With the major indexes hitting new highs, most health-care stocks enjoyed nice gains. Not all of them, though. A select few brought nothing but misery to shareholders. Here are the three most horrendous health-care stocks over the past week.
By far the biggest loser on this week's list is Prosensa (NASDAQ:RNA). Shares plunged 70% for the week on surprisingly poor results from a late-stage study of Duchenne muscular dystrophy, or DMD, drug drisapersen.
Prosensa and partner GlaxoSmithKline (NYSE:GSK) announced on Friday that drisapersen failed to meet its primary endpoint of improving performance on the six-minute walk test used to assess DMD patients. While the two companies still plan to review the results more fully, the situation looks bleak for Prosensa right now.
The biotech's bad news ended up being good news for chief rival Sarepta Therapeutics (NASDAQ:SRPT), which is seeking approval for its DMD drug eteplirsen. Shares of Sarepta see-sawed early in the day following the drisapersen announcement. That changed big-time by late morning. Sarepta finished up around 16% as investors saw Prosensa's stumble as a significant opportunity for eteplirsen.
There was no late-stage clinical failure for Questcor Pharmaceuticals (NASDAQ:QCOR). Actually, there wasn't any significant news whatsoever. The stock still dropped by 12%, though.
The most probable impetus behind the decline could be some insider selling that began in late August and continued into this week. Dave Medeiros, Questcor's chief technical officer, sold more than $4 million worth of shares on Aug. 26 as he exercised some stock options. Last Friday, CEO Don Bailey took the same path in a transaction of nearly $2.6 million. Virgil Thompson, a member of Questcor's board of directors, sold more than $318,000 in a stock option exercise earlier this week.
Insider sell-offs can sometimes spook investors. Of course, it's hard to blame anyone from selling somewhat with a stock that has more than doubled so far this year.
It isn't often that a stock falling by less than double digits makes the "horrendous" list, but Sangamo BioSciences (NASDAQ:SGMO) managed to do so this week. Shares fell 9% on Sangamo's announcement of a secondary stock offering.
The biotech is selling 6.1 million shares at a price of $10.58. That level is 6% below where Sangamo traded at the end of last week.
Sangamo's lead drug candidate is SB-728, which is in a mid-stage study as a potential treatment for HIV/AIDS. The company also has partnered with Shire on hemophilia and Huntington's disease drugs that are in the pre-clinical stage.
Most likely to succeed
Of this week's group of horrendous health-care stocks, I pick Questcor as the most likely to do well in the days ahead. The company continues to execute well on its strategy of expanding indications for Acthar. Rumors that major insurers would severely limit reimbursement for the drug have been overblown so far.
Even with a triple-digit jump in the company's stock in 2013, Questcor doesn't appear to be unreasonably valued. Its trailing price-to-earnings multiple is below 15. If Acthar's sales grow as expected, the stock should see brighter days ahead.
Fool contributor Keith Speights and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.