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

This study tests a drug called DCR-PHXC (also known as nedosiran) in people with a rare inherited kidney disease called Primary Hyperoxaluria Type 1 (PH1) who have severe kidney failure (end-stage renal disease, ESRD). PH1 causes the body to overproduce oxalate, which builds up and damages the kidneys. **You may be eligible if...** - You are currently under 6 years of age (note: only this age group is currently enrolling) - You have a confirmed genetic diagnosis of PH1 - Your kidney function is severely reduced (estimated GFR below 30 mL/min) - Your blood oxalate levels are elevated - If you are on dialysis, you have been on it for less than 24 months and your dialysis schedule has been stable **You may NOT be eligible if...** - You have normal or mildly reduced kidney function - You are pregnant or breastfeeding - You are not willing to use contraception as required by the study Talk to your doctor to see if this trial is right for you.