Sarepta gets boost from perceived ambiguity in drisapersen trial results

|About: Sarepta Therapeutics, Inc. (SRPT)|By:, SA News Editor

Sarepta Therapeutics (SRPT) jumps 7% premarket as investors digest new data from a Phase 2 trial of GlaxoSmithKline (GSK) and Prosensa's (RNA) eteplirsen competitor drisapersen.

While SRPT and GSK use different definitions for what counts as a dystrophin response (this may be key), it's worth noting that at continuous and intermittent 6mg/kg doses, increases from baseline on at least one of three assays were observed in 72% and 59% of patients for drisapersen, while SRPT claims a 100% effect with eteplirsen.

Here's Baird's take: Although drisapersen "may be underdosed ... there appears to be no effort to look at higher doses, despite claims that the proteinuria associated with drisapersen is not clinically relevant."

Baird seems to think that any perceived unwillingness on the part of GSK to pursue higher doses may be evidence for claims that drisapersen's safety profile is worse than eteplirsen's.