PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders)

PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders) (NCT04532047) is a Phase 1 interventional studying MPS I and MPS II, sponsored by University of California, San Francisco. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For MPS I, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 10 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - 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 willing to sign a consent form and comply with the requirements of the study. Who Should NOT Join This Trial: - 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. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

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.

Treatments Being Tested

DRUG

Aldurazyme (laronidase)

Enzyme replacement therapy for lysosomal storage diseases

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

University of California

San Francisco, California, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04532047), the sponsor (University of California, San Francisco), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04532047 clinical trial studying?

For detailed information, please view our study website: https://pearltrial.ucsf.edu/ The investigators aims to determine the the maternal and fetal safety and feasibility of in utero fetal enzyme replacement therapy in fetuses with Lysosomal Storage Diseases. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04532047?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04532047?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04532047. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04532047. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.