New hope for rare kidney disease: drug targets oxalate buildup in severe cases
NCT ID NCT04580420
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This phase 2 study tests a drug called nedosiran (DCR-PHXC) in 28 people with primary hyperoxaluria type 1 (PH1) who have severe kidney impairment, with or without dialysis. The goal is to see if the drug safely lowers plasma oxalate levels, which can cause kidney stones and damage. The trial is currently only enrolling children under 6 years old.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- nedosiran (DCR-PHXC)
- What this could lead to
- If it works, this could point toward a treatment to lower harmful oxalate levels in patients with PH1 and severe kidney problems, potentially reducing complications.
- What could go wrong
- This is a small, early-phase trial with only 28 participants, so results may not apply to everyone. The drug may not work well in patients on dialysis, and safety risks are still being studied.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
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About 28 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Apr 2021
- Expected to finish
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Jan 2032
An estimate. End dates often move.
- Lead sponsor
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A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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Children (under 18), adults (18 to 64) and older adults (65 and over)
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Note: Currently, the DCR-PHXC-204 study is only enrolling potential participants under 6 years of age. Inclusion Criteria: 1. Four age groups of participants will be enrolled: 1. adults and adolescents (aged ≥ 12 years) 2. children 6 to 11 years of age 3. children 2 to 5 years of age 4. infants and newborns from birth to \< 2 years of age 2. . Documented diagnosis of PH1, confirmed by genotyping 3. Estimated GFR at Screening \<30mL/min normalized to 1.73m\^2 BSA 4. Mean of 2 Plasma Oxalate \>20μmol/L during screening 5. For participants receiving hemodialysis or peritoneal dialysis total duration of hemodialysis or peritoneal dialysis must be less than 24 months and hemodialysis or peritoneal dialysis regimen must have been stable for at least 2 weeks prior to Screening. 6. Male or Female 1. Male participants: * A male participant with a female partner of childbearing potential must agree to use contraception during the treatment period and for at least 12 weeks after the last dose of study intervention and refrain from donating sperm during this period. 2. Female participants: * A female participant is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies: Not a woman of childbearing potential (WOCBP). * OR * A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at least 12 weeks after the last dose of study intervention and agrees to refrain from harvesting/freezing eggs during this period. 3. Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. 7. Participant (and/or participant's parent or legal guardian if participant is a minor \[defined as patient \<18 years of age, or younger than the age of majority according to local regulations\]) is capable of giving signed informed consent, which includes compliance with the requirement and restrictions listed in the informed consent form (ICF) and in the protocol. 1. Adolescents (12 to \< 18 years of age, or older than 12 years but younger than the age of majority according to local regulations) must be able to provide written assent for participation. 2. For children younger than 12 years of age, assent will be based on local regulations 8. Affiliated with or is a beneficiary of a health insurance system (if applicable per national regulations) Exclusion Criteria: 1. Prior hepatic transplantation; or scheduled transplantation within 6 months of Day 1. Prior renal transplantation is allowed. 2. Documented evidence of clinical manifestations of severe systemic oxalosis (including preexisting retinal, heart, or skin calcifications, or history of severe bone pain, pathological fractures, or bone deformations) 3. Presence of any condition or comorbidities that would interfere with study compliance or data interpretation or potentially impact patient safety including, but not restricted to: 1. Severe intercurrent illness 2. Known causes of active liver disease/injury (e.g., alcoholic liver disease, nonalcoholic fatty liver disease/steatohepatitis) 3. Non-PH related conditions contributing to renal insufficiency 4. Physician concerns about intake of drugs of abuse or excessive alcohol intake, or history of excessive alcohol intake in the 2 years prior to enrollment (defined as ≥ 21 units of alcohol per week in men and ≥ 14 units of alcohol per week in women; where a "unit" of alcohol is equivalent to a 12-ounce beer, 4-ounce glass of wine, or 1ounce shot of hard liquor) 4. Use of an RNAi drug, other DCR-PHXC, within the last 6 months 5. History of one or more of the following reactions to an oligonucleotide-based therapy: 1. Severe thrombocytopenia (platelet count ≤ 100,000/µL) 2. Hepatotoxicity, defined as alanine transaminase (ALT) or aspartate transaminase (AST) \> 3 times the upper limit of normal (ULN) and total bilirubin \> 2 × ULN or international normalized ratio (INR) \>1.5 3. Severe flu-like symptoms leading to discontinuation of therapy 4. Localized skin reaction from the injection (graded severe) leading to discontinuation of therapy 5. Coagulopathy/clinically significant prolongation of clotting time 6. Participation in any clinical study in which they received an investigational medicinal product (IMP) other than DCR-PHXC within 4 months before Screening. 7. Liver function test abnormalities: ALT and/or AST \>1.5 × ULN for age and gender 8. Positive anti-double-stranded deoxyribonucleic acid (anti-dsDNA) antibody test at Screening 9. Known hypersensitivity to DCR-PHXC or any of its ingredients 10. Inability or unwillingness to comply with the specified study procedures, including the lifestyle considerations
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The study's own enquiry address
This study publishes an address for enquiries. See it below .
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The places running it
6 sites in 6 countries. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Show contact details
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Study contacts
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Contact
Email: •••••@•••••
Locations
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Clinical Trial Site
ACTIVE_NOT_RECRUITINGSan Francisco, California, 94143, United States
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Clinical Trial Site
ACTIVE_NOT_RECRUITINGBoston, Massachusetts, 02115, United States
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Clinical Trial Site
RECRUITINGRochester, Minnesota, 55905, United States
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Clinical Trial Site
ACTIVE_NOT_RECRUITINGNew York, New York, 10016, United States
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Clinical Trial Site
WITHDRAWNBron, 69677, France
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Clinical Trial Site
WITHDRAWNParis, 75019, France
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Clinical Trial Site
RECRUITINGBonn, 53127, Germany
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Clinical Trial Site
WITHDRAWNHeidelberg, 69120, Germany
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Clinical Trial Site
WITHDRAWNRoma, 00165, Italy
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Clinical Trial Site
RECRUITINGBeirut, 00001, Lebanon
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Clinical Trial Site
WITHDRAWNCasablanca, 2025, Morocco
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Clinical Trial Site
WITHDRAWNOradea, 410469, Romania
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Clinical Trial Site
WITHDRAWNOradea, 410562, Romania
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Clinical Trial Site
RECRUITINGBarcelona, 08035, Spain
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Clinical Trial Site
WITHDRAWNSanta Cruz de Tenerife, 38320, Spain
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Clinical Trial Site
RECRUITINGDubai, +971, United Arab Emirates
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Clinical Trial Site
WITHDRAWNLondon, NWG 2Q3, United Kingdom
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Clinical Trial Site
RECRUITINGLondon, WC1N3JH, United Kingdom
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