Prosensa plummets on DMD data

Prosensa Holding N.V. (NASDAQ:RNA) and GlaxoSmithKline plc (LSE:GSK; NYSE:GSK) said drisapersen ( PRO051) missed the primary endpoint in a Phase III trial to treat Duchenne muscular dystrophy (DMD), sending Prosensa's shares down $16.86 (70%) to $7.14 on Friday. The partners said that in the DEMAND 3 (DMD114044) trial, once-weekly subcutaneous 6 mg/kg drisapersen led to a mean reduction of about 43 meters in six-minute walk distance (6MWD), the primary endpoint, from baseline to week 48 vs. about 53 meters for placebo (p=0.415). The double-blind trial enrolled 186 ambulant boys at least five years of age.

Prosensa said analysis of dystrophin levels is ongoing. GSK will present results excluding dystrophin data at the World Muscle Society meeting on Oct. 5 and the Oligonucleotide Therapeutics Society meeting on Oct. 8. ...