MedPath

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

Phase 1
Completed
Conditions
Severe Combined Immunodeficiency Due to ADA Deficiency
Interventions
Genetic: Infusion of autologous cryopreserved EFS-ADA LV CD34+ cells (OTL-101)
Drug: Peg-Ada
Registration Number
NCT03765632
Lead Sponsor
Great Ormond Street Hospital for Children NHS Foundation Trust
Brief Summary

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 \<18 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.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
13
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:

    1. . Evidence of ADA deficiency, defined as: i. Decreased ADA enzymatic activity in erythrocytes, leukocytes, skin fibroblasts, or in cultured foetal 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,
    2. . 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 <400 cells/mL) OR absence or low number of T-cells (absolute CD3+ count < 300 cells/mL), 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 or with no available matched family donor for 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 (HSC) procedure.

  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. Haematologic abnormality, defined as:

    Anaemia (Hb <8.0 g/dl). Evidence of bi/trilineage cytopaenia (haemoglobin <8 g/dl, neutrophils <0.5 x 109/L, platelets 50 x 109/L). Thrombocytopaenia (platelet count <50,000/mm3). Prothrombin time or 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 of Peripheral Blood (PB), BM or amniotic fluid (if available). If cytogenetic testing has not been performed on cells from amniocentesis, assessment should be by karyotype, Comparative genomic hybridization (CGH), and or whole exome sequencing (WES).
    • Prior allogeneic HSC transplant (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. Known history of significant renal abnormality.

  8. Known history of significant hepatic or gastrointestinal abnormality.

  9. Oncologic disease, defined as:

    • Evidence of active malignant disease other than Dermatofibrosarcoma Protuberans( DFSP) 2.
    • 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 reactions (PCR) positive at time of screening assessment according to local protocols/procedures (including HIV-1 and hepatitis B).

  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 & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Gene TherapyPeg-AdaInfusion of autologous cryopreserved EFS-ADA LV CD34+ cells
Gene TherapyInfusion of autologous cryopreserved EFS-ADA LV CD34+ cells (OTL-101)Infusion of autologous cryopreserved EFS-ADA LV CD34+ cells
Gene TherapyBusulfanInfusion of autologous cryopreserved EFS-ADA LV CD34+ cells
Primary Outcome Measures
NameTimeMethod
Event free survival at 12 months post OTL-101 infusion12 Months

Event-free survival is defined as the proportion of subjects alive with no "event", an "event" being the resumption of Peg-Ada ERT or the need for a rescue stem cell transplant (SCT), or death

Overall survival at 12 months post OTL-101 infusion12 Months

Overall survival is defined as the proportion of subjects alive

Secondary Outcome Measures
NameTimeMethod
Overall survival at 24 months post OTL-101 infusion24 months

Overall survival is defined as the proportion of subjects alive

Safety evaluation including immune reconstitution12 and 24 months
Event free survival at 24 months post OTL-101 infusion24 Months

Event-free survival is defined as the proportion of subjects alive with no "event", an "event" being the resumption of Peg-Ada ERT or the need for a rescue stem cell transplant (SCT), or death

Safety evaluation including infection rates12 and 24 months
Safety evaluation including performance outcomes12 and 24 months

Trial Locations

Locations (1)

Great Ormond Street Hospital for Children NHS Foundation Trust

🇬🇧

London, United Kingdom

© Copyright 2025. All Rights Reserved by MedPath