of graft rejection, transplant-related morbidity, as well as disease-free and overall survival.

Conditions

• Sickle Cell Disease

Interventions

Type	Name	Description
PROCEDURE	haploidentical stem cell transplant	haploidentical stem cell transplant
DRUG	Sirolimus	conditioning regimen
DRUG	Alemtuzumab	conditioning regimen
DRUG	Pentostatin	conditioning regimen
DRUG	Cyclophosphamide	conditioning regimen
DRUG	Hydroxyurea	conditioning regimen
DRUG	Filgrastim	A haploidentical relative donor will receive filgrastim (G-CSF) 10 to 16 µg/kg/d subcutaneously or intravenously for up to 6 days with apheresis collections of peripheral blood hematopoietic progenitor cells (PBPC) after the 5th day (and after the 6th day if required).

Timeline

• Start date: 2017-04-06
• Primary completion: 2023-07-27
• Completion: 2026-08-31
• First posted: 2017-03-13
• Last updated: 2024-08-07
• Results posted: 2024-08-07

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study