A Phase 1/2 interventional study of BOOST cells in Osteogenesis Imperfecta, sponsored by Karolinska Institutet. Active, not recruiting at 1 site in Sweden. Open to participants aged Up to 18 Months. Per ClinicalTrials.gov, last updated 2025-09-12.
Sponsored by Karolinska Institutet · Phase 1/2, Interventional, and Treatment
An exploratory, open label, multiple dose, multicentre phase I/II trial evaluating safety and efficacy of postnatal or prenatal and postnatal administration of allogeneic expanded fetal mesenchymal stem cells for the treatment of severe Osteogenesis Imperfecta compared with a combination of historical and untreated prospective controls.
Inclusion Criteria Postnatal Group:
Inclusion Criteria Prenatal Group:
Inclusion Criteria Historical Control Group:
Inclusion Criteria Prospective Untreated Control Group:
Exclusion Criteria Postnatal Group:
Exclusion Criteria Prenatal Group:
Exclusion Criteria Historical Control Group:
Exclusion Criteria Prospective Untreated Control Group:
15 participants. Administration of four postnatal doses of BOOST cells with the first dose as soon as possible after birth and the three additional doses at +4, +8 and +12 months after the first dose. Each dose is 3x10\^6 MSC/kg body weight.
Biological: BOOST cells
3 participants. Administration of one prenatal dose of BOOST cells followed by three postnatal doses at +4, +8 and +12 months after the first dose. Each dose is 3x10\^6 MSC/kg body weight.
Biological: BOOST cells
1-30 participants. Subjects eligible for the trial but not willing/able to participate in any of the experimental arms.
18-90 participants (1-5 per included and treated subject). Matched historical controls. Subjects will be identified in historical registries and data will be retrieved from national OI registers and the OI Variant Database (Dalgleish 2018).
Four doses of expanded human 1st trimester fetal liver-derived mesenchymal stem cells.
Safety and tolerability measured as seriousness, severity and frequency of treatment related adverse events.
The primary endpoint is safety and tolerability measured as seriousness, severity and frequency of treatment related adverse events (AEs), with specific focus on the following: 1. Vital signs in conjunction with the MSC administration 2. Transfusion reactions (administration toxicity, allergy, embolism) 3. Immune reaction with or without symptoms of inflammation, potentially resulting in rejection of the cells or development of donor-specific antibodies: * Allergy or Hypersensitivity responses to antibiotics or antimycotics * Development of Fetal Bovine Serum-specific antibodies * Hypersensitivity responses to Human Serum Albumin * Hypersensitivity to impurities in the IMP 4. Prenatal complications (miscarriage/intrauterine fetal death, premature birth, infection in utero or persistent \[\>1 min\] fetal bradycardia) in the prenatal group 5. Adverse effects of feto-maternal transmission of donor cells in the prenatal group 6. Tumourigenicity 7. Mortality/morbidity
Time frame: From baseline to the long-time follow-up (10 years after the first dose).
Number of fractures.
Number of fractures.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and therafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Time (days) to first fracture after each stem cell administration.
Time (days) to first fracture after each stem cell administration.
Time frame: From each dose of stem cells to the time point of the first fracture. Assessed up to 10 years after the first stem cell dose.
Numbers of fractures at birth.
Numbers of fractures at birth.
Time frame: Evaluated at birth.
Change in bone-marrow density (g/cm2).
Change in bone-marrow density (g/cm2).
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Growth (cm).
Growth (cm) as assessed by clinician.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Growth (kg).
Growth (kg) as assessed by clinician.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Change in clinical status of OI.
Change in clinical status of OI based on parameters defined under efficacy assessments described in protocol, as assessed by OI clinician.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Assessment of biochemical bone turnover by analysis of the markers P-Calcium, P-Phosphate, P-Albumin, S-ALP, fP-PTH, S-25-OH Vitamin D, Bone specific S-ALP, S-CTx, S-Osteocalcin and U-DPD/Krea and U-NTx/Krea in blood and urine samples.
Assessment of biochemical bone turnover.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Impact on the subjects Quality of Life: Infant Toddler Quality of Life Questionnaire™ (ITQOL)
Quality of life assessed using the Infant Toddler Quality of Life Questionnaire™ (ITQOL).
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Incidence of donor cells engrafted into patient tissue samples assessed by histology.
Donor cell engraftment.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Analysis of an array of cytokines and micro vesicles to evaluate paracrine effects.
Paracrine effects will be analysed from plasma isolated from peripheral blood.
Time frame: From baseline to the primary follow-up (6 and 12 months after the last dose) and thereafter assessed annually to the end of the long-time follow-up (10 years after the first dose).
Assess the potential of non-invasive methods of prenatal diagnosis for OI by genetic analysis of parent DNA.
Non-invasive prenatal diagnosis will be studied during the trial.
Time frame: From baseline to birth for prenatal group.
Plan to share: Yes — Individual participant data that underlie the results reported in this trial, after deidentification (text, tables, figures, and appendices).
Supporting information: Study protocol, Icf, Csr
This study is active, not recruiting, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Karolinska Institutet