Why PTC Therapeutics, Inc. Dropped Today

PTC Therapeutics (NASDAQ: PTCT) fell 10.9% on Tuesday after disclosing data for RG7916 in patients with Type 2 and Type 3 spinal muscular atrophy (SMA).

It's been a roller coaster for PTC Therapeutics, falling last week after FDA briefing documents didn't paint its Duchenne muscular dystrophy drug, Translarna, in the best light. The advisory committee agreed, voting 10-1 against recommending an approval, but investors sent shares higher, hoping the agency might ignore its panel of outside experts.

Now PTC is out with data for a different drug, RG7916, at the 22nd International World Muscle Congress. There doesn't seem to be anything inherently wrong with the data, but it wasn't super-exciting, either; this may be a sell-the-news kind of event rather than a long-term valuation change.

Source: Fool.com