Vector Distribution and Vector Shedding
Pariglasgene brecaparvovec-opnr vector DNA levels were measured and quantified in blood and various shedding matrices using a quantitative polymerase chain reaction (qPCR) assay. This assay is sensitive and specific to pariglasgene brecaparvovec-opnr vector DNA, including DNA fragments with an intact target sequence.
Nonclinical Data
Biodistribution of vector genome DNA was evaluated following a single intravenous administration of pariglasgene brecaparvovec-opnr in adult C57BL/6N mice at a dose of 1.8 × 1013 gc/kg. At 13 weeks post dose, vector genome DNA was detected in all major organs analyzed, with the highest quantities detected in the liver followed by lower levels in the kidney, lung, heart, gonads, and spleen. The expression of human G6PC mRNA transcripts was primarily detected in the liver, with at least 100-fold higher level than those measured in extrahepatic tissues.
Vector genome determination in blood and vector shedding in urine, stool, saliva, and semen was evaluated in mice up to 90 days following an intravenous administration of pariglasgene brecaparvovec-opnr at 1.8 × 1013 gc/kg. The highest concentration of vector genome DNA was found in blood followed by stool, urine, semen, and saliva. Vector genome DNA dropped below the limit of detection in saliva after 1 week, in stool and urine after 1 month, and in semen and blood after 3 months.
Clinical Data
Biodistribution of vector genome DNA in blood and vector shedding in urine, stool, and saliva were assessed in 12 patients at baseline and on follow-up (Day 2, Week 4, 6, 12, 24, 36, and 52 for blood samples, Day 4 and 12, Week 4, 6, and 12 for other urine, stool and saliva samples) until three consecutive measurements were below the limit of detection (LOD). Peak levels of vector genome DNA occurred at the first post-dose assessment on Day 2 in blood and between Day 3 and Day 13 in stool, saliva, and urine. At a dose of 6.0 × 1012 gc/kg measured using qPCR (which is equivalent to the recommended dose of 1.0 × 1013 gc/kg measured using digital droplet polymerase chain reaction (ddPCR), the highest individual peak concentration of vector genome DNA observed in blood was 6.8 × 107 gc/100 ng and in the stool was 1.7 × 106 gc/100 ng. Blood vector genome DNA in most patients reached below the limit of detection (LOD = 10 copies of target DNA/100 ng DNA) approximately 24 weeks post infusion. Clearance of vector DNA was defined as measurement of 3 consecutive results below the limit of detection. Based on this definition, vector genome DNA was cleared from saliva within 7 weeks and from urine and stool within 13 weeks post-infusion.
Pharmacokinetics in Specific Populations
No dedicated pharmacokinetic studies using pariglasgene brecaparvovec-opnr have been conducted in special populations.