Efficacy and Safety of the Cryopreserved Formulation of OTL-101 in Subjects With ADA-SCID

August 1, 2022 updated by: Donald B. Kohn, M.D., University of California, Los Angeles

Efficacy and Safety of Cryopreserved Formulation of Autologous CD34+ Hematopoietic Stem Cells Transduced Ex Vivo With Elongation Factor 1 Alpha Shortened (EFS) Lentiviral Vector Encoding for Human ADA Gene in Subjects With Severe Combined Immunodeficiency Due to ADA Deficiency

This is a prospective, non-randomized, single-cohort, longitudinal, single-center, clinical study designed to assess the efficacy and safety of a cryopreserved formulation of OTL-101 (autologous CD34+ hematopoietic stem/progenitor cells transduced ex vivo with EFS (Elongation Factor 1α Short form) Lentiviral Vector (LV) encoding for the human ADA gene) administered to ADA-SCID subjects between the ages of 30 days and 17 years of age, who are not eligible for an Human Leukocyte Antigen (HLA) matched sibling/family donor and meeting the inclusion/exclusion criteria. The OTL-101 product is infused after a minimal interval of at least 24 hours following the completion of reduced intensity conditioning. For subjects who successfully receive the OTL-101 product, pegademase bovine (PEG-ADA) Enzyme Replacement Therapy (ERT) is discontinued at Day+30 (-3/+15) after the transplant. After their discharge from hospital, the subjects will be seen at regular intervals to review their history, perform examinations and draw blood samples to assess immunity and safety.

Study Overview

Study Type

Interventional

Enrollment (Actual)

10

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • California
      • Los Angeles, California, United States, 90095
        • University of California, Los Angeles

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

1 year to 15 years (Child)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Provision of written informed consent prior to any study related procedures. In this study consent must be provided by the parents/legal guardians and, where applicable according to local laws, a signed assent from the child,
  2. Subjects ≥30 days and <18 years of age,
  3. With a diagnosis of ADA-SCID based on:

    Evidence of ADA deficiency, defined as:

    i. Decreased ADA enzymatic activity in erythrocytes, leukocytes, skin fibroblasts, or in cultured fetal cells to levels consistent with ADA-SCID as determined by the reference laboratory, or ii. Identified mutations in ADA alleles consistent with a severe reduction in ADA activity,

    Evidence of ADA-SCID based on either:

    i. Family history of a first order relative with ADA deficiency and clinical and laboratory evidence of severe immunologic deficiency, or ii. Evidence of severe immunologic deficiency in subjects prior to the institution of immune restorative therapy, based on

    • Lymphopenia (absolute lymphocyte count (ALC) <400 cells/µL) OR absence or low number of T cells (absolute CD3+ count < 300 cells/µL), or
    • Severely decreased T lymphocyte blastogenic responses to phytohemagglutinin (either <10% of lower limit of normal controls for the diagnostic laboratory, or <10% of the response of the normal control of the day, or stimulation index <10), or
    • Identification of SCID by neonatal screening revealing low T cell Receptor Excision Circle (TREC) levels.
  4. Ineligible for matched family allogeneic Bone Marrow (BM) transplantation, defined as the absence of a medically eligible HLA-identical sibling or family donor, with normal immune function, who could serve as an allogeneic bone marrow donor.
  5. Females of child-bearing age will be required to provide a negative pregnancy test 30 days prior to Visit 2.
  6. Subjects and their parents/legal guardians must be willing and able to comply with study restrictions and to remain at the clinic for the required duration during the study period and willing to return to the clinic for the follow up evaluation as specified in the protocol.

