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

At P16, vehicle-treated D7 mice were significantly smaller and dying compared to heterozygous control littermates. In contrast, D7 mice treated with high doses of SMN-C3 exhibited phenotypes similar to the heterozygous controls. SMN-C3 treatment in D7 mice induces dose-dependent body weight gain, with some achieving ~80% of heterozygous control weight. SMN-C3 also normalizes D7 motor behavior, allowing rapid self-righting and comparable locomotor activity to heterozygous controls. Importantly, vehicle-treated mice die within 3 weeks post-birth (median survival of 18 days), whereas SMN-C3 extends survival dose-dependently, with a median of 28 days at low dose (0.3 mg/kg/day) and ~90% survival beyond P65 in the higher doses (1 and 3 mg/kg/day) [1].