SMN-C3 (MV8T2MCK57) is an orally active modulator of SMN2 splicing, and has the potential to treat spinal muscular atrophy (SMA).

At P16, the vehicle-treated D7 mice were much smaller than the control group of heterozygous litter pups and were dying. In contrast, D7 mice treated with high doses of SMN-C3 showed a phenotype similar to the heterozygous control.In the D7 mice, SMN-C3 treatment induces a dose-dependent bodyweight gain , with some animals showing a body weight that is ~80% that of heterozygous controls. SMN-C3 normalizes the motor behavior of D7 mice, illustrated by the ability of the mice to right themselves as quickly as heterozygous controls and by their level of locomotor activity. Most importantly, whereas vehicle-treated mice die within 3 weeks after birth with a median survival of 18 days, SMN-C3 treatment increases survival in a dose-dependent manner to a median survival time of 28 days in the low-dose (0.3 mg/kg per day) group. In the two higher-dose groups (1 and 3 mg/kg per day), ~90% of animals survive beyond P65 when the study is completed[1].