In Vitro: For NVS-SM2, the molecular mechanism of action is via stabilization of the transient double-strand RNA structure formed by the SMN2 pre-mRNA and U1 small nuclear ribonucleic protein (snRNP) complex. The binding affinity of U1 snRNP to the 5' splice site is increased in a sequence-selective manner, discrete from constitutive recognition.
In Vivo: NVS-SM2 (0.1-1 mg/kg; s.c.; for 30 days) treatment extends survival in a severe SMA mouse model. Pharmacokinetic analysis demonstrate that NVS-SM2 is readily available in the brain after IV and oral (PO) administration in mouse and rat with Tmax of 3 h after PO with 3 mg/kg in mice, and NVS-SM2 treatment induces a 1.5-fold increase in SMN protein levels in the mouse brain.