NSG mouse toxicity dose gave only a 1.6-fold margin over the maximum human cell dose
“The dose level of 1 x 106 CD34+ hHSPCs/mouse administered in the single dose toxicity study is acceptable, despite the fact that there is only a 1.6-fold safety margin as compared to the max. human dose level of 20 x 106 cells/kg.”
1x10^6 cells/mouse well tolerated; minor non-adverse red cell changes and spleen/thymus round-cell infiltration; no tumors
“The single dose GLP toxicology study with an observation period of 20 weeks revealed that the single IV injection of 1 x 106 cells/animal of unedited or SPY101-RNP-edited CD34+ hHSPCs into non-lethally irradiated NSG mice was well-tolerated.”