In utero enzyme replacement therapy for lysosomal storage disorders

PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders)

PHASE1 · University of California, San Francisco · NCT04532047

This study is testing whether giving enzyme replacement therapy to unborn babies with lysosomal storage disorders can improve their health and development before they are born.

Quick facts

PhasePHASE1
Study typeInterventional
Enrollment10 (estimated)
Ages18 Years to 50 Years
SexFemale
SponsorUniversity of California, San Francisco (other)
Locations1 site (San Francisco, California)
Trial IDNCT04532047 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the safety and feasibility of administering enzyme replacement therapy to fetuses diagnosed with lysosomal storage disorders (LSDs) during pregnancy. The study focuses on fetuses at risk of serious complications, particularly those with Non-Immune Hydrops Fetalis (NIHF), which has a high perinatal mortality rate. By delivering the enzyme therapy in utero, the researchers hope to improve outcomes and potentially enhance neurodevelopmental results by addressing the condition during critical developmental periods. This phase 1 trial will assess the initial safety of the treatment approach.

Who should consider this trial

Good fit: Ideal candidates include pregnant women aged 18 to 50 carrying live fetuses diagnosed with specific lysosomal storage disorders between 18 to 34 weeks of gestation.

Not a fit: Patients with fetuses that have severe structural anomalies or additional unrelated pathogenic genetic variants may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly reduce perinatal morbidity and mortality for fetuses affected by lysosomal storage disorders.

How similar studies have performed: While the concept of in utero treatment is promising, this specific approach to enzyme replacement therapy for lysosomal storage disorders is novel and has not been extensively tested in previous studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Live male or female fetuses at 18 0/7 weeks to 34 6/7 weeks gestation
* Diagnosis of one of the 8 included LSDs in utero by genetic or enzymatic analyses performed on amniotic fluid, fetal blood, placental tissue, or other samples through chorionic villus sampling (CVS), amniocentesis, cordocentesis, cell free fetal DNA, or other procedures. In the event that parents are identified as genetic carriers for a LSD, diagnostic testing for the fetus would be performed to confirm the diagnosis
* Pregnant women age 18 years to 50 years, carrying a live male or female fetus at 18 0/7 weeks to 34 6/7 weeks gestation
* Identified through the above listed means to be carrying a fetus with an LSD.
* Ability to give written informed consent and comply with the requirements of the study.

Exclusion Criteria:

* Fetuses with a concurrent severe structural anomaly
* Fetuses with an additional pathogenic genetic variant not related to the underlying LSD that contribute a significant risk of morbidity or mortality.

Hydrops fetalis will not be an exclusion criterion because ERT has the possibility of significant benefit in this situation.

* Women with one or more significant comorbidities that would preclude fetal intervention including, but not limited to:

  1. inability to complete the procedure secondary to maternal body habitus or placental location
  2. significant cardiopulmonary disease
  3. mirror syndrome
  4. end organ failure
  5. altered mental status
  6. placental abruption
  7. active preterm labor
  8. preterm premature rupture of membranes.
* Mother will require therapeutic dosing of anticoagulation within 24 hours prior to or following the intervention.

Where this trial is running

San Francisco, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: MPS I, MPS II, MPS IVA, MPS VI, Mps VII, Gaucher Disease, Type 2, Gaucher Disease, Type 3, Pompe Disease Infantile-Onset

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.