Exclusion Criteria:

  1. Ineligible for autologous Hematopoietic Stem Cell Transplantation (HSCT) as per clinical site criteria.
  2. Other conditions which in the opinion of the Principal Investigator and/or Co Investigators, contraindicate the harvest of bone marrow, the administration of Busulfan and the infusion of transduced cells, or which indicate an inability of the subject or subject's parent/legal guardian to comply with the protocol.
  3. Hematologic abnormality, defined as:

    • Anemia (Hb <8.0 g/dl).
    • Neutropenia (ANC <500/mm3). Note: ANC <500 with absence of myelodysplastic syndrome on bone marrow aspirate and biopsy and normal marrow cytogenetics are acceptable for eligibility.
    • Thrombocytopenia (platelet count <50,000/mm3, at any age).
    • Prothrombin time or international normalized ratio (INR) and partial thromboplastin time (PTT) >2 x upper limit of normal (ULN) (subjects with a correctable deficiency controlled on medication will not be excluded).
    • Cytogenetic abnormalities on peripheral blood or bone marrow or amniotic fluid (if available).
    • Prior allogeneic HSCT with cytoreductive conditioning.
  4. Pulmonary abnormality, defined as:

    • Resting O2 saturation by pulse oximetry <90% on room air.
    • Chest X-ray indicating active or progressive pulmonary disease. Note: Chest X ray indicating residual signs of treated pneumonitis is acceptable for eligibility.
  5. Cardiac abnormality, defined as:

    • Abnormal ECG indicating cardiac pathology.
    • Uncorrected congenital cardiac malformation with clinical symptoms.
    • Active cardiac disease, including clinical evidence of congestive heart failure, cyanosis, hypotension.
    • Poor cardiac function as evidenced by left ventricular ejection fraction <40% on echocardiogram.
  6. Neurologic abnormality, defined as:

    • Significant neurologic abnormality revealed by examination.
    • Uncontrolled seizure disorder.
  7. Renal abnormality, defined as:

    • Renal insufficiency: serum creatinine ≥1.2 mg/dl (106 µmol/L), or ≥3+ proteinuria.
    • Abnormal serum sodium, potassium, calcium, magnesium or phosphate levels at >2 x ULN.
  8. Hepatic/gastrointestinal abnormality, defined as:

    • Serum transaminases >5 x ULN.
    • Serum bilirubin >2 x ULN.
    • Serum glucose >1.5 x ULN.
  9. Oncologic disease, defined as:

    • Evidence of active malignant disease other than dermatofibrosarcoma protuberans (DFSP).
    • Evidence of DFSP expected to require anti-neoplastic therapy within the 5 years following the infusion of genetically corrected cells (if anti-neoplastic therapy has been completed, a subject with a history of DFSP can be included).
    • Evidence of DFSP expected to be life limiting within the 5 years following the infusion of genetically corrected cells.
  10. Known sensitivity to Busulfan.
  11. Confirmation of an infectious disease by deoxyribonucleic acid (DNA) Polymerase chain reaction (PCR) positive at time of screening assessment for the following:

    • HIV-1,
    • Hepatitis B,
    • Parvovirus B19.
  12. The subject is pregnant or has a major congenital anomaly.
  13. Is likely to require treatment during the study with drugs that are not permitted by the study protocol.
  14. The subject has previously received another form of gene therapy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Gene Therapy
Infusion of autologous cryopreserved EFS-ADA LV CD34+ cells
Busulfan is used for non-myeloablative conditioning
PEG-ADA ERT is discontinued at Day +30 (-3/+15 days) after successful engraftment
autologous cryopreserved EFS-ADA LV CD34+ cells (OTL-101) are infused intravenously
Other Names:
  • OTL-101

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Participants With Treatment Efficacy After Treatment With OTL 101 (6 Months)
Time Frame: 6 months

Efficacy of OTL-101 treatment at 6 months post OTL-101 infusion based on the following parameters and thresholds:

