Haploidentical HCT for Severe Aplastic Anemia

Aplastic Anemia Clinical Trial

Official title: Haploidentical Donor Hematopoietic Cell Transplantation for Patients With Severe Aplastic Anemia

Status Active, not recruiting

Clinical Trial Summary

This study is a prospective, single center phase II clinical trial in which patients with Severe Aplastic Anemia (SAA) ) will receive a haploidentical transplantation. The purpose of this study is to learn more about newer methods of transplanting blood forming cells donated by a family member that is not fully matched to the patient. This includes studying the effects of the chemotherapy, radiation, the transplanted cell product and additional white blood cell (lymphocyte) infusions on the patient's body, disease and overall survival. The primary objective is to assess the rate of engraftment at 30 days and overall survival (OS) and event free survival (EFS) at 1 year post-hematopoietic cell transplantation (HCT).

Primary Objectives

• To estimate the rate of engraftment at 30 days after TCR αβ+ T-cell-depleted graft infusion in patients receiving a single dose of post graft infusion cyclophosphamide.

• To estimate the overall survival and event free survival at 1-year post transplantation.

Secondary Objectives

• To calculate the incidence of acute and chronic GVHD after HCT.

• To calculate the rate of secondary graft rejection at 1-year post transplantation

• To calculate the cumulative incidence of viral reactivation (CMV, EBV and adenovirus).

• To describe the immune reconstitution after TCR αβ+ T-cell-depleted graft infusion at 1 month, 3 months, 6 months, 9 months, and 1 year.

Exploratory Objectives

• To longitudinally assess the phenotype and epigenetic profile of T-cells in SAA patients receiving HCT for SAA.

• To assess the phenotype and epigenetic profile of T-cells in DLI administered to SAA patients post HCT.

• To longitudinally assess CD8 T cell differentiation status in SAA patients using an epigenetic atlas of human CD8 T cell differentiation.

• To examine the effector functions and proliferative capacity of CD8 T cells isolated from SAA patients before and after DLI.

• Quantify donor derived Treg cells at different time points in patients received HCT.

• Determine Treg activation status at different stages after HCT.

• Are specific features of the DLI product associated with particular immune repertoire profiles post-transplant?

• How does the diversity and functional profile of the DLI product alter the response to pathogens in the recipient?

• Do baseline features of the recipient's innate and adaptive immune cells correlate with post-transplant immune repertoires and response profiles?

Clinical Trial Description

Immunosuppressant therapy (IST) is the main treatment for SAA for patients who do not have an HLA-matched sibling donor available for transplant. But some patients with SAA do not respond to IST and some others relapse after IST. HCT using an unrelated but HLA-matched donor is the only curative option for these patients but many patients lack a suitable HLA-matched donor. St Jude is trying to increase donor options for these patients by using novel therapeutic strategies by combining two widely used of GVHD prophylaxis methods: i) selective T cell depletion and ii) use of post-transplant cyclophosphamide. This will allow expansion of the donor pool to include haploidentical donors as well as reduce the risk of GVHD. The goal of this protocol is to test whether combining these GVHD prophylaxis approaches will allow use of haploidentical donors, reduce risk of GVHD, reduce transfusion dependence and improve immune reconstitution.

For this study chemotherapy, antibodies and radiation will be given to prepare the body to receive donor cells. Participants will then be given the donor cell infusion.

Patients will receive two types of donor blood cell products - a progenitor blood cell infusion and then a donor lymphocyte infusion. Both the progenitor blood cell and the donor lymphocyte infusion will be processed in a laboratory at St. Jude using a machine called the CliniMACS™.

In this clinical trial, participants will receive a special type of progenitor blood cells (called TCRαβ- depleted blood cells) from the donor.

After the donor progenitor cells have started to grow within the body (engraftment), participants will receive a second product that contains mature immune cells. These immune cells called CD45RA-depleted lymphocytes or donor lymphocyte infusion (DLI) will help fight infections in the body after the transplant and strengthen the developing immune system. ;

Related Conditions & MeSH terms

• Anemia
• Anemia, Aplastic
• Aplastic Anemia
• Bone Marrow Failure Disorders
• Bone Marrow Failure Syndrome
• Pancytopenia

• NCT number: NCT04558736
• Study type: Interventional
• Source: St. Jude Children's Research Hospital
• Status: Active, not recruiting
• Phase: Phase 2
• Start date: January 21, 2021
• Completion date: July 1, 2026