A Phase 2 interventional study of YOLT-203 and Placebo in Primary Hyperoxaluria Type 1 and PH1, sponsored by YolTech Therapeutics Co., Ltd. Recruiting at 4 sites in United States. Open to participants aged 6 Years and older. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by YolTech Therapeutics Co., Ltd · Phase 2, Interventional, and Treatment
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.
22 studies on the registry are indexed under Primary hyperoxaluria type 1; 8 are open to participants now.
This study's planned enrollment of 36 is above the median of 28 across 16 interventional studies indexed under Primary hyperoxaluria type 1.
Browse Primary hyperoxaluria type 1 studies →YolTech Therapeutics Co., Ltd is the lead sponsor of 3 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
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.
Also known as: Investigational Gene Editing Therapy
Placebo is a matching intravenous infusion administered over 1 hour.
Percent Change From Baseline in 24-Hour Urinary Oxalate (BSA-Corrected)
Percent change from baseline in 24-hour urinary oxalate excretion corrected for body surface area (BSA) across Months 2 to 6.
Time frame: Months 2 to 6
Change From Baseline in Plasma Oxalate
Percent and absolute change from baseline in plasma oxalate levels across Months 2 to 6.
Time frame: Months 2 to 6
Change in Estimated Glomerular Filtration Rate (eGFR)
Change from baseline in estimated glomerular filtration rate (eGFR).
Time frame: Baseline to Month 6
Change in Kidney Stone Burden
Change from baseline in number and summed surface area of kidney stones as assessed by renal ultrasound.
Time frame: Baseline to Month 6
Proportion of Participants Achieving Urinary Oxalate Thresholds
Proportion of participants achieving urinary oxalate levels ≤ upper limit of normal (ULN) and ≤ 1.5 × ULN at Month 6.
Time frame: Month 6
Incidence of Adverse Events
Incidence and severity of adverse events (AEs) and serious adverse events (SAEs), graded using CTCAE v6.0.
Time frame: Day 1 to Month 12
Pharmacokinetic Parameters of YOLT-203 (Cmax)
Cmax for YOLT-203 components (mRNA, CRISPR RNA, and lipid nanoparticles).
Time frame: Dosing through Month 1
Pharmacokinetic Parameters of YOLT-203 (AUC0-inf)
AUC0-inf for YOLT-203 components (mRNA, CRISPR RNA, and lipid nanoparticles).
Time frame: Dosing through Month 1
Health-Related Quality of Life
Change from baseline in EQ-5D Health State Profile and Visual Analog Scale (VAS) scores.
Time frame: Baseline through Month 12
Change in urinary and plasma glycolate
Change from baseline in urinary and plasma glycolate levels.
Time frame: Baseline to Month 6
Change in urinary oxalate:creatinine ratio
Change from baseline in urinary oxalate:creatinine ratio from spot urine samples.
Time frame: Baseline to Month 6
Anti-Drug Antibody Incidence
Incidence of anti-drug antibodies (ADAs) against polyethylene glycol (PEG) and CRISPR-associated protein 12 (Cas12).
Time frame: Baseline to Month 6
Kidney stone events
Number of kidney stone events occurring during the study period.
Time frame: Baseline to Month 6
Started Sep 2026 (actual). Primary completion is estimated for Aug 2027, 11 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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YolTech Therapeutics Co., Ltd