Friday's Health Winners & Losers

Shares of Columbia Laboratories(CBRX Quote) sank Friday despite the company's announcement that it completed the treatment phase of a late-stage study.

The phase III trial involved Prochieve, a drug intended to prevent preterm births. Phase III is the stage of trials conducted just before a drug is reviewed by the Food and Drug Administration for marketing approval. The stock fell 5.4% to $5.24.

Bentley Pharmaceuticals(BNT Quote) announced that its marketing partner Perrigo received regulatory approval for a generic version of Merck's (MRK Quote) blockbuster cholesterol drug Zocor. Bentley also said the FDA approved the manufacturing facility where the generic drug, known as simvastatin, will be produced. Shares gained 11.7% to $10.89.

Arena Pharmaceuticals(ARNA Quote) was up 5.1% to $13.54 on an upgrade by A.G. Edwards analyst Aaron Reamer. Since reaching a recent high of $17.69, "the stock's valuation has come back into a range which we feel undervalues the market opportunity" offered by a company with three drugs in human trials, five more in early trials, and partnerships with health care giant Johnson & Johnson(JNJ Quote), the analyst wrote in a research report Friday. He upgraded the stock to buy from hold with a price target of $18.

Among other health stocks rising were Novo Nordisk(NVO Quote), 1.8% higher to $84.36; Par Pharmaceutical(PRX Quote), up 2% to $21.66; Immunomedics(IMMU Quote), gaining 11.4% to $3.91; Hi Tech Pharmacal(HITK Quote), up 1% to $12.18; Repros Therapeutics(RPRX Quote), rising 15% to $8.88; and Ariad Pharmaceuticals(ARIA Quote), up 3.6% to $4.88.

Losers included Bayer(BAY Quote), falling 1.5% to $52.81; Keryx Biopharmaceuticals(KERX Quote), off 1.3% to $13.68; Catalyst Pharmaceutical Partners(CPRX Quote), down 2.1% to $4.75; and Minrad International(BUF Quote), falling 2.8% to $5.15.