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A Study to Assess the Safety, Tolerability, and Efficacy of ST-400 for Treatment of Transfusion-Dependent Beta-thalassemia (TDT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT03432364
Recruitment Status : Completed
First Posted : February 14, 2018
Last Update Posted : February 1, 2023
Information provided by (Responsible Party):
Sangamo Therapeutics

Brief Summary:
This is a single-arm, multi-site, single-dose, Phase 1/2 study to assess ST-400 in 6 subjects with transfusion-dependent β-thalassemia (TDT) who are ≥18 and ≤40 years of age. ST-400 is a type of investigational therapy that consists of gene edited cells. ST-400 is composed of the patient's own blood stem cells which are genetically modified in the laboratory using Sangamo's zinc finger nuclease (ZFN) technology to disrupt a precise and specific sequence of the enhancer of the BCL11A gene (which normally suppresses fetal hemoglobin production in erythrocytes). This process is intended to boost fetal hemoglobin (HbF), which can substitute for reduced or absent adult (defective) hemoglobin. ST-400 is then infused back into the patient after receiving conditioning chemotherapy to make room for the new cells in the bone marrow, with the aim of producing new erythrocytes with increased amounts of HbF. The primary objective is to understand safety and tolerability of ST-400, and secondary objectives are to assess the effects on HbF levels and transfusion requirements.

Condition or disease Intervention/treatment Phase
Transfusion Dependent Beta-thalassemia Genetic: ST-400 Investigational product Phase 1 Phase 2

Detailed Description:

Once consented, study participants will progress through the following stages:

  • Screening: in-person visit at the study site to confirm eligibility for proceeding
  • Collection: autologous (self) blood stem cells are harvested at the study site, also known as apheresis
  • Manufacturing of ST-400: no study participant activities expected
  • Infusion: conditioning chemotherapy, followed by infusion of ST-400, occurs at the study site
  • Follow-up: follow up at the study site to monitor for safety and effectiveness of the study

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 5 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase 1/2, Open-label, Single-arm Study to Assess the Safety, Tolerability, and Efficacy of ST-400 Autologous Hematopoietic Stem Cell Transplant for Treatment of Transfusion-Dependent Beta-thalassemia (TDT)
Actual Study Start Date : March 29, 2018
Actual Primary Completion Date : November 17, 2022
Actual Study Completion Date : November 17, 2022

Arm Intervention/treatment
Experimental: ST-400 Investigational product
ST-400 Investigational product is composed of autologous CD34+ hematopoietic stem/progenitor cells that are genetically modified ex vivo at the erythroid-specific enhancer of the BCL11A gene
Genetic: ST-400 Investigational product
Single dose of ST-400 following chemotherapy conditioning with busulfan

Primary Outcome Measures :
  1. Safety and tolerability assessed by Incidence of Adverse Events (AEs) and Serious Adverse Events (SAEs) during the Primary Study Period. [ Time Frame: Up to 156 weeks after the ST-400 infusion ]

Secondary Outcome Measures :
  1. Change from baseline clinical laboratory measurement of Hb fractions (A and F in g/dL). [ Time Frame: Up to 156 weeks after ST-400 infusion ]
  2. Change from baseline in percent (%) HbF. [ Time Frame: Up to 156 weeks after ST-400 infusion ]
  3. Change from baseline in annualized frequency of packed RBC transfusions [ Time Frame: Up to 156 weeks after ST-400 infusion ]
    Historical baseline defined as transfusion support in the 2 years prior to screening.

  4. Change from baseline in annualized volume (mL) of packed RBC transfusions [ Time Frame: Up to 156 weeks after ST-400 infusion ]
    Historical baseline defined as transfusion support in the 2 years prior to screening.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Informed Consent
  2. Clinical diagnosis of TDT with ≥ 8 documented RBC transfusion events per year on an annualized basis in the 2-years prior to screening
  3. Confirmed beta-thalassemia diagnosis by molecular genetic testing
  4. Clinically stable and eligible to receive conditioning chemotherapy
  5. Able and willing to use an effective method of contraception from the signing of the informed consent and for one year following ST-400 infusion.

Exclusion Criteria:

  1. Previous history of autologous or allogeneic blood stem cell transplantation or solid organ transplantation
  2. Pregnant or breastfeeding female
  3. Medical contraindication to mobilization, apheresis, or conditioning
  4. Significant liver, lung, heart, or kidney dysfunction
  5. Diagnosis of HIV or evidence of active HBV or HCV
  6. History of significant bleeding disorder or uncontrolled seizures
  7. History of active malignancy in past 5 years (non-melanoma skin cancer or cervical cancer in situ permitted) any history of hematologic malignancy, or family history of cancer predisposition syndrome without negative testing result in the study candidate.
  8. Currently participating in another clinical trial using an investigational study medication, or recent participation in such a trial
  9. Previous treatment with gene therapy

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03432364

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United States, California
University of California, Los Angeles
Los Angeles, California, United States, 90095-1678
UCSF Benioff Children's Hospital Oakland
Oakland, California, United States, 94609
United States, Georgia
Children's Healthcare of Atlanta
Atlanta, Georgia, United States, 30322
United States, Massachusetts
Dana-Farber Boston Children's Cancer and Blood Disorders Center
Boston, Massachusetts, United States, 02116
United States, Minnesota
University of Minnesota
Minneapolis, Minnesota, United States, 55455
United States, Pennsylvania
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, United States, 19104
Sponsors and Collaborators
Sangamo Therapeutics
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Study Director: Medical Monitor Sangamo Therapeutics, Inc.
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Sangamo Therapeutics
ClinicalTrials.gov Identifier: NCT03432364    
Other Study ID Numbers: ST-400-01
First Posted: February 14, 2018    Key Record Dates
Last Update Posted: February 1, 2023
Last Verified: January 2023
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Sangamo Therapeutics:
Beta thalassemia
Thalassemia major
Cooley's anemia
ZFN mediated genome editing
zinc finger nuclease
Additional relevant MeSH terms:
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Anemia, Hemolytic, Congenital
Anemia, Hemolytic
Hematologic Diseases
Genetic Diseases, Inborn