  1. ADA enzyme activity in erythrocytes above baseline/pretreatment level (i.e., >0 units). ADA enzyme activity is measured to assess the amount of functional gene product produced from the normal ADA transgene delivered by EFS-ADA LV.
  2. Absolute CD3+ T cell counts ≥200 cells/μL. Increase in CD3+ T cell counts is a marker of immune reconstitution.
  3. Granulocyte samples positive for vector sequences by quantitative Polymerase Chain Reaction (PCR) (≥1/10,000 cells). Vector copy number (VCN) in the Peripheral Blood (PB) Granulocytes fraction that was T cell depleted, is a surrogate for amount of engrafted genetically modified Hematopoietic stem cell (HSC) that are producing granulocytes every 3-5 days.
6 months
Overall Survival (OS) of Subjects Treated With Investigational Medicinal Product (IMP) (1 Year)
Time Frame: 12 Months
Overall survival is defined as the percentage of subjects alive at 12 months post- treatment with cryopreserved OTL-101.
12 Months
Event-free Survival (EvFS) of Subjects Treated With Investigational Medicinal Product (IMP) (1 Year)
Time Frame: 12 Months
Event-free survival is defined as the percentage of subjects alive with no "event", an "event" being the resumption of PEG-ADA ERT or the need for a rescue allogeneic Hematopoietic Stem Cell Transplant (HSCT), or death.
12 Months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EvFS of Subjects Treated With Investigational Medicinal Product (IMP) (2 Years)
Time Frame: 24 months
Event-free survival is defined as the percentage of subjects alive with no "event", an "event" being the resumption of PEG-ADA ERT or the need for a rescue allogenic Hematopoietic Stem Cell Transplant (HSCT), or death.
24 months
OS of Subjects Treated With Investigational Medicinal Product (IMP) (2 Years)
Time Frame: 24 months
OS is defined as the percentage of subjects alive at 24 months post- treatment with cryopreserved OTL-101.
24 months
Change From Baseline in CD3+ T Cell Counts (2 Years)
Time Frame: 24 months
Immune reconstitution was assessed by change in CD3+ T Cell counts over time.
24 months
Severe Infections Excluding First 3 Months After Treatment
Time Frame: 24 months
The infections of interest in this study were severe infections or opportunistic infectious episodes, defined as infections requiring hospitalization or prolonging hospitalization and/or documented infections by opportunistic pathogens. Infections that took place in the first 3 months of follow-up post treatment were excluded from calculations to avoid possible bias introduced in the data by the effects of conditioning.
24 months
Change From Baseline in Quality of Life Measures (2 Years)
Time Frame: 24 months
Assessment of quality of life was measured by the Lansky Performance Status Scale. The maximum score on the Lansky Performance Scale is 100 - the child is fully active and able to carry on normal activity with no special care needed. The minimum score is 10 - the child is completely disabled, not even passive play. The scores at baseline (pre-treatment with OTL-101) and scores at Month 24 post-treatment with OTL-101 were compared to establish if there were any changes in the child's score in this timeframe.
24 months
Percentage of Patients Who Stopped Immunoglobulin Replacement Therapy (IgRT) (2 Years)
Time Frame: 24 months
Use of immunoglobulin replacement therapies prior to and after gene therapy were monitored. Indications for considering the discontinuation of immunoglobulin replacement therapy included: absolute CD4+ >200, absolute B cell >100/μl, IgA or IgM > lower limit of normal for age or gene marking >1% detectable in B cells.
24 months
Time to Cessation of IgRT for Those Who Stopped (2 Years)
Time Frame: 24 months
Use of immunoglobulin replacement therapies prior to and after gene therapy were monitored. For subjects who stopped IgRT during the study, the time of cessation was recorded.
24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Director: Donald B. Kohn, MD, University of California, Los Angeles

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 16, 2016

Primary Completion (Actual)

October 11, 2018

Study Completion (Actual)

September 26, 2019

Study Registration Dates

First Submitted

December 19, 2016

First Submitted That Met QC Criteria

December 20, 2016

First Posted (Estimate)

December 21, 2016

Study Record Updates

Last Update Posted (Actual)

August 3, 2022

Last Update Submitted That Met QC Criteria

August 1, 2022

Last Verified

August 1, 2022

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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