Transgenic SMA mouse models expressing human SMN2 (ICV and IT dosing)
“In vivo studies (using intracerebroventricular and intrathecal [IT] administration) were conducted in transgenic mouse models of SMA because only humans are known to have the SMN2 gene.”
✓ VerifiedFDA pharmacology/toxicology review, p. 79Source ↗
Why that model
SMN2 exists only in humans, so in vivo pharmacology required mice with mouse Smn removed and human SMN2 expressed
“Since humans are the only species known to have the SMN2 gene, in vivo pharmacology was examined in mouse models of SMA in which the endogenous mouse gene has been removed and the human SMN2 gene is expressed.”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Reviewer's view of the efficacy data
FDA: nusinersen increased SMN2 exon 7 inclusion in cells and animals with beneficial effects in SMA mouse models
“In cell culture and animals, ISIS 396443 increased SMN2 exon 7 inclusion and had beneficial effects in mouse models of SMA.”
✓ VerifiedFDA pharmacology/toxicology review, p. 71Source ↗