DMD and Duchenne muscular dystrophy: In 2019, a two-part Ph2 trial (NCT04004065) was started, with Part A to evaluate the safety and tolerability in DMD patients, ages 7–21, after receiving ascending doses of SRP-5051 every 4 weeks, and Part B to further evaluate SRP-5051 doses recommended from Part A. Results at 12 weeks showed that SRP-5051 dosed monthly at 30 mg/kg increased mean dystrophin expression to 6.55%, consistently higher than the other dosing cohorts and weekly eteplirsen at 24 weeks (Sarepta, 2021b).