A Study to Evaluate Lumasiran in Children and Adults With Primary Hyperoxaluria Type 1

- Willing to provide written informed consent or assent and to comply with study requirements

- Confirmation of PH1 disease

- Meet the 24 hour urine oxalate excretion requirements

- If taking Vitamin B6 (pyridoxine), must have been on stable regimen for at least 90 days

- Clinically significant health concerns (with the exception of PH1) or clinical evidence of extrarenal systemic oxalosis

- Clinically significant abnormal laboratory results

- Known active or evidence of HIV or hepatitis B or C infection

- An estimated GFR of < 30 mL/min/1.73m^2 at screening

- Received an investigational agent within 30 days or 5 half-lives before the first dose of study drug or are in follow-up of another clinical study

- History of kidney or liver transplant

- Known history of multiple drug allergies or allergic reaction to an oligonucleotide or GalNAc

- History of intolerance to subcutaneous injection

- Women who are pregnant, planning a pregnancy, or breast-feeding or those of child bearing potential and not willing to use contraception

- History of alcohol abuse within the last 12 months, or unable or unwilling to limit alcohol consumption throughout the study