“Antigenicity endpoints were included in single dose toxicity studies, capsid antigens generally caused high titres of anti AAV5 antibodies. In addition, anti-human FIX antibodies were observed inconsistently in NHP.”
Liver highest, then adrenal, spinal cord; vector in testis/epididymis/semen at 26 wks; saliva/urine clear by ~week 8-12
“Vector DNA was also identified in the adrenal glands and spinal cord, followed by limited vector presence in various tissue types.”
✓ VerifiedFDA summary basis for approval, p. 11Source ↗
Modality-specific risk
AAV integration/insertional oncogenesis (dose-dependent), germline transmission, thrombosis from high FIX activity, DRG toxicity
“Dose is considered a pivotal factor with regards to the frequency of integration and with that a main contributor to the risk of insertional oncogenesis.”
Anti-hFIX antibodies in 5 of 12 NHPs, correlating with declining circulating hFIX from 13 weeks
“Anti-hFIX antibodies developed in 5 out of 12 NHPs administered HEMGENIX, which correlated with a decline in circulating hFIX protein levels beginning at 13 weeks post-dose.”
Sustained humoral response to AAV5 capsid in all patients (N=54)
“In the clinical efficacy study (N=54), sustained humoral immune response to infused AAV5 capsid was observed in all patients following treatment with HEMGENIX.”