Safety & Efficacy of DCR-PHXC in Patients With PH1 and ESRD

Inclusion Criteria

• •Note: Currently, the DCR-PHXC-204 study is only enrolling potential participants under 6 years of age.
• •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)