Study of YOLT-203 in Children and Adults With Primary Hyperoxaluria Type 1 (PH1)

August 7, 2026 updated by: YolTech Therapeutics Co., Ltd

A Randomized, Double-blind, Placebo-controlled Study Followed by a Treatment Extension to Evaluate the Efficacy and Safety of YOLT-203 in Children and Adults With Primary Hyperoxaluria Type 1

This study will be conducted to evaluate the efficacy and safety of YOLT-203 in children and adults with Primary Hyperoxaluria Type 1.

After the initial randomized, 6-month double-blind, placebo-controlled period, participants who were initially assigned to placebo will receive a single-dose of YOLT-203 treatment whereas participants in the YOLT-203 group will receive a single-dose of placebo infusion.

For patients interested in additional information on how to participate, please follow this link: https://mytomorro.ws/ph1trial.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • Phase 2

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35249
        • Recruiting
        • University of Alabama at Birmingham (UAB Hospital)
        • Contact:

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  • You are 6 years old or older.
  • You have been diagnosed with PH1 (primary hyperoxaluria type 1) through genetic testing.
  • Urine tests show that your oxalate levels are not within certain limits (based on at least two 24-hour urine collections).
  • If you take vitamin B6, your dose has been stable for at least 3 months, and you are willing to keep it the same during the study.
  • You (and/or your parent or legal guardian, if you are under 18) understand the study and agree to follow all study requirements, including signing a consent form.

Exclusion Criteria

  • You have signs that oxalate has affected parts of your body outside the kidneys.
  • Your liver blood tests are not within certain limits.
  • You have certain abnormal blood clotting results (unless controlled with medication like warfarin).
  • You have HIV, or active or chronic hepatitis C.
  • You are pregnant, planning to become pregnant, or breastfeeding.
  • You are not willing to use birth control during the study and for 6 months after (if applicable).
  • You are unable to limit alcohol intake to no more than about 2 drinks per day.
  • You have had alcohol or drug abuse in the past year.
  • You are unable to follow standard treatments for PH1 (such as drinking plenty of fluids, taking prescribed medications like potassium citrate, or following dietary advice).

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: YOLT-203
Participants will receive both study treatments in sequential treatment periods according to randomized assignment. Participants who initially receive YOLT-203 during the double-blind treatment period and will cross over to the placebo treatment in the subsequent treatment period, followed by safety and efficacy follow-up.
Genetic: YOLT-203
YOLT-203 is an investigational gene editing therapy being evaluated for the treatment of Primary Hyperoxaluria Type 1 (PH1). It is administered by intravenous infusion over 1 hour.
Other Names:
  • Investigational Gene Editing Therapy
Placebo Comparator: Placebo
Participants will receive both study treatments in sequential treatment periods according to randomized assignment. Participants who initially receive placebo during the double-blind treatment period and will cross over to the YOLT-203 treatment in the subsequent treatment period, followed by safety and efficacy follow-up.
Drug: Placebo
Placebo is a matching intravenous infusion administered over 1 hour.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Change From Baseline in 24-Hour Urinary Oxalate (BSA-Corrected)
Time Frame: Months 2 to 6
Percent change from baseline in 24-hour urinary oxalate excretion corrected for body surface area (BSA) across Months 2 to 6.
Months 2 to 6

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Plasma Oxalate
Time Frame: Months 2 to 6
Percent and absolute change from baseline in plasma oxalate levels across Months 2 to 6.
Months 2 to 6
Change in Estimated Glomerular Filtration Rate (eGFR)
Time Frame: Baseline to Month 6
Change from baseline in estimated glomerular filtration rate (eGFR).
Baseline to Month 6
Change in Kidney Stone Burden
Time Frame: Baseline to Month 6
Change from baseline in number and summed surface area of kidney stones as assessed by renal ultrasound.
Baseline to Month 6
Proportion of Participants Achieving Urinary Oxalate Thresholds
Time Frame: Month 6
Proportion of participants achieving urinary oxalate levels ≤ upper limit of normal (ULN) and ≤ 1.5 × ULN at Month 6.
Month 6
Incidence of Adverse Events
Time Frame: Day 1 to Month 12
Incidence and severity of adverse events (AEs) and serious adverse events (SAEs), graded using CTCAE v6.0.
Day 1 to Month 12
Pharmacokinetic Parameters of YOLT-203 (Cmax)
Time Frame: Dosing through Month 1
Cmax for YOLT-203 components (mRNA, CRISPR RNA, and lipid nanoparticles).
Dosing through Month 1
Pharmacokinetic Parameters of YOLT-203 (AUC0-inf)
Time Frame: Dosing through Month 1
AUC0-inf for YOLT-203 components (mRNA, CRISPR RNA, and lipid nanoparticles).
Dosing through Month 1

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Health-Related Quality of Life
Time Frame: Baseline through Month 12
Change from baseline in EQ-5D Health State Profile and Visual Analog Scale (VAS) scores.
Baseline through Month 12
Change in urinary and plasma glycolate
Time Frame: Baseline to Month 6
Change from baseline in urinary and plasma glycolate levels.
Baseline to Month 6
Change in urinary oxalate:creatinine ratio
Time Frame: Baseline to Month 6
Change from baseline in urinary oxalate:creatinine ratio from spot urine samples.
Baseline to Month 6
Anti-Drug Antibody Incidence
Time Frame: Baseline to Month 6
Incidence of anti-drug antibodies (ADAs) against polyethylene glycol (PEG) and CRISPR-associated protein 12 (Cas12).
Baseline to Month 6
Kidney stone events
Time Frame: Baseline to Month 6
Number of kidney stone events occurring during the study period.
Baseline to Month 6

Collaborators and Investigators

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

Sponsor

YolTech Therapeutics Co., Ltd

Investigators

  • Study Director: Ling Xiao, MD, PhD, YolTech Therapeutics

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.

Helpful Links

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 (Estimated)

August 1, 2026

Primary Completion (Estimated)

August 1, 2027

Study Completion (Estimated)

February 1, 2028

Study Registration Dates

First Submitted

May 1, 2026

First Submitted That Met QC Criteria

May 7, 2026

First Posted (Actual)

May 14, 2026

Study Record Updates

Last Update Posted (Actual)

August 12, 2026

Last Update Submitted That Met QC Criteria

August 7, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PH1-YOLT-203-2001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

